Просмотр исходного текста страницы Java/Game/Game Texture Shading

== Shading Test 1  ==






   
  <!-- start source code -->
   
    <source lang="java">
       /*
DEVELOPING GAME IN JAVA 
Caracteristiques
Editeur : NEW RIDERS 
Auteur : BRACKEEN 
Parution : 09 2003 
Pages : 972 
Isbn : 1-59273-005-1 
Reliure : Paperback 
Disponibilite : Disponible a la librairie 
*/

import java.awt.AWTException;
import java.awt.Color;
import java.awt.ruponent;
import java.awt.Cursor;
import java.awt.DisplayMode;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Image;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.Window;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.awt.image.DataBuffer;
import java.awt.image.DataBufferByte;
import java.awt.image.DataBufferUShort;
import java.awt.image.IndexColorModel;
import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.ref.SoftReference;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import javax.imageio.ImageIO;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.DataLine;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.Mixer;
import javax.sound.sampled.SourceDataLine;
import javax.sound.sampled.UnsupportedAudioFileException;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
public class ShadingTest1 extends TextureMapTest2 {
  public static void main(String[] args) {
    new ShadingTest1().run();
  }
  private GameAction brighterLight = new GameAction("brighter");
  private GameAction dimmerLight = new GameAction("dimmer");
  private PointLight3D light;
  public void init() {
    init(LOW_RES_MODES);
    inputManager.mapToKey(brighterLight, KeyEvent.VK_PLUS);
    inputManager.mapToKey(brighterLight, KeyEvent.VK_ADD);
    inputManager.mapToKey(brighterLight, KeyEvent.VK_EQUALS);
    inputManager.mapToKey(dimmerLight, KeyEvent.VK_SUBTRACT);
    inputManager.mapToKey(dimmerLight, KeyEvent.VK_MINUS);
  }
  public Texture loadTexture(String imageName) {
    return Texture.createTexture(imageName, true);
  }
  public void createPolygonRenderer() {
    viewWindow = new ViewWindow(0, 0, screen.getWidth(),
        screen.getHeight(), (float) Math.toRadians(75));
    Transform3D camera = new Transform3D(0, 100, 0);
    ShadedTexturedPolygonRenderer polygonRenderer = new ShadedTexturedPolygonRenderer(
        camera, viewWindow);
    light = new PointLight3D(-500, 500, 0, 1f);
    light.setDistanceFalloff(2000);
    polygonRenderer.setLightSource(light);
    polygonRenderer.setAmbientLightIntensity(.05f);
    this.polygonRenderer = polygonRenderer;
  }
  public void draw(Graphics2D g) {
    super.draw(g);
    g.setColor(Color.WHITE);
    g.drawString("Press +/- to change the light intensity.", 5,
        fontSize * 2);
  }
  public void update(long elapsedTime) {
    super.update(elapsedTime);
    if (brighterLight.isPressed()) {
      light.setIntensity(Math.min(5, light.getIntensity() + .005f
          * elapsedTime));
    }
    if (dimmerLight.isPressed()) {
      light.setIntensity(Math.max(0, light.getIntensity() - .005f
          * elapsedTime));
    }
  }
}
/**
 * The ShadedTexturedPolygonRenderer class is a PolygonRenderer that renders
 * ShadedTextured dynamically with one light source. By default, the ambient
 * light intensity is 0.5 and there is no point light.
 */
class ShadedTexturedPolygonRenderer extends FastTexturedPolygonRenderer {
  private PointLight3D lightSource;
  private float ambientLightIntensity = 0.5f;
  private Vector3D directionToLight = new Vector3D();
  public ShadedTexturedPolygonRenderer(Transform3D camera,
      ViewWindow viewWindow) {
    this(camera, viewWindow, true);
  }
  public ShadedTexturedPolygonRenderer(Transform3D camera,
      ViewWindow viewWindow, boolean clearViewEveryFrame) {
    super(camera, viewWindow, clearViewEveryFrame);
  }
  /**
   * Gets the light source for this renderer.
   */
  public PointLight3D getLightSource() {
    return lightSource;
  }
  /**
   * Sets the light source for this renderer.
   */
  public void setLightSource(PointLight3D lightSource) {
    this.lightSource = lightSource;
  }
  /**
   * Gets the ambient light intensity.
   */
  public float getAmbientLightIntensity() {
    return ambientLightIntensity;
  }
  /**
   * Sets the ambient light intensity, generally between 0 and 1.
   */
  public void setAmbientLightIntensity(float i) {
    ambientLightIntensity = i;
  }
  protected void drawCurrentPolygon(Graphics2D g) {
    // set the shade level of the polygon before drawing it
    if (sourcePolygon instanceof TexturedPolygon3D) {
      TexturedPolygon3D poly = ((TexturedPolygon3D) sourcePolygon);
      Texture texture = poly.getTexture();
      if (texture instanceof ShadedTexture) {
        calcShadeLevel();
      }
    }
    super.drawCurrentPolygon(g);
  }
  /**
   * Calculates the shade level of the current polygon
   */
  private void calcShadeLevel() {
    TexturedPolygon3D poly = (TexturedPolygon3D) sourcePolygon;
    float intensity = 0;
    if (lightSource != null) {
      // average all the vertices in the polygon
      directionToLight.setTo(0, 0, 0);
      for (int i = 0; i < poly.getNumVertices(); i++) {
        directionToLight.add(poly.getVertex(i));
      }
      directionToLight.divide(poly.getNumVertices());
      // make the vector from the average vertex
      // to the light
      directionToLight.subtract(lightSource);
      directionToLight.multiply(-1);
      // get the distance to the light for falloff
      float distance = directionToLight.length();
      // compute the diffuse reflect
      directionToLight.normalize();
      Vector3D normal = poly.getNormal();
      intensity = lightSource.getIntensity(distance)
          * directionToLight.getDotProduct(normal);
      intensity = Math.min(intensity, 1);
      intensity = Math.max(intensity, 0);
    }
    intensity += ambientLightIntensity;
    intensity = Math.min(intensity, 1);
    intensity = Math.max(intensity, 0);
    int level = Math.round(intensity * ShadedTexture.MAX_LEVEL);
    ((ShadedTexture) poly.getTexture()).setDefaultShadeLevel(level);
  }
}
class TextureMapTest2 extends GameCore3D {
  public static void main(String[] args) {
    new TextureMapTest2().run();
  }
  public void init() {
    init(LOW_RES_MODES);
  }
  // create a house (convex polyhedra)
  public void createPolygons() {
    // create Textures
    Texture wall = loadTexture("../images/wall1.png");
    Texture roof = loadTexture("../images/roof1.png");
    TexturedPolygon3D poly;
    // walls
    poly = new TexturedPolygon3D(new Vector3D(-200, 250, -1000),
        new Vector3D(-200, 0, -1000), new Vector3D(200, 0, -1000),
        new Vector3D(200, 250, -1000));
    setTexture(poly, wall);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(200, 250, -1400),
        new Vector3D(200, 0, -1400), new Vector3D(-200, 0, -1400),
        new Vector3D(-200, 250, -1400));
    setTexture(poly, wall);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(-200, 250, -1400),
        new Vector3D(-200, 0, -1400), new Vector3D(-200, 0, -1000),
        new Vector3D(-200, 250, -1000));
    setTexture(poly, wall);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(200, 250, -1000),
        new Vector3D(200, 0, -1000), new Vector3D(200, 0, -1400),
        new Vector3D(200, 250, -1400));
    setTexture(poly, wall);
    polygons.add(poly);
    // roof
    poly = new TexturedPolygon3D(new Vector3D(-200, 250, -1000),
        new Vector3D(200, 250, -1000), new Vector3D(75, 400, -1200),
        new Vector3D(-75, 400, -1200));
    setTexture(poly, roof);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(-200, 250, -1400),
        new Vector3D(-200, 250, -1000), new Vector3D(-75, 400, -1200));
    setTexture(poly, roof);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(200, 250, -1400),
        new Vector3D(-200, 250, -1400), new Vector3D(-75, 400, -1200),
        new Vector3D(75, 400, -1200));
    setTexture(poly, roof);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(200, 250, -1000),
        new Vector3D(200, 250, -1400), new Vector3D(75, 400, -1200));
    setTexture(poly, roof);
    polygons.add(poly);
  }
  public void setTexture(TexturedPolygon3D poly, Texture texture) {
    Vector3D origin = poly.getVertex(0);
    Vector3D dv = new Vector3D(poly.getVertex(1));
    dv.subtract(origin);
    Vector3D du = new Vector3D();
    du.setToCrossProduct(poly.getNormal(), dv);
    Rectangle3D textureBounds = new Rectangle3D(origin, du, dv, texture
        .getWidth(), texture.getHeight());
    poly.setTexture(texture, textureBounds);
  }
  public Texture loadTexture(String imageName) {
    return Texture.createTexture(imageName);
  }
  public void createPolygonRenderer() {
    viewWindow = new ViewWindow(0, 0, screen.getWidth(),
        screen.getHeight(), (float) Math.toRadians(75));
    Transform3D camera = new Transform3D(0, 100, 0);
    polygonRenderer = new FastTexturedPolygonRenderer(camera, viewWindow);
  }
}
/**
 * The FastTexturedPolygonRenderer is a PolygonRenderer that efficiently renders
 * Textures.
 */
class FastTexturedPolygonRenderer extends PolygonRenderer {
  public static final int SCALE_BITS = 12;
  public static final int SCALE = 1 << SCALE_BITS;
  public static final int INTERP_SIZE_BITS = 4;
  public static final int INTERP_SIZE = 1 << INTERP_SIZE_BITS;
  protected Vector3D a = new Vector3D();
  protected Vector3D b = new Vector3D();
  protected Vector3D c = new Vector3D();
  protected Vector3D viewPos = new Vector3D();
  protected BufferedImage doubleBuffer;
  protected short[] doubleBufferData;
  protected HashMap scanRenderers;
  public FastTexturedPolygonRenderer(Transform3D camera, ViewWindow viewWindow) {
    this(camera, viewWindow, true);
  }
  public FastTexturedPolygonRenderer(Transform3D camera,
      ViewWindow viewWindow, boolean clearViewEveryFrame) {
    super(camera, viewWindow, clearViewEveryFrame);
  }
  protected void init() {
    destPolygon = new TexturedPolygon3D();
    scanConverter = new ScanConverter(viewWindow);
    // create renders for each texture (HotSpot optimization)
    scanRenderers = new HashMap();
    scanRenderers.put(PowerOf2Texture.class, new PowerOf2TextureRenderer());
    scanRenderers.put(ShadedTexture.class, new ShadedTextureRenderer());
    scanRenderers.put(ShadedSurface.class, new ShadedSurfaceRenderer());
  }
  public void startFrame(Graphics2D g) {
    // initialize buffer
    if (doubleBuffer == null
        || doubleBuffer.getWidth() != viewWindow.getWidth()
        || doubleBuffer.getHeight() != viewWindow.getHeight()) {
      doubleBuffer = new BufferedImage(viewWindow.getWidth(), viewWindow
          .getHeight(), BufferedImage.TYPE_USHORT_565_RGB);
      //doubleBuffer = g.getDeviceConfiguration().createCompatibleImage(
      //viewWindow.getWidth(), viewWindow.getHeight());
      DataBuffer dest = doubleBuffer.getRaster().getDataBuffer();
      doubleBufferData = ((DataBufferUShort) dest).getData();
    }
    // clear view
    if (clearViewEveryFrame) {
      for (int i = 0; i < doubleBufferData.length; i++) {
        doubleBufferData[i] = 0;
      }
    }
  }
  public void endFrame(Graphics2D g) {
    // draw the double buffer onto the screen
    g.drawImage(doubleBuffer, viewWindow.getLeftOffset(), viewWindow
        .getTopOffset(), null);
  }
  protected void drawCurrentPolygon(Graphics2D g) {
    if (!(sourcePolygon instanceof TexturedPolygon3D)) {
      // not a textured polygon - return
      return;
    }
    TexturedPolygon3D poly = (TexturedPolygon3D) destPolygon;
    Texture texture = poly.getTexture();
    ScanRenderer scanRenderer = (ScanRenderer) scanRenderers.get(texture
        .getClass());
    scanRenderer.setTexture(texture);
    Rectangle3D textureBounds = poly.getTextureBounds();
    a.setToCrossProduct(textureBounds.getDirectionV(), textureBounds
        .getOrigin());
    b.setToCrossProduct(textureBounds.getOrigin(), textureBounds
        .getDirectionU());
    c.setToCrossProduct(textureBounds.getDirectionU(), textureBounds
        .getDirectionV());
    int y = scanConverter.getTopBoundary();
    viewPos.y = viewWindow.convertFromScreenYToViewY(y);
    viewPos.z = -viewWindow.getDistance();
    while (y <= scanConverter.getBottomBoundary()) {
      ScanConverter.Scan scan = scanConverter.getScan(y);
      if (scan.isValid()) {
        viewPos.x = viewWindow.convertFromScreenXToViewX(scan.left);
        int offset = (y - viewWindow.getTopOffset())
            * viewWindow.getWidth()
            + (scan.left - viewWindow.getLeftOffset());
        scanRenderer.render(offset, scan.left, scan.right);
      }
      y++;
      viewPos.y--;
    }
  }
  /**
   * The ScanRenderer class is an abstract inner class of
   * FastTexturedPolygonRenderer that provides an interface for rendering a
   * horizontal scan line.
   */
  public abstract class ScanRenderer {
    protected Texture currentTexture;
    public void setTexture(Texture texture) {
      this.currentTexture = texture;
    }
    public abstract void render(int offset, int left, int right);
  }
  //================================================
  // FASTEST METHOD: no texture (for comparison)
  //================================================
  public class Method0 extends ScanRenderer {
    public void render(int offset, int left, int right) {
      for (int x = left; x <= right; x++) {
        doubleBufferData[offset++] = (short) 0x0007;
      }
    }
  }
  //================================================
  // METHOD 1: access pixel buffers directly
  // and use textures sizes that are a power of 2
  //================================================
  public class Method1 extends ScanRenderer {
    public void render(int offset, int left, int right) {
      for (int x = left; x <= right; x++) {
        int tx = (int) (a.getDotProduct(viewPos) / c
            .getDotProduct(viewPos));
        int ty = (int) (b.getDotProduct(viewPos) / c
            .getDotProduct(viewPos));
        doubleBufferData[offset++] = currentTexture.getColor(tx, ty);
        viewPos.x++;
      }
    }
  }
  //================================================
  // METHOD 2: avoid redundant calculations
  //================================================
  public class Method2 extends ScanRenderer {
    public void render(int offset, int left, int right) {
      float u = a.getDotProduct(viewPos);
      float v = b.getDotProduct(viewPos);
      float z = c.getDotProduct(viewPos);
      float du = a.x;
      float dv = b.x;
      float dz = c.x;
      for (int x = left; x <= right; x++) {
        doubleBufferData[offset++] = currentTexture.getColor(
            (int) (u / z), (int) (v / z));
        u += du;
        v += dv;
        z += dz;
      }
    }
  }
  //================================================
  // METHOD 3: use ints instead of floats
  //================================================
  public class Method3 extends ScanRenderer {
    public void render(int offset, int left, int right) {
      int u = (int) (SCALE * a.getDotProduct(viewPos));
      int v = (int) (SCALE * b.getDotProduct(viewPos));
      int z = (int) (SCALE * c.getDotProduct(viewPos));
      int du = (int) (SCALE * a.x);
      int dv = (int) (SCALE * b.x);
      int dz = (int) (SCALE * c.x);
      for (int x = left; x <= right; x++) {
        doubleBufferData[offset++] = currentTexture.getColor(u / z, v
            / z);
        u += du;
        v += dv;
        z += dz;
      }
    }
  }
  //================================================
  // METHOD 4: reduce the number of divides
  // (interpolate every 16 pixels)
  // Also, apply a VM optimization by referring to
  // the texture"s class rather than it"s parent class.
  //================================================
  // the following three ScanRenderers are the same, but refer
  // to textures explicitly as either a PowerOf2Texture, a
  // ShadedTexture, or a ShadedSurface.
  // This allows HotSpot to do some inlining of the textures"
  // getColor() method, which significantly increases
  // performance.
  public class PowerOf2TextureRenderer extends ScanRenderer {
    public void render(int offset, int left, int right) {
      PowerOf2Texture texture = (PowerOf2Texture) currentTexture;
      float u = SCALE * a.getDotProduct(viewPos);
      float v = SCALE * b.getDotProduct(viewPos);
      float z = c.getDotProduct(viewPos);
      float du = INTERP_SIZE * SCALE * a.x;
      float dv = INTERP_SIZE * SCALE * b.x;
      float dz = INTERP_SIZE * c.x;
      int nextTx = (int) (u / z);
      int nextTy = (int) (v / z);
      int x = left;
      while (x <= right) {
        int tx = nextTx;
        int ty = nextTy;
        int maxLength = right - x + 1;
        if (maxLength > INTERP_SIZE) {
          u += du;
          v += dv;
          z += dz;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) >> INTERP_SIZE_BITS;
          int dty = (nextTy - ty) >> INTERP_SIZE_BITS;
          int endOffset = offset + INTERP_SIZE;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += INTERP_SIZE;
        } else {
          // variable interpolation size
          int interpSize = maxLength;
          u += interpSize * SCALE * a.x;
          v += interpSize * SCALE * b.x;
          z += interpSize * c.x;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) / interpSize;
          int dty = (nextTy - ty) / interpSize;
          int endOffset = offset + interpSize;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += interpSize;
        }
      }
    }
  }
  public class ShadedTextureRenderer extends ScanRenderer {
    public void render(int offset, int left, int right) {
      ShadedTexture texture = (ShadedTexture) currentTexture;
      float u = SCALE * a.getDotProduct(viewPos);
      float v = SCALE * b.getDotProduct(viewPos);
      float z = c.getDotProduct(viewPos);
      float du = INTERP_SIZE * SCALE * a.x;
      float dv = INTERP_SIZE * SCALE * b.x;
      float dz = INTERP_SIZE * c.x;
      int nextTx = (int) (u / z);
      int nextTy = (int) (v / z);
      int x = left;
      while (x <= right) {
        int tx = nextTx;
        int ty = nextTy;
        int maxLength = right - x + 1;
        if (maxLength > INTERP_SIZE) {
          u += du;
          v += dv;
          z += dz;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) >> INTERP_SIZE_BITS;
          int dty = (nextTy - ty) >> INTERP_SIZE_BITS;
          int endOffset = offset + INTERP_SIZE;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += INTERP_SIZE;
        } else {
          // variable interpolation size
          int interpSize = maxLength;
          u += interpSize * SCALE * a.x;
          v += interpSize * SCALE * b.x;
          z += interpSize * c.x;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) / interpSize;
          int dty = (nextTy - ty) / interpSize;
          int endOffset = offset + interpSize;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += interpSize;
        }
      }
    }
  }
  public class ShadedSurfaceRenderer extends ScanRenderer {
    public int checkBounds(int vScaled, int bounds) {
      int v = vScaled >> SCALE_BITS;
      if (v < 0) {
        vScaled = 0;
      } else if (v >= bounds) {
        vScaled = (bounds - 1) << SCALE_BITS;
      }
      return vScaled;
    }
    public void render(int offset, int left, int right) {
      ShadedSurface texture = (ShadedSurface) currentTexture;
      float u = SCALE * a.getDotProduct(viewPos);
      float v = SCALE * b.getDotProduct(viewPos);
      float z = c.getDotProduct(viewPos);
      float du = INTERP_SIZE * SCALE * a.x;
      float dv = INTERP_SIZE * SCALE * b.x;
      float dz = INTERP_SIZE * c.x;
      int nextTx = (int) (u / z);
      int nextTy = (int) (v / z);
      int x = left;
      while (x <= right) {
        int tx = nextTx;
        int ty = nextTy;
        int maxLength = right - x + 1;
        if (maxLength > INTERP_SIZE) {
          u += du;
          v += dv;
          z += dz;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) >> INTERP_SIZE_BITS;
          int dty = (nextTy - ty) >> INTERP_SIZE_BITS;
          int endOffset = offset + INTERP_SIZE;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += INTERP_SIZE;
        } else {
          // variable interpolation size
          int interpSize = maxLength;
          u += interpSize * SCALE * a.x;
          v += interpSize * SCALE * b.x;
          z += interpSize * c.x;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          // make sure tx, ty, nextTx, and nextTy are
          // all within bounds
          tx = checkBounds(tx, texture.getWidth());
          ty = checkBounds(ty, texture.getHeight());
          nextTx = checkBounds(nextTx, texture.getWidth());
          nextTy = checkBounds(nextTy, texture.getHeight());
          int dtx = (nextTx - tx) / interpSize;
          int dty = (nextTy - ty) / interpSize;
          int endOffset = offset + interpSize;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += interpSize;
        }
      }
    }
  }
}
/**
 * A ShadedSurface is a pre-shaded Texture that maps onto a polygon.
 */
final class ShadedSurface extends Texture {
  public static final int SURFACE_BORDER_SIZE = 1;
  public static final int SHADE_RES_BITS = 4;
  public static final int SHADE_RES = 1 << SHADE_RES_BITS;
  public static final int SHADE_RES_MASK = SHADE_RES - 1;
  public static final int SHADE_RES_SQ = SHADE_RES * SHADE_RES;
  public static final int SHADE_RES_SQ_BITS = SHADE_RES_BITS * 2;
  private short[] buffer;
  private SoftReference bufferReference;
  private boolean dirty;
  private ShadedTexture sourceTexture;
  private Rectangle3D sourceTextureBounds;
  private Rectangle3D surfaceBounds;
  private byte[] shadeMap;
  private int shadeMapWidth;
  private int shadeMapHeight;
  // for incrementally calculating shade values
  private int shadeValue;
  private int shadeValueInc;
  /**
   * Creates a ShadedSurface with the specified width and height.
   */
  public ShadedSurface(int width, int height) {
    this(null, width, height);
  }
  /**
   * Creates a ShadedSurface with the specified buffer, width and height.
   */
  public ShadedSurface(short[] buffer, int width, int height) {
    super(width, height);
    this.buffer = buffer;
    bufferReference = new SoftReference(buffer);
    sourceTextureBounds = new Rectangle3D();
    dirty = true;
  }
  /**
   * Creates a ShadedSurface for the specified polygon. The shade map is
   * created from the specified list of point lights and ambient light
   * intensity.
   */
  public static void createShadedSurface(TexturedPolygon3D poly,
      ShadedTexture texture, List lights, float ambientLightIntensity) {
    // create the texture bounds
    Vector3D origin = poly.getVertex(0);
    Vector3D dv = new Vector3D(poly.getVertex(1));
    dv.subtract(origin);
    Vector3D du = new Vector3D();
    du.setToCrossProduct(poly.getNormal(), dv);
    Rectangle3D bounds = new Rectangle3D(origin, du, dv,
        texture.getWidth(), texture.getHeight());
    createShadedSurface(poly, texture, bounds, lights,
        ambientLightIntensity);
  }
  /**
   * Creates a ShadedSurface for the specified polygon. The shade map is
   * created from the specified list of point lights and ambient light
   * intensity.
   */
  public static void createShadedSurface(TexturedPolygon3D poly,
      ShadedTexture texture, Rectangle3D textureBounds, List lights,
      float ambientLightIntensity) {
    // create the surface bounds
    poly.setTexture(texture, textureBounds);
    Rectangle3D surfaceBounds = poly.calcBoundingRectangle();
    // give the surfaceBounds a border to correct for
    // slight errors when texture mapping
    Vector3D du = new Vector3D(surfaceBounds.getDirectionU());
    Vector3D dv = new Vector3D(surfaceBounds.getDirectionV());
    du.multiply(SURFACE_BORDER_SIZE);
    dv.multiply(SURFACE_BORDER_SIZE);
    surfaceBounds.getOrigin().subtract(du);
    surfaceBounds.getOrigin().subtract(dv);
    int width = (int) Math.ceil(surfaceBounds.getWidth()
        + SURFACE_BORDER_SIZE * 2);
    int height = (int) Math.ceil(surfaceBounds.getHeight()
        + SURFACE_BORDER_SIZE * 2);
    surfaceBounds.setWidth(width);
    surfaceBounds.setHeight(height);
    // create the shaded surface texture
    ShadedSurface surface = new ShadedSurface(width, height);
    surface.setTexture(texture, textureBounds);
    surface.setSurfaceBounds(surfaceBounds);
    // create the surface"s shade map
    surface.buildShadeMap(lights, ambientLightIntensity);
    // set the polygon"s surface
    poly.setTexture(surface, surfaceBounds);
  }
  /**
   * Gets the 16-bit color of the pixel at location (x,y) in the bitmap. The x
   * and y values are assumbed to be within the bounds of the surface;
   * otherwise an ArrayIndexOutOfBoundsException occurs.
   */
  public short getColor(int x, int y) {
    //try {
    return buffer[x + y * width];
    //}
    //catch (ArrayIndexOutOfBoundsException ex) {
    //    return -2048;
    //}
  }
  /**
   * Gets the 16-bit color of the pixel at location (x,y) in the bitmap. The x
   * and y values are checked to be within the bounds of the surface, and if
   * not, the pixel on the edge of the texture is returned.
   */
  public short getColorChecked(int x, int y) {
    if (x < 0) {
      x = 0;
    } else if (x >= width) {
      x = width - 1;
    }
    if (y < 0) {
      y = 0;
    } else if (y >= height) {
      y = height - 1;
    }
    return getColor(x, y);
  }
  /**
   * Marks whether this surface is dirty. Surfaces marked as dirty may be
   * cleared externally.
   */
  public void setDirty(boolean dirty) {
    this.dirty = dirty;
  }
  /**
   * Checks wether this surface is dirty. Surfaces marked as dirty may be
   * cleared externally.
   */
  public boolean isDirty() {
    return dirty;
  }
  /**
   * Creates a new surface and add a SoftReference to it.
   */
  protected void newSurface(int width, int height) {
    buffer = new short[width * height];
    bufferReference = new SoftReference(buffer);
  }
  /**
   * Clears this surface, allowing the garbage collector to remove it from
   * memory if needed.
   */
  public void clearSurface() {
    buffer = null;
  }
  /**
   * Checks if the surface has been cleared.
   */
  public boolean isCleared() {
    return (buffer == null);
  }
  /**
   * If the buffer has been previously built and cleared but not yet removed
   * from memory by the garbage collector, then this method attempts to
   * retrieve it. Returns true if successfull.
   */
  public boolean retrieveSurface() {
    if (buffer == null) {
      buffer = (short[]) bufferReference.get();
    }
    return !(buffer == null);
  }
  /**
   * Sets the source texture for this ShadedSurface.
   */
  public void setTexture(ShadedTexture texture) {
    this.sourceTexture = texture;
    sourceTextureBounds.setWidth(texture.getWidth());
    sourceTextureBounds.setHeight(texture.getHeight());
  }
  /**
   * Sets the source texture and source bounds for this ShadedSurface.
   */
  public void setTexture(ShadedTexture texture, Rectangle3D bounds) {
    setTexture(texture);
    sourceTextureBounds.setTo(bounds);
  }
  /**
   * Sets the surface bounds for this ShadedSurface.
   */
  public void setSurfaceBounds(Rectangle3D surfaceBounds) {
    this.surfaceBounds = surfaceBounds;
  }
  /**
   * Gets the surface bounds for this ShadedSurface.
   */
  public Rectangle3D getSurfaceBounds() {
    return surfaceBounds;
  }
  /**
   * Builds the surface. First, this method calls retrieveSurface() to see if
   * the surface needs to be rebuilt. If not, the surface is built by tiling
   * the source texture and apply the shade map.
   */
  public void buildSurface() {
    if (retrieveSurface()) {
      return;
    }
    int width = (int) surfaceBounds.getWidth();
    int height = (int) surfaceBounds.getHeight();
    // create a new surface (buffer)
    newSurface(width, height);
    // builds the surface.
    // assume surface bounds and texture bounds are aligned
    // (possibly with different origins)
    Vector3D origin = sourceTextureBounds.getOrigin();
    Vector3D directionU = sourceTextureBounds.getDirectionU();
    Vector3D directionV = sourceTextureBounds.getDirectionV();
    Vector3D d = new Vector3D(surfaceBounds.getOrigin());
    d.subtract(origin);
    int startU = (int) ((d.getDotProduct(directionU) - SURFACE_BORDER_SIZE));
    int startV = (int) ((d.getDotProduct(directionV) - SURFACE_BORDER_SIZE));
    int offset = 0;
    int shadeMapOffsetU = SHADE_RES - SURFACE_BORDER_SIZE - startU;
    int shadeMapOffsetV = SHADE_RES - SURFACE_BORDER_SIZE - startV;
    for (int v = startV; v < startV + height; v++) {
      sourceTexture.setCurrRow(v);
      int u = startU;
      int amount = SURFACE_BORDER_SIZE;
      while (u < startU + width) {
        getInterpolatedShade(u + shadeMapOffsetU, v + shadeMapOffsetV);
        // keep drawing until we need to recalculate
        // the interpolated shade. (every SHADE_RES pixels)
        int endU = Math.min(startU + width, u + amount);
        while (u < endU) {
          buffer[offset++] = sourceTexture.getColorCurrRow(u,
              shadeValue >> SHADE_RES_SQ_BITS);
          shadeValue += shadeValueInc;
          u++;
        }
        amount = SHADE_RES;
      }
    }
    // if the surface bounds is not aligned with the texture
    // bounds, use this (slower) code.
    /*
     * Vector3D origin = sourceTextureBounds.getOrigin(); Vector3D
     * directionU = sourceTextureBounds.getDirectionU(); Vector3D directionV =
     * sourceTextureBounds.getDirectionV();
     * 
     * Vector3D d = new Vector3D(surfaceBounds.getOrigin());
     * d.subtract(origin); int initTextureU = (int)(SCALE *
     * (d.getDotProduct(directionU) - SURFACE_BORDER_SIZE)); int
     * initTextureV = (int)(SCALE * (d.getDotProduct(directionV) -
     * SURFACE_BORDER_SIZE)); int textureDu1 = (int)(SCALE *
     * directionU.getDotProduct( surfaceBounds.getDirectionV())); int
     * textureDv1 = (int)(SCALE * directionV.getDotProduct(
     * surfaceBounds.getDirectionV())); int textureDu2 = (int)(SCALE *
     * directionU.getDotProduct( surfaceBounds.getDirectionU())); int
     * textureDv2 = (int)(SCALE * directionV.getDotProduct(
     * surfaceBounds.getDirectionU()));
     * 
     * int shadeMapOffset = SHADE_RES - SURFACE_BORDER_SIZE;
     * 
     * for (int v=0; v <height; v++) { int textureU = initTextureU; int
     * textureV = initTextureV;
     * 
     * for (int u=0; u <width; u++) { if (((u + shadeMapOffset) &
     * SHADE_RES_MASK) == 0) { getInterpolatedShade(u + shadeMapOffset, v +
     * shadeMapOffset); } buffer[offset++] = sourceTexture.getColor(
     * textureU >> SCALE_BITS, textureV >> SCALE_BITS, shadeValue >>
     * SHADE_RES_SQ_BITS); textureU+=textureDu2; textureV+=textureDv2;
     * shadeValue+=shadeValueInc; } initTextureU+=textureDu1;
     * initTextureV+=textureDv1; }
     */
  }
  /**
   * Gets the shade (from the shade map) for the specified (u,v) location. The
   * u and v values should be left-shifted by SHADE_RES_BITS, and the extra
   * bits are used to interpolate between values. For an interpolation
   * example, a location halfway between shade values 1 and 3 would return 2.
   */
  public int getInterpolatedShade(int u, int v) {
    int fracU = u & SHADE_RES_MASK;
    int fracV = v & SHADE_RES_MASK;
    int offset = (u >> SHADE_RES_BITS)
        + ((v >> SHADE_RES_BITS) * shadeMapWidth);
    int shade00 = (SHADE_RES - fracV) * shadeMap[offset];
    int shade01 = fracV * shadeMap[offset + shadeMapWidth];
    int shade10 = (SHADE_RES - fracV) * shadeMap[offset + 1];
    int shade11 = fracV * shadeMap[offset + shadeMapWidth + 1];
    shadeValue = SHADE_RES_SQ / 2 + (SHADE_RES - fracU) * shade00
        + (SHADE_RES - fracU) * shade01 + fracU * shade10 + fracU
        * shade11;
    // the value to increment as u increments
    shadeValueInc = -shade00 - shade01 + shade10 + shade11;
    return shadeValue >> SHADE_RES_SQ_BITS;
  }
  /**
   * Gets the shade (from the built shade map) for the specified (u,v)
   * location.
   */
  public int getShade(int u, int v) {
    return shadeMap[u + v * shadeMapWidth];
  }
  /**
   * Builds the shade map for this surface from the specified list of point
   * lights and the ambiant light intensity.
   */
  public void buildShadeMap(List pointLights, float ambientLightIntensity) {
    Vector3D surfaceNormal = surfaceBounds.getNormal();
    int polyWidth = (int) surfaceBounds.getWidth() - SURFACE_BORDER_SIZE
        * 2;
    int polyHeight = (int) surfaceBounds.getHeight() - SURFACE_BORDER_SIZE
        * 2;
    // assume SURFACE_BORDER_SIZE is <= SHADE_RES
    shadeMapWidth = polyWidth / SHADE_RES + 4;
    shadeMapHeight = polyHeight / SHADE_RES + 4;
    shadeMap = new byte[shadeMapWidth * shadeMapHeight];
    // calculate the shade map origin
    Vector3D origin = new Vector3D(surfaceBounds.getOrigin());
    Vector3D du = new Vector3D(surfaceBounds.getDirectionU());
    Vector3D dv = new Vector3D(surfaceBounds.getDirectionV());
    du.multiply(SHADE_RES - SURFACE_BORDER_SIZE);
    dv.multiply(SHADE_RES - SURFACE_BORDER_SIZE);
    origin.subtract(du);
    origin.subtract(dv);
    // calculate the shade for each sample point.
    Vector3D point = new Vector3D();
    du.setTo(surfaceBounds.getDirectionU());
    dv.setTo(surfaceBounds.getDirectionV());
    du.multiply(SHADE_RES);
    dv.multiply(SHADE_RES);
    for (int v = 0; v < shadeMapHeight; v++) {
      point.setTo(origin);
      for (int u = 0; u < shadeMapWidth; u++) {
        shadeMap[u + v * shadeMapWidth] = calcShade(surfaceNormal,
            point, pointLights, ambientLightIntensity);
        point.add(du);
      }
      origin.add(dv);
    }
  }
  /**
   * Determine the shade of a point on the polygon. This computes the
   * Lambertian reflection for a point on the plane. Each point light has an
   * intensity and a distance falloff value, but no specular reflection or
   * shadows from other polygons are computed. The value returned is from 0 to
   * ShadedTexture.MAX_LEVEL.
   */
  protected byte calcShade(Vector3D normal, Vector3D point, List pointLights,
      float ambientLightIntensity) {
    float intensity = 0;
    Vector3D directionToLight = new Vector3D();
    for (int i = 0; i < pointLights.size(); i++) {
      PointLight3D light = (PointLight3D) pointLights.get(i);
      directionToLight.setTo(light);
      directionToLight.subtract(point);
      float distance = directionToLight.length();
      directionToLight.normalize();
      float lightIntensity = light.getIntensity(distance)
          * directionToLight.getDotProduct(normal);
      lightIntensity = Math.min(lightIntensity, 1);
      lightIntensity = Math.max(lightIntensity, 0);
      intensity += lightIntensity;
    }
    intensity = Math.min(intensity, 1);
    intensity = Math.max(intensity, 0);
    intensity += ambientLightIntensity;
    intensity = Math.min(intensity, 1);
    intensity = Math.max(intensity, 0);
    int level = Math.round(intensity * ShadedTexture.MAX_LEVEL);
    return (byte) level;
  }
}
/**
 * A PointLight3D is a point light that has an intensity (between 0 and 1) and
 * optionally a distance falloff value, which causes the light to diminish with
 * distance.
 */
class PointLight3D extends Vector3D {
  public static final float NO_DISTANCE_FALLOFF = -1;
  private float intensity;
  private float distanceFalloff;
  /**
   * Creates a new PointLight3D at (0,0,0) with an intensity of 1 and no
   * distance falloff.
   */
  public PointLight3D() {
    this(0, 0, 0, 1, NO_DISTANCE_FALLOFF);
  }
  /**
   * Creates a copy of the specified PointLight3D.
   */
  public PointLight3D(PointLight3D p) {
    setTo(p);
  }
  /**
   * Creates a new PointLight3D with the specified location and intensity. The
   * created light has no distance falloff.
   */
  public PointLight3D(float x, float y, float z, float intensity) {
    this(x, y, z, intensity, NO_DISTANCE_FALLOFF);
  }
  /**
   * Creates a new PointLight3D with the specified location. intensity, and no
   * distance falloff.
   */
  public PointLight3D(float x, float y, float z, float intensity,
      float distanceFalloff) {
    setTo(x, y, z);
    setIntensity(intensity);
    setDistanceFalloff(distanceFalloff);
  }
  /**
   * Sets this PointLight3D to the same location, intensity, and distance
   * falloff as the specified PointLight3D.
   */
  public void setTo(PointLight3D p) {
    setTo(p.x, p.y, p.z);
    setIntensity(p.getIntensity());
    setDistanceFalloff(p.getDistanceFalloff());
  }
  /**
   * Gets the intensity of this light from the specified distance.
   */
  public float getIntensity(float distance) {
    if (distanceFalloff == NO_DISTANCE_FALLOFF) {
      return intensity;
    } else if (distance >= distanceFalloff) {
      return 0;
    } else {
      return intensity * (distanceFalloff - distance)
          / (distanceFalloff + distance);
    }
  }
  /**
   * Gets the intensity of this light.
   */
  public float getIntensity() {
    return intensity;
  }
  /**
   * Sets the intensity of this light.
   */
  public void setIntensity(float intensity) {
    this.intensity = intensity;
  }
  /**
   * Gets the distances falloff value. The light intensity is zero beyond this
   * distance.
   */
  public float getDistanceFalloff() {
    return distanceFalloff;
  }
  /**
   * Sets the distances falloff value. The light intensity is zero beyond this
   * distance. Set to NO_DISTANCE_FALLOFF if the light does not diminish with
   * distance.
   */
  public void setDistanceFalloff(float distanceFalloff) {
    this.distanceFalloff = distanceFalloff;
  }
}
/**
 * The Transform3D class represents a rotation and translation.
 */
class Transform3D {
  protected Vector3D location;
  private float cosAngleX;
  private float sinAngleX;
  private float cosAngleY;
  private float sinAngleY;
  private float cosAngleZ;
  private float sinAngleZ;
  /**
   * Creates a new Transform3D with no translation or rotation.
   */
  public Transform3D() {
    this(0, 0, 0);
  }
  /**
   * Creates a new Transform3D with the specified translation and no rotation.
   */
  public Transform3D(float x, float y, float z) {
    location = new Vector3D(x, y, z);
    setAngle(0, 0, 0);
  }
  /**
   * Creates a new Transform3D
   */
  public Transform3D(Transform3D v) {
    location = new Vector3D();
    setTo(v);
  }
  public Object clone() {
    return new Transform3D(this);
  }
  /**
   * Sets this Transform3D to the specified Transform3D.
   */
  public void setTo(Transform3D v) {
    location.setTo(v.location);
    this.cosAngleX = v.cosAngleX;
    this.sinAngleX = v.sinAngleX;
    this.cosAngleY = v.cosAngleY;
    this.sinAngleY = v.sinAngleY;
    this.cosAngleZ = v.cosAngleZ;
    this.sinAngleZ = v.sinAngleZ;
  }
  /**
   * Gets the location (translation) of this transform.
   */
  public Vector3D getLocation() {
    return location;
  }
  public float getCosAngleX() {
    return cosAngleX;
  }
  public float getSinAngleX() {
    return sinAngleX;
  }
  public float getCosAngleY() {
    return cosAngleY;
  }
  public float getSinAngleY() {
    return sinAngleY;
  }
  public float getCosAngleZ() {
    return cosAngleZ;
  }
  public float getSinAngleZ() {
    return sinAngleZ;
  }
  public float getAngleX() {
    return (float) Math.atan2(sinAngleX, cosAngleX);
  }
  public float getAngleY() {
    return (float) Math.atan2(sinAngleY, cosAngleY);
  }
  public float getAngleZ() {
    return (float) Math.atan2(sinAngleZ, cosAngleZ);
  }
  public void setAngleX(float angleX) {
    cosAngleX = (float) Math.cos(angleX);
    sinAngleX = (float) Math.sin(angleX);
  }
  public void setAngleY(float angleY) {
    cosAngleY = (float) Math.cos(angleY);
    sinAngleY = (float) Math.sin(angleY);
  }
  public void setAngleZ(float angleZ) {
    cosAngleZ = (float) Math.cos(angleZ);
    sinAngleZ = (float) Math.sin(angleZ);
  }
  public void setAngle(float angleX, float angleY, float angleZ) {
    setAngleX(angleX);
    setAngleY(angleY);
    setAngleZ(angleZ);
  }
  public void rotateAngleX(float angle) {
    if (angle != 0) {
      setAngleX(getAngleX() + angle);
    }
  }
  public void rotateAngleY(float angle) {
    if (angle != 0) {
      setAngleY(getAngleY() + angle);
    }
  }
  public void rotateAngleZ(float angle) {
    if (angle != 0) {
      setAngleZ(getAngleZ() + angle);
    }
  }
  public void rotateAngle(float angleX, float angleY, float angleZ) {
    rotateAngleX(angleX);
    rotateAngleY(angleY);
    rotateAngleZ(angleZ);
  }
}
/**
 * The ViewWindow class represents the geometry of a view window for 3D viewing.
 */
class ViewWindow {
  private Rectangle bounds;
  private float angle;
  private float distanceToCamera;
  /**
   * Creates a new ViewWindow with the specified bounds on the screen and
   * horizontal view angle.
   */
  public ViewWindow(int left, int top, int width, int height, float angle) {
    bounds = new Rectangle();
    this.angle = angle;
    setBounds(left, top, width, height);
  }
  /**
   * Sets the bounds for this ViewWindow on the screen.
   */
  public void setBounds(int left, int top, int width, int height) {
    bounds.x = left;
    bounds.y = top;
    bounds.width = width;
    bounds.height = height;
    distanceToCamera = (bounds.width / 2) / (float) Math.tan(angle / 2);
  }
  /**
   * Sets the horizontal view angle for this ViewWindow.
   */
  public void setAngle(float angle) {
    this.angle = angle;
    distanceToCamera = (bounds.width / 2) / (float) Math.tan(angle / 2);
  }
  /**
   * Gets the horizontal view angle of this view window.
   */
  public float getAngle() {
    return angle;
  }
  /**
   * Gets the width of this view window.
   */
  public int getWidth() {
    return bounds.width;
  }
  /**
   * Gets the height of this view window.
   */
  public int getHeight() {
    return bounds.height;
  }
  /**
   * Gets the y offset of this view window on the screen.
   */
  public int getTopOffset() {
    return bounds.y;
  }
  /**
   * Gets the x offset of this view window on the screen.
   */
  public int getLeftOffset() {
    return bounds.x;
  }
  /**
   * Gets the distance from the camera to to this view window.
   */
  public float getDistance() {
    return distanceToCamera;
  }
  /**
   * Converts an x coordinate on this view window to the corresponding x
   * coordinate on the screen.
   */
  public float convertFromViewXToScreenX(float x) {
    return x + bounds.x + bounds.width / 2;
  }
  /**
   * Converts a y coordinate on this view window to the corresponding y
   * coordinate on the screen.
   */
  public float convertFromViewYToScreenY(float y) {
    return -y + bounds.y + bounds.height / 2;
  }
  /**
   * Converts an x coordinate on the screen to the corresponding x coordinate
   * on this view window.
   */
  public float convertFromScreenXToViewX(float x) {
    return x - bounds.x - bounds.width / 2;
  }
  /**
   * Converts an y coordinate on the screen to the corresponding y coordinate
   * on this view window.
   */
  public float convertFromScreenYToViewY(float y) {
    return -y + bounds.y + bounds.height / 2;
  }
  /**
   * Projects the specified vector to the screen.
   */
  public void project(Vector3D v) {
    // project to view window
    v.x = distanceToCamera * v.x / -v.z;
    v.y = distanceToCamera * v.y / -v.z;
    // convert to screen coordinates
    v.x = convertFromViewXToScreenX(v.x);
    v.y = convertFromViewYToScreenY(v.y);
  }
}
/**
 * The Texture class is an sabstract class that represents a 16-bit color
 * texture.
 */
abstract class Texture {
  protected int width;
  protected int height;
  /**
   * Creates a new Texture with the specified width and height.
   */
  public Texture(int width, int height) {
    this.width = width;
    this.height = height;
  }
  /**
   * Gets the width of this Texture.
   */
  public int getWidth() {
    return width;
  }
  /**
   * Gets the height of this Texture.
   */
  public int getHeight() {
    return height;
  }
  /**
   * Gets the 16-bit color of this Texture at the specified (x,y) location.
   */
  public abstract short getColor(int x, int y);
  /**
   * Creates an unshaded Texture from the specified image file.
   */
  public static Texture createTexture(String filename) {
    return createTexture(filename, false);
  }
  /**
   * Creates an Texture from the specified image file. If shaded is true, then
   * a ShadedTexture is returned.
   */
  public static Texture createTexture(String filename, boolean shaded) {
    try {
      return createTexture(ImageIO.read(new File(filename)), shaded);
    } catch (IOException ex) {
      ex.printStackTrace();
      return null;
    }
  }
  /**
   * Creates an unshaded Texture from the specified image.
   */
  public static Texture createTexture(BufferedImage image) {
    return createTexture(image, false);
  }
  /**
   * Creates an Texture from the specified image. If shaded is true, then a
   * ShadedTexture is returned.
   */
  public static Texture createTexture(BufferedImage image, boolean shaded) {
    int type = image.getType();
    int width = image.getWidth();
    int height = image.getHeight();
    if (!isPowerOfTwo(width) || !isPowerOfTwo(height)) {
      throw new IllegalArgumentException(
          "Size of texture must be a power of two.");
    }
    if (shaded) {
      // convert image to an indexed image
      if (type != BufferedImage.TYPE_BYTE_INDEXED) {
        System.out.println("Warning: image converted to "
            + "256-color indexed image. Some quality may "
            + "be lost.");
        BufferedImage newImage = new BufferedImage(image.getWidth(),
            image.getHeight(), BufferedImage.TYPE_BYTE_INDEXED);
        Graphics2D g = newImage.createGraphics();
        g.drawImage(image, 0, 0, null);
        g.dispose();
        image = newImage;
      }
      DataBuffer dest = image.getRaster().getDataBuffer();
      return new ShadedTexture(((DataBufferByte) dest).getData(),
          countbits(width - 1), countbits(height - 1),
          (IndexColorModel) image.getColorModel());
    } else {
      // convert image to an 16-bit image
      if (type != BufferedImage.TYPE_USHORT_565_RGB) {
        BufferedImage newImage = new BufferedImage(image.getWidth(),
            image.getHeight(), BufferedImage.TYPE_USHORT_565_RGB);
        Graphics2D g = newImage.createGraphics();
        g.drawImage(image, 0, 0, null);
        g.dispose();
        image = newImage;
      }
      DataBuffer dest = image.getRaster().getDataBuffer();
      return new PowerOf2Texture(((DataBufferUShort) dest).getData(),
          countbits(width - 1), countbits(height - 1));
    }
  }
  /**
   * Returns true if the specified number is a power of 2.
   */
  public static boolean isPowerOfTwo(int n) {
    return ((n & (n - 1)) == 0);
  }
  /**
   * Counts the number of "on" bits in an integer.
   */
  public static int countbits(int n) {
    int count = 0;
    while (n > 0) {
      count += (n & 1);
      n >>= 1;
    }
    return count;
  }
}
/**
 * The ShadedTexture class is a Texture that has multiple shades. The texture
 * source image is stored as a 8-bit image with a palette for every shade.
 */
final class ShadedTexture extends Texture {
  public static final int NUM_SHADE_LEVELS = 64;
  public static final int MAX_LEVEL = NUM_SHADE_LEVELS - 1;
  private static final int PALETTE_SIZE_BITS = 8;
  private static final int PALETTE_SIZE = 1 << PALETTE_SIZE_BITS;
  private byte[] buffer;
  private IndexColorModel palette;
  private short[] shadeTable;
  private int defaultShadeLevel;
  private int widthBits;
  private int widthMask;
  private int heightBits;
  private int heightMask;
  // the row set in setCurrRow and used in getColorCurrRow
  private int currRow;
  /**
   * Creates a new ShadedTexture from the specified 8-bit image buffer and
   * palette. The width of the bitmap is 2 to the power of widthBits, or (1 < <
   * widthBits). Likewise, the height of the bitmap is 2 to the power of
   * heightBits, or (1 < < heightBits). The texture is shaded from it"s
   * original color to black.
   */
  public ShadedTexture(byte[] buffer, int widthBits, int heightBits,
      IndexColorModel palette) {
    this(buffer, widthBits, heightBits, palette, Color.BLACK);
  }
  /**
   * Creates a new ShadedTexture from the specified 8-bit image buffer,
   * palette, and target shaded. The width of the bitmap is 2 to the power of
   * widthBits, or (1 < < widthBits). Likewise, the height of the bitmap is 2
   * to the power of heightBits, or (1 < < heightBits). The texture is shaded
   * from it"s original color to the target shade.
   */
  public ShadedTexture(byte[] buffer, int widthBits, int heightBits,
      IndexColorModel palette, Color targetShade) {
    super(1 << widthBits, 1 << heightBits);
    this.buffer = buffer;
    this.widthBits = widthBits;
    this.heightBits = heightBits;
    this.widthMask = getWidth() - 1;
    this.heightMask = getHeight() - 1;
    this.buffer = buffer;
    this.palette = palette;
    defaultShadeLevel = MAX_LEVEL;
    makeShadeTable(targetShade);
  }
  /**
   * Creates the shade table for this ShadedTexture. Each entry in the palette
   * is shaded from the original color to the specified target color.
   */
  public void makeShadeTable(Color targetShade) {
    shadeTable = new short[NUM_SHADE_LEVELS * PALETTE_SIZE];
    for (int level = 0; level < NUM_SHADE_LEVELS; level++) {
      for (int i = 0; i < palette.getMapSize(); i++) {
        int red = calcColor(palette.getRed(i), targetShade.getRed(),
            level);
        int green = calcColor(palette.getGreen(i), targetShade
            .getGreen(), level);
        int blue = calcColor(palette.getBlue(i), targetShade.getBlue(),
            level);
        int index = level * PALETTE_SIZE + i;
        // RGB 5:6:5
        shadeTable[index] = (short) (((red >> 3) << 11)
            | ((green >> 2) << 5) | (blue >> 3));
      }
    }
  }
  private int calcColor(int palColor, int target, int level) {
    return (palColor - target) * (level + 1) / NUM_SHADE_LEVELS + target;
  }
  /**
   * Sets the default shade level that is used when getColor() is called.
   */
  public void setDefaultShadeLevel(int level) {
    defaultShadeLevel = level;
  }
  /**
   * Gets the default shade level that is used when getColor() is called.
   */
  public int getDefaultShadeLevel() {
    return defaultShadeLevel;
  }
  /**
   * Gets the 16-bit color of this Texture at the specified (x,y) location,
   * using the default shade level.
   */
  public short getColor(int x, int y) {
    return getColor(x, y, defaultShadeLevel);
  }
  /**
   * Gets the 16-bit color of this Texture at the specified (x,y) location,
   * using the specified shade level.
   */
  public short getColor(int x, int y, int shadeLevel) {
    return shadeTable[(shadeLevel << PALETTE_SIZE_BITS)
        | (0xff & buffer[(x & widthMask)
            | ((y & heightMask) << widthBits)])];
  }
  /**
   * Sets the current row for getColorCurrRow(). Pre-calculates the offset for
   * this row.
   */
  public void setCurrRow(int y) {
    currRow = (y & heightMask) << widthBits;
  }
  /**
   * Gets the color at the specified x location at the specified shade level.
   * The current row defined in setCurrRow is used.
   */
  public short getColorCurrRow(int x, int shadeLevel) {
    return shadeTable[(shadeLevel << PALETTE_SIZE_BITS)
        | (0xff & buffer[(x & widthMask) | currRow])];
  }
}
/**
 * The PowerOf2Texture class is a Texture with a width and height that are a
 * power of 2 (32, 128, etc.).
 */
final class PowerOf2Texture extends Texture {
  private short[] buffer;
  private int widthBits;
  private int widthMask;
  private int heightBits;
  private int heightMask;
  /**
   * Creates a new PowerOf2Texture with the specified buffer. The width of the
   * bitmap is 2 to the power of widthBits, or (1 < < widthBits). Likewise,
   * the height of the bitmap is 2 to the power of heightBits, or (1 < <
   * heightBits).
   */
  public PowerOf2Texture(short[] buffer, int widthBits, int heightBits) {
    super(1 << widthBits, 1 << heightBits);
    this.buffer = buffer;
    this.widthBits = widthBits;
    this.heightBits = heightBits;
    this.widthMask = getWidth() - 1;
    this.heightMask = getHeight() - 1;
  }
  /**
   * Gets the 16-bit color of the pixel at location (x,y) in the bitmap.
   */
  public short getColor(int x, int y) {
    return buffer[(x & widthMask) + ((y & heightMask) << widthBits)];
  }
}
/**
 * Simple abstract class used for testing. Subclasses should implement the
 * draw() method.
 */
abstract class GameCore {
  protected static final int DEFAULT_FONT_SIZE = 24;
  // various lists of modes, ordered by preference
  protected static final DisplayMode[] MID_RES_MODES = {
      new DisplayMode(800, 600, 16, 0), new DisplayMode(800, 600, 32, 0),
      new DisplayMode(800, 600, 24, 0), new DisplayMode(640, 480, 16, 0),
      new DisplayMode(640, 480, 32, 0), new DisplayMode(640, 480, 24, 0),
      new DisplayMode(1024, 768, 16, 0),
      new DisplayMode(1024, 768, 32, 0),
      new DisplayMode(1024, 768, 24, 0), };
  protected static final DisplayMode[] LOW_RES_MODES = {
      new DisplayMode(640, 480, 16, 0), new DisplayMode(640, 480, 32, 0),
      new DisplayMode(640, 480, 24, 0), new DisplayMode(800, 600, 16, 0),
      new DisplayMode(800, 600, 32, 0), new DisplayMode(800, 600, 24, 0),
      new DisplayMode(1024, 768, 16, 0),
      new DisplayMode(1024, 768, 32, 0),
      new DisplayMode(1024, 768, 24, 0), };
  protected static final DisplayMode[] VERY_LOW_RES_MODES = {
      new DisplayMode(320, 240, 16, 0), new DisplayMode(400, 300, 16, 0),
      new DisplayMode(512, 384, 16, 0), new DisplayMode(640, 480, 16, 0),
      new DisplayMode(800, 600, 16, 0), };
  private boolean isRunning;
  protected ScreenManager screen;
  protected int fontSize = DEFAULT_FONT_SIZE;
  /**
   * Signals the game loop that it"s time to quit
   */
  public void stop() {
    isRunning = false;
  }
  /**
   * Calls init() and gameLoop()
   */
  public void run() {
    try {
      init();
      gameLoop();
    } finally {
      if (screen != null) {
        screen.restoreScreen();
      }
      lazilyExit();
    }
  }
  /**
   * Exits the VM from a daemon thread. The daemon thread waits 2 seconds then
   * calls System.exit(0). Since the VM should exit when only daemon threads
   * are running, this makes sure System.exit(0) is only called if neccesary.
   * It"s neccesary if the Java Sound system is running.
   */
  public void lazilyExit() {
    Thread thread = new Thread() {
      public void run() {
        // first, wait for the VM exit on its own.
        try {
          Thread.sleep(2000);
        } catch (InterruptedException ex) {
        }
        // system is still running, so force an exit
        System.exit(0);
      }
    };
    thread.setDaemon(true);
    thread.start();
  }
  /**
   * Sets full screen mode and initiates and objects.
   */
  public void init() {
    init(MID_RES_MODES);
  }
  /**
   * Sets full screen mode and initiates and objects.
   */
  public void init(DisplayMode[] possibleModes) {
    screen = new ScreenManager();
    DisplayMode displayMode = screen.findFirstCompatibleMode(possibleModes);
    screen.setFullScreen(displayMode);
    Window window = screen.getFullScreenWindow();
    window.setFont(new Font("Dialog", Font.PLAIN, fontSize));
    window.setBackground(Color.blue);
    window.setForeground(Color.white);
    isRunning = true;
  }
  public Image loadImage(String fileName) {
    return new ImageIcon(fileName).getImage();
  }
  /**
   * Runs through the game loop until stop() is called.
   */
  public void gameLoop() {
    long startTime = System.currentTimeMillis();
    long currTime = startTime;
    while (isRunning) {
      long elapsedTime = System.currentTimeMillis() - currTime;
      currTime += elapsedTime;
      // update
      update(elapsedTime);
      // draw the screen
      Graphics2D g = screen.getGraphics();
      draw(g);
      g.dispose();
      screen.update();
      // don"t take a nap! run as fast as possible
      /*
       * try { Thread.sleep(20); } catch (InterruptedException ex) { }
       */
    }
  }
  /**
   * Updates the state of the game/animation based on the amount of elapsed
   * time that has passed.
   */
  public void update(long elapsedTime) {
    // do nothing
  }
  /**
   * Draws to the screen. Subclasses must override this method.
   */
  public abstract void draw(Graphics2D g);
}
/**
 * The ScreenManager class manages initializing and displaying full screen
 * graphics modes.
 */
class ScreenManager {
  private GraphicsDevice device;
  /**
   * Creates a new ScreenManager object.
   */
  public ScreenManager() {
    GraphicsEnvironment environment = GraphicsEnvironment
        .getLocalGraphicsEnvironment();
    device = environment.getDefaultScreenDevice();
  }
  /**
   * Returns a list of compatible display modes for the default device on the
   * system.
   */
  public DisplayMode[] getCompatibleDisplayModes() {
    return device.getDisplayModes();
  }
  /**
   * Returns the first compatible mode in a list of modes. Returns null if no
   * modes are compatible.
   */
  public DisplayMode findFirstCompatibleMode(DisplayMode modes[]) {
    DisplayMode goodModes[] = device.getDisplayModes();
    for (int i = 0; i < modes.length; i++) {
      for (int j = 0; j < goodModes.length; j++) {
        if (displayModesMatch(modes[i], goodModes[j])) {
          return modes[i];
        }
      }
    }
    return null;
  }
  /**
   * Returns the current display mode.
   */
  public DisplayMode getCurrentDisplayMode() {
    return device.getDisplayMode();
  }
  /**
   * Determines if two display modes "match". Two display modes match if they
   * have the same resolution, bit depth, and refresh rate. The bit depth is
   * ignored if one of the modes has a bit depth of
   * DisplayMode.BIT_DEPTH_MULTI. Likewise, the refresh rate is ignored if one
   * of the modes has a refresh rate of DisplayMode.REFRESH_RATE_UNKNOWN.
   */
  public boolean displayModesMatch(DisplayMode mode1, DisplayMode mode2)
  {
    if (mode1.getWidth() != mode2.getWidth()
        || mode1.getHeight() != mode2.getHeight()) {
      return false;
    }
    if (mode1.getBitDepth() != DisplayMode.BIT_DEPTH_MULTI
        && mode2.getBitDepth() != DisplayMode.BIT_DEPTH_MULTI
        && mode1.getBitDepth() != mode2.getBitDepth()) {
      return false;
    }
    if (mode1.getRefreshRate() != DisplayMode.REFRESH_RATE_UNKNOWN
        && mode2.getRefreshRate() != DisplayMode.REFRESH_RATE_UNKNOWN
        && mode1.getRefreshRate() != mode2.getRefreshRate()) {
      return false;
    }
    return true;
  }
  /**
   * Enters full screen mode and changes the display mode. If the specified
   * display mode is null or not compatible with this device, or if the
   * display mode cannot be changed on this system, the current display mode
   * is used.
   * <p>
   * The display uses a BufferStrategy with 2 buffers.
   */
  public void setFullScreen(DisplayMode displayMode) {
    final JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setUndecorated(true);
    frame.setIgnoreRepaint(true);
    frame.setResizable(false);
    device.setFullScreenWindow(frame);
    if (displayMode != null && device.isDisplayChangeSupported()) {
      try {
        device.setDisplayMode(displayMode);
      } catch (IllegalArgumentException ex) {
      }
      // fix for mac os x
      frame.setSize(displayMode.getWidth(), displayMode.getHeight());
    }
    // avoid potential deadlock in 1.4.1_02
    try {
      EventQueue.invokeAndWait(new Runnable() {
        public void run() {
          frame.createBufferStrategy(2);
        }
      });
    } catch (InterruptedException ex) {
      // ignore
    } catch (InvocationTargetException ex) {
      // ignore
    }
  }
  /**
   * Gets the graphics context for the display. The ScreenManager uses double
   * buffering, so applications must call update() to show any graphics drawn.
   * <p>
   * The application must dispose of the graphics object.
   */
  public Graphics2D getGraphics() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      BufferStrategy strategy = window.getBufferStrategy();
      return (Graphics2D) strategy.getDrawGraphics();
    } else {
      return null;
    }
  }
  /**
   * Updates the display.
   */
  public void update() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      BufferStrategy strategy = window.getBufferStrategy();
      if (!strategy.contentsLost()) {
        strategy.show();
      }
    }
    // Sync the display on some systems.
    // (on Linux, this fixes event queue problems)
    //Toolkit.getDefaultToolkit().sync();
  }
  /**
   * Returns the window currently used in full screen mode. Returns null if
   * the device is not in full screen mode.
   */
  public JFrame getFullScreenWindow() {
    return (JFrame) device.getFullScreenWindow();
  }
  /**
   * Returns the width of the window currently used in full screen mode.
   * Returns 0 if the device is not in full screen mode.
   */
  public int getWidth() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      return window.getWidth();
    } else {
      return 0;
    }
  }
  /**
   * Returns the height of the window currently used in full screen mode.
   * Returns 0 if the device is not in full screen mode.
   */
  public int getHeight() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      return window.getHeight();
    } else {
      return 0;
    }
  }
  /**
   * Restores the screen"s display mode.
   */
  public void restoreScreen() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      window.dispose();
    }
    device.setFullScreenWindow(null);
  }
  /**
   * Creates an image compatible with the current display.
   */
  public BufferedImage createCompatibleImage(int w, int h, int transparancy) {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      GraphicsConfiguration gc = window.getGraphicsConfiguration();
      return gc.createCompatibleImage(w, h, transparancy);
    }
    return null;
  }
}
/**
 * A thread pool is a group of a limited number of threads that are used to
 * execute tasks.
 */
class ThreadPool extends ThreadGroup {
  private boolean isAlive;
  private LinkedList taskQueue;
  private int threadID;
  private static int threadPoolID;
  /**
   * Creates a new ThreadPool.
   * 
   * @param numThreads
   *            The number of threads in the pool.
   */
  public ThreadPool(int numThreads) {
    super("ThreadPool-" + (threadPoolID++));
    setDaemon(true);
    isAlive = true;
    taskQueue = new LinkedList();
    for (int i = 0; i < numThreads; i++) {
      new PooledThread().start();
    }
  }
  /**
   * Requests a new task to run. This method returns immediately, and the task
   * executes on the next available idle thread in this ThreadPool.
   * <p>
   * Tasks start execution in the order they are received.
   * 
   * @param task
   *            The task to run. If null, no action is taken.
   * @throws IllegalStateException
   *             if this ThreadPool is already closed.
   */
  public synchronized void runTask(Runnable task) {
    if (!isAlive) {
      throw new IllegalStateException();
    }
    if (task != null) {
      taskQueue.add(task);
      notify();
    }
  }
  protected synchronized Runnable getTask() throws InterruptedException {
    while (taskQueue.size() == 0) {
      if (!isAlive) {
        return null;
      }
      wait();
    }
    return (Runnable) taskQueue.removeFirst();
  }
  /**
   * Closes this ThreadPool and returns immediately. All threads are stopped,
   * and any waiting tasks are not executed. Once a ThreadPool is closed, no
   * more tasks can be run on this ThreadPool.
   */
  public synchronized void close() {
    if (isAlive) {
      isAlive = false;
      taskQueue.clear();
      interrupt();
    }
  }
  /**
   * Closes this ThreadPool and waits for all running threads to finish. Any
   * waiting tasks are executed.
   */
  public void join() {
    // notify all waiting threads that this ThreadPool is no
    // longer alive
    synchronized (this) {
      isAlive = false;
      notifyAll();
    }
    // wait for all threads to finish
    Thread[] threads = new Thread[activeCount()];
    int count = enumerate(threads);
    for (int i = 0; i < count; i++) {
      try {
        threads[i].join();
      } catch (InterruptedException ex) {
      }
    }
  }
  /**
   * Signals that a PooledThread has started. This method does nothing by
   * default; subclasses should override to do any thread-specific startup
   * tasks.
   */
  protected void threadStarted() {
    // do nothing
  }
  /**
   * Signals that a PooledThread has stopped. This method does nothing by
   * default; subclasses should override to do any thread-specific cleanup
   * tasks.
   */
  protected void threadStopped() {
    // do nothing
  }
  /**
   * A PooledThread is a Thread in a ThreadPool group, designed to run tasks
   * (Runnables).
   */
  private class PooledThread extends Thread {
    public PooledThread() {
      super(ThreadPool.this, "PooledThread-" + (threadID++));
    }
    public void run() {
      // signal that this thread has started
      threadStarted();
      while (!isInterrupted()) {
        // get a task to run
        Runnable task = null;
        try {
          task = getTask();
        } catch (InterruptedException ex) {
        }
        // if getTask() returned null or was interrupted,
        // close this thread.
        if (task == null) {
          break;
        }
        // run the task, and eat any exceptions it throws
        try {
          task.run();
        } catch (Throwable t) {
          uncaughtException(this, t);
        }
      }
      // signal that this thread has stopped
      threadStopped();
    }
  }
}
/**
 * The SoundManager class manages sound playback. The SoundManager is a
 * ThreadPool, with each thread playing back one sound at a time. This allows
 * the SoundManager to easily limit the number of simultaneous sounds being
 * played.
 * <p>
 * Possible ideas to extend this class:
 * <ul>
 * <li>add a setMasterVolume() method, which uses Controls to set the volume
 * for each line.
 * <li>don"t play a sound if more than, say, 500ms has passed since the request
 * to play
 * </ul>
 */
class SoundManager extends ThreadPool {
  private AudioFormat playbackFormat;
  private ThreadLocal localLine;
  private ThreadLocal localBuffer;
  private Object pausedLock;
  private boolean paused;
  /**
   * Creates a new SoundManager using the maximum number of simultaneous
   * sounds.
   */
  public SoundManager(AudioFormat playbackFormat) {
    this(playbackFormat, getMaxSimultaneousSounds(playbackFormat));
  }
  /**
   * Creates a new SoundManager with the specified maximum number of
   * simultaneous sounds.
   */
  public SoundManager(AudioFormat playbackFormat, int maxSimultaneousSounds) {
    super(Math.min(maxSimultaneousSounds,
        getMaxSimultaneousSounds(playbackFormat)));
    this.playbackFormat = playbackFormat;
    localLine = new ThreadLocal();
    localBuffer = new ThreadLocal();
    pausedLock = new Object();
    // notify threads in pool it"s ok to start
    synchronized (this) {
      notifyAll();
    }
  }
  /**
   * Gets the maximum number of simultaneous sounds with the specified
   * AudioFormat that the default mixer can play.
   */
  public static int getMaxSimultaneousSounds(AudioFormat playbackFormat) {
    DataLine.Info lineInfo = new DataLine.Info(SourceDataLine.class,
        playbackFormat);
    Mixer mixer = AudioSystem.getMixer(null);
    return mixer.getMaxLines(lineInfo);
  }
  /**
   * Does any clean up before closing.
   */
  protected void cleanUp() {
    // signal to unpause
    setPaused(false);
    // close the mixer (stops any running sounds)
    Mixer mixer = AudioSystem.getMixer(null);
    if (mixer.isOpen()) {
      mixer.close();
    }
  }
  public void close() {
    cleanUp();
    super.close();
  }
  public void join() {
    cleanUp();
    super.join();
  }
  /**
   * Sets the paused state. Sounds may not pause immediately.
   */
  public void setPaused(boolean paused) {
    if (this.paused != paused) {
      synchronized (pausedLock) {
        this.paused = paused;
        if (!paused) {
          // restart sounds
          pausedLock.notifyAll();
        }
      }
    }
  }
  /**
   * Returns the paused state.
   */
  public boolean isPaused() {
    return paused;
  }
  /**
   * Loads a Sound from the file system. Returns null if an error occurs.
   */
  public Sound getSound(String filename) {
    return getSound(getAudioInputStream(filename));
  }
  /**
   * Loads a Sound from an input stream. Returns null if an error occurs.
   */
  public Sound getSound(InputStream is) {
    return getSound(getAudioInputStream(is));
  }
  /**
   * Loads a Sound from an AudioInputStream.
   */
  public Sound getSound(AudioInputStream audioStream) {
    if (audioStream == null) {
      return null;
    }
    // get the number of bytes to read
    int length = (int) (audioStream.getFrameLength() * audioStream
        .getFormat().getFrameSize());
    // read the entire stream
    byte[] samples = new byte[length];
    DataInputStream is = new DataInputStream(audioStream);
    try {
      is.readFully(samples);
      is.close();
    } catch (IOException ex) {
      ex.printStackTrace();
    }
    // return the samples
    return new Sound(samples);
  }
  /**
   * Creates an AudioInputStream from a sound from the file system.
   */
  public AudioInputStream getAudioInputStream(String filename) {
    try {
      return getAudioInputStream(new FileInputStream(filename));
    } catch (IOException ex) {
      ex.printStackTrace();
      return null;
    }
  }
  /**
   * Creates an AudioInputStream from a sound from an input stream
   */
  public AudioInputStream getAudioInputStream(InputStream is) {
    try {
      if (!is.markSupported()) {
        is = new BufferedInputStream(is);
      }
      // open the source stream
      AudioInputStream source = AudioSystem.getAudioInputStream(is);
      // convert to playback format
      return AudioSystem.getAudioInputStream(playbackFormat, source);
    } catch (UnsupportedAudioFileException ex) {
      ex.printStackTrace();
    } catch (IOException ex) {
      ex.printStackTrace();
    } catch (IllegalArgumentException ex) {
      ex.printStackTrace();
    }
    return null;
  }
  /**
   * Plays a sound. This method returns immediately.
   */
  public InputStream play(Sound sound) {
    return play(sound, null, false);
  }
  /**
   * Plays a sound with an optional SoundFilter, and optionally looping. This
   * method returns immediately.
   */
  public InputStream play(Sound sound, SoundFilter filter, boolean loop) {
    InputStream is;
    if (sound != null) {
      if (loop) {
        is = new LoopingByteInputStream(sound.getSamples());
      } else {
        is = new ByteArrayInputStream(sound.getSamples());
      }
      return play(is, filter);
    }
    return null;
  }
  /**
   * Plays a sound from an InputStream. This method returns immediately.
   */
  public InputStream play(InputStream is) {
    return play(is, null);
  }
  /**
   * Plays a sound from an InputStream with an optional sound filter. This
   * method returns immediately.
   */
  public InputStream play(InputStream is, SoundFilter filter) {
    if (is != null) {
      if (filter != null) {
        is = new FilteredSoundStream(is, filter);
      }
      runTask(new SoundPlayer(is));
    }
    return is;
  }
  /**
   * Signals that a PooledThread has started. Creates the Thread"s line and
   * buffer.
   */
  protected void threadStarted() {
    // wait for the SoundManager constructor to finish
    synchronized (this) {
      try {
        wait();
      } catch (InterruptedException ex) {
      }
    }
    // use a short, 100ms (1/10th sec) buffer for filters that
    // change in real-time
    int bufferSize = playbackFormat.getFrameSize()
        * Math.round(playbackFormat.getSampleRate() / 10);
    // create, open, and start the line
    SourceDataLine line;
    DataLine.Info lineInfo = new DataLine.Info(SourceDataLine.class,
        playbackFormat);
    try {
      line = (SourceDataLine) AudioSystem.getLine(lineInfo);
      line.open(playbackFormat, bufferSize);
    } catch (LineUnavailableException ex) {
      // the line is unavailable - signal to end this thread
      Thread.currentThread().interrupt();
      return;
    }
    line.start();
    // create the buffer
    byte[] buffer = new byte[bufferSize];
    // set this thread"s locals
    localLine.set(line);
    localBuffer.set(buffer);
  }
  /**
   * Signals that a PooledThread has stopped. Drains and closes the Thread"s
   * Line.
   */
  protected void threadStopped() {
    SourceDataLine line = (SourceDataLine) localLine.get();
    if (line != null) {
      line.drain();
      line.close();
    }
  }
  /**
   * The SoundPlayer class is a task for the PooledThreads to run. It receives
   * the threads"s Line and byte buffer from the ThreadLocal variables and
   * plays a sound from an InputStream.
   * <p>
   * This class only works when called from a PooledThread.
   */
  protected class SoundPlayer implements Runnable {
    private InputStream source;
    public SoundPlayer(InputStream source) {
      this.source = source;
    }
    public void run() {
      // get line and buffer from ThreadLocals
      SourceDataLine line = (SourceDataLine) localLine.get();
      byte[] buffer = (byte[]) localBuffer.get();
      if (line == null || buffer == null) {
        // the line is unavailable
        return;
      }
      // copy data to the line
      try {
        int numBytesRead = 0;
        while (numBytesRead != -1) {
          // if paused, wait until unpaused
          synchronized (pausedLock) {
            if (paused) {
              try {
                pausedLock.wait();
              } catch (InterruptedException ex) {
                return;
              }
            }
          }
          // copy data
          numBytesRead = source.read(buffer, 0, buffer.length);
          if (numBytesRead != -1) {
            line.write(buffer, 0, numBytesRead);
          }
        }
      } catch (IOException ex) {
        ex.printStackTrace();
      }
    }
  }
}
/**
 * The LoopingByteInputStream is a ByteArrayInputStream that loops indefinitly.
 * The looping stops when the close() method is called.
 * <p>
 * Possible ideas to extend this class:
 * <ul>
 * <li>Add an option to only loop a certain number of times.
 * </ul>
 */
class LoopingByteInputStream extends ByteArrayInputStream {
  private boolean closed;
  /**
   * Creates a new LoopingByteInputStream with the specified byte array. The
   * array is not copied.
   */
  public LoopingByteInputStream(byte[] buffer) {
    super(buffer);
    closed = false;
  }
  /**
   * Reads <code>length</code> bytes from the array. If the end of the array
   * is reached, the reading starts over from the beginning of the array.
   * Returns -1 if the array has been closed.
   */
  public int read(byte[] buffer, int offset, int length) {
    if (closed) {
      return -1;
    }
    int totalBytesRead = 0;
    while (totalBytesRead < length) {
      int numBytesRead = super.read(buffer, offset + totalBytesRead,
          length - totalBytesRead);
      if (numBytesRead > 0) {
        totalBytesRead += numBytesRead;
      } else {
        reset();
      }
    }
    return totalBytesRead;
  }
  /**
   * Closes the stream. Future calls to the read() methods will return 1.
   */
  public void close() throws IOException {
    super.close();
    closed = true;
  }
}
/**
 * A abstract class designed to filter sound samples. Since SoundFilters may use
 * internal buffering of samples, a new SoundFilter object should be created for
 * every sound played. However, SoundFilters can be reused after they are
 * finished by called the reset() method.
 * <p>
 * Assumes all samples are 16-bit, signed, little-endian format.
 * 
 * @see FilteredSoundStream
 */
abstract class SoundFilter {
  /**
   * Resets this SoundFilter. Does nothing by default.
   */
  public void reset() {
    // do nothing
  }
  /**
   * Gets the remaining size, in bytes, that this filter plays after the sound
   * is finished. An example would be an echo that plays longer than it"s
   * original sound. This method returns 0 by default.
   */
  public int getRemainingSize() {
    return 0;
  }
  /**
   * Filters an array of samples. Samples should be in 16-bit, signed,
   * little-endian format.
   */
  public void filter(byte[] samples) {
    filter(samples, 0, samples.length);
  }
  /**
   * Filters an array of samples. Samples should be in 16-bit, signed,
   * little-endian format. This method should be implemented by subclasses.
   */
  public abstract void filter(byte[] samples, int offset, int length);
  /**
   * Convenience method for getting a 16-bit sample from a byte array. Samples
   * should be in 16-bit, signed, little-endian format.
   */
  public static short getSample(byte[] buffer, int position) {
    return (short) (((buffer[position + 1] & 0xff) << 8) | (buffer[position] & 0xff));
  }
  /**
   * Convenience method for setting a 16-bit sample in a byte array. Samples
   * should be in 16-bit, signed, little-endian format.
   */
  public static void setSample(byte[] buffer, int position, short sample) {
    buffer[position] = (byte) (sample & 0xff);
    buffer[position + 1] = (byte) ((sample >> 8) & 0xff);
  }
}
/**
 * The FilteredSoundStream class is a FilterInputStream that applies a
 * SoundFilter to the underlying input stream.
 * 
 * @see SoundFilter
 */
class FilteredSoundStream extends FilterInputStream {
  private static final int REMAINING_SIZE_UNKNOWN = -1;
  private SoundFilter soundFilter;
  private int remainingSize;
  /**
   * Creates a new FilteredSoundStream object with the specified InputStream
   * and SoundFilter.
   */
  public FilteredSoundStream(InputStream in, SoundFilter soundFilter) {
    super(in);
    this.soundFilter = soundFilter;
    remainingSize = REMAINING_SIZE_UNKNOWN;
  }
  /**
   * Overrides the FilterInputStream method to apply this filter whenever
   * bytes are read
   */
  public int read(byte[] samples, int offset, int length) throws IOException {
    // read and filter the sound samples in the stream
    int bytesRead = super.read(samples, offset, length);
    if (bytesRead > 0) {
      soundFilter.filter(samples, offset, bytesRead);
      return bytesRead;
    }
    // if there are no remaining bytes in the sound stream,
    // check if the filter has any remaining bytes ("echoes").
    if (remainingSize == REMAINING_SIZE_UNKNOWN) {
      remainingSize = soundFilter.getRemainingSize();
      // round down to nearest multiple of 4
      // (typical frame size)
      remainingSize = remainingSize / 4 * 4;
    }
    if (remainingSize > 0) {
      length = Math.min(length, remainingSize);
      // clear the buffer
      for (int i = offset; i < offset + length; i++) {
        samples[i] = 0;
      }
      // filter the remaining bytes
      soundFilter.filter(samples, offset, length);
      remainingSize -= length;
      // return
      return length;
    } else {
      // end of stream
      return -1;
    }
  }
}
/**
 * The MoreMath class provides functions not contained in the java.lang.Math or
 * java.lang.StrictMath classes.
 */
class MoreMath {
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(short v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(int v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(long v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(float v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(double v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Faster ceil function to convert a float to an int. Contrary to the
   * java.lang.Math ceil function, this function takes a float as an argument,
   * returns an int instead of a double, and does not consider special cases.
   */
  public static int ceil(float f) {
    if (f > 0) {
      return (int) f + 1;
    } else {
      return (int) f;
    }
  }
  /**
   * Faster floor function to convert a float to an int. Contrary to the
   * java.lang.Math floor function, this function takes a float as an
   * argument, returns an int instead of a double, and does not consider
   * special cases.
   */
  public static int floor(float f) {
    if (f >= 0) {
      return (int) f;
    } else {
      return (int) f - 1;
    }
  }
  /**
   * Returns true if the specified number is a power of 2.
   */
  public static boolean isPowerOfTwo(int n) {
    return ((n & (n - 1)) == 0);
  }
  /**
   * Gets the number of "on" bits in an integer.
   */
  public static int getBitCount(int n) {
    int count = 0;
    while (n > 0) {
      count += (n & 1);
      n >>= 1;
    }
    return count;
  }
}
/**
 * The ScanConverter class converts a projected polygon into a series of
 * horizontal scans for drawing.
 */
class ScanConverter {
  private static final int SCALE_BITS = 16;
  private static final int SCALE = 1 << SCALE_BITS;
  private static final int SCALE_MASK = SCALE - 1;
  protected ViewWindow view;
  protected Scan[] scans;
  protected int top;
  protected int bottom;
  /**
   * A horizontal scan line.
   */
  public static class Scan {
    public int left;
    public int right;
    /**
     * Sets the left and right boundary for this scan if the x value is
     * outside the current boundary.
     */
    public void setBoundary(int x) {
      if (x < left) {
        left = x;
      }
      if (x - 1 > right) {
        right = x - 1;
      }
    }
    /**
     * Clears this scan line.
     */
    public void clear() {
      left = Integer.MAX_VALUE;
      right = Integer.MIN_VALUE;
    }
    /**
     * Determines if this scan is valid (if left <= right).
     */
    public boolean isValid() {
      return (left <= right);
    }
    /**
     * Sets this scan.
     */
    public void setTo(int left, int right) {
      this.left = left;
      this.right = right;
    }
    /**
     * Checks if this scan is equal to the specified values.
     */
    public boolean equals(int left, int right) {
      return (this.left == left && this.right == right);
    }
  }
  /**
   * Creates a new ScanConverter for the specified ViewWindow. The
   * ViewWindow"s properties can change in between scan conversions.
   */
  public ScanConverter(ViewWindow view) {
    this.view = view;
  }
  /**
   * Gets the top boundary of the last scan-converted polygon.
   */
  public int getTopBoundary() {
    return top;
  }
  /**
   * Gets the bottom boundary of the last scan-converted polygon.
   */
  public int getBottomBoundary() {
    return bottom;
  }
  /**
   * Gets the scan line for the specified y value.
   */
  public Scan getScan(int y) {
    return scans[y];
  }
  /**
   * Ensures this ScanConverter has the capacity to scan-convert a polygon to
   * the ViewWindow.
   */
  protected void ensureCapacity() {
    int height = view.getTopOffset() + view.getHeight();
    if (scans == null || scans.length != height) {
      scans = new Scan[height];
      for (int i = 0; i < height; i++) {
        scans[i] = new Scan();
      }
      // set top and bottom so clearCurrentScan clears all
      top = 0;
      bottom = height - 1;
    }
  }
  /**
   * Clears the current scan.
   */
  private void clearCurrentScan() {
    for (int i = top; i <= bottom; i++) {
      scans[i].clear();
    }
    top = Integer.MAX_VALUE;
    bottom = Integer.MIN_VALUE;
  }
  /**
   * Scan-converts a projected polygon. Returns true if the polygon is visible
   * in the view window.
   */
  public boolean convert(Polygon3D polygon) {
    ensureCapacity();
    clearCurrentScan();
    int minX = view.getLeftOffset();
    int maxX = view.getLeftOffset() + view.getWidth() - 1;
    int minY = view.getTopOffset();
    int maxY = view.getTopOffset() + view.getHeight() - 1;
    int numVertices = polygon.getNumVertices();
    for (int i = 0; i < numVertices; i++) {
      Vector3D v1 = polygon.getVertex(i);
      Vector3D v2;
      if (i == numVertices - 1) {
        v2 = polygon.getVertex(0);
      } else {
        v2 = polygon.getVertex(i + 1);
      }
      // ensure v1.y < v2.y
      if (v1.y > v2.y) {
        Vector3D temp = v1;
        v1 = v2;
        v2 = temp;
      }
      float dy = v2.y - v1.y;
      // ignore horizontal lines
      if (dy == 0) {
        continue;
      }
      int startY = Math.max(MoreMath.ceil(v1.y), minY);
      int endY = Math.min(MoreMath.ceil(v2.y) - 1, maxY);
      top = Math.min(top, startY);
      bottom = Math.max(bottom, endY);
      float dx = v2.x - v1.x;
      // special case: vertical line
      if (dx == 0) {
        int x = MoreMath.ceil(v1.x);
        // ensure x within view bounds
        x = Math.min(maxX + 1, Math.max(x, minX));
        for (int y = startY; y <= endY; y++) {
          scans[y].setBoundary(x);
        }
      } else {
        // scan-convert this edge (line equation)
        float gradient = dx / dy;
        // (slower version)
        /*
         * for (int y=startY; y <=endY; y++) { int x =
         * MoreMath.ceil(v1.x + (y - v1.y) * gradient); // ensure x
         * within view bounds x = Math.min(maxX+1, Math.max(x, minX));
         * scans[y].setBoundary(x); }
         */
        // (faster version)
        // trim start of line
        float startX = v1.x + (startY - v1.y) * gradient;
        if (startX < minX) {
          int yInt = (int) (v1.y + (minX - v1.x) / gradient);
          yInt = Math.min(yInt, endY);
          while (startY <= yInt) {
            scans[startY].setBoundary(minX);
            startY++;
          }
        } else if (startX > maxX) {
          int yInt = (int) (v1.y + (maxX - v1.x) / gradient);
          yInt = Math.min(yInt, endY);
          while (startY <= yInt) {
            scans[startY].setBoundary(maxX + 1);
            startY++;
          }
        }
        if (startY > endY) {
          continue;
        }
        // trim back of line
        float endX = v1.x + (endY - v1.y) * gradient;
        if (endX < minX) {
          int yInt = MoreMath.ceil(v1.y + (minX - v1.x) / gradient);
          yInt = Math.max(yInt, startY);
          while (endY >= yInt) {
            scans[endY].setBoundary(minX);
            endY--;
          }
        } else if (endX > maxX) {
          int yInt = MoreMath.ceil(v1.y + (maxX - v1.x) / gradient);
          yInt = Math.max(yInt, startY);
          while (endY >= yInt) {
            scans[endY].setBoundary(maxX + 1);
            endY--;
          }
        }
        if (startY > endY) {
          continue;
        }
        // line equation using integers
        int xScaled = (int) (SCALE * v1.x + SCALE * (startY - v1.y)
            * dx / dy)
            + SCALE_MASK;
        int dxScaled = (int) (dx * SCALE / dy);
        for (int y = startY; y <= endY; y++) {
          scans[y].setBoundary(xScaled >> SCALE_BITS);
          xScaled += dxScaled;
        }
      }
    }
    // check if visible (any valid scans)
    for (int i = top; i <= bottom; i++) {
      if (scans[i].isValid()) {
        return true;
      }
    }
    return false;
  }
}
/**
 * The PolygonRenderer class is an abstract class that transforms and draws
 * polygons onto the screen.
 */
abstract class PolygonRenderer {
  protected ScanConverter scanConverter;
  protected Transform3D camera;
  protected ViewWindow viewWindow;
  protected boolean clearViewEveryFrame;
  protected Polygon3D sourcePolygon;
  protected Polygon3D destPolygon;
  /**
   * Creates a new PolygonRenderer with the specified Transform3D (camera) and
   * ViewWindow. The view is cleared when startFrame() is called.
   */
  public PolygonRenderer(Transform3D camera, ViewWindow viewWindow) {
    this(camera, viewWindow, true);
  }
  /**
   * Creates a new PolygonRenderer with the specified Transform3D (camera) and
   * ViewWindow. If clearViewEveryFrame is true, the view is cleared when
   * startFrame() is called.
   */
  public PolygonRenderer(Transform3D camera, ViewWindow viewWindow,
      boolean clearViewEveryFrame) {
    this.camera = camera;
    this.viewWindow = viewWindow;
    this.clearViewEveryFrame = clearViewEveryFrame;
    init();
  }
  /**
   * Create the scan converter and dest polygon.
   */
  protected void init() {
    destPolygon = new Polygon3D();
    scanConverter = new ScanConverter(viewWindow);
  }
  /**
   * Gets the camera used for this PolygonRenderer.
   */
  public Transform3D getCamera() {
    return camera;
  }
  /**
   * Indicates the start of rendering of a frame. This method should be called
   * every frame before any polygons are drawn.
   */
  public void startFrame(Graphics2D g) {
    if (clearViewEveryFrame) {
      g.setColor(Color.black);
      g.fillRect(viewWindow.getLeftOffset(), viewWindow.getTopOffset(),
          viewWindow.getWidth(), viewWindow.getHeight());
    }
  }
  /**
   * Indicates the end of rendering of a frame. This method should be called
   * every frame after all polygons are drawn.
   */
  public void endFrame(Graphics2D g) {
    // do nothing, for now.
  }
  /**
   * Transforms and draws a polygon.
   */
  public boolean draw(Graphics2D g, Polygon3D poly) {
    if (poly.isFacing(camera.getLocation())) {
      sourcePolygon = poly;
      destPolygon.setTo(poly);
      destPolygon.subtract(camera);
      boolean visible = destPolygon.clip(-1);
      if (visible) {
        destPolygon.project(viewWindow);
        visible = scanConverter.convert(destPolygon);
        if (visible) {
          drawCurrentPolygon(g);
          return true;
        }
      }
    }
    return false;
  }
  /**
   * Draws the current polygon. At this point, the current polygon is
   * transformed, clipped, projected, scan-converted, and visible.
   */
  protected abstract void drawCurrentPolygon(Graphics2D g);
}
/**
 * The Sound class is a container for sound samples. The sound samples are
 * format-agnostic and are stored as a byte array.
 */
class Sound {
  private byte[] samples;
  /**
   * Create a new Sound object with the specified byte array. The array is not
   * copied.
   */
  public Sound(byte[] samples) {
    this.samples = samples;
  }
  /**
   * Returns this Sound"s objects samples as a byte array.
   */
  public byte[] getSamples() {
    return samples;
  }
}
/**
 * The InputManager manages input of key and mouse events. Events are mapped to
 * GameActions.
 */
class InputManager implements KeyListener, MouseListener, MouseMotionListener,
    MouseWheelListener {
  /**
   * An invisible cursor.
   */
  public static final Cursor INVISIBLE_CURSOR = Toolkit.getDefaultToolkit()
      .createCustomCursor(Toolkit.getDefaultToolkit().getImage(""),
          new Point(0, 0), "invisible");
  // mouse codes
  public static final int MOUSE_MOVE_LEFT = 0;
  public static final int MOUSE_MOVE_RIGHT = 1;
  public static final int MOUSE_MOVE_UP = 2;
  public static final int MOUSE_MOVE_DOWN = 3;
  public static final int MOUSE_WHEEL_UP = 4;
  public static final int MOUSE_WHEEL_DOWN = 5;
  public static final int MOUSE_BUTTON_1 = 6;
  public static final int MOUSE_BUTTON_2 = 7;
  public static final int MOUSE_BUTTON_3 = 8;
  private static final int NUM_MOUSE_CODES = 9;
  // key codes are defined in java.awt.KeyEvent.
  // most of the codes (except for some rare ones like
  // "alt graph") are less than 600.
  private static final int NUM_KEY_CODES = 600;
  private GameAction[] keyActions = new GameAction[NUM_KEY_CODES];
  private GameAction[] mouseActions = new GameAction[NUM_MOUSE_CODES];
  private Point mouseLocation;
  private Point centerLocation;
  private Component comp;
  private Robot robot;
  private boolean isRecentering;
  /**
   * Creates a new InputManager that listens to input from the specified
   * component.
   */
  public InputManager(Component comp) {
    this.rup = comp;
    mouseLocation = new Point();
    centerLocation = new Point();
    // register key and mouse listeners
    comp.addKeyListener(this);
    comp.addMouseListener(this);
    comp.addMouseMotionListener(this);
    comp.addMouseWheelListener(this);
    // allow input of the TAB key and other keys normally
    // used for focus traversal
    comp.setFocusTraversalKeysEnabled(false);
  }
  /**
   * Sets the cursor on this InputManager"s input component.
   */
  public void setCursor(Cursor cursor) {
    comp.setCursor(cursor);
  }
  /**
   * Sets whether realtive mouse mode is on or not. For relative mouse mode,
   * the mouse is "locked" in the center of the screen, and only the changed
   * in mouse movement is measured. In normal mode, the mouse is free to move
   * about the screen.
   */
  public void setRelativeMouseMode(boolean mode) {
    if (mode == isRelativeMouseMode()) {
      return;
    }
    if (mode) {
      try {
        robot = new Robot();
        mouseLocation.x = comp.getWidth() / 2;
        mouseLocation.y = comp.getHeight() / 2;
        recenterMouse();
      } catch (AWTException ex) {
        // couldn"t create robot!
        robot = null;
      }
    } else {
      robot = null;
    }
  }
  /**
   * Returns whether or not relative mouse mode is on.
   */
  public boolean isRelativeMouseMode() {
    return (robot != null);
  }
  /**
   * Maps a GameAction to a specific key. The key codes are defined in
   * java.awt.KeyEvent. If the key already has a GameAction mapped to it, the
   * new GameAction overwrites it.
   */
  public void mapToKey(GameAction gameAction, int keyCode) {
    keyActions[keyCode] = gameAction;
  }
  /**
   * Maps a GameAction to a specific mouse action. The mouse codes are defined
   * herer in InputManager (MOUSE_MOVE_LEFT, MOUSE_BUTTON_1, etc). If the
   * mouse action already has a GameAction mapped to it, the new GameAction
   * overwrites it.
   */
  public void mapToMouse(GameAction gameAction, int mouseCode) {
    mouseActions[mouseCode] = gameAction;
  }
  /**
   * Clears all mapped keys and mouse actions to this GameAction.
   */
  public void clearMap(GameAction gameAction) {
    for (int i = 0; i < keyActions.length; i++) {
      if (keyActions[i] == gameAction) {
        keyActions[i] = null;
      }
    }
    for (int i = 0; i < mouseActions.length; i++) {
      if (mouseActions[i] == gameAction) {
        mouseActions[i] = null;
      }
    }
    gameAction.reset();
  }
  /**
   * Gets a List of names of the keys and mouse actions mapped to this
   * GameAction. Each entry in the List is a String.
   */
  public List getMaps(GameAction gameCode) {
    ArrayList list = new ArrayList();
    for (int i = 0; i < keyActions.length; i++) {
      if (keyActions[i] == gameCode) {
        list.add(getKeyName(i));
      }
    }
    for (int i = 0; i < mouseActions.length; i++) {
      if (mouseActions[i] == gameCode) {
        list.add(getMouseName(i));
      }
    }
    return list;
  }
  /**
   * Resets all GameActions so they appear like they haven"t been pressed.
   */
  public void resetAllGameActions() {
    for (int i = 0; i < keyActions.length; i++) {
      if (keyActions[i] != null) {
        keyActions[i].reset();
      }
    }
    for (int i = 0; i < mouseActions.length; i++) {
      if (mouseActions[i] != null) {
        mouseActions[i].reset();
      }
    }
  }
  /**
   * Gets the name of a key code.
   */
  public static String getKeyName(int keyCode) {
    return KeyEvent.getKeyText(keyCode);
  }
  /**
   * Gets the name of a mouse code.
   */
  public static String getMouseName(int mouseCode) {
    switch (mouseCode) {
    case MOUSE_MOVE_LEFT:
      return "Mouse Left";
    case MOUSE_MOVE_RIGHT:
      return "Mouse Right";
    case MOUSE_MOVE_UP:
      return "Mouse Up";
    case MOUSE_MOVE_DOWN:
      return "Mouse Down";
    case MOUSE_WHEEL_UP:
      return "Mouse Wheel Up";
    case MOUSE_WHEEL_DOWN:
      return "Mouse Wheel Down";
    case MOUSE_BUTTON_1:
      return "Mouse Button 1";
    case MOUSE_BUTTON_2:
      return "Mouse Button 2";
    case MOUSE_BUTTON_3:
      return "Mouse Button 3";
    default:
      return "Unknown mouse code " + mouseCode;
    }
  }
  /**
   * Gets the x position of the mouse.
   */
  public int getMouseX() {
    return mouseLocation.x;
  }
  /**
   * Gets the y position of the mouse.
   */
  public int getMouseY() {
    return mouseLocation.y;
  }
  /**
   * Uses the Robot class to try to postion the mouse in the center of the
   * screen.
   * <p>
   * Note that use of the Robot class may not be available on all platforms.
   */
  private synchronized void recenterMouse() {
    if (robot != null && comp.isShowing()) {
      centerLocation.x = comp.getWidth() / 2;
      centerLocation.y = comp.getHeight() / 2;
      SwingUtilities.convertPointToScreen(centerLocation, comp);
      isRecentering = true;
      robot.mouseMove(centerLocation.x, centerLocation.y);
    }
  }
  private GameAction getKeyAction(KeyEvent e) {
    int keyCode = e.getKeyCode();
    if (keyCode < keyActions.length) {
      return keyActions[keyCode];
    } else {
      return null;
    }
  }
  /**
   * Gets the mouse code for the button specified in this MouseEvent.
   */
  public static int getMouseButtonCode(MouseEvent e) {
    switch (e.getButton()) {
    case MouseEvent.BUTTON1:
      return MOUSE_BUTTON_1;
    case MouseEvent.BUTTON2:
      return MOUSE_BUTTON_2;
    case MouseEvent.BUTTON3:
      return MOUSE_BUTTON_3;
    default:
      return -1;
    }
  }
  private GameAction getMouseButtonAction(MouseEvent e) {
    int mouseCode = getMouseButtonCode(e);
    if (mouseCode != -1) {
      return mouseActions[mouseCode];
    } else {
      return null;
    }
  }
  // from the KeyListener interface
  public void keyPressed(KeyEvent e) {
    GameAction gameAction = getKeyAction(e);
    if (gameAction != null) {
      gameAction.press();
    }
    // make sure the key isn"t processed for anything else
    e.consume();
  }
  // from the KeyListener interface
  public void keyReleased(KeyEvent e) {
    GameAction gameAction = getKeyAction(e);
    if (gameAction != null) {
      gameAction.release();
    }
    // make sure the key isn"t processed for anything else
    e.consume();
  }
  // from the KeyListener interface
  public void keyTyped(KeyEvent e) {
    // make sure the key isn"t processed for anything else
    e.consume();
  }
  // from the MouseListener interface
  public void mousePressed(MouseEvent e) {
    GameAction gameAction = getMouseButtonAction(e);
    if (gameAction != null) {
      gameAction.press();
    }
  }
  // from the MouseListener interface
  public void mouseReleased(MouseEvent e) {
    GameAction gameAction = getMouseButtonAction(e);
    if (gameAction != null) {
      gameAction.release();
    }
  }
  // from the MouseListener interface
  public void mouseClicked(MouseEvent e) {
    // do nothing
  }
  // from the MouseListener interface
  public void mouseEntered(MouseEvent e) {
    mouseMoved(e);
  }
  // from the MouseListener interface
  public void mouseExited(MouseEvent e) {
    mouseMoved(e);
  }
  // from the MouseMotionListener interface
  public void mouseDragged(MouseEvent e) {
    mouseMoved(e);
  }
  // from the MouseMotionListener interface
  public synchronized void mouseMoved(MouseEvent e) {
    // this event is from re-centering the mouse - ignore it
    if (isRecentering && centerLocation.x == e.getX()
        && centerLocation.y == e.getY()) {
      isRecentering = false;
    } else {
      int dx = e.getX() - mouseLocation.x;
      int dy = e.getY() - mouseLocation.y;
      mouseHelper(MOUSE_MOVE_LEFT, MOUSE_MOVE_RIGHT, dx);
      mouseHelper(MOUSE_MOVE_UP, MOUSE_MOVE_DOWN, dy);
      if (isRelativeMouseMode()) {
        recenterMouse();
      }
    }
    mouseLocation.x = e.getX();
    mouseLocation.y = e.getY();
  }
  // from the MouseWheelListener interface
  public void mouseWheelMoved(MouseWheelEvent e) {
    mouseHelper(MOUSE_WHEEL_UP, MOUSE_WHEEL_DOWN, e.getWheelRotation());
  }
  private void mouseHelper(int codeNeg, int codePos, int amount) {
    GameAction gameAction;
    if (amount < 0) {
      gameAction = mouseActions[codeNeg];
    } else {
      gameAction = mouseActions[codePos];
    }
    if (gameAction != null) {
      gameAction.press(Math.abs(amount));
      gameAction.release();
    }
  }
}
/**
 * The GameAction class is an abstract to a user-initiated action, like jumping
 * or moving. GameActions can be mapped to keys or the mouse with the
 * InputManager.
 */
class GameAction {
  /**
   * Normal behavior. The isPressed() method returns true as long as the key
   * is held down.
   */
  public static final int NORMAL = 0;
  /**
   * Initial press behavior. The isPressed() method returns true only after
   * the key is first pressed, and not again until the key is released and
   * pressed again.
   */
  public static final int DETECT_INITAL_PRESS_ONLY = 1;
  private static final int STATE_RELEASED = 0;
  private static final int STATE_PRESSED = 1;
  private static final int STATE_WAITING_FOR_RELEASE = 2;
  private String name;
  private int behavior;
  private int amount;
  private int state;
  /**
   * Create a new GameAction with the NORMAL behavior.
   */
  public GameAction(String name) {
    this(name, NORMAL);
  }
  /**
   * Create a new GameAction with the specified behavior.
   */
  public GameAction(String name, int behavior) {
    this.name = name;
    this.behavior = behavior;
    reset();
  }
  /**
   * Gets the name of this GameAction.
   */
  public String getName() {
    return name;
  }
  /**
   * Resets this GameAction so that it appears like it hasn"t been pressed.
   */
  public void reset() {
    state = STATE_RELEASED;
    amount = 0;
  }
  /**
   * Taps this GameAction. Same as calling press() followed by release().
   */
  public synchronized void tap() {
    press();
    release();
  }
  /**
   * Signals that the key was pressed.
   */
  public synchronized void press() {
    press(1);
  }
  /**
   * Signals that the key was pressed a specified number of times, or that the
   * mouse move a spcified distance.
   */
  public synchronized void press(int amount) {
    if (state != STATE_WAITING_FOR_RELEASE) {
      this.amount += amount;
      state = STATE_PRESSED;
    }
  }
  /**
   * Signals that the key was released
   */
  public synchronized void release() {
    state = STATE_RELEASED;
  }
  /**
   * Returns whether the key was pressed or not since last checked.
   */
  public synchronized boolean isPressed() {
    return (getAmount() != 0);
  }
  /**
   * For keys, this is the number of times the key was pressed since it was
   * last checked. For mouse movement, this is the distance moved.
   */
  public synchronized int getAmount() {
    int retVal = amount;
    if (retVal != 0) {
      if (state == STATE_RELEASED) {
        amount = 0;
      } else if (behavior == DETECT_INITAL_PRESS_ONLY) {
        state = STATE_WAITING_FOR_RELEASE;
        amount = 0;
      }
    }
    return retVal;
  }
}
/**
 * The SolidPolygonRenderer class transforms and draws solid-colored polygons
 * onto the screen.
 */
class SolidPolygonRenderer extends PolygonRenderer {
  public SolidPolygonRenderer(Transform3D camera, ViewWindow viewWindow) {
    this(camera, viewWindow, true);
  }
  public SolidPolygonRenderer(Transform3D camera, ViewWindow viewWindow,
      boolean clearViewEveryFrame) {
    super(camera, viewWindow, clearViewEveryFrame);
  }
  /**
   * Draws the current polygon. At this point, the current polygon is
   * transformed, clipped, projected, scan-converted, and visible.
   */
  protected void drawCurrentPolygon(Graphics2D g) {
    // set the color
    if (sourcePolygon instanceof SolidPolygon3D) {
      g.setColor(((SolidPolygon3D) sourcePolygon).getColor());
    } else {
      g.setColor(Color.GREEN);
    }
    // draw the scans
    int y = scanConverter.getTopBoundary();
    while (y <= scanConverter.getBottomBoundary()) {
      ScanConverter.Scan scan = scanConverter.getScan(y);
      if (scan.isValid()) {
        g.drawLine(scan.left, y, scan.right, y);
      }
      y++;
    }
  }
}
/**
 * The SolidPolygon3D class is a Polygon with a color.
 */
class SolidPolygon3D extends Polygon3D {
  private Color color = Color.GREEN;
  public SolidPolygon3D() {
    super();
  }
  public SolidPolygon3D(Vector3D v0, Vector3D v1, Vector3D v2) {
    this(new Vector3D[] { v0, v1, v2 });
  }
  public SolidPolygon3D(Vector3D v0, Vector3D v1, Vector3D v2, Vector3D v3) {
    this(new Vector3D[] { v0, v1, v2, v3 });
  }
  public SolidPolygon3D(Vector3D[] vertices) {
    super(vertices);
  }
  public void setTo(Polygon3D polygon) {
    super.setTo(polygon);
    if (polygon instanceof SolidPolygon3D) {
      color = ((SolidPolygon3D) polygon).color;
    }
  }
  /**
   * Gets the color of this solid-colored polygon used for rendering this
   * polygon.
   */
  public Color getColor() {
    return color;
  }
  /**
   * Sets the color of this solid-colored polygon used for rendering this
   * polygon.
   */
  public void setColor(Color color) {
    this.color = color;
  }
}
abstract class GameCore3D extends GameCore {
  protected PolygonRenderer polygonRenderer;
  protected ViewWindow viewWindow;
  protected List polygons;
  private boolean drawFrameRate = false;
  private boolean drawInstructions = true;
  // for calculating frame rate
  private int numFrames;
  private long startTime;
  private float frameRate;
  protected InputManager inputManager;
  private GameAction exit = new GameAction("exit");
  private GameAction smallerView = new GameAction("smallerView",
      GameAction.DETECT_INITAL_PRESS_ONLY);
  private GameAction largerView = new GameAction("largerView",
      GameAction.DETECT_INITAL_PRESS_ONLY);
  private GameAction frameRateToggle = new GameAction("frameRateToggle",
      GameAction.DETECT_INITAL_PRESS_ONLY);
  protected GameAction goForward = new GameAction("goForward");
  protected GameAction goBackward = new GameAction("goBackward");
  protected GameAction goUp = new GameAction("goUp");
  protected GameAction goDown = new GameAction("goDown");
  protected GameAction goLeft = new GameAction("goLeft");
  protected GameAction goRight = new GameAction("goRight");
  protected GameAction turnLeft = new GameAction("turnLeft");
  protected GameAction turnRight = new GameAction("turnRight");
  protected GameAction tiltUp = new GameAction("tiltUp");
  protected GameAction tiltDown = new GameAction("tiltDown");
  protected GameAction tiltLeft = new GameAction("tiltLeft");
  protected GameAction tiltRight = new GameAction("tiltRight");
  public void init(DisplayMode[] modes) {
    super.init(modes);
    inputManager = new InputManager(screen.getFullScreenWindow());
    inputManager.setRelativeMouseMode(true);
    inputManager.setCursor(InputManager.INVISIBLE_CURSOR);
    inputManager.mapToKey(exit, KeyEvent.VK_ESCAPE);
    inputManager.mapToKey(goForward, KeyEvent.VK_W);
    inputManager.mapToKey(goForward, KeyEvent.VK_UP);
    inputManager.mapToKey(goBackward, KeyEvent.VK_S);
    inputManager.mapToKey(goBackward, KeyEvent.VK_DOWN);
    inputManager.mapToKey(goLeft, KeyEvent.VK_A);
    inputManager.mapToKey(goLeft, KeyEvent.VK_LEFT);
    inputManager.mapToKey(goRight, KeyEvent.VK_D);
    inputManager.mapToKey(goRight, KeyEvent.VK_RIGHT);
    inputManager.mapToKey(goUp, KeyEvent.VK_PAGE_UP);
    inputManager.mapToKey(goDown, KeyEvent.VK_PAGE_DOWN);
    inputManager.mapToMouse(turnLeft, InputManager.MOUSE_MOVE_LEFT);
    inputManager.mapToMouse(turnRight, InputManager.MOUSE_MOVE_RIGHT);
    inputManager.mapToMouse(tiltUp, InputManager.MOUSE_MOVE_UP);
    inputManager.mapToMouse(tiltDown, InputManager.MOUSE_MOVE_DOWN);
    inputManager.mapToKey(tiltLeft, KeyEvent.VK_INSERT);
    inputManager.mapToKey(tiltRight, KeyEvent.VK_DELETE);
    inputManager.mapToKey(smallerView, KeyEvent.VK_SUBTRACT);
    inputManager.mapToKey(smallerView, KeyEvent.VK_MINUS);
    inputManager.mapToKey(largerView, KeyEvent.VK_ADD);
    inputManager.mapToKey(largerView, KeyEvent.VK_PLUS);
    inputManager.mapToKey(largerView, KeyEvent.VK_EQUALS);
    inputManager.mapToKey(frameRateToggle, KeyEvent.VK_R);
    // create the polygon renderer
    createPolygonRenderer();
    // create polygons
    polygons = new ArrayList();
    createPolygons();
  }
  public abstract void createPolygons();
  public void createPolygonRenderer() {
    // make the view window the entire screen
    viewWindow = new ViewWindow(0, 0, screen.getWidth(),
        screen.getHeight(), (float) Math.toRadians(75));
    Transform3D camera = new Transform3D(0, 100, 0);
    polygonRenderer = new SolidPolygonRenderer(camera, viewWindow);
  }
  /**
   * Sets the view bounds, centering the view on the screen.
   */
  public void setViewBounds(int width, int height) {
    width = Math.min(width, screen.getWidth());
    height = Math.min(height, screen.getHeight());
    width = Math.max(64, width);
    height = Math.max(48, height);
    viewWindow.setBounds((screen.getWidth() - width) / 2, (screen
        .getHeight() - height) / 2, width, height);
    // clear the screen if view size changed
    // (clear both buffers)
    for (int i = 0; i < 2; i++) {
      Graphics2D g = screen.getGraphics();
      g.setColor(Color.BLACK);
      g.fillRect(0, 0, screen.getWidth(), screen.getHeight());
      screen.update();
    }
  }
  public void update(long elapsedTime) {
    // check options
    if (exit.isPressed()) {
      stop();
      return;
    }
    if (largerView.isPressed()) {
      setViewBounds(viewWindow.getWidth() + 64,
          viewWindow.getHeight() + 48);
    } else if (smallerView.isPressed()) {
      setViewBounds(viewWindow.getWidth() - 64,
          viewWindow.getHeight() - 48);
    }
    if (frameRateToggle.isPressed()) {
      drawFrameRate = !drawFrameRate;
    }
    updateWorld(elapsedTime);
  }
  public void updateWorld(long elapsedTime) {
    // cap elapsedTime
    elapsedTime = Math.min(elapsedTime, 100);
    float angleChange = 0.0002f * elapsedTime;
    float distanceChange = .5f * elapsedTime;
    Transform3D camera = polygonRenderer.getCamera();
    Vector3D cameraLoc = camera.getLocation();
    // apply movement
    if (goForward.isPressed()) {
      cameraLoc.x -= distanceChange * camera.getSinAngleY();
      cameraLoc.z -= distanceChange * camera.getCosAngleY();
    }
    if (goBackward.isPressed()) {
      cameraLoc.x += distanceChange * camera.getSinAngleY();
      cameraLoc.z += distanceChange * camera.getCosAngleY();
    }
    if (goLeft.isPressed()) {
      cameraLoc.x -= distanceChange * camera.getCosAngleY();
      cameraLoc.z += distanceChange * camera.getSinAngleY();
    }
    if (goRight.isPressed()) {
      cameraLoc.x += distanceChange * camera.getCosAngleY();
      cameraLoc.z -= distanceChange * camera.getSinAngleY();
    }
    if (goUp.isPressed()) {
      cameraLoc.y += distanceChange;
    }
    if (goDown.isPressed()) {
      cameraLoc.y -= distanceChange;
    }
    // look up/down (rotate around x)
    int tilt = tiltUp.getAmount() - tiltDown.getAmount();
    tilt = Math.min(tilt, 200);
    tilt = Math.max(tilt, -200);
    // limit how far you can look up/down
    float newAngleX = camera.getAngleX() + tilt * angleChange;
    newAngleX = Math.max(newAngleX, (float) -Math.PI / 2);
    newAngleX = Math.min(newAngleX, (float) Math.PI / 2);
    camera.setAngleX(newAngleX);
    // turn (rotate around y)
    int turn = turnLeft.getAmount() - turnRight.getAmount();
    turn = Math.min(turn, 200);
    turn = Math.max(turn, -200);
    camera.rotateAngleY(turn * angleChange);
    // tilet head left/right (rotate around z)
    if (tiltLeft.isPressed()) {
      camera.rotateAngleZ(10 * angleChange);
    }
    if (tiltRight.isPressed()) {
      camera.rotateAngleZ(-10 * angleChange);
    }
  }
  public void draw(Graphics2D g) {
    int viewX1 = viewWindow.getLeftOffset();
    int viewY1 = viewWindow.getTopOffset();
    int viewX2 = viewX1 + viewWindow.getWidth();
    int viewY2 = viewY1 + viewWindow.getHeight();
    if (viewX1 != 0 || viewY1 != 0) {
      g.setColor(Color.BLACK);
      g.fillRect(0, 0, viewX1, screen.getHeight());
      g.fillRect(viewX2, 0, screen.getWidth() - viewX2, screen
          .getHeight());
      g.fillRect(viewX1, 0, viewWindow.getWidth(), viewY1);
      g.fillRect(viewX1, viewY2, viewWindow.getWidth(), screen
          .getHeight()
          - viewY2);
    }
    drawPolygons(g);
    drawText(g);
  }
  public void drawPolygons(Graphics2D g) {
    polygonRenderer.startFrame(g);
    for (int i = 0; i < polygons.size(); i++) {
      polygonRenderer.draw(g, (Polygon3D) polygons.get(i));
    }
    polygonRenderer.endFrame(g);
  }
  public void drawText(Graphics2D g) {
    g.setColor(Color.WHITE);
    // draw text
    if (drawInstructions) {
      g.drawString("Use the mouse/arrow keys to move. "
          + "Press Esc to exit.", 5, fontSize);
    }
    // (you may have to turn off the BufferStrategy in
    // ScreenManager for more accurate tests)
    if (drawFrameRate) {
      calcFrameRate();
      g.drawString(frameRate + " frames/sec", 5, screen.getHeight() - 5);
    }
  }
  public void calcFrameRate() {
    numFrames++;
    long currTime = System.currentTimeMillis();
    // calculate the frame rate every 500 milliseconds
    if (currTime > startTime + 500) {
      frameRate = (float) numFrames * 1000 / (currTime - startTime);
      startTime = currTime;
      numFrames = 0;
    }
  }
}
interface Transformable {
  public void add(Vector3D u);
  public void subtract(Vector3D u);
  public void add(Transform3D xform);
  public void subtract(Transform3D xform);
  public void addRotation(Transform3D xform);
  public void subtractRotation(Transform3D xform);
}
/**
 * The Polygon3D class represents a polygon as a series of vertices.
 */
class Polygon3D implements Transformable {
  // temporary vectors used for calculation
  private static Vector3D temp1 = new Vector3D();
  private static Vector3D temp2 = new Vector3D();
  private Vector3D[] v;
  private int numVertices;
  private Vector3D normal;
  /**
   * Creates an empty polygon that can be used as a "scratch" polygon for
   * transforms, projections, etc.
   */
  public Polygon3D() {
    numVertices = 0;
    v = new Vector3D[0];
    normal = new Vector3D();
  }
  /**
   * Creates a new Polygon3D with the specified vertices.
   */
  public Polygon3D(Vector3D v0, Vector3D v1, Vector3D v2) {
    this(new Vector3D[] { v0, v1, v2 });
  }
  /**
   * Creates a new Polygon3D with the specified vertices. All the vertices are
   * assumed to be in the same plane.
   */
  public Polygon3D(Vector3D v0, Vector3D v1, Vector3D v2, Vector3D v3) {
    this(new Vector3D[] { v0, v1, v2, v3 });
  }
  /**
   * Creates a new Polygon3D with the specified vertices. All the vertices are
   * assumed to be in the same plane.
   */
  public Polygon3D(Vector3D[] vertices) {
    this.v = vertices;
    numVertices = vertices.length;
    calcNormal();
  }
  /**
   * Sets this polygon to the same vertices as the specfied polygon.
   */
  public void setTo(Polygon3D polygon) {
    numVertices = polygon.numVertices;
    normal.setTo(polygon.normal);
    ensureCapacity(numVertices);
    for (int i = 0; i < numVertices; i++) {
      v[i].setTo(polygon.v[i]);
    }
  }
  /**
   * Ensures this polgon has enough capacity to hold the specified number of
   * vertices.
   */
  protected void ensureCapacity(int length) {
    if (v.length < length) {
      Vector3D[] newV = new Vector3D[length];
      System.arraycopy(v, 0, newV, 0, v.length);
      for (int i = v.length; i < newV.length; i++) {
        newV[i] = new Vector3D();
      }
      v = newV;
    }
  }
  /**
   * Gets the number of vertices this polygon has.
   */
  public int getNumVertices() {
    return numVertices;
  }
  /**
   * Gets the vertex at the specified index.
   */
  public Vector3D getVertex(int index) {
    return v[index];
  }
  /**
   * Projects this polygon onto the view window.
   */
  public void project(ViewWindow view) {
    for (int i = 0; i < numVertices; i++) {
      view.project(v[i]);
    }
  }
  // methods from the Transformable interface.
  public void add(Vector3D u) {
    for (int i = 0; i < numVertices; i++) {
      v[i].add(u);
    }
  }
  public void subtract(Vector3D u) {
    for (int i = 0; i < numVertices; i++) {
      v[i].subtract(u);
    }
  }
  public void add(Transform3D xform) {
    addRotation(xform);
    add(xform.getLocation());
  }
  public void subtract(Transform3D xform) {
    subtract(xform.getLocation());
    subtractRotation(xform);
  }
  public void addRotation(Transform3D xform) {
    for (int i = 0; i < numVertices; i++) {
      v[i].addRotation(xform);
    }
    normal.addRotation(xform);
  }
  public void subtractRotation(Transform3D xform) {
    for (int i = 0; i < numVertices; i++) {
      v[i].subtractRotation(xform);
    }
    normal.subtractRotation(xform);
  }
  /**
   * Calculates the unit-vector normal of this polygon. This method uses the
   * first, second, and third vertices to calcuate the normal, so if these
   * vertices are collinear, this method will not work. In this case, you can
   * get the normal from the bounding rectangle. Use setNormal() to explicitly
   * set the normal. This method uses static objects in the Polygon3D class
   * for calculations, so this method is not thread-safe across all instances
   * of Polygon3D.
   */
  public Vector3D calcNormal() {
    if (normal == null) {
      normal = new Vector3D();
    }
    temp1.setTo(v[2]);
    temp1.subtract(v[1]);
    temp2.setTo(v[0]);
    temp2.subtract(v[1]);
    normal.setToCrossProduct(temp1, temp2);
    normal.normalize();
    return normal;
  }
  /**
   * Gets the normal of this polygon. Use calcNormal() if any vertices have
   * changed.
   */
  public Vector3D getNormal() {
    return normal;
  }
  /**
   * Sets the normal of this polygon.
   */
  public void setNormal(Vector3D n) {
    if (normal == null) {
      normal = new Vector3D(n);
    } else {
      normal.setTo(n);
    }
  }
  /**
   * Tests if this polygon is facing the specified location. This method uses
   * static objects in the Polygon3D class for calculations, so this method is
   * not thread-safe across all instances of Polygon3D.
   */
  public boolean isFacing(Vector3D u) {
    temp1.setTo(u);
    temp1.subtract(v[0]);
    return (normal.getDotProduct(temp1) >= 0);
  }
  /**
   * Clips this polygon so that all vertices are in front of the clip plane,
   * clipZ (in other words, all vertices have z <= clipZ). The value of clipZ
   * should not be 0, as this causes divide-by-zero problems. Returns true if
   * the polygon is at least partially in front of the clip plane.
   */
  public boolean clip(float clipZ) {
    ensureCapacity(numVertices * 3);
    boolean isCompletelyHidden = true;
    // insert vertices so all edges are either completly
    // in front or behind the clip plane
    for (int i = 0; i < numVertices; i++) {
      int next = (i + 1) % numVertices;
      Vector3D v1 = v[i];
      Vector3D v2 = v[next];
      if (v1.z < clipZ) {
        isCompletelyHidden = false;
      }
      // ensure v1.z < v2.z
      if (v1.z > v2.z) {
        Vector3D temp = v1;
        v1 = v2;
        v2 = temp;
      }
      if (v1.z < clipZ && v2.z > clipZ) {
        float scale = (clipZ - v1.z) / (v2.z - v1.z);
        insertVertex(next, v1.x + scale * (v2.x - v1.x), v1.y + scale
            * (v2.y - v1.y), clipZ);
        // skip the vertex we just created
        i++;
      }
    }
    if (isCompletelyHidden) {
      return false;
    }
    // delete all vertices that have z > clipZ
    for (int i = numVertices - 1; i >= 0; i--) {
      if (v[i].z > clipZ) {
        deleteVertex(i);
      }
    }
    return (numVertices >= 3);
  }
  /**
   * Inserts a new vertex at the specified index.
   */
  protected void insertVertex(int index, float x, float y, float z) {
    Vector3D newVertex = v[v.length - 1];
    newVertex.x = x;
    newVertex.y = y;
    newVertex.z = z;
    for (int i = v.length - 1; i > index; i--) {
      v[i] = v[i - 1];
    }
    v[index] = newVertex;
    numVertices++;
  }
  /**
   * Delete the vertex at the specified index.
   */
  protected void deleteVertex(int index) {
    Vector3D deleted = v[index];
    for (int i = index; i < v.length - 1; i++) {
      v[i] = v[i + 1];
    }
    v[v.length - 1] = deleted;
    numVertices--;
  }
  /**
   * Inserts a vertex into this polygon at the specified index. The exact
   * vertex in inserted (not a copy).
   */
  public void insertVertex(int index, Vector3D vertex) {
    Vector3D[] newV = new Vector3D[numVertices + 1];
    System.arraycopy(v, 0, newV, 0, index);
    newV[index] = vertex;
    System.arraycopy(v, index, newV, index + 1, numVertices - index);
    v = newV;
    numVertices++;
  }
  /**
   * Calculates and returns the smallest bounding rectangle for this polygon.
   */
  public Rectangle3D calcBoundingRectangle() {
    // the smallest bounding rectangle for a polygon shares
    // at least one edge with the polygon. so, this method
    // finds the bounding rectangle for every edge in the
    // polygon, and returns the smallest one.
    Rectangle3D boundingRect = new Rectangle3D();
    float minimumArea = Float.MAX_VALUE;
    Vector3D u = new Vector3D();
    Vector3D v = new Vector3D();
    Vector3D d = new Vector3D();
    for (int i = 0; i < getNumVertices(); i++) {
      u.setTo(getVertex((i + 1) % getNumVertices()));
      u.subtract(getVertex(i));
      u.normalize();
      v.setToCrossProduct(getNormal(), u);
      v.normalize();
      float uMin = 0;
      float uMax = 0;
      float vMin = 0;
      float vMax = 0;
      for (int j = 0; j < getNumVertices(); j++) {
        if (j != i) {
          d.setTo(getVertex(j));
          d.subtract(getVertex(i));
          float uLength = d.getDotProduct(u);
          float vLength = d.getDotProduct(v);
          uMin = Math.min(uLength, uMin);
          uMax = Math.max(uLength, uMax);
          vMin = Math.min(vLength, vMin);
          vMax = Math.max(vLength, vMax);
        }
      }
      // if this calculated area is the smallest, set
      // the bounding rectangle
      float area = (uMax - uMin) * (vMax - vMin);
      if (area < minimumArea) {
        minimumArea = area;
        Vector3D origin = boundingRect.getOrigin();
        origin.setTo(getVertex(i));
        d.setTo(u);
        d.multiply(uMin);
        origin.add(d);
        d.setTo(v);
        d.multiply(vMin);
        origin.add(d);
        boundingRect.getDirectionU().setTo(u);
        boundingRect.getDirectionV().setTo(v);
        boundingRect.setWidth(uMax - uMin);
        boundingRect.setHeight(vMax - vMin);
      }
    }
    return boundingRect;
  }
}
/**
 * The TexturedPolygon3D class is a Polygon with a texture.
 */
class TexturedPolygon3D extends Polygon3D {
  protected Rectangle3D textureBounds;
  protected Texture texture;
  public TexturedPolygon3D() {
    textureBounds = new Rectangle3D();
  }
  public TexturedPolygon3D(Vector3D v0, Vector3D v1, Vector3D v2) {
    this(new Vector3D[] { v0, v1, v2 });
  }
  public TexturedPolygon3D(Vector3D v0, Vector3D v1, Vector3D v2, Vector3D v3) {
    this(new Vector3D[] { v0, v1, v2, v3 });
  }
  public TexturedPolygon3D(Vector3D[] vertices) {
    super(vertices);
    textureBounds = new Rectangle3D();
  }
  public void setTo(Polygon3D poly) {
    super.setTo(poly);
    if (poly instanceof TexturedPolygon3D) {
      TexturedPolygon3D tPoly = (TexturedPolygon3D) poly;
      textureBounds.setTo(tPoly.textureBounds);
      texture = tPoly.texture;
    }
  }
  /**
   * Gets this polygon"s texture.
   */
  public Texture getTexture() {
    return texture;
  }
  /**
   * Gets this polygon"s texture bounds.
   */
  public Rectangle3D getTextureBounds() {
    return textureBounds;
  }
  /**
   * Sets this polygon"s texture.
   */
  public void setTexture(Texture texture) {
    this.texture = texture;
    textureBounds.setWidth(texture.getWidth());
    textureBounds.setHeight(texture.getHeight());
  }
  /**
   * Sets this polygon"s texture and texture bounds.
   */
  public void setTexture(Texture texture, Rectangle3D bounds) {
    setTexture(texture);
    textureBounds.setTo(bounds);
  }
  public void add(Vector3D u) {
    super.add(u);
    textureBounds.add(u);
  }
  public void subtract(Vector3D u) {
    super.subtract(u);
    textureBounds.subtract(u);
  }
  public void addRotation(Transform3D xform) {
    super.addRotation(xform);
    textureBounds.addRotation(xform);
  }
  public void subtractRotation(Transform3D xform) {
    super.subtractRotation(xform);
    textureBounds.subtractRotation(xform);
  }
  /**
   * Calculates the bounding rectangle for this polygon that is aligned with
   * the texture bounds.
   */
  public Rectangle3D calcBoundingRectangle() {
    Vector3D u = new Vector3D(textureBounds.getDirectionU());
    Vector3D v = new Vector3D(textureBounds.getDirectionV());
    Vector3D d = new Vector3D();
    u.normalize();
    v.normalize();
    float uMin = 0;
    float uMax = 0;
    float vMin = 0;
    float vMax = 0;
    for (int i = 0; i < getNumVertices(); i++) {
      d.setTo(getVertex(i));
      d.subtract(getVertex(0));
      float uLength = d.getDotProduct(u);
      float vLength = d.getDotProduct(v);
      uMin = Math.min(uLength, uMin);
      uMax = Math.max(uLength, uMax);
      vMin = Math.min(vLength, vMin);
      vMax = Math.max(vLength, vMax);
    }
    Rectangle3D boundingRect = new Rectangle3D();
    Vector3D origin = boundingRect.getOrigin();
    origin.setTo(getVertex(0));
    d.setTo(u);
    d.multiply(uMin);
    origin.add(d);
    d.setTo(v);
    d.multiply(vMin);
    origin.add(d);
    boundingRect.getDirectionU().setTo(u);
    boundingRect.getDirectionV().setTo(v);
    boundingRect.setWidth(uMax - uMin);
    boundingRect.setHeight(vMax - vMin);
    // explictly set the normal since the texture directions
    // could create a normal negative to the polygon normal
    boundingRect.setNormal(getNormal());
    return boundingRect;
  }
}
/**
 * The Vector3D class implements a 3D vector with the floating-point values x,
 * y, and z. Vectors can be thought of either as a (x,y,z) point or as a vector
 * from (0,0,0) to (x,y,z).
 */
class Vector3D implements Transformable {
  public float x;
  public float y;
  public float z;
  /**
   * Creates a new Vector3D at (0,0,0).
   */
  public Vector3D() {
    this(0, 0, 0);
  }
  /**
   * Creates a new Vector3D with the same values as the specified Vector3D.
   */
  public Vector3D(Vector3D v) {
    this(v.x, v.y, v.z);
  }
  /**
   * Creates a new Vector3D with the specified (x, y, z) values.
   */
  public Vector3D(float x, float y, float z) {
    setTo(x, y, z);
  }
  /**
   * Checks if this Vector3D is equal to the specified Object. They are equal
   * only if the specified Object is a Vector3D and the two Vector3D"s x, y,
   * and z coordinates are equal.
   */
  public boolean equals(Object obj) {
    Vector3D v = (Vector3D) obj;
    return (v.x == x && v.y == y && v.z == z);
  }
  /**
   * Checks if this Vector3D is equal to the specified x, y, and z
   * coordinates.
   */
  public boolean equals(float x, float y, float z) {
    return (this.x == x && this.y == y && this.z == z);
  }
  /**
   * Sets the vector to the same values as the specified Vector3D.
   */
  public void setTo(Vector3D v) {
    setTo(v.x, v.y, v.z);
  }
  /**
   * Sets this vector to the specified (x, y, z) values.
   */
  public void setTo(float x, float y, float z) {
    this.x = x;
    this.y = y;
    this.z = z;
  }
  /**
   * Adds the specified (x, y, z) values to this vector.
   */
  public void add(float x, float y, float z) {
    this.x += x;
    this.y += y;
    this.z += z;
  }
  /**
   * Subtracts the specified (x, y, z) values to this vector.
   */
  public void subtract(float x, float y, float z) {
    add(-x, -y, -z);
  }
  /**
   * Adds the specified vector to this vector.
   */
  public void add(Vector3D v) {
    add(v.x, v.y, v.z);
  }
  /**
   * Subtracts the specified vector from this vector.
   */
  public void subtract(Vector3D v) {
    add(-v.x, -v.y, -v.z);
  }
  /**
   * Multiplies this vector by the specified value. The new length of this
   * vector will be length()*s.
   */
  public void multiply(float s) {
    x *= s;
    y *= s;
    z *= s;
  }
  /**
   * Divides this vector by the specified value. The new length of this vector
   * will be length()/s.
   */
  public void divide(float s) {
    x /= s;
    y /= s;
    z /= s;
  }
  /**
   * Returns the length of this vector as a float.
   */
  public float length() {
    return (float) Math.sqrt(x * x + y * y + z * z);
  }
  /**
   * Converts this Vector3D to a unit vector, or in other words, a vector of
   * length 1. Same as calling v.divide(v.length()).
   */
  public void normalize() {
    divide(length());
  }
  /**
   * Converts this Vector3D to a String representation.
   */
  public String toString() {
    return "(" + x + ", " + y + ", " + z + ")";
  }
  /**
   * Rotate this vector around the x axis the specified amount. The specified
   * angle is in radians. Use Math.toRadians() to convert from degrees to
   * radians.
   */
  public void rotateX(float angle) {
    rotateX((float) Math.cos(angle), (float) Math.sin(angle));
  }
  /**
   * Rotate this vector around the y axis the specified amount. The specified
   * angle is in radians. Use Math.toRadians() to convert from degrees to
   * radians.
   */
  public void rotateY(float angle) {
    rotateY((float) Math.cos(angle), (float) Math.sin(angle));
  }
  /**
   * Rotate this vector around the z axis the specified amount. The specified
   * angle is in radians. Use Math.toRadians() to convert from degrees to
   * radians.
   */
  public void rotateZ(float angle) {
    rotateZ((float) Math.cos(angle), (float) Math.sin(angle));
  }
  /**
   * Rotate this vector around the x axis the specified amount, using
   * pre-computed cosine and sine values of the angle to rotate.
   */
  public void rotateX(float cosAngle, float sinAngle) {
    float newY = y * cosAngle - z * sinAngle;
    float newZ = y * sinAngle + z * cosAngle;
    y = newY;
    z = newZ;
  }
  /**
   * Rotate this vector around the y axis the specified amount, using
   * pre-computed cosine and sine values of the angle to rotate.
   */
  public void rotateY(float cosAngle, float sinAngle) {
    float newX = z * sinAngle + x * cosAngle;
    float newZ = z * cosAngle - x * sinAngle;
    x = newX;
    z = newZ;
  }
  /**
   * Rotate this vector around the y axis the specified amount, using
   * pre-computed cosine and sine values of the angle to rotate.
   */
  public void rotateZ(float cosAngle, float sinAngle) {
    float newX = x * cosAngle - y * sinAngle;
    float newY = x * sinAngle + y * cosAngle;
    x = newX;
    y = newY;
  }
  /**
   * Adds the specified transform to this vector. This vector is first
   * rotated, then translated.
   */
  public void add(Transform3D xform) {
    // rotate
    addRotation(xform);
    // translate
    add(xform.getLocation());
  }
  /**
   * Subtracts the specified transform to this vector. This vector translated,
   * then rotated.
   */
  public void subtract(Transform3D xform) {
    // translate
    subtract(xform.getLocation());
    // rotate
    subtractRotation(xform);
  }
  /**
   * Rotates this vector with the angle of the specified transform.
   */
  public void addRotation(Transform3D xform) {
    rotateX(xform.getCosAngleX(), xform.getSinAngleX());
    rotateZ(xform.getCosAngleZ(), xform.getSinAngleZ());
    rotateY(xform.getCosAngleY(), xform.getSinAngleY());
  }
  /**
   * Rotates this vector with the opposite angle of the specified transform.
   */
  public void subtractRotation(Transform3D xform) {
    // note that sin(-x) == -sin(x) and cos(-x) == cos(x)
    rotateY(xform.getCosAngleY(), -xform.getSinAngleY());
    rotateZ(xform.getCosAngleZ(), -xform.getSinAngleZ());
    rotateX(xform.getCosAngleX(), -xform.getSinAngleX());
  }
  /**
   * Returns the dot product of this vector and the specified vector.
   */
  public float getDotProduct(Vector3D v) {
    return x * v.x + y * v.y + z * v.z;
  }
  /**
   * Sets this vector to the cross product of the two specified vectors.
   * Either of the specified vectors can be this vector.
   */
  public void setToCrossProduct(Vector3D u, Vector3D v) {
    // assign to local vars first in case u or v is "this"
    float x = u.y * v.z - u.z * v.y;
    float y = u.z * v.x - u.x * v.z;
    float z = u.x * v.y - u.y * v.x;
    this.x = x;
    this.y = y;
    this.z = z;
  }
}
/**
 * A Rectangle3D is a rectangle in 3D space, defined as an origin and vectors
 * pointing in the directions of the base (width) and side (height).
 */
class Rectangle3D implements Transformable {
  private Vector3D origin;
  private Vector3D directionU;
  private Vector3D directionV;
  private Vector3D normal;
  private float width;
  private float height;
  /**
   * Creates a rectangle at the origin with a width and height of zero.
   */
  public Rectangle3D() {
    origin = new Vector3D();
    directionU = new Vector3D(1, 0, 0);
    directionV = new Vector3D(0, 1, 0);
    width = 0;
    height = 0;
  }
  /**
   * Creates a new Rectangle3D with the specified origin, direction of the
   * base (directionU) and direction of the side (directionV).
   */
  public Rectangle3D(Vector3D origin, Vector3D directionU,
      Vector3D directionV, float width, float height) {
    this.origin = new Vector3D(origin);
    this.directionU = new Vector3D(directionU);
    this.directionU.normalize();
    this.directionV = new Vector3D(directionV);
    this.directionV.normalize();
    this.width = width;
    this.height = height;
  }
  /**
   * Sets the values of this Rectangle3D to the specified Rectangle3D.
   */
  public void setTo(Rectangle3D rect) {
    origin.setTo(rect.origin);
    directionU.setTo(rect.directionU);
    directionV.setTo(rect.directionV);
    width = rect.width;
    height = rect.height;
  }
  /**
   * Gets the origin of this Rectangle3D.
   */
  public Vector3D getOrigin() {
    return origin;
  }
  /**
   * Gets the direction of the base of this Rectangle3D.
   */
  public Vector3D getDirectionU() {
    return directionU;
  }
  /**
   * Gets the direction of the side of this Rectangle3D.
   */
  public Vector3D getDirectionV() {
    return directionV;
  }
  /**
   * Gets the width of this Rectangle3D.
   */
  public float getWidth() {
    return width;
  }
  /**
   * Sets the width of this Rectangle3D.
   */
  public void setWidth(float width) {
    this.width = width;
  }
  /**
   * Gets the height of this Rectangle3D.
   */
  public float getHeight() {
    return height;
  }
  /**
   * Sets the height of this Rectangle3D.
   */
  public void setHeight(float height) {
    this.height = height;
  }
  /**
   * Calculates the normal vector of this Rectange3D.
   */
  protected Vector3D calcNormal() {
    if (normal == null) {
      normal = new Vector3D();
    }
    normal.setToCrossProduct(directionU, directionV);
    normal.normalize();
    return normal;
  }
  /**
   * Gets the normal of this Rectangle3D.
   */
  public Vector3D getNormal() {
    if (normal == null) {
      calcNormal();
    }
    return normal;
  }
  /**
   * Sets the normal of this Rectangle3D.
   */
  public void setNormal(Vector3D n) {
    if (normal == null) {
      normal = new Vector3D(n);
    } else {
      normal.setTo(n);
    }
  }
  public void add(Vector3D u) {
    origin.add(u);
    // don"t translate direction vectors or size
  }
  public void subtract(Vector3D u) {
    origin.subtract(u);
    // don"t translate direction vectors or size
  }
  public void add(Transform3D xform) {
    addRotation(xform);
    add(xform.getLocation());
  }
  public void subtract(Transform3D xform) {
    subtract(xform.getLocation());
    subtractRotation(xform);
  }
  public void addRotation(Transform3D xform) {
    origin.addRotation(xform);
    directionU.addRotation(xform);
    directionV.addRotation(xform);
  }
  public void subtractRotation(Transform3D xform) {
    origin.subtractRotation(xform);
    directionU.subtractRotation(xform);
    directionV.subtractRotation(xform);
  }
}
           
       </source>
    
   
  <!-- end source code -->
   




== Shading Test 2  ==






   
  <!-- start source code -->
   
    <source lang="java">
       /*
DEVELOPING GAME IN JAVA 
Caracteristiques
Editeur : NEW RIDERS 
Auteur : BRACKEEN 
Parution : 09 2003 
Pages : 972 
Isbn : 1-59273-005-1 
Reliure : Paperback 
Disponibilite : Disponible a la librairie 
*/

import java.awt.AWTException;
import java.awt.Color;
import java.awt.ruponent;
import java.awt.Cursor;
import java.awt.DisplayMode;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Image;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.Window;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.awt.image.DataBuffer;
import java.awt.image.DataBufferByte;
import java.awt.image.DataBufferUShort;
import java.awt.image.IndexColorModel;
import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.ref.SoftReference;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import javax.imageio.ImageIO;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.DataLine;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.Mixer;
import javax.sound.sampled.SourceDataLine;
import javax.sound.sampled.UnsupportedAudioFileException;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
public class ShadingTest2 extends TextureMapTest2 {
  public static void main(String[] args) {
    new ShadingTest2().run();
  }
  private List lights;
  private float ambientLightIntensity;
  public void init() {
    ambientLightIntensity = .05f;
    lights = new ArrayList();
    lights.add(new PointLight3D(-100, 100, -975, 1f, 500));
    lights.add(new PointLight3D(50, 150, -700, 1f, 500));
    lights.add(new PointLight3D(2000, 2000, -2000, .1f, -1));
    lights.add(new PointLight3D(-250, 250, -1200, 1f, 500));
    super.init(LOW_RES_MODES);
  }
  public void setTexture(TexturedPolygon3D poly, Texture texture) {
    ShadedSurface.createShadedSurface(poly, (ShadedTexture) texture,
        lights, ambientLightIntensity);
  }
  public Texture loadTexture(String imageName) {
    return Texture.createTexture(imageName, true);
  }
  public void createPolygonRenderer() {
    viewWindow = new ViewWindow(0, 0, screen.getWidth(),
        screen.getHeight(), (float) Math.toRadians(75));
    Transform3D camera = new Transform3D(0, 100, 0);
    polygonRenderer = new ShadedSurfacePolygonRenderer(camera, viewWindow);
  }
}
/**
 * The ShadedSurfacePolygonRenderer is a PolygonRenderer that renders polygons
 * with ShadedSurfaces. It keeps track of built surfaces, and clears any
 * surfaces that weren"t used in the last rendered frame to save memory.
 */
class ShadedSurfacePolygonRenderer extends FastTexturedPolygonRenderer {
  private List builtSurfaces = new LinkedList();
  public ShadedSurfacePolygonRenderer(Transform3D camera,
      ViewWindow viewWindow) {
    this(camera, viewWindow, true);
  }
  public ShadedSurfacePolygonRenderer(Transform3D camera,
      ViewWindow viewWindow, boolean eraseView) {
    super(camera, viewWindow, eraseView);
  }
  public void endFrame(Graphics2D g) {
    super.endFrame(g);
    // clear all built surfaces that weren"t used this frame.
    Iterator i = builtSurfaces.iterator();
    while (i.hasNext()) {
      ShadedSurface surface = (ShadedSurface) i.next();
      if (surface.isDirty()) {
        surface.clearSurface();
        i.remove();
      } else {
        surface.setDirty(true);
      }
    }
  }
  protected void drawCurrentPolygon(Graphics2D g) {
    buildSurface();
    super.drawCurrentPolygon(g);
  }
  /**
   * Builds the surface of the polygon if it has a ShadedSurface that is
   * cleared.
   */
  protected void buildSurface() {
    // build surface, if needed
    if (sourcePolygon instanceof TexturedPolygon3D) {
      Texture texture = ((TexturedPolygon3D) sourcePolygon).getTexture();
      if (texture instanceof ShadedSurface) {
        ShadedSurface surface = (ShadedSurface) texture;
        if (surface.isCleared()) {
          surface.buildSurface();
          builtSurfaces.add(surface);
        }
        surface.setDirty(false);
      }
    }
  }
}
class TextureMapTest2 extends GameCore3D {
  public static void main(String[] args) {
    new TextureMapTest2().run();
  }
  public void init() {
    init(LOW_RES_MODES);
  }
  // create a house (convex polyhedra)
  public void createPolygons() {
    // create Textures
    Texture wall = loadTexture("../images/wall1.png");
    Texture roof = loadTexture("../images/roof1.png");
    TexturedPolygon3D poly;
    // walls
    poly = new TexturedPolygon3D(new Vector3D(-200, 250, -1000),
        new Vector3D(-200, 0, -1000), new Vector3D(200, 0, -1000),
        new Vector3D(200, 250, -1000));
    setTexture(poly, wall);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(200, 250, -1400),
        new Vector3D(200, 0, -1400), new Vector3D(-200, 0, -1400),
        new Vector3D(-200, 250, -1400));
    setTexture(poly, wall);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(-200, 250, -1400),
        new Vector3D(-200, 0, -1400), new Vector3D(-200, 0, -1000),
        new Vector3D(-200, 250, -1000));
    setTexture(poly, wall);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(200, 250, -1000),
        new Vector3D(200, 0, -1000), new Vector3D(200, 0, -1400),
        new Vector3D(200, 250, -1400));
    setTexture(poly, wall);
    polygons.add(poly);
    // roof
    poly = new TexturedPolygon3D(new Vector3D(-200, 250, -1000),
        new Vector3D(200, 250, -1000), new Vector3D(75, 400, -1200),
        new Vector3D(-75, 400, -1200));
    setTexture(poly, roof);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(-200, 250, -1400),
        new Vector3D(-200, 250, -1000), new Vector3D(-75, 400, -1200));
    setTexture(poly, roof);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(200, 250, -1400),
        new Vector3D(-200, 250, -1400), new Vector3D(-75, 400, -1200),
        new Vector3D(75, 400, -1200));
    setTexture(poly, roof);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(200, 250, -1000),
        new Vector3D(200, 250, -1400), new Vector3D(75, 400, -1200));
    setTexture(poly, roof);
    polygons.add(poly);
  }
  public void setTexture(TexturedPolygon3D poly, Texture texture) {
    Vector3D origin = poly.getVertex(0);
    Vector3D dv = new Vector3D(poly.getVertex(1));
    dv.subtract(origin);
    Vector3D du = new Vector3D();
    du.setToCrossProduct(poly.getNormal(), dv);
    Rectangle3D textureBounds = new Rectangle3D(origin, du, dv, texture
        .getWidth(), texture.getHeight());
    poly.setTexture(texture, textureBounds);
  }
  public Texture loadTexture(String imageName) {
    return Texture.createTexture(imageName);
  }
  public void createPolygonRenderer() {
    viewWindow = new ViewWindow(0, 0, screen.getWidth(),
        screen.getHeight(), (float) Math.toRadians(75));
    Transform3D camera = new Transform3D(0, 100, 0);
    polygonRenderer = new FastTexturedPolygonRenderer(camera, viewWindow);
  }
}
/**
 * The FastTexturedPolygonRenderer is a PolygonRenderer that efficiently renders
 * Textures.
 */
class FastTexturedPolygonRenderer extends PolygonRenderer {
  public static final int SCALE_BITS = 12;
  public static final int SCALE = 1 << SCALE_BITS;
  public static final int INTERP_SIZE_BITS = 4;
  public static final int INTERP_SIZE = 1 << INTERP_SIZE_BITS;
  protected Vector3D a = new Vector3D();
  protected Vector3D b = new Vector3D();
  protected Vector3D c = new Vector3D();
  protected Vector3D viewPos = new Vector3D();
  protected BufferedImage doubleBuffer;
  protected short[] doubleBufferData;
  protected HashMap scanRenderers;
  public FastTexturedPolygonRenderer(Transform3D camera, ViewWindow viewWindow) {
    this(camera, viewWindow, true);
  }
  public FastTexturedPolygonRenderer(Transform3D camera,
      ViewWindow viewWindow, boolean clearViewEveryFrame) {
    super(camera, viewWindow, clearViewEveryFrame);
  }
  protected void init() {
    destPolygon = new TexturedPolygon3D();
    scanConverter = new ScanConverter(viewWindow);
    // create renders for each texture (HotSpot optimization)
    scanRenderers = new HashMap();
    scanRenderers.put(PowerOf2Texture.class, new PowerOf2TextureRenderer());
    scanRenderers.put(ShadedTexture.class, new ShadedTextureRenderer());
    scanRenderers.put(ShadedSurface.class, new ShadedSurfaceRenderer());
  }
  public void startFrame(Graphics2D g) {
    // initialize buffer
    if (doubleBuffer == null
        || doubleBuffer.getWidth() != viewWindow.getWidth()
        || doubleBuffer.getHeight() != viewWindow.getHeight()) {
      doubleBuffer = new BufferedImage(viewWindow.getWidth(), viewWindow
          .getHeight(), BufferedImage.TYPE_USHORT_565_RGB);
      //doubleBuffer = g.getDeviceConfiguration().createCompatibleImage(
      //viewWindow.getWidth(), viewWindow.getHeight());
      DataBuffer dest = doubleBuffer.getRaster().getDataBuffer();
      doubleBufferData = ((DataBufferUShort) dest).getData();
    }
    // clear view
    if (clearViewEveryFrame) {
      for (int i = 0; i < doubleBufferData.length; i++) {
        doubleBufferData[i] = 0;
      }
    }
  }
  public void endFrame(Graphics2D g) {
    // draw the double buffer onto the screen
    g.drawImage(doubleBuffer, viewWindow.getLeftOffset(), viewWindow
        .getTopOffset(), null);
  }
  protected void drawCurrentPolygon(Graphics2D g) {
    if (!(sourcePolygon instanceof TexturedPolygon3D)) {
      // not a textured polygon - return
      return;
    }
    TexturedPolygon3D poly = (TexturedPolygon3D) destPolygon;
    Texture texture = poly.getTexture();
    ScanRenderer scanRenderer = (ScanRenderer) scanRenderers.get(texture
        .getClass());
    scanRenderer.setTexture(texture);
    Rectangle3D textureBounds = poly.getTextureBounds();
    a.setToCrossProduct(textureBounds.getDirectionV(), textureBounds
        .getOrigin());
    b.setToCrossProduct(textureBounds.getOrigin(), textureBounds
        .getDirectionU());
    c.setToCrossProduct(textureBounds.getDirectionU(), textureBounds
        .getDirectionV());
    int y = scanConverter.getTopBoundary();
    viewPos.y = viewWindow.convertFromScreenYToViewY(y);
    viewPos.z = -viewWindow.getDistance();
    while (y <= scanConverter.getBottomBoundary()) {
      ScanConverter.Scan scan = scanConverter.getScan(y);
      if (scan.isValid()) {
        viewPos.x = viewWindow.convertFromScreenXToViewX(scan.left);
        int offset = (y - viewWindow.getTopOffset())
            * viewWindow.getWidth()
            + (scan.left - viewWindow.getLeftOffset());
        scanRenderer.render(offset, scan.left, scan.right);
      }
      y++;
      viewPos.y--;
    }
  }
  /**
   * The ScanRenderer class is an abstract inner class of
   * FastTexturedPolygonRenderer that provides an interface for rendering a
   * horizontal scan line.
   */
  public abstract class ScanRenderer {
    protected Texture currentTexture;
    public void setTexture(Texture texture) {
      this.currentTexture = texture;
    }
    public abstract void render(int offset, int left, int right);
  }
  //================================================
  // FASTEST METHOD: no texture (for comparison)
  //================================================
  public class Method0 extends ScanRenderer {
    public void render(int offset, int left, int right) {
      for (int x = left; x <= right; x++) {
        doubleBufferData[offset++] = (short) 0x0007;
      }
    }
  }
  //================================================
  // METHOD 1: access pixel buffers directly
  // and use textures sizes that are a power of 2
  //================================================
  public class Method1 extends ScanRenderer {
    public void render(int offset, int left, int right) {
      for (int x = left; x <= right; x++) {
        int tx = (int) (a.getDotProduct(viewPos) / c
            .getDotProduct(viewPos));
        int ty = (int) (b.getDotProduct(viewPos) / c
            .getDotProduct(viewPos));
        doubleBufferData[offset++] = currentTexture.getColor(tx, ty);
        viewPos.x++;
      }
    }
  }
  //================================================
  // METHOD 2: avoid redundant calculations
  //================================================
  public class Method2 extends ScanRenderer {
    public void render(int offset, int left, int right) {
      float u = a.getDotProduct(viewPos);
      float v = b.getDotProduct(viewPos);
      float z = c.getDotProduct(viewPos);
      float du = a.x;
      float dv = b.x;
      float dz = c.x;
      for (int x = left; x <= right; x++) {
        doubleBufferData[offset++] = currentTexture.getColor(
            (int) (u / z), (int) (v / z));
        u += du;
        v += dv;
        z += dz;
      }
    }
  }
  //================================================
  // METHOD 3: use ints instead of floats
  //================================================
  public class Method3 extends ScanRenderer {
    public void render(int offset, int left, int right) {
      int u = (int) (SCALE * a.getDotProduct(viewPos));
      int v = (int) (SCALE * b.getDotProduct(viewPos));
      int z = (int) (SCALE * c.getDotProduct(viewPos));
      int du = (int) (SCALE * a.x);
      int dv = (int) (SCALE * b.x);
      int dz = (int) (SCALE * c.x);
      for (int x = left; x <= right; x++) {
        doubleBufferData[offset++] = currentTexture.getColor(u / z, v
            / z);
        u += du;
        v += dv;
        z += dz;
      }
    }
  }
  //================================================
  // METHOD 4: reduce the number of divides
  // (interpolate every 16 pixels)
  // Also, apply a VM optimization by referring to
  // the texture"s class rather than it"s parent class.
  //================================================
  // the following three ScanRenderers are the same, but refer
  // to textures explicitly as either a PowerOf2Texture, a
  // ShadedTexture, or a ShadedSurface.
  // This allows HotSpot to do some inlining of the textures"
  // getColor() method, which significantly increases
  // performance.
  public class PowerOf2TextureRenderer extends ScanRenderer {
    public void render(int offset, int left, int right) {
      PowerOf2Texture texture = (PowerOf2Texture) currentTexture;
      float u = SCALE * a.getDotProduct(viewPos);
      float v = SCALE * b.getDotProduct(viewPos);
      float z = c.getDotProduct(viewPos);
      float du = INTERP_SIZE * SCALE * a.x;
      float dv = INTERP_SIZE * SCALE * b.x;
      float dz = INTERP_SIZE * c.x;
      int nextTx = (int) (u / z);
      int nextTy = (int) (v / z);
      int x = left;
      while (x <= right) {
        int tx = nextTx;
        int ty = nextTy;
        int maxLength = right - x + 1;
        if (maxLength > INTERP_SIZE) {
          u += du;
          v += dv;
          z += dz;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) >> INTERP_SIZE_BITS;
          int dty = (nextTy - ty) >> INTERP_SIZE_BITS;
          int endOffset = offset + INTERP_SIZE;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += INTERP_SIZE;
        } else {
          // variable interpolation size
          int interpSize = maxLength;
          u += interpSize * SCALE * a.x;
          v += interpSize * SCALE * b.x;
          z += interpSize * c.x;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) / interpSize;
          int dty = (nextTy - ty) / interpSize;
          int endOffset = offset + interpSize;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += interpSize;
        }
      }
    }
  }
  public class ShadedTextureRenderer extends ScanRenderer {
    public void render(int offset, int left, int right) {
      ShadedTexture texture = (ShadedTexture) currentTexture;
      float u = SCALE * a.getDotProduct(viewPos);
      float v = SCALE * b.getDotProduct(viewPos);
      float z = c.getDotProduct(viewPos);
      float du = INTERP_SIZE * SCALE * a.x;
      float dv = INTERP_SIZE * SCALE * b.x;
      float dz = INTERP_SIZE * c.x;
      int nextTx = (int) (u / z);
      int nextTy = (int) (v / z);
      int x = left;
      while (x <= right) {
        int tx = nextTx;
        int ty = nextTy;
        int maxLength = right - x + 1;
        if (maxLength > INTERP_SIZE) {
          u += du;
          v += dv;
          z += dz;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) >> INTERP_SIZE_BITS;
          int dty = (nextTy - ty) >> INTERP_SIZE_BITS;
          int endOffset = offset + INTERP_SIZE;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += INTERP_SIZE;
        } else {
          // variable interpolation size
          int interpSize = maxLength;
          u += interpSize * SCALE * a.x;
          v += interpSize * SCALE * b.x;
          z += interpSize * c.x;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) / interpSize;
          int dty = (nextTy - ty) / interpSize;
          int endOffset = offset + interpSize;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += interpSize;
        }
      }
    }
  }
  public class ShadedSurfaceRenderer extends ScanRenderer {
    public int checkBounds(int vScaled, int bounds) {
      int v = vScaled >> SCALE_BITS;
      if (v < 0) {
        vScaled = 0;
      } else if (v >= bounds) {
        vScaled = (bounds - 1) << SCALE_BITS;
      }
      return vScaled;
    }
    public void render(int offset, int left, int right) {
      ShadedSurface texture = (ShadedSurface) currentTexture;
      float u = SCALE * a.getDotProduct(viewPos);
      float v = SCALE * b.getDotProduct(viewPos);
      float z = c.getDotProduct(viewPos);
      float du = INTERP_SIZE * SCALE * a.x;
      float dv = INTERP_SIZE * SCALE * b.x;
      float dz = INTERP_SIZE * c.x;
      int nextTx = (int) (u / z);
      int nextTy = (int) (v / z);
      int x = left;
      while (x <= right) {
        int tx = nextTx;
        int ty = nextTy;
        int maxLength = right - x + 1;
        if (maxLength > INTERP_SIZE) {
          u += du;
          v += dv;
          z += dz;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) >> INTERP_SIZE_BITS;
          int dty = (nextTy - ty) >> INTERP_SIZE_BITS;
          int endOffset = offset + INTERP_SIZE;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += INTERP_SIZE;
        } else {
          // variable interpolation size
          int interpSize = maxLength;
          u += interpSize * SCALE * a.x;
          v += interpSize * SCALE * b.x;
          z += interpSize * c.x;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          // make sure tx, ty, nextTx, and nextTy are
          // all within bounds
          tx = checkBounds(tx, texture.getWidth());
          ty = checkBounds(ty, texture.getHeight());
          nextTx = checkBounds(nextTx, texture.getWidth());
          nextTy = checkBounds(nextTy, texture.getHeight());
          int dtx = (nextTx - tx) / interpSize;
          int dty = (nextTy - ty) / interpSize;
          int endOffset = offset + interpSize;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += interpSize;
        }
      }
    }
  }
}
/**
 * A ShadedSurface is a pre-shaded Texture that maps onto a polygon.
 */
final class ShadedSurface extends Texture {
  public static final int SURFACE_BORDER_SIZE = 1;
  public static final int SHADE_RES_BITS = 4;
  public static final int SHADE_RES = 1 << SHADE_RES_BITS;
  public static final int SHADE_RES_MASK = SHADE_RES - 1;
  public static final int SHADE_RES_SQ = SHADE_RES * SHADE_RES;
  public static final int SHADE_RES_SQ_BITS = SHADE_RES_BITS * 2;
  private short[] buffer;
  private SoftReference bufferReference;
  private boolean dirty;
  private ShadedTexture sourceTexture;
  private Rectangle3D sourceTextureBounds;
  private Rectangle3D surfaceBounds;
  private byte[] shadeMap;
  private int shadeMapWidth;
  private int shadeMapHeight;
  // for incrementally calculating shade values
  private int shadeValue;
  private int shadeValueInc;
  /**
   * Creates a ShadedSurface with the specified width and height.
   */
  public ShadedSurface(int width, int height) {
    this(null, width, height);
  }
  /**
   * Creates a ShadedSurface with the specified buffer, width and height.
   */
  public ShadedSurface(short[] buffer, int width, int height) {
    super(width, height);
    this.buffer = buffer;
    bufferReference = new SoftReference(buffer);
    sourceTextureBounds = new Rectangle3D();
    dirty = true;
  }
  /**
   * Creates a ShadedSurface for the specified polygon. The shade map is
   * created from the specified list of point lights and ambient light
   * intensity.
   */
  public static void createShadedSurface(TexturedPolygon3D poly,
      ShadedTexture texture, List lights, float ambientLightIntensity) {
    // create the texture bounds
    Vector3D origin = poly.getVertex(0);
    Vector3D dv = new Vector3D(poly.getVertex(1));
    dv.subtract(origin);
    Vector3D du = new Vector3D();
    du.setToCrossProduct(poly.getNormal(), dv);
    Rectangle3D bounds = new Rectangle3D(origin, du, dv,
        texture.getWidth(), texture.getHeight());
    createShadedSurface(poly, texture, bounds, lights,
        ambientLightIntensity);
  }
  /**
   * Creates a ShadedSurface for the specified polygon. The shade map is
   * created from the specified list of point lights and ambient light
   * intensity.
   */
  public static void createShadedSurface(TexturedPolygon3D poly,
      ShadedTexture texture, Rectangle3D textureBounds, List lights,
      float ambientLightIntensity) {
    // create the surface bounds
    poly.setTexture(texture, textureBounds);
    Rectangle3D surfaceBounds = poly.calcBoundingRectangle();
    // give the surfaceBounds a border to correct for
    // slight errors when texture mapping
    Vector3D du = new Vector3D(surfaceBounds.getDirectionU());
    Vector3D dv = new Vector3D(surfaceBounds.getDirectionV());
    du.multiply(SURFACE_BORDER_SIZE);
    dv.multiply(SURFACE_BORDER_SIZE);
    surfaceBounds.getOrigin().subtract(du);
    surfaceBounds.getOrigin().subtract(dv);
    int width = (int) Math.ceil(surfaceBounds.getWidth()
        + SURFACE_BORDER_SIZE * 2);
    int height = (int) Math.ceil(surfaceBounds.getHeight()
        + SURFACE_BORDER_SIZE * 2);
    surfaceBounds.setWidth(width);
    surfaceBounds.setHeight(height);
    // create the shaded surface texture
    ShadedSurface surface = new ShadedSurface(width, height);
    surface.setTexture(texture, textureBounds);
    surface.setSurfaceBounds(surfaceBounds);
    // create the surface"s shade map
    surface.buildShadeMap(lights, ambientLightIntensity);
    // set the polygon"s surface
    poly.setTexture(surface, surfaceBounds);
  }
  /**
   * Gets the 16-bit color of the pixel at location (x,y) in the bitmap. The x
   * and y values are assumbed to be within the bounds of the surface;
   * otherwise an ArrayIndexOutOfBoundsException occurs.
   */
  public short getColor(int x, int y) {
    //try {
    return buffer[x + y * width];
    //}
    //catch (ArrayIndexOutOfBoundsException ex) {
    //    return -2048;
    //}
  }
  /**
   * Gets the 16-bit color of the pixel at location (x,y) in the bitmap. The x
   * and y values are checked to be within the bounds of the surface, and if
   * not, the pixel on the edge of the texture is returned.
   */
  public short getColorChecked(int x, int y) {
    if (x < 0) {
      x = 0;
    } else if (x >= width) {
      x = width - 1;
    }
    if (y < 0) {
      y = 0;
    } else if (y >= height) {
      y = height - 1;
    }
    return getColor(x, y);
  }
  /**
   * Marks whether this surface is dirty. Surfaces marked as dirty may be
   * cleared externally.
   */
  public void setDirty(boolean dirty) {
    this.dirty = dirty;
  }
  /**
   * Checks wether this surface is dirty. Surfaces marked as dirty may be
   * cleared externally.
   */
  public boolean isDirty() {
    return dirty;
  }
  /**
   * Creates a new surface and add a SoftReference to it.
   */
  protected void newSurface(int width, int height) {
    buffer = new short[width * height];
    bufferReference = new SoftReference(buffer);
  }
  /**
   * Clears this surface, allowing the garbage collector to remove it from
   * memory if needed.
   */
  public void clearSurface() {
    buffer = null;
  }
  /**
   * Checks if the surface has been cleared.
   */
  public boolean isCleared() {
    return (buffer == null);
  }
  /**
   * If the buffer has been previously built and cleared but not yet removed
   * from memory by the garbage collector, then this method attempts to
   * retrieve it. Returns true if successfull.
   */
  public boolean retrieveSurface() {
    if (buffer == null) {
      buffer = (short[]) bufferReference.get();
    }
    return !(buffer == null);
  }
  /**
   * Sets the source texture for this ShadedSurface.
   */
  public void setTexture(ShadedTexture texture) {
    this.sourceTexture = texture;
    sourceTextureBounds.setWidth(texture.getWidth());
    sourceTextureBounds.setHeight(texture.getHeight());
  }
  /**
   * Sets the source texture and source bounds for this ShadedSurface.
   */
  public void setTexture(ShadedTexture texture, Rectangle3D bounds) {
    setTexture(texture);
    sourceTextureBounds.setTo(bounds);
  }
  /**
   * Sets the surface bounds for this ShadedSurface.
   */
  public void setSurfaceBounds(Rectangle3D surfaceBounds) {
    this.surfaceBounds = surfaceBounds;
  }
  /**
   * Gets the surface bounds for this ShadedSurface.
   */
  public Rectangle3D getSurfaceBounds() {
    return surfaceBounds;
  }
  /**
   * Builds the surface. First, this method calls retrieveSurface() to see if
   * the surface needs to be rebuilt. If not, the surface is built by tiling
   * the source texture and apply the shade map.
   */
  public void buildSurface() {
    if (retrieveSurface()) {
      return;
    }
    int width = (int) surfaceBounds.getWidth();
    int height = (int) surfaceBounds.getHeight();
    // create a new surface (buffer)
    newSurface(width, height);
    // builds the surface.
    // assume surface bounds and texture bounds are aligned
    // (possibly with different origins)
    Vector3D origin = sourceTextureBounds.getOrigin();
    Vector3D directionU = sourceTextureBounds.getDirectionU();
    Vector3D directionV = sourceTextureBounds.getDirectionV();
    Vector3D d = new Vector3D(surfaceBounds.getOrigin());
    d.subtract(origin);
    int startU = (int) ((d.getDotProduct(directionU) - SURFACE_BORDER_SIZE));
    int startV = (int) ((d.getDotProduct(directionV) - SURFACE_BORDER_SIZE));
    int offset = 0;
    int shadeMapOffsetU = SHADE_RES - SURFACE_BORDER_SIZE - startU;
    int shadeMapOffsetV = SHADE_RES - SURFACE_BORDER_SIZE - startV;
    for (int v = startV; v < startV + height; v++) {
      sourceTexture.setCurrRow(v);
      int u = startU;
      int amount = SURFACE_BORDER_SIZE;
      while (u < startU + width) {
        getInterpolatedShade(u + shadeMapOffsetU, v + shadeMapOffsetV);
        // keep drawing until we need to recalculate
        // the interpolated shade. (every SHADE_RES pixels)
        int endU = Math.min(startU + width, u + amount);
        while (u < endU) {
          buffer[offset++] = sourceTexture.getColorCurrRow(u,
              shadeValue >> SHADE_RES_SQ_BITS);
          shadeValue += shadeValueInc;
          u++;
        }
        amount = SHADE_RES;
      }
    }
    // if the surface bounds is not aligned with the texture
    // bounds, use this (slower) code.
    /*
     * Vector3D origin = sourceTextureBounds.getOrigin(); Vector3D
     * directionU = sourceTextureBounds.getDirectionU(); Vector3D directionV =
     * sourceTextureBounds.getDirectionV();
     * 
     * Vector3D d = new Vector3D(surfaceBounds.getOrigin());
     * d.subtract(origin); int initTextureU = (int)(SCALE *
     * (d.getDotProduct(directionU) - SURFACE_BORDER_SIZE)); int
     * initTextureV = (int)(SCALE * (d.getDotProduct(directionV) -
     * SURFACE_BORDER_SIZE)); int textureDu1 = (int)(SCALE *
     * directionU.getDotProduct( surfaceBounds.getDirectionV())); int
     * textureDv1 = (int)(SCALE * directionV.getDotProduct(
     * surfaceBounds.getDirectionV())); int textureDu2 = (int)(SCALE *
     * directionU.getDotProduct( surfaceBounds.getDirectionU())); int
     * textureDv2 = (int)(SCALE * directionV.getDotProduct(
     * surfaceBounds.getDirectionU()));
     * 
     * int shadeMapOffset = SHADE_RES - SURFACE_BORDER_SIZE;
     * 
     * for (int v=0; v <height; v++) { int textureU = initTextureU; int
     * textureV = initTextureV;
     * 
     * for (int u=0; u <width; u++) { if (((u + shadeMapOffset) &
     * SHADE_RES_MASK) == 0) { getInterpolatedShade(u + shadeMapOffset, v +
     * shadeMapOffset); } buffer[offset++] = sourceTexture.getColor(
     * textureU >> SCALE_BITS, textureV >> SCALE_BITS, shadeValue >>
     * SHADE_RES_SQ_BITS); textureU+=textureDu2; textureV+=textureDv2;
     * shadeValue+=shadeValueInc; } initTextureU+=textureDu1;
     * initTextureV+=textureDv1; }
     */
  }
  /**
   * Gets the shade (from the shade map) for the specified (u,v) location. The
   * u and v values should be left-shifted by SHADE_RES_BITS, and the extra
   * bits are used to interpolate between values. For an interpolation
   * example, a location halfway between shade values 1 and 3 would return 2.
   */
  public int getInterpolatedShade(int u, int v) {
    int fracU = u & SHADE_RES_MASK;
    int fracV = v & SHADE_RES_MASK;
    int offset = (u >> SHADE_RES_BITS)
        + ((v >> SHADE_RES_BITS) * shadeMapWidth);
    int shade00 = (SHADE_RES - fracV) * shadeMap[offset];
    int shade01 = fracV * shadeMap[offset + shadeMapWidth];
    int shade10 = (SHADE_RES - fracV) * shadeMap[offset + 1];
    int shade11 = fracV * shadeMap[offset + shadeMapWidth + 1];
    shadeValue = SHADE_RES_SQ / 2 + (SHADE_RES - fracU) * shade00
        + (SHADE_RES - fracU) * shade01 + fracU * shade10 + fracU
        * shade11;
    // the value to increment as u increments
    shadeValueInc = -shade00 - shade01 + shade10 + shade11;
    return shadeValue >> SHADE_RES_SQ_BITS;
  }
  /**
   * Gets the shade (from the built shade map) for the specified (u,v)
   * location.
   */
  public int getShade(int u, int v) {
    return shadeMap[u + v * shadeMapWidth];
  }
  /**
   * Builds the shade map for this surface from the specified list of point
   * lights and the ambiant light intensity.
   */
  public void buildShadeMap(List pointLights, float ambientLightIntensity) {
    Vector3D surfaceNormal = surfaceBounds.getNormal();
    int polyWidth = (int) surfaceBounds.getWidth() - SURFACE_BORDER_SIZE
        * 2;
    int polyHeight = (int) surfaceBounds.getHeight() - SURFACE_BORDER_SIZE
        * 2;
    // assume SURFACE_BORDER_SIZE is <= SHADE_RES
    shadeMapWidth = polyWidth / SHADE_RES + 4;
    shadeMapHeight = polyHeight / SHADE_RES + 4;
    shadeMap = new byte[shadeMapWidth * shadeMapHeight];
    // calculate the shade map origin
    Vector3D origin = new Vector3D(surfaceBounds.getOrigin());
    Vector3D du = new Vector3D(surfaceBounds.getDirectionU());
    Vector3D dv = new Vector3D(surfaceBounds.getDirectionV());
    du.multiply(SHADE_RES - SURFACE_BORDER_SIZE);
    dv.multiply(SHADE_RES - SURFACE_BORDER_SIZE);
    origin.subtract(du);
    origin.subtract(dv);
    // calculate the shade for each sample point.
    Vector3D point = new Vector3D();
    du.setTo(surfaceBounds.getDirectionU());
    dv.setTo(surfaceBounds.getDirectionV());
    du.multiply(SHADE_RES);
    dv.multiply(SHADE_RES);
    for (int v = 0; v < shadeMapHeight; v++) {
      point.setTo(origin);
      for (int u = 0; u < shadeMapWidth; u++) {
        shadeMap[u + v * shadeMapWidth] = calcShade(surfaceNormal,
            point, pointLights, ambientLightIntensity);
        point.add(du);
      }
      origin.add(dv);
    }
  }
  /**
   * Determine the shade of a point on the polygon. This computes the
   * Lambertian reflection for a point on the plane. Each point light has an
   * intensity and a distance falloff value, but no specular reflection or
   * shadows from other polygons are computed. The value returned is from 0 to
   * ShadedTexture.MAX_LEVEL.
   */
  protected byte calcShade(Vector3D normal, Vector3D point, List pointLights,
      float ambientLightIntensity) {
    float intensity = 0;
    Vector3D directionToLight = new Vector3D();
    for (int i = 0; i < pointLights.size(); i++) {
      PointLight3D light = (PointLight3D) pointLights.get(i);
      directionToLight.setTo(light);
      directionToLight.subtract(point);
      float distance = directionToLight.length();
      directionToLight.normalize();
      float lightIntensity = light.getIntensity(distance)
          * directionToLight.getDotProduct(normal);
      lightIntensity = Math.min(lightIntensity, 1);
      lightIntensity = Math.max(lightIntensity, 0);
      intensity += lightIntensity;
    }
    intensity = Math.min(intensity, 1);
    intensity = Math.max(intensity, 0);
    intensity += ambientLightIntensity;
    intensity = Math.min(intensity, 1);
    intensity = Math.max(intensity, 0);
    int level = Math.round(intensity * ShadedTexture.MAX_LEVEL);
    return (byte) level;
  }
}
/**
 * A PointLight3D is a point light that has an intensity (between 0 and 1) and
 * optionally a distance falloff value, which causes the light to diminish with
 * distance.
 */
class PointLight3D extends Vector3D {
  public static final float NO_DISTANCE_FALLOFF = -1;
  private float intensity;
  private float distanceFalloff;
  /**
   * Creates a new PointLight3D at (0,0,0) with an intensity of 1 and no
   * distance falloff.
   */
  public PointLight3D() {
    this(0, 0, 0, 1, NO_DISTANCE_FALLOFF);
  }
  /**
   * Creates a copy of the specified PointLight3D.
   */
  public PointLight3D(PointLight3D p) {
    setTo(p);
  }
  /**
   * Creates a new PointLight3D with the specified location and intensity. The
   * created light has no distance falloff.
   */
  public PointLight3D(float x, float y, float z, float intensity) {
    this(x, y, z, intensity, NO_DISTANCE_FALLOFF);
  }
  /**
   * Creates a new PointLight3D with the specified location. intensity, and no
   * distance falloff.
   */
  public PointLight3D(float x, float y, float z, float intensity,
      float distanceFalloff) {
    setTo(x, y, z);
    setIntensity(intensity);
    setDistanceFalloff(distanceFalloff);
  }
  /**
   * Sets this PointLight3D to the same location, intensity, and distance
   * falloff as the specified PointLight3D.
   */
  public void setTo(PointLight3D p) {
    setTo(p.x, p.y, p.z);
    setIntensity(p.getIntensity());
    setDistanceFalloff(p.getDistanceFalloff());
  }
  /**
   * Gets the intensity of this light from the specified distance.
   */
  public float getIntensity(float distance) {
    if (distanceFalloff == NO_DISTANCE_FALLOFF) {
      return intensity;
    } else if (distance >= distanceFalloff) {
      return 0;
    } else {
      return intensity * (distanceFalloff - distance)
          / (distanceFalloff + distance);
    }
  }
  /**
   * Gets the intensity of this light.
   */
  public float getIntensity() {
    return intensity;
  }
  /**
   * Sets the intensity of this light.
   */
  public void setIntensity(float intensity) {
    this.intensity = intensity;
  }
  /**
   * Gets the distances falloff value. The light intensity is zero beyond this
   * distance.
   */
  public float getDistanceFalloff() {
    return distanceFalloff;
  }
  /**
   * Sets the distances falloff value. The light intensity is zero beyond this
   * distance. Set to NO_DISTANCE_FALLOFF if the light does not diminish with
   * distance.
   */
  public void setDistanceFalloff(float distanceFalloff) {
    this.distanceFalloff = distanceFalloff;
  }
}
/**
 * The Transform3D class represents a rotation and translation.
 */
class Transform3D {
  protected Vector3D location;
  private float cosAngleX;
  private float sinAngleX;
  private float cosAngleY;
  private float sinAngleY;
  private float cosAngleZ;
  private float sinAngleZ;
  /**
   * Creates a new Transform3D with no translation or rotation.
   */
  public Transform3D() {
    this(0, 0, 0);
  }
  /**
   * Creates a new Transform3D with the specified translation and no rotation.
   */
  public Transform3D(float x, float y, float z) {
    location = new Vector3D(x, y, z);
    setAngle(0, 0, 0);
  }
  /**
   * Creates a new Transform3D
   */
  public Transform3D(Transform3D v) {
    location = new Vector3D();
    setTo(v);
  }
  public Object clone() {
    return new Transform3D(this);
  }
  /**
   * Sets this Transform3D to the specified Transform3D.
   */
  public void setTo(Transform3D v) {
    location.setTo(v.location);
    this.cosAngleX = v.cosAngleX;
    this.sinAngleX = v.sinAngleX;
    this.cosAngleY = v.cosAngleY;
    this.sinAngleY = v.sinAngleY;
    this.cosAngleZ = v.cosAngleZ;
    this.sinAngleZ = v.sinAngleZ;
  }
  /**
   * Gets the location (translation) of this transform.
   */
  public Vector3D getLocation() {
    return location;
  }
  public float getCosAngleX() {
    return cosAngleX;
  }
  public float getSinAngleX() {
    return sinAngleX;
  }
  public float getCosAngleY() {
    return cosAngleY;
  }
  public float getSinAngleY() {
    return sinAngleY;
  }
  public float getCosAngleZ() {
    return cosAngleZ;
  }
  public float getSinAngleZ() {
    return sinAngleZ;
  }
  public float getAngleX() {
    return (float) Math.atan2(sinAngleX, cosAngleX);
  }
  public float getAngleY() {
    return (float) Math.atan2(sinAngleY, cosAngleY);
  }
  public float getAngleZ() {
    return (float) Math.atan2(sinAngleZ, cosAngleZ);
  }
  public void setAngleX(float angleX) {
    cosAngleX = (float) Math.cos(angleX);
    sinAngleX = (float) Math.sin(angleX);
  }
  public void setAngleY(float angleY) {
    cosAngleY = (float) Math.cos(angleY);
    sinAngleY = (float) Math.sin(angleY);
  }
  public void setAngleZ(float angleZ) {
    cosAngleZ = (float) Math.cos(angleZ);
    sinAngleZ = (float) Math.sin(angleZ);
  }
  public void setAngle(float angleX, float angleY, float angleZ) {
    setAngleX(angleX);
    setAngleY(angleY);
    setAngleZ(angleZ);
  }
  public void rotateAngleX(float angle) {
    if (angle != 0) {
      setAngleX(getAngleX() + angle);
    }
  }
  public void rotateAngleY(float angle) {
    if (angle != 0) {
      setAngleY(getAngleY() + angle);
    }
  }
  public void rotateAngleZ(float angle) {
    if (angle != 0) {
      setAngleZ(getAngleZ() + angle);
    }
  }
  public void rotateAngle(float angleX, float angleY, float angleZ) {
    rotateAngleX(angleX);
    rotateAngleY(angleY);
    rotateAngleZ(angleZ);
  }
}
/**
 * The ViewWindow class represents the geometry of a view window for 3D viewing.
 */
class ViewWindow {
  private Rectangle bounds;
  private float angle;
  private float distanceToCamera;
  /**
   * Creates a new ViewWindow with the specified bounds on the screen and
   * horizontal view angle.
   */
  public ViewWindow(int left, int top, int width, int height, float angle) {
    bounds = new Rectangle();
    this.angle = angle;
    setBounds(left, top, width, height);
  }
  /**
   * Sets the bounds for this ViewWindow on the screen.
   */
  public void setBounds(int left, int top, int width, int height) {
    bounds.x = left;
    bounds.y = top;
    bounds.width = width;
    bounds.height = height;
    distanceToCamera = (bounds.width / 2) / (float) Math.tan(angle / 2);
  }
  /**
   * Sets the horizontal view angle for this ViewWindow.
   */
  public void setAngle(float angle) {
    this.angle = angle;
    distanceToCamera = (bounds.width / 2) / (float) Math.tan(angle / 2);
  }
  /**
   * Gets the horizontal view angle of this view window.
   */
  public float getAngle() {
    return angle;
  }
  /**
   * Gets the width of this view window.
   */
  public int getWidth() {
    return bounds.width;
  }
  /**
   * Gets the height of this view window.
   */
  public int getHeight() {
    return bounds.height;
  }
  /**
   * Gets the y offset of this view window on the screen.
   */
  public int getTopOffset() {
    return bounds.y;
  }
  /**
   * Gets the x offset of this view window on the screen.
   */
  public int getLeftOffset() {
    return bounds.x;
  }
  /**
   * Gets the distance from the camera to to this view window.
   */
  public float getDistance() {
    return distanceToCamera;
  }
  /**
   * Converts an x coordinate on this view window to the corresponding x
   * coordinate on the screen.
   */
  public float convertFromViewXToScreenX(float x) {
    return x + bounds.x + bounds.width / 2;
  }
  /**
   * Converts a y coordinate on this view window to the corresponding y
   * coordinate on the screen.
   */
  public float convertFromViewYToScreenY(float y) {
    return -y + bounds.y + bounds.height / 2;
  }
  /**
   * Converts an x coordinate on the screen to the corresponding x coordinate
   * on this view window.
   */
  public float convertFromScreenXToViewX(float x) {
    return x - bounds.x - bounds.width / 2;
  }
  /**
   * Converts an y coordinate on the screen to the corresponding y coordinate
   * on this view window.
   */
  public float convertFromScreenYToViewY(float y) {
    return -y + bounds.y + bounds.height / 2;
  }
  /**
   * Projects the specified vector to the screen.
   */
  public void project(Vector3D v) {
    // project to view window
    v.x = distanceToCamera * v.x / -v.z;
    v.y = distanceToCamera * v.y / -v.z;
    // convert to screen coordinates
    v.x = convertFromViewXToScreenX(v.x);
    v.y = convertFromViewYToScreenY(v.y);
  }
}
/**
 * The Texture class is an sabstract class that represents a 16-bit color
 * texture.
 */
abstract class Texture {
  protected int width;
  protected int height;
  /**
   * Creates a new Texture with the specified width and height.
   */
  public Texture(int width, int height) {
    this.width = width;
    this.height = height;
  }
  /**
   * Gets the width of this Texture.
   */
  public int getWidth() {
    return width;
  }
  /**
   * Gets the height of this Texture.
   */
  public int getHeight() {
    return height;
  }
  /**
   * Gets the 16-bit color of this Texture at the specified (x,y) location.
   */
  public abstract short getColor(int x, int y);
  /**
   * Creates an unshaded Texture from the specified image file.
   */
  public static Texture createTexture(String filename) {
    return createTexture(filename, false);
  }
  /**
   * Creates an Texture from the specified image file. If shaded is true, then
   * a ShadedTexture is returned.
   */
  public static Texture createTexture(String filename, boolean shaded) {
    try {
      return createTexture(ImageIO.read(new File(filename)), shaded);
    } catch (IOException ex) {
      ex.printStackTrace();
      return null;
    }
  }
  /**
   * Creates an unshaded Texture from the specified image.
   */
  public static Texture createTexture(BufferedImage image) {
    return createTexture(image, false);
  }
  /**
   * Creates an Texture from the specified image. If shaded is true, then a
   * ShadedTexture is returned.
   */
  public static Texture createTexture(BufferedImage image, boolean shaded) {
    int type = image.getType();
    int width = image.getWidth();
    int height = image.getHeight();
    if (!isPowerOfTwo(width) || !isPowerOfTwo(height)) {
      throw new IllegalArgumentException(
          "Size of texture must be a power of two.");
    }
    if (shaded) {
      // convert image to an indexed image
      if (type != BufferedImage.TYPE_BYTE_INDEXED) {
        System.out.println("Warning: image converted to "
            + "256-color indexed image. Some quality may "
            + "be lost.");
        BufferedImage newImage = new BufferedImage(image.getWidth(),
            image.getHeight(), BufferedImage.TYPE_BYTE_INDEXED);
        Graphics2D g = newImage.createGraphics();
        g.drawImage(image, 0, 0, null);
        g.dispose();
        image = newImage;
      }
      DataBuffer dest = image.getRaster().getDataBuffer();
      return new ShadedTexture(((DataBufferByte) dest).getData(),
          countbits(width - 1), countbits(height - 1),
          (IndexColorModel) image.getColorModel());
    } else {
      // convert image to an 16-bit image
      if (type != BufferedImage.TYPE_USHORT_565_RGB) {
        BufferedImage newImage = new BufferedImage(image.getWidth(),
            image.getHeight(), BufferedImage.TYPE_USHORT_565_RGB);
        Graphics2D g = newImage.createGraphics();
        g.drawImage(image, 0, 0, null);
        g.dispose();
        image = newImage;
      }
      DataBuffer dest = image.getRaster().getDataBuffer();
      return new PowerOf2Texture(((DataBufferUShort) dest).getData(),
          countbits(width - 1), countbits(height - 1));
    }
  }
  /**
   * Returns true if the specified number is a power of 2.
   */
  public static boolean isPowerOfTwo(int n) {
    return ((n & (n - 1)) == 0);
  }
  /**
   * Counts the number of "on" bits in an integer.
   */
  public static int countbits(int n) {
    int count = 0;
    while (n > 0) {
      count += (n & 1);
      n >>= 1;
    }
    return count;
  }
}
/**
 * The ShadedTexture class is a Texture that has multiple shades. The texture
 * source image is stored as a 8-bit image with a palette for every shade.
 */
final class ShadedTexture extends Texture {
  public static final int NUM_SHADE_LEVELS = 64;
  public static final int MAX_LEVEL = NUM_SHADE_LEVELS - 1;
  private static final int PALETTE_SIZE_BITS = 8;
  private static final int PALETTE_SIZE = 1 << PALETTE_SIZE_BITS;
  private byte[] buffer;
  private IndexColorModel palette;
  private short[] shadeTable;
  private int defaultShadeLevel;
  private int widthBits;
  private int widthMask;
  private int heightBits;
  private int heightMask;
  // the row set in setCurrRow and used in getColorCurrRow
  private int currRow;
  /**
   * Creates a new ShadedTexture from the specified 8-bit image buffer and
   * palette. The width of the bitmap is 2 to the power of widthBits, or (1 < <
   * widthBits). Likewise, the height of the bitmap is 2 to the power of
   * heightBits, or (1 < < heightBits). The texture is shaded from it"s
   * original color to black.
   */
  public ShadedTexture(byte[] buffer, int widthBits, int heightBits,
      IndexColorModel palette) {
    this(buffer, widthBits, heightBits, palette, Color.BLACK);
  }
  /**
   * Creates a new ShadedTexture from the specified 8-bit image buffer,
   * palette, and target shaded. The width of the bitmap is 2 to the power of
   * widthBits, or (1 < < widthBits). Likewise, the height of the bitmap is 2
   * to the power of heightBits, or (1 < < heightBits). The texture is shaded
   * from it"s original color to the target shade.
   */
  public ShadedTexture(byte[] buffer, int widthBits, int heightBits,
      IndexColorModel palette, Color targetShade) {
    super(1 << widthBits, 1 << heightBits);
    this.buffer = buffer;
    this.widthBits = widthBits;
    this.heightBits = heightBits;
    this.widthMask = getWidth() - 1;
    this.heightMask = getHeight() - 1;
    this.buffer = buffer;
    this.palette = palette;
    defaultShadeLevel = MAX_LEVEL;
    makeShadeTable(targetShade);
  }
  /**
   * Creates the shade table for this ShadedTexture. Each entry in the palette
   * is shaded from the original color to the specified target color.
   */
  public void makeShadeTable(Color targetShade) {
    shadeTable = new short[NUM_SHADE_LEVELS * PALETTE_SIZE];
    for (int level = 0; level < NUM_SHADE_LEVELS; level++) {
      for (int i = 0; i < palette.getMapSize(); i++) {
        int red = calcColor(palette.getRed(i), targetShade.getRed(),
            level);
        int green = calcColor(palette.getGreen(i), targetShade
            .getGreen(), level);
        int blue = calcColor(palette.getBlue(i), targetShade.getBlue(),
            level);
        int index = level * PALETTE_SIZE + i;
        // RGB 5:6:5
        shadeTable[index] = (short) (((red >> 3) << 11)
            | ((green >> 2) << 5) | (blue >> 3));
      }
    }
  }
  private int calcColor(int palColor, int target, int level) {
    return (palColor - target) * (level + 1) / NUM_SHADE_LEVELS + target;
  }
  /**
   * Sets the default shade level that is used when getColor() is called.
   */
  public void setDefaultShadeLevel(int level) {
    defaultShadeLevel = level;
  }
  /**
   * Gets the default shade level that is used when getColor() is called.
   */
  public int getDefaultShadeLevel() {
    return defaultShadeLevel;
  }
  /**
   * Gets the 16-bit color of this Texture at the specified (x,y) location,
   * using the default shade level.
   */
  public short getColor(int x, int y) {
    return getColor(x, y, defaultShadeLevel);
  }
  /**
   * Gets the 16-bit color of this Texture at the specified (x,y) location,
   * using the specified shade level.
   */
  public short getColor(int x, int y, int shadeLevel) {
    return shadeTable[(shadeLevel << PALETTE_SIZE_BITS)
        | (0xff & buffer[(x & widthMask)
            | ((y & heightMask) << widthBits)])];
  }
  /**
   * Sets the current row for getColorCurrRow(). Pre-calculates the offset for
   * this row.
   */
  public void setCurrRow(int y) {
    currRow = (y & heightMask) << widthBits;
  }
  /**
   * Gets the color at the specified x location at the specified shade level.
   * The current row defined in setCurrRow is used.
   */
  public short getColorCurrRow(int x, int shadeLevel) {
    return shadeTable[(shadeLevel << PALETTE_SIZE_BITS)
        | (0xff & buffer[(x & widthMask) | currRow])];
  }
}
/**
 * The PowerOf2Texture class is a Texture with a width and height that are a
 * power of 2 (32, 128, etc.).
 */
final class PowerOf2Texture extends Texture {
  private short[] buffer;
  private int widthBits;
  private int widthMask;
  private int heightBits;
  private int heightMask;
  /**
   * Creates a new PowerOf2Texture with the specified buffer. The width of the
   * bitmap is 2 to the power of widthBits, or (1 < < widthBits). Likewise,
   * the height of the bitmap is 2 to the power of heightBits, or (1 < <
   * heightBits).
   */
  public PowerOf2Texture(short[] buffer, int widthBits, int heightBits) {
    super(1 << widthBits, 1 << heightBits);
    this.buffer = buffer;
    this.widthBits = widthBits;
    this.heightBits = heightBits;
    this.widthMask = getWidth() - 1;
    this.heightMask = getHeight() - 1;
  }
  /**
   * Gets the 16-bit color of the pixel at location (x,y) in the bitmap.
   */
  public short getColor(int x, int y) {
    return buffer[(x & widthMask) + ((y & heightMask) << widthBits)];
  }
}
/**
 * Simple abstract class used for testing. Subclasses should implement the
 * draw() method.
 */
abstract class GameCore {
  protected static final int DEFAULT_FONT_SIZE = 24;
  // various lists of modes, ordered by preference
  protected static final DisplayMode[] MID_RES_MODES = {
      new DisplayMode(800, 600, 16, 0), new DisplayMode(800, 600, 32, 0),
      new DisplayMode(800, 600, 24, 0), new DisplayMode(640, 480, 16, 0),
      new DisplayMode(640, 480, 32, 0), new DisplayMode(640, 480, 24, 0),
      new DisplayMode(1024, 768, 16, 0),
      new DisplayMode(1024, 768, 32, 0),
      new DisplayMode(1024, 768, 24, 0), };
  protected static final DisplayMode[] LOW_RES_MODES = {
      new DisplayMode(640, 480, 16, 0), new DisplayMode(640, 480, 32, 0),
      new DisplayMode(640, 480, 24, 0), new DisplayMode(800, 600, 16, 0),
      new DisplayMode(800, 600, 32, 0), new DisplayMode(800, 600, 24, 0),
      new DisplayMode(1024, 768, 16, 0),
      new DisplayMode(1024, 768, 32, 0),
      new DisplayMode(1024, 768, 24, 0), };
  protected static final DisplayMode[] VERY_LOW_RES_MODES = {
      new DisplayMode(320, 240, 16, 0), new DisplayMode(400, 300, 16, 0),
      new DisplayMode(512, 384, 16, 0), new DisplayMode(640, 480, 16, 0),
      new DisplayMode(800, 600, 16, 0), };
  private boolean isRunning;
  protected ScreenManager screen;
  protected int fontSize = DEFAULT_FONT_SIZE;
  /**
   * Signals the game loop that it"s time to quit
   */
  public void stop() {
    isRunning = false;
  }
  /**
   * Calls init() and gameLoop()
   */
  public void run() {
    try {
      init();
      gameLoop();
    } finally {
      if (screen != null) {
        screen.restoreScreen();
      }
      lazilyExit();
    }
  }
  /**
   * Exits the VM from a daemon thread. The daemon thread waits 2 seconds then
   * calls System.exit(0). Since the VM should exit when only daemon threads
   * are running, this makes sure System.exit(0) is only called if neccesary.
   * It"s neccesary if the Java Sound system is running.
   */
  public void lazilyExit() {
    Thread thread = new Thread() {
      public void run() {
        // first, wait for the VM exit on its own.
        try {
          Thread.sleep(2000);
        } catch (InterruptedException ex) {
        }
        // system is still running, so force an exit
        System.exit(0);
      }
    };
    thread.setDaemon(true);
    thread.start();
  }
  /**
   * Sets full screen mode and initiates and objects.
   */
  public void init() {
    init(MID_RES_MODES);
  }
  /**
   * Sets full screen mode and initiates and objects.
   */
  public void init(DisplayMode[] possibleModes) {
    screen = new ScreenManager();
    DisplayMode displayMode = screen.findFirstCompatibleMode(possibleModes);
    screen.setFullScreen(displayMode);
    Window window = screen.getFullScreenWindow();
    window.setFont(new Font("Dialog", Font.PLAIN, fontSize));
    window.setBackground(Color.blue);
    window.setForeground(Color.white);
    isRunning = true;
  }
  public Image loadImage(String fileName) {
    return new ImageIcon(fileName).getImage();
  }
  /**
   * Runs through the game loop until stop() is called.
   */
  public void gameLoop() {
    long startTime = System.currentTimeMillis();
    long currTime = startTime;
    while (isRunning) {
      long elapsedTime = System.currentTimeMillis() - currTime;
      currTime += elapsedTime;
      // update
      update(elapsedTime);
      // draw the screen
      Graphics2D g = screen.getGraphics();
      draw(g);
      g.dispose();
      screen.update();
      // don"t take a nap! run as fast as possible
      /*
       * try { Thread.sleep(20); } catch (InterruptedException ex) { }
       */
    }
  }
  /**
   * Updates the state of the game/animation based on the amount of elapsed
   * time that has passed.
   */
  public void update(long elapsedTime) {
    // do nothing
  }
  /**
   * Draws to the screen. Subclasses must override this method.
   */
  public abstract void draw(Graphics2D g);
}
/**
 * The ScreenManager class manages initializing and displaying full screen
 * graphics modes.
 */
class ScreenManager {
  private GraphicsDevice device;
  /**
   * Creates a new ScreenManager object.
   */
  public ScreenManager() {
    GraphicsEnvironment environment = GraphicsEnvironment
        .getLocalGraphicsEnvironment();
    device = environment.getDefaultScreenDevice();
  }
  /**
   * Returns a list of compatible display modes for the default device on the
   * system.
   */
  public DisplayMode[] getCompatibleDisplayModes() {
    return device.getDisplayModes();
  }
  /**
   * Returns the first compatible mode in a list of modes. Returns null if no
   * modes are compatible.
   */
  public DisplayMode findFirstCompatibleMode(DisplayMode modes[]) {
    DisplayMode goodModes[] = device.getDisplayModes();
    for (int i = 0; i < modes.length; i++) {
      for (int j = 0; j < goodModes.length; j++) {
        if (displayModesMatch(modes[i], goodModes[j])) {
          return modes[i];
        }
      }
    }
    return null;
  }
  /**
   * Returns the current display mode.
   */
  public DisplayMode getCurrentDisplayMode() {
    return device.getDisplayMode();
  }
  /**
   * Determines if two display modes "match". Two display modes match if they
   * have the same resolution, bit depth, and refresh rate. The bit depth is
   * ignored if one of the modes has a bit depth of
   * DisplayMode.BIT_DEPTH_MULTI. Likewise, the refresh rate is ignored if one
   * of the modes has a refresh rate of DisplayMode.REFRESH_RATE_UNKNOWN.
   */
  public boolean displayModesMatch(DisplayMode mode1, DisplayMode mode2)
  {
    if (mode1.getWidth() != mode2.getWidth()
        || mode1.getHeight() != mode2.getHeight()) {
      return false;
    }
    if (mode1.getBitDepth() != DisplayMode.BIT_DEPTH_MULTI
        && mode2.getBitDepth() != DisplayMode.BIT_DEPTH_MULTI
        && mode1.getBitDepth() != mode2.getBitDepth()) {
      return false;
    }
    if (mode1.getRefreshRate() != DisplayMode.REFRESH_RATE_UNKNOWN
        && mode2.getRefreshRate() != DisplayMode.REFRESH_RATE_UNKNOWN
        && mode1.getRefreshRate() != mode2.getRefreshRate()) {
      return false;
    }
    return true;
  }
  /**
   * Enters full screen mode and changes the display mode. If the specified
   * display mode is null or not compatible with this device, or if the
   * display mode cannot be changed on this system, the current display mode
   * is used.
   * <p>
   * The display uses a BufferStrategy with 2 buffers.
   */
  public void setFullScreen(DisplayMode displayMode) {
    final JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setUndecorated(true);
    frame.setIgnoreRepaint(true);
    frame.setResizable(false);
    device.setFullScreenWindow(frame);
    if (displayMode != null && device.isDisplayChangeSupported()) {
      try {
        device.setDisplayMode(displayMode);
      } catch (IllegalArgumentException ex) {
      }
      // fix for mac os x
      frame.setSize(displayMode.getWidth(), displayMode.getHeight());
    }
    // avoid potential deadlock in 1.4.1_02
    try {
      EventQueue.invokeAndWait(new Runnable() {
        public void run() {
          frame.createBufferStrategy(2);
        }
      });
    } catch (InterruptedException ex) {
      // ignore
    } catch (InvocationTargetException ex) {
      // ignore
    }
  }
  /**
   * Gets the graphics context for the display. The ScreenManager uses double
   * buffering, so applications must call update() to show any graphics drawn.
   * <p>
   * The application must dispose of the graphics object.
   */
  public Graphics2D getGraphics() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      BufferStrategy strategy = window.getBufferStrategy();
      return (Graphics2D) strategy.getDrawGraphics();
    } else {
      return null;
    }
  }
  /**
   * Updates the display.
   */
  public void update() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      BufferStrategy strategy = window.getBufferStrategy();
      if (!strategy.contentsLost()) {
        strategy.show();
      }
    }
    // Sync the display on some systems.
    // (on Linux, this fixes event queue problems)
    //Toolkit.getDefaultToolkit().sync();
  }
  /**
   * Returns the window currently used in full screen mode. Returns null if
   * the device is not in full screen mode.
   */
  public JFrame getFullScreenWindow() {
    return (JFrame) device.getFullScreenWindow();
  }
  /**
   * Returns the width of the window currently used in full screen mode.
   * Returns 0 if the device is not in full screen mode.
   */
  public int getWidth() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      return window.getWidth();
    } else {
      return 0;
    }
  }
  /**
   * Returns the height of the window currently used in full screen mode.
   * Returns 0 if the device is not in full screen mode.
   */
  public int getHeight() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      return window.getHeight();
    } else {
      return 0;
    }
  }
  /**
   * Restores the screen"s display mode.
   */
  public void restoreScreen() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      window.dispose();
    }
    device.setFullScreenWindow(null);
  }
  /**
   * Creates an image compatible with the current display.
   */
  public BufferedImage createCompatibleImage(int w, int h, int transparancy) {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      GraphicsConfiguration gc = window.getGraphicsConfiguration();
      return gc.createCompatibleImage(w, h, transparancy);
    }
    return null;
  }
}
/**
 * A thread pool is a group of a limited number of threads that are used to
 * execute tasks.
 */
class ThreadPool extends ThreadGroup {
  private boolean isAlive;
  private LinkedList taskQueue;
  private int threadID;
  private static int threadPoolID;
  /**
   * Creates a new ThreadPool.
   * 
   * @param numThreads
   *            The number of threads in the pool.
   */
  public ThreadPool(int numThreads) {
    super("ThreadPool-" + (threadPoolID++));
    setDaemon(true);
    isAlive = true;
    taskQueue = new LinkedList();
    for (int i = 0; i < numThreads; i++) {
      new PooledThread().start();
    }
  }
  /**
   * Requests a new task to run. This method returns immediately, and the task
   * executes on the next available idle thread in this ThreadPool.
   * <p>
   * Tasks start execution in the order they are received.
   * 
   * @param task
   *            The task to run. If null, no action is taken.
   * @throws IllegalStateException
   *             if this ThreadPool is already closed.
   */
  public synchronized void runTask(Runnable task) {
    if (!isAlive) {
      throw new IllegalStateException();
    }
    if (task != null) {
      taskQueue.add(task);
      notify();
    }
  }
  protected synchronized Runnable getTask() throws InterruptedException {
    while (taskQueue.size() == 0) {
      if (!isAlive) {
        return null;
      }
      wait();
    }
    return (Runnable) taskQueue.removeFirst();
  }
  /**
   * Closes this ThreadPool and returns immediately. All threads are stopped,
   * and any waiting tasks are not executed. Once a ThreadPool is closed, no
   * more tasks can be run on this ThreadPool.
   */
  public synchronized void close() {
    if (isAlive) {
      isAlive = false;
      taskQueue.clear();
      interrupt();
    }
  }
  /**
   * Closes this ThreadPool and waits for all running threads to finish. Any
   * waiting tasks are executed.
   */
  public void join() {
    // notify all waiting threads that this ThreadPool is no
    // longer alive
    synchronized (this) {
      isAlive = false;
      notifyAll();
    }
    // wait for all threads to finish
    Thread[] threads = new Thread[activeCount()];
    int count = enumerate(threads);
    for (int i = 0; i < count; i++) {
      try {
        threads[i].join();
      } catch (InterruptedException ex) {
      }
    }
  }
  /**
   * Signals that a PooledThread has started. This method does nothing by
   * default; subclasses should override to do any thread-specific startup
   * tasks.
   */
  protected void threadStarted() {
    // do nothing
  }
  /**
   * Signals that a PooledThread has stopped. This method does nothing by
   * default; subclasses should override to do any thread-specific cleanup
   * tasks.
   */
  protected void threadStopped() {
    // do nothing
  }
  /**
   * A PooledThread is a Thread in a ThreadPool group, designed to run tasks
   * (Runnables).
   */
  private class PooledThread extends Thread {
    public PooledThread() {
      super(ThreadPool.this, "PooledThread-" + (threadID++));
    }
    public void run() {
      // signal that this thread has started
      threadStarted();
      while (!isInterrupted()) {
        // get a task to run
        Runnable task = null;
        try {
          task = getTask();
        } catch (InterruptedException ex) {
        }
        // if getTask() returned null or was interrupted,
        // close this thread.
        if (task == null) {
          break;
        }
        // run the task, and eat any exceptions it throws
        try {
          task.run();
        } catch (Throwable t) {
          uncaughtException(this, t);
        }
      }
      // signal that this thread has stopped
      threadStopped();
    }
  }
}
/**
 * The SoundManager class manages sound playback. The SoundManager is a
 * ThreadPool, with each thread playing back one sound at a time. This allows
 * the SoundManager to easily limit the number of simultaneous sounds being
 * played.
 * <p>
 * Possible ideas to extend this class:
 * <ul>
 * <li>add a setMasterVolume() method, which uses Controls to set the volume
 * for each line.
 * <li>don"t play a sound if more than, say, 500ms has passed since the request
 * to play
 * </ul>
 */
class SoundManager extends ThreadPool {
  private AudioFormat playbackFormat;
  private ThreadLocal localLine;
  private ThreadLocal localBuffer;
  private Object pausedLock;
  private boolean paused;
  /**
   * Creates a new SoundManager using the maximum number of simultaneous
   * sounds.
   */
  public SoundManager(AudioFormat playbackFormat) {
    this(playbackFormat, getMaxSimultaneousSounds(playbackFormat));
  }
  /**
   * Creates a new SoundManager with the specified maximum number of
   * simultaneous sounds.
   */
  public SoundManager(AudioFormat playbackFormat, int maxSimultaneousSounds) {
    super(Math.min(maxSimultaneousSounds,
        getMaxSimultaneousSounds(playbackFormat)));
    this.playbackFormat = playbackFormat;
    localLine = new ThreadLocal();
    localBuffer = new ThreadLocal();
    pausedLock = new Object();
    // notify threads in pool it"s ok to start
    synchronized (this) {
      notifyAll();
    }
  }
  /**
   * Gets the maximum number of simultaneous sounds with the specified
   * AudioFormat that the default mixer can play.
   */
  public static int getMaxSimultaneousSounds(AudioFormat playbackFormat) {
    DataLine.Info lineInfo = new DataLine.Info(SourceDataLine.class,
        playbackFormat);
    Mixer mixer = AudioSystem.getMixer(null);
    return mixer.getMaxLines(lineInfo);
  }
  /**
   * Does any clean up before closing.
   */
  protected void cleanUp() {
    // signal to unpause
    setPaused(false);
    // close the mixer (stops any running sounds)
    Mixer mixer = AudioSystem.getMixer(null);
    if (mixer.isOpen()) {
      mixer.close();
    }
  }
  public void close() {
    cleanUp();
    super.close();
  }
  public void join() {
    cleanUp();
    super.join();
  }
  /**
   * Sets the paused state. Sounds may not pause immediately.
   */
  public void setPaused(boolean paused) {
    if (this.paused != paused) {
      synchronized (pausedLock) {
        this.paused = paused;
        if (!paused) {
          // restart sounds
          pausedLock.notifyAll();
        }
      }
    }
  }
  /**
   * Returns the paused state.
   */
  public boolean isPaused() {
    return paused;
  }
  /**
   * Loads a Sound from the file system. Returns null if an error occurs.
   */
  public Sound getSound(String filename) {
    return getSound(getAudioInputStream(filename));
  }
  /**
   * Loads a Sound from an input stream. Returns null if an error occurs.
   */
  public Sound getSound(InputStream is) {
    return getSound(getAudioInputStream(is));
  }
  /**
   * Loads a Sound from an AudioInputStream.
   */
  public Sound getSound(AudioInputStream audioStream) {
    if (audioStream == null) {
      return null;
    }
    // get the number of bytes to read
    int length = (int) (audioStream.getFrameLength() * audioStream
        .getFormat().getFrameSize());
    // read the entire stream
    byte[] samples = new byte[length];
    DataInputStream is = new DataInputStream(audioStream);
    try {
      is.readFully(samples);
      is.close();
    } catch (IOException ex) {
      ex.printStackTrace();
    }
    // return the samples
    return new Sound(samples);
  }
  /**
   * Creates an AudioInputStream from a sound from the file system.
   */
  public AudioInputStream getAudioInputStream(String filename) {
    try {
      return getAudioInputStream(new FileInputStream(filename));
    } catch (IOException ex) {
      ex.printStackTrace();
      return null;
    }
  }
  /**
   * Creates an AudioInputStream from a sound from an input stream
   */
  public AudioInputStream getAudioInputStream(InputStream is) {
    try {
      if (!is.markSupported()) {
        is = new BufferedInputStream(is);
      }
      // open the source stream
      AudioInputStream source = AudioSystem.getAudioInputStream(is);
      // convert to playback format
      return AudioSystem.getAudioInputStream(playbackFormat, source);
    } catch (UnsupportedAudioFileException ex) {
      ex.printStackTrace();
    } catch (IOException ex) {
      ex.printStackTrace();
    } catch (IllegalArgumentException ex) {
      ex.printStackTrace();
    }
    return null;
  }
  /**
   * Plays a sound. This method returns immediately.
   */
  public InputStream play(Sound sound) {
    return play(sound, null, false);
  }
  /**
   * Plays a sound with an optional SoundFilter, and optionally looping. This
   * method returns immediately.
   */
  public InputStream play(Sound sound, SoundFilter filter, boolean loop) {
    InputStream is;
    if (sound != null) {
      if (loop) {
        is = new LoopingByteInputStream(sound.getSamples());
      } else {
        is = new ByteArrayInputStream(sound.getSamples());
      }
      return play(is, filter);
    }
    return null;
  }
  /**
   * Plays a sound from an InputStream. This method returns immediately.
   */
  public InputStream play(InputStream is) {
    return play(is, null);
  }
  /**
   * Plays a sound from an InputStream with an optional sound filter. This
   * method returns immediately.
   */
  public InputStream play(InputStream is, SoundFilter filter) {
    if (is != null) {
      if (filter != null) {
        is = new FilteredSoundStream(is, filter);
      }
      runTask(new SoundPlayer(is));
    }
    return is;
  }
  /**
   * Signals that a PooledThread has started. Creates the Thread"s line and
   * buffer.
   */
  protected void threadStarted() {
    // wait for the SoundManager constructor to finish
    synchronized (this) {
      try {
        wait();
      } catch (InterruptedException ex) {
      }
    }
    // use a short, 100ms (1/10th sec) buffer for filters that
    // change in real-time
    int bufferSize = playbackFormat.getFrameSize()
        * Math.round(playbackFormat.getSampleRate() / 10);
    // create, open, and start the line
    SourceDataLine line;
    DataLine.Info lineInfo = new DataLine.Info(SourceDataLine.class,
        playbackFormat);
    try {
      line = (SourceDataLine) AudioSystem.getLine(lineInfo);
      line.open(playbackFormat, bufferSize);
    } catch (LineUnavailableException ex) {
      // the line is unavailable - signal to end this thread
      Thread.currentThread().interrupt();
      return;
    }
    line.start();
    // create the buffer
    byte[] buffer = new byte[bufferSize];
    // set this thread"s locals
    localLine.set(line);
    localBuffer.set(buffer);
  }
  /**
   * Signals that a PooledThread has stopped. Drains and closes the Thread"s
   * Line.
   */
  protected void threadStopped() {
    SourceDataLine line = (SourceDataLine) localLine.get();
    if (line != null) {
      line.drain();
      line.close();
    }
  }
  /**
   * The SoundPlayer class is a task for the PooledThreads to run. It receives
   * the threads"s Line and byte buffer from the ThreadLocal variables and
   * plays a sound from an InputStream.
   * <p>
   * This class only works when called from a PooledThread.
   */
  protected class SoundPlayer implements Runnable {
    private InputStream source;
    public SoundPlayer(InputStream source) {
      this.source = source;
    }
    public void run() {
      // get line and buffer from ThreadLocals
      SourceDataLine line = (SourceDataLine) localLine.get();
      byte[] buffer = (byte[]) localBuffer.get();
      if (line == null || buffer == null) {
        // the line is unavailable
        return;
      }
      // copy data to the line
      try {
        int numBytesRead = 0;
        while (numBytesRead != -1) {
          // if paused, wait until unpaused
          synchronized (pausedLock) {
            if (paused) {
              try {
                pausedLock.wait();
              } catch (InterruptedException ex) {
                return;
              }
            }
          }
          // copy data
          numBytesRead = source.read(buffer, 0, buffer.length);
          if (numBytesRead != -1) {
            line.write(buffer, 0, numBytesRead);
          }
        }
      } catch (IOException ex) {
        ex.printStackTrace();
      }
    }
  }
}
/**
 * The LoopingByteInputStream is a ByteArrayInputStream that loops indefinitly.
 * The looping stops when the close() method is called.
 * <p>
 * Possible ideas to extend this class:
 * <ul>
 * <li>Add an option to only loop a certain number of times.
 * </ul>
 */
class LoopingByteInputStream extends ByteArrayInputStream {
  private boolean closed;
  /**
   * Creates a new LoopingByteInputStream with the specified byte array. The
   * array is not copied.
   */
  public LoopingByteInputStream(byte[] buffer) {
    super(buffer);
    closed = false;
  }
  /**
   * Reads <code>length</code> bytes from the array. If the end of the array
   * is reached, the reading starts over from the beginning of the array.
   * Returns -1 if the array has been closed.
   */
  public int read(byte[] buffer, int offset, int length) {
    if (closed) {
      return -1;
    }
    int totalBytesRead = 0;
    while (totalBytesRead < length) {
      int numBytesRead = super.read(buffer, offset + totalBytesRead,
          length - totalBytesRead);
      if (numBytesRead > 0) {
        totalBytesRead += numBytesRead;
      } else {
        reset();
      }
    }
    return totalBytesRead;
  }
  /**
   * Closes the stream. Future calls to the read() methods will return 1.
   */
  public void close() throws IOException {
    super.close();
    closed = true;
  }
}
/**
 * A abstract class designed to filter sound samples. Since SoundFilters may use
 * internal buffering of samples, a new SoundFilter object should be created for
 * every sound played. However, SoundFilters can be reused after they are
 * finished by called the reset() method.
 * <p>
 * Assumes all samples are 16-bit, signed, little-endian format.
 * 
 * @see FilteredSoundStream
 */
abstract class SoundFilter {
  /**
   * Resets this SoundFilter. Does nothing by default.
   */
  public void reset() {
    // do nothing
  }
  /**
   * Gets the remaining size, in bytes, that this filter plays after the sound
   * is finished. An example would be an echo that plays longer than it"s
   * original sound. This method returns 0 by default.
   */
  public int getRemainingSize() {
    return 0;
  }
  /**
   * Filters an array of samples. Samples should be in 16-bit, signed,
   * little-endian format.
   */
  public void filter(byte[] samples) {
    filter(samples, 0, samples.length);
  }
  /**
   * Filters an array of samples. Samples should be in 16-bit, signed,
   * little-endian format. This method should be implemented by subclasses.
   */
  public abstract void filter(byte[] samples, int offset, int length);
  /**
   * Convenience method for getting a 16-bit sample from a byte array. Samples
   * should be in 16-bit, signed, little-endian format.
   */
  public static short getSample(byte[] buffer, int position) {
    return (short) (((buffer[position + 1] & 0xff) << 8) | (buffer[position] & 0xff));
  }
  /**
   * Convenience method for setting a 16-bit sample in a byte array. Samples
   * should be in 16-bit, signed, little-endian format.
   */
  public static void setSample(byte[] buffer, int position, short sample) {
    buffer[position] = (byte) (sample & 0xff);
    buffer[position + 1] = (byte) ((sample >> 8) & 0xff);
  }
}
/**
 * The FilteredSoundStream class is a FilterInputStream that applies a
 * SoundFilter to the underlying input stream.
 * 
 * @see SoundFilter
 */
class FilteredSoundStream extends FilterInputStream {
  private static final int REMAINING_SIZE_UNKNOWN = -1;
  private SoundFilter soundFilter;
  private int remainingSize;
  /**
   * Creates a new FilteredSoundStream object with the specified InputStream
   * and SoundFilter.
   */
  public FilteredSoundStream(InputStream in, SoundFilter soundFilter) {
    super(in);
    this.soundFilter = soundFilter;
    remainingSize = REMAINING_SIZE_UNKNOWN;
  }
  /**
   * Overrides the FilterInputStream method to apply this filter whenever
   * bytes are read
   */
  public int read(byte[] samples, int offset, int length) throws IOException {
    // read and filter the sound samples in the stream
    int bytesRead = super.read(samples, offset, length);
    if (bytesRead > 0) {
      soundFilter.filter(samples, offset, bytesRead);
      return bytesRead;
    }
    // if there are no remaining bytes in the sound stream,
    // check if the filter has any remaining bytes ("echoes").
    if (remainingSize == REMAINING_SIZE_UNKNOWN) {
      remainingSize = soundFilter.getRemainingSize();
      // round down to nearest multiple of 4
      // (typical frame size)
      remainingSize = remainingSize / 4 * 4;
    }
    if (remainingSize > 0) {
      length = Math.min(length, remainingSize);
      // clear the buffer
      for (int i = offset; i < offset + length; i++) {
        samples[i] = 0;
      }
      // filter the remaining bytes
      soundFilter.filter(samples, offset, length);
      remainingSize -= length;
      // return
      return length;
    } else {
      // end of stream
      return -1;
    }
  }
}
/**
 * The MoreMath class provides functions not contained in the java.lang.Math or
 * java.lang.StrictMath classes.
 */
class MoreMath {
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(short v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(int v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(long v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(float v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(double v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Faster ceil function to convert a float to an int. Contrary to the
   * java.lang.Math ceil function, this function takes a float as an argument,
   * returns an int instead of a double, and does not consider special cases.
   */
  public static int ceil(float f) {
    if (f > 0) {
      return (int) f + 1;
    } else {
      return (int) f;
    }
  }
  /**
   * Faster floor function to convert a float to an int. Contrary to the
   * java.lang.Math floor function, this function takes a float as an
   * argument, returns an int instead of a double, and does not consider
   * special cases.
   */
  public static int floor(float f) {
    if (f >= 0) {
      return (int) f;
    } else {
      return (int) f - 1;
    }
  }
  /**
   * Returns true if the specified number is a power of 2.
   */
  public static boolean isPowerOfTwo(int n) {
    return ((n & (n - 1)) == 0);
  }
  /**
   * Gets the number of "on" bits in an integer.
   */
  public static int getBitCount(int n) {
    int count = 0;
    while (n > 0) {
      count += (n & 1);
      n >>= 1;
    }
    return count;
  }
}
/**
 * The ScanConverter class converts a projected polygon into a series of
 * horizontal scans for drawing.
 */
class ScanConverter {
  private static final int SCALE_BITS = 16;
  private static final int SCALE = 1 << SCALE_BITS;
  private static final int SCALE_MASK = SCALE - 1;
  protected ViewWindow view;
  protected Scan[] scans;
  protected int top;
  protected int bottom;
  /**
   * A horizontal scan line.
   */
  public static class Scan {
    public int left;
    public int right;
    /**
     * Sets the left and right boundary for this scan if the x value is
     * outside the current boundary.
     */
    public void setBoundary(int x) {
      if (x < left) {
        left = x;
      }
      if (x - 1 > right) {
        right = x - 1;
      }
    }
    /**
     * Clears this scan line.
     */
    public void clear() {
      left = Integer.MAX_VALUE;
      right = Integer.MIN_VALUE;
    }
    /**
     * Determines if this scan is valid (if left <= right).
     */
    public boolean isValid() {
      return (left <= right);
    }
    /**
     * Sets this scan.
     */
    public void setTo(int left, int right) {
      this.left = left;
      this.right = right;
    }
    /**
     * Checks if this scan is equal to the specified values.
     */
    public boolean equals(int left, int right) {
      return (this.left == left && this.right == right);
    }
  }
  /**
   * Creates a new ScanConverter for the specified ViewWindow. The
   * ViewWindow"s properties can change in between scan conversions.
   */
  public ScanConverter(ViewWindow view) {
    this.view = view;
  }
  /**
   * Gets the top boundary of the last scan-converted polygon.
   */
  public int getTopBoundary() {
    return top;
  }
  /**
   * Gets the bottom boundary of the last scan-converted polygon.
   */
  public int getBottomBoundary() {
    return bottom;
  }
  /**
   * Gets the scan line for the specified y value.
   */
  public Scan getScan(int y) {
    return scans[y];
  }
  /**
   * Ensures this ScanConverter has the capacity to scan-convert a polygon to
   * the ViewWindow.
   */
  protected void ensureCapacity() {
    int height = view.getTopOffset() + view.getHeight();
    if (scans == null || scans.length != height) {
      scans = new Scan[height];
      for (int i = 0; i < height; i++) {
        scans[i] = new Scan();
      }
      // set top and bottom so clearCurrentScan clears all
      top = 0;
      bottom = height - 1;
    }
  }
  /**
   * Clears the current scan.
   */
  private void clearCurrentScan() {
    for (int i = top; i <= bottom; i++) {
      scans[i].clear();
    }
    top = Integer.MAX_VALUE;
    bottom = Integer.MIN_VALUE;
  }
  /**
   * Scan-converts a projected polygon. Returns true if the polygon is visible
   * in the view window.
   */
  public boolean convert(Polygon3D polygon) {
    ensureCapacity();
    clearCurrentScan();
    int minX = view.getLeftOffset();
    int maxX = view.getLeftOffset() + view.getWidth() - 1;
    int minY = view.getTopOffset();
    int maxY = view.getTopOffset() + view.getHeight() - 1;
    int numVertices = polygon.getNumVertices();
    for (int i = 0; i < numVertices; i++) {
      Vector3D v1 = polygon.getVertex(i);
      Vector3D v2;
      if (i == numVertices - 1) {
        v2 = polygon.getVertex(0);
      } else {
        v2 = polygon.getVertex(i + 1);
      }
      // ensure v1.y < v2.y
      if (v1.y > v2.y) {
        Vector3D temp = v1;
        v1 = v2;
        v2 = temp;
      }
      float dy = v2.y - v1.y;
      // ignore horizontal lines
      if (dy == 0) {
        continue;
      }
      int startY = Math.max(MoreMath.ceil(v1.y), minY);
      int endY = Math.min(MoreMath.ceil(v2.y) - 1, maxY);
      top = Math.min(top, startY);
      bottom = Math.max(bottom, endY);
      float dx = v2.x - v1.x;
      // special case: vertical line
      if (dx == 0) {
        int x = MoreMath.ceil(v1.x);
        // ensure x within view bounds
        x = Math.min(maxX + 1, Math.max(x, minX));
        for (int y = startY; y <= endY; y++) {
          scans[y].setBoundary(x);
        }
      } else {
        // scan-convert this edge (line equation)
        float gradient = dx / dy;
        // (slower version)
        /*
         * for (int y=startY; y <=endY; y++) { int x =
         * MoreMath.ceil(v1.x + (y - v1.y) * gradient); // ensure x
         * within view bounds x = Math.min(maxX+1, Math.max(x, minX));
         * scans[y].setBoundary(x); }
         */
        // (faster version)
        // trim start of line
        float startX = v1.x + (startY - v1.y) * gradient;
        if (startX < minX) {
          int yInt = (int) (v1.y + (minX - v1.x) / gradient);
          yInt = Math.min(yInt, endY);
          while (startY <= yInt) {
            scans[startY].setBoundary(minX);
            startY++;
          }
        } else if (startX > maxX) {
          int yInt = (int) (v1.y + (maxX - v1.x) / gradient);
          yInt = Math.min(yInt, endY);
          while (startY <= yInt) {
            scans[startY].setBoundary(maxX + 1);
            startY++;
          }
        }
        if (startY > endY) {
          continue;
        }
        // trim back of line
        float endX = v1.x + (endY - v1.y) * gradient;
        if (endX < minX) {
          int yInt = MoreMath.ceil(v1.y + (minX - v1.x) / gradient);
          yInt = Math.max(yInt, startY);
          while (endY >= yInt) {
            scans[endY].setBoundary(minX);
            endY--;
          }
        } else if (endX > maxX) {
          int yInt = MoreMath.ceil(v1.y + (maxX - v1.x) / gradient);
          yInt = Math.max(yInt, startY);
          while (endY >= yInt) {
            scans[endY].setBoundary(maxX + 1);
            endY--;
          }
        }
        if (startY > endY) {
          continue;
        }
        // line equation using integers
        int xScaled = (int) (SCALE * v1.x + SCALE * (startY - v1.y)
            * dx / dy)
            + SCALE_MASK;
        int dxScaled = (int) (dx * SCALE / dy);
        for (int y = startY; y <= endY; y++) {
          scans[y].setBoundary(xScaled >> SCALE_BITS);
          xScaled += dxScaled;
        }
      }
    }
    // check if visible (any valid scans)
    for (int i = top; i <= bottom; i++) {
      if (scans[i].isValid()) {
        return true;
      }
    }
    return false;
  }
}
/**
 * The PolygonRenderer class is an abstract class that transforms and draws
 * polygons onto the screen.
 */
abstract class PolygonRenderer {
  protected ScanConverter scanConverter;
  protected Transform3D camera;
  protected ViewWindow viewWindow;
  protected boolean clearViewEveryFrame;
  protected Polygon3D sourcePolygon;
  protected Polygon3D destPolygon;
  /**
   * Creates a new PolygonRenderer with the specified Transform3D (camera) and
   * ViewWindow. The view is cleared when startFrame() is called.
   */
  public PolygonRenderer(Transform3D camera, ViewWindow viewWindow) {
    this(camera, viewWindow, true);
  }
  /**
   * Creates a new PolygonRenderer with the specified Transform3D (camera) and
   * ViewWindow. If clearViewEveryFrame is true, the view is cleared when
   * startFrame() is called.
   */
  public PolygonRenderer(Transform3D camera, ViewWindow viewWindow,
      boolean clearViewEveryFrame) {
    this.camera = camera;
    this.viewWindow = viewWindow;
    this.clearViewEveryFrame = clearViewEveryFrame;
    init();
  }
  /**
   * Create the scan converter and dest polygon.
   */
  protected void init() {
    destPolygon = new Polygon3D();
    scanConverter = new ScanConverter(viewWindow);
  }
  /**
   * Gets the camera used for this PolygonRenderer.
   */
  public Transform3D getCamera() {
    return camera;
  }
  /**
   * Indicates the start of rendering of a frame. This method should be called
   * every frame before any polygons are drawn.
   */
  public void startFrame(Graphics2D g) {
    if (clearViewEveryFrame) {
      g.setColor(Color.black);
      g.fillRect(viewWindow.getLeftOffset(), viewWindow.getTopOffset(),
          viewWindow.getWidth(), viewWindow.getHeight());
    }
  }
  /**
   * Indicates the end of rendering of a frame. This method should be called
   * every frame after all polygons are drawn.
   */
  public void endFrame(Graphics2D g) {
    // do nothing, for now.
  }
  /**
   * Transforms and draws a polygon.
   */
  public boolean draw(Graphics2D g, Polygon3D poly) {
    if (poly.isFacing(camera.getLocation())) {
      sourcePolygon = poly;
      destPolygon.setTo(poly);
      destPolygon.subtract(camera);
      boolean visible = destPolygon.clip(-1);
      if (visible) {
        destPolygon.project(viewWindow);
        visible = scanConverter.convert(destPolygon);
        if (visible) {
          drawCurrentPolygon(g);
          return true;
        }
      }
    }
    return false;
  }
  /**
   * Draws the current polygon. At this point, the current polygon is
   * transformed, clipped, projected, scan-converted, and visible.
   */
  protected abstract void drawCurrentPolygon(Graphics2D g);
}
/**
 * The Sound class is a container for sound samples. The sound samples are
 * format-agnostic and are stored as a byte array.
 */
class Sound {
  private byte[] samples;
  /**
   * Create a new Sound object with the specified byte array. The array is not
   * copied.
   */
  public Sound(byte[] samples) {
    this.samples = samples;
  }
  /**
   * Returns this Sound"s objects samples as a byte array.
   */
  public byte[] getSamples() {
    return samples;
  }
}
/**
 * The InputManager manages input of key and mouse events. Events are mapped to
 * GameActions.
 */
class InputManager implements KeyListener, MouseListener, MouseMotionListener,
    MouseWheelListener {
  /**
   * An invisible cursor.
   */
  public static final Cursor INVISIBLE_CURSOR = Toolkit.getDefaultToolkit()
      .createCustomCursor(Toolkit.getDefaultToolkit().getImage(""),
          new Point(0, 0), "invisible");
  // mouse codes
  public static final int MOUSE_MOVE_LEFT = 0;
  public static final int MOUSE_MOVE_RIGHT = 1;
  public static final int MOUSE_MOVE_UP = 2;
  public static final int MOUSE_MOVE_DOWN = 3;
  public static final int MOUSE_WHEEL_UP = 4;
  public static final int MOUSE_WHEEL_DOWN = 5;
  public static final int MOUSE_BUTTON_1 = 6;
  public static final int MOUSE_BUTTON_2 = 7;
  public static final int MOUSE_BUTTON_3 = 8;
  private static final int NUM_MOUSE_CODES = 9;
  // key codes are defined in java.awt.KeyEvent.
  // most of the codes (except for some rare ones like
  // "alt graph") are less than 600.
  private static final int NUM_KEY_CODES = 600;
  private GameAction[] keyActions = new GameAction[NUM_KEY_CODES];
  private GameAction[] mouseActions = new GameAction[NUM_MOUSE_CODES];
  private Point mouseLocation;
  private Point centerLocation;
  private Component comp;
  private Robot robot;
  private boolean isRecentering;
  /**
   * Creates a new InputManager that listens to input from the specified
   * component.
   */
  public InputManager(Component comp) {
    this.rup = comp;
    mouseLocation = new Point();
    centerLocation = new Point();
    // register key and mouse listeners
    comp.addKeyListener(this);
    comp.addMouseListener(this);
    comp.addMouseMotionListener(this);
    comp.addMouseWheelListener(this);
    // allow input of the TAB key and other keys normally
    // used for focus traversal
    comp.setFocusTraversalKeysEnabled(false);
  }
  /**
   * Sets the cursor on this InputManager"s input component.
   */
  public void setCursor(Cursor cursor) {
    comp.setCursor(cursor);
  }
  /**
   * Sets whether realtive mouse mode is on or not. For relative mouse mode,
   * the mouse is "locked" in the center of the screen, and only the changed
   * in mouse movement is measured. In normal mode, the mouse is free to move
   * about the screen.
   */
  public void setRelativeMouseMode(boolean mode) {
    if (mode == isRelativeMouseMode()) {
      return;
    }
    if (mode) {
      try {
        robot = new Robot();
        mouseLocation.x = comp.getWidth() / 2;
        mouseLocation.y = comp.getHeight() / 2;
        recenterMouse();
      } catch (AWTException ex) {
        // couldn"t create robot!
        robot = null;
      }
    } else {
      robot = null;
    }
  }
  /**
   * Returns whether or not relative mouse mode is on.
   */
  public boolean isRelativeMouseMode() {
    return (robot != null);
  }
  /**
   * Maps a GameAction to a specific key. The key codes are defined in
   * java.awt.KeyEvent. If the key already has a GameAction mapped to it, the
   * new GameAction overwrites it.
   */
  public void mapToKey(GameAction gameAction, int keyCode) {
    keyActions[keyCode] = gameAction;
  }
  /**
   * Maps a GameAction to a specific mouse action. The mouse codes are defined
   * herer in InputManager (MOUSE_MOVE_LEFT, MOUSE_BUTTON_1, etc). If the
   * mouse action already has a GameAction mapped to it, the new GameAction
   * overwrites it.
   */
  public void mapToMouse(GameAction gameAction, int mouseCode) {
    mouseActions[mouseCode] = gameAction;
  }
  /**
   * Clears all mapped keys and mouse actions to this GameAction.
   */
  public void clearMap(GameAction gameAction) {
    for (int i = 0; i < keyActions.length; i++) {
      if (keyActions[i] == gameAction) {
        keyActions[i] = null;
      }
    }
    for (int i = 0; i < mouseActions.length; i++) {
      if (mouseActions[i] == gameAction) {
        mouseActions[i] = null;
      }
    }
    gameAction.reset();
  }
  /**
   * Gets a List of names of the keys and mouse actions mapped to this
   * GameAction. Each entry in the List is a String.
   */
  public List getMaps(GameAction gameCode) {
    ArrayList list = new ArrayList();
    for (int i = 0; i < keyActions.length; i++) {
      if (keyActions[i] == gameCode) {
        list.add(getKeyName(i));
      }
    }
    for (int i = 0; i < mouseActions.length; i++) {
      if (mouseActions[i] == gameCode) {
        list.add(getMouseName(i));
      }
    }
    return list;
  }
  /**
   * Resets all GameActions so they appear like they haven"t been pressed.
   */
  public void resetAllGameActions() {
    for (int i = 0; i < keyActions.length; i++) {
      if (keyActions[i] != null) {
        keyActions[i].reset();
      }
    }
    for (int i = 0; i < mouseActions.length; i++) {
      if (mouseActions[i] != null) {
        mouseActions[i].reset();
      }
    }
  }
  /**
   * Gets the name of a key code.
   */
  public static String getKeyName(int keyCode) {
    return KeyEvent.getKeyText(keyCode);
  }
  /**
   * Gets the name of a mouse code.
   */
  public static String getMouseName(int mouseCode) {
    switch (mouseCode) {
    case MOUSE_MOVE_LEFT:
      return "Mouse Left";
    case MOUSE_MOVE_RIGHT:
      return "Mouse Right";
    case MOUSE_MOVE_UP:
      return "Mouse Up";
    case MOUSE_MOVE_DOWN:
      return "Mouse Down";
    case MOUSE_WHEEL_UP:
      return "Mouse Wheel Up";
    case MOUSE_WHEEL_DOWN:
      return "Mouse Wheel Down";
    case MOUSE_BUTTON_1:
      return "Mouse Button 1";
    case MOUSE_BUTTON_2:
      return "Mouse Button 2";
    case MOUSE_BUTTON_3:
      return "Mouse Button 3";
    default:
      return "Unknown mouse code " + mouseCode;
    }
  }
  /**
   * Gets the x position of the mouse.
   */
  public int getMouseX() {
    return mouseLocation.x;
  }
  /**
   * Gets the y position of the mouse.
   */
  public int getMouseY() {
    return mouseLocation.y;
  }
  /**
   * Uses the Robot class to try to postion the mouse in the center of the
   * screen.
   * <p>
   * Note that use of the Robot class may not be available on all platforms.
   */
  private synchronized void recenterMouse() {
    if (robot != null && comp.isShowing()) {
      centerLocation.x = comp.getWidth() / 2;
      centerLocation.y = comp.getHeight() / 2;
      SwingUtilities.convertPointToScreen(centerLocation, comp);
      isRecentering = true;
      robot.mouseMove(centerLocation.x, centerLocation.y);
    }
  }
  private GameAction getKeyAction(KeyEvent e) {
    int keyCode = e.getKeyCode();
    if (keyCode < keyActions.length) {
      return keyActions[keyCode];
    } else {
      return null;
    }
  }
  /**
   * Gets the mouse code for the button specified in this MouseEvent.
   */
  public static int getMouseButtonCode(MouseEvent e) {
    switch (e.getButton()) {
    case MouseEvent.BUTTON1:
      return MOUSE_BUTTON_1;
    case MouseEvent.BUTTON2:
      return MOUSE_BUTTON_2;
    case MouseEvent.BUTTON3:
      return MOUSE_BUTTON_3;
    default:
      return -1;
    }
  }
  private GameAction getMouseButtonAction(MouseEvent e) {
    int mouseCode = getMouseButtonCode(e);
    if (mouseCode != -1) {
      return mouseActions[mouseCode];
    } else {
      return null;
    }
  }
  // from the KeyListener interface
  public void keyPressed(KeyEvent e) {
    GameAction gameAction = getKeyAction(e);
    if (gameAction != null) {
      gameAction.press();
    }
    // make sure the key isn"t processed for anything else
    e.consume();
  }
  // from the KeyListener interface
  public void keyReleased(KeyEvent e) {
    GameAction gameAction = getKeyAction(e);
    if (gameAction != null) {
      gameAction.release();
    }
    // make sure the key isn"t processed for anything else
    e.consume();
  }
  // from the KeyListener interface
  public void keyTyped(KeyEvent e) {
    // make sure the key isn"t processed for anything else
    e.consume();
  }
  // from the MouseListener interface
  public void mousePressed(MouseEvent e) {
    GameAction gameAction = getMouseButtonAction(e);
    if (gameAction != null) {
      gameAction.press();
    }
  }
  // from the MouseListener interface
  public void mouseReleased(MouseEvent e) {
    GameAction gameAction = getMouseButtonAction(e);
    if (gameAction != null) {
      gameAction.release();
    }
  }
  // from the MouseListener interface
  public void mouseClicked(MouseEvent e) {
    // do nothing
  }
  // from the MouseListener interface
  public void mouseEntered(MouseEvent e) {
    mouseMoved(e);
  }
  // from the MouseListener interface
  public void mouseExited(MouseEvent e) {
    mouseMoved(e);
  }
  // from the MouseMotionListener interface
  public void mouseDragged(MouseEvent e) {
    mouseMoved(e);
  }
  // from the MouseMotionListener interface
  public synchronized void mouseMoved(MouseEvent e) {
    // this event is from re-centering the mouse - ignore it
    if (isRecentering && centerLocation.x == e.getX()
        && centerLocation.y == e.getY()) {
      isRecentering = false;
    } else {
      int dx = e.getX() - mouseLocation.x;
      int dy = e.getY() - mouseLocation.y;
      mouseHelper(MOUSE_MOVE_LEFT, MOUSE_MOVE_RIGHT, dx);
      mouseHelper(MOUSE_MOVE_UP, MOUSE_MOVE_DOWN, dy);
      if (isRelativeMouseMode()) {
        recenterMouse();
      }
    }
    mouseLocation.x = e.getX();
    mouseLocation.y = e.getY();
  }
  // from the MouseWheelListener interface
  public void mouseWheelMoved(MouseWheelEvent e) {
    mouseHelper(MOUSE_WHEEL_UP, MOUSE_WHEEL_DOWN, e.getWheelRotation());
  }
  private void mouseHelper(int codeNeg, int codePos, int amount) {
    GameAction gameAction;
    if (amount < 0) {
      gameAction = mouseActions[codeNeg];
    } else {
      gameAction = mouseActions[codePos];
    }
    if (gameAction != null) {
      gameAction.press(Math.abs(amount));
      gameAction.release();
    }
  }
}
/**
 * The GameAction class is an abstract to a user-initiated action, like jumping
 * or moving. GameActions can be mapped to keys or the mouse with the
 * InputManager.
 */
class GameAction {
  /**
   * Normal behavior. The isPressed() method returns true as long as the key
   * is held down.
   */
  public static final int NORMAL = 0;
  /**
   * Initial press behavior. The isPressed() method returns true only after
   * the key is first pressed, and not again until the key is released and
   * pressed again.
   */
  public static final int DETECT_INITAL_PRESS_ONLY = 1;
  private static final int STATE_RELEASED = 0;
  private static final int STATE_PRESSED = 1;
  private static final int STATE_WAITING_FOR_RELEASE = 2;
  private String name;
  private int behavior;
  private int amount;
  private int state;
  /**
   * Create a new GameAction with the NORMAL behavior.
   */
  public GameAction(String name) {
    this(name, NORMAL);
  }
  /**
   * Create a new GameAction with the specified behavior.
   */
  public GameAction(String name, int behavior) {
    this.name = name;
    this.behavior = behavior;
    reset();
  }
  /**
   * Gets the name of this GameAction.
   */
  public String getName() {
    return name;
  }
  /**
   * Resets this GameAction so that it appears like it hasn"t been pressed.
   */
  public void reset() {
    state = STATE_RELEASED;
    amount = 0;
  }
  /**
   * Taps this GameAction. Same as calling press() followed by release().
   */
  public synchronized void tap() {
    press();
    release();
  }
  /**
   * Signals that the key was pressed.
   */
  public synchronized void press() {
    press(1);
  }
  /**
   * Signals that the key was pressed a specified number of times, or that the
   * mouse move a spcified distance.
   */
  public synchronized void press(int amount) {
    if (state != STATE_WAITING_FOR_RELEASE) {
      this.amount += amount;
      state = STATE_PRESSED;
    }
  }
  /**
   * Signals that the key was released
   */
  public synchronized void release() {
    state = STATE_RELEASED;
  }
  /**
   * Returns whether the key was pressed or not since last checked.
   */
  public synchronized boolean isPressed() {
    return (getAmount() != 0);
  }
  /**
   * For keys, this is the number of times the key was pressed since it was
   * last checked. For mouse movement, this is the distance moved.
   */
  public synchronized int getAmount() {
    int retVal = amount;
    if (retVal != 0) {
      if (state == STATE_RELEASED) {
        amount = 0;
      } else if (behavior == DETECT_INITAL_PRESS_ONLY) {
        state = STATE_WAITING_FOR_RELEASE;
        amount = 0;
      }
    }
    return retVal;
  }
}
/**
 * The SolidPolygonRenderer class transforms and draws solid-colored polygons
 * onto the screen.
 */
class SolidPolygonRenderer extends PolygonRenderer {
  public SolidPolygonRenderer(Transform3D camera, ViewWindow viewWindow) {
    this(camera, viewWindow, true);
  }
  public SolidPolygonRenderer(Transform3D camera, ViewWindow viewWindow,
      boolean clearViewEveryFrame) {
    super(camera, viewWindow, clearViewEveryFrame);
  }
  /**
   * Draws the current polygon. At this point, the current polygon is
   * transformed, clipped, projected, scan-converted, and visible.
   */
  protected void drawCurrentPolygon(Graphics2D g) {
    // set the color
    if (sourcePolygon instanceof SolidPolygon3D) {
      g.setColor(((SolidPolygon3D) sourcePolygon).getColor());
    } else {
      g.setColor(Color.GREEN);
    }
    // draw the scans
    int y = scanConverter.getTopBoundary();
    while (y <= scanConverter.getBottomBoundary()) {
      ScanConverter.Scan scan = scanConverter.getScan(y);
      if (scan.isValid()) {
        g.drawLine(scan.left, y, scan.right, y);
      }
      y++;
    }
  }
}
/**
 * The SolidPolygon3D class is a Polygon with a color.
 */
class SolidPolygon3D extends Polygon3D {
  private Color color = Color.GREEN;
  public SolidPolygon3D() {
    super();
  }
  public SolidPolygon3D(Vector3D v0, Vector3D v1, Vector3D v2) {
    this(new Vector3D[] { v0, v1, v2 });
  }
  public SolidPolygon3D(Vector3D v0, Vector3D v1, Vector3D v2, Vector3D v3) {
    this(new Vector3D[] { v0, v1, v2, v3 });
  }
  public SolidPolygon3D(Vector3D[] vertices) {
    super(vertices);
  }
  public void setTo(Polygon3D polygon) {
    super.setTo(polygon);
    if (polygon instanceof SolidPolygon3D) {
      color = ((SolidPolygon3D) polygon).color;
    }
  }
  /**
   * Gets the color of this solid-colored polygon used for rendering this
   * polygon.
   */
  public Color getColor() {
    return color;
  }
  /**
   * Sets the color of this solid-colored polygon used for rendering this
   * polygon.
   */
  public void setColor(Color color) {
    this.color = color;
  }
}
abstract class GameCore3D extends GameCore {
  protected PolygonRenderer polygonRenderer;
  protected ViewWindow viewWindow;
  protected List polygons;
  private boolean drawFrameRate = false;
  private boolean drawInstructions = true;
  // for calculating frame rate
  private int numFrames;
  private long startTime;
  private float frameRate;
  protected InputManager inputManager;
  private GameAction exit = new GameAction("exit");
  private GameAction smallerView = new GameAction("smallerView",
      GameAction.DETECT_INITAL_PRESS_ONLY);
  private GameAction largerView = new GameAction("largerView",
      GameAction.DETECT_INITAL_PRESS_ONLY);
  private GameAction frameRateToggle = new GameAction("frameRateToggle",
      GameAction.DETECT_INITAL_PRESS_ONLY);
  protected GameAction goForward = new GameAction("goForward");
  protected GameAction goBackward = new GameAction("goBackward");
  protected GameAction goUp = new GameAction("goUp");
  protected GameAction goDown = new GameAction("goDown");
  protected GameAction goLeft = new GameAction("goLeft");
  protected GameAction goRight = new GameAction("goRight");
  protected GameAction turnLeft = new GameAction("turnLeft");
  protected GameAction turnRight = new GameAction("turnRight");
  protected GameAction tiltUp = new GameAction("tiltUp");
  protected GameAction tiltDown = new GameAction("tiltDown");
  protected GameAction tiltLeft = new GameAction("tiltLeft");
  protected GameAction tiltRight = new GameAction("tiltRight");
  public void init(DisplayMode[] modes) {
    super.init(modes);
    inputManager = new InputManager(screen.getFullScreenWindow());
    inputManager.setRelativeMouseMode(true);
    inputManager.setCursor(InputManager.INVISIBLE_CURSOR);
    inputManager.mapToKey(exit, KeyEvent.VK_ESCAPE);
    inputManager.mapToKey(goForward, KeyEvent.VK_W);
    inputManager.mapToKey(goForward, KeyEvent.VK_UP);
    inputManager.mapToKey(goBackward, KeyEvent.VK_S);
    inputManager.mapToKey(goBackward, KeyEvent.VK_DOWN);
    inputManager.mapToKey(goLeft, KeyEvent.VK_A);
    inputManager.mapToKey(goLeft, KeyEvent.VK_LEFT);
    inputManager.mapToKey(goRight, KeyEvent.VK_D);
    inputManager.mapToKey(goRight, KeyEvent.VK_RIGHT);
    inputManager.mapToKey(goUp, KeyEvent.VK_PAGE_UP);
    inputManager.mapToKey(goDown, KeyEvent.VK_PAGE_DOWN);
    inputManager.mapToMouse(turnLeft, InputManager.MOUSE_MOVE_LEFT);
    inputManager.mapToMouse(turnRight, InputManager.MOUSE_MOVE_RIGHT);
    inputManager.mapToMouse(tiltUp, InputManager.MOUSE_MOVE_UP);
    inputManager.mapToMouse(tiltDown, InputManager.MOUSE_MOVE_DOWN);
    inputManager.mapToKey(tiltLeft, KeyEvent.VK_INSERT);
    inputManager.mapToKey(tiltRight, KeyEvent.VK_DELETE);
    inputManager.mapToKey(smallerView, KeyEvent.VK_SUBTRACT);
    inputManager.mapToKey(smallerView, KeyEvent.VK_MINUS);
    inputManager.mapToKey(largerView, KeyEvent.VK_ADD);
    inputManager.mapToKey(largerView, KeyEvent.VK_PLUS);
    inputManager.mapToKey(largerView, KeyEvent.VK_EQUALS);
    inputManager.mapToKey(frameRateToggle, KeyEvent.VK_R);
    // create the polygon renderer
    createPolygonRenderer();
    // create polygons
    polygons = new ArrayList();
    createPolygons();
  }
  public abstract void createPolygons();
  public void createPolygonRenderer() {
    // make the view window the entire screen
    viewWindow = new ViewWindow(0, 0, screen.getWidth(),
        screen.getHeight(), (float) Math.toRadians(75));
    Transform3D camera = new Transform3D(0, 100, 0);
    polygonRenderer = new SolidPolygonRenderer(camera, viewWindow);
  }
  /**
   * Sets the view bounds, centering the view on the screen.
   */
  public void setViewBounds(int width, int height) {
    width = Math.min(width, screen.getWidth());
    height = Math.min(height, screen.getHeight());
    width = Math.max(64, width);
    height = Math.max(48, height);
    viewWindow.setBounds((screen.getWidth() - width) / 2, (screen
        .getHeight() - height) / 2, width, height);
    // clear the screen if view size changed
    // (clear both buffers)
    for (int i = 0; i < 2; i++) {
      Graphics2D g = screen.getGraphics();
      g.setColor(Color.BLACK);
      g.fillRect(0, 0, screen.getWidth(), screen.getHeight());
      screen.update();
    }
  }
  public void update(long elapsedTime) {
    // check options
    if (exit.isPressed()) {
      stop();
      return;
    }
    if (largerView.isPressed()) {
      setViewBounds(viewWindow.getWidth() + 64,
          viewWindow.getHeight() + 48);
    } else if (smallerView.isPressed()) {
      setViewBounds(viewWindow.getWidth() - 64,
          viewWindow.getHeight() - 48);
    }
    if (frameRateToggle.isPressed()) {
      drawFrameRate = !drawFrameRate;
    }
    updateWorld(elapsedTime);
  }
  public void updateWorld(long elapsedTime) {
    // cap elapsedTime
    elapsedTime = Math.min(elapsedTime, 100);
    float angleChange = 0.0002f * elapsedTime;
    float distanceChange = .5f * elapsedTime;
    Transform3D camera = polygonRenderer.getCamera();
    Vector3D cameraLoc = camera.getLocation();
    // apply movement
    if (goForward.isPressed()) {
      cameraLoc.x -= distanceChange * camera.getSinAngleY();
      cameraLoc.z -= distanceChange * camera.getCosAngleY();
    }
    if (goBackward.isPressed()) {
      cameraLoc.x += distanceChange * camera.getSinAngleY();
      cameraLoc.z += distanceChange * camera.getCosAngleY();
    }
    if (goLeft.isPressed()) {
      cameraLoc.x -= distanceChange * camera.getCosAngleY();
      cameraLoc.z += distanceChange * camera.getSinAngleY();
    }
    if (goRight.isPressed()) {
      cameraLoc.x += distanceChange * camera.getCosAngleY();
      cameraLoc.z -= distanceChange * camera.getSinAngleY();
    }
    if (goUp.isPressed()) {
      cameraLoc.y += distanceChange;
    }
    if (goDown.isPressed()) {
      cameraLoc.y -= distanceChange;
    }
    // look up/down (rotate around x)
    int tilt = tiltUp.getAmount() - tiltDown.getAmount();
    tilt = Math.min(tilt, 200);
    tilt = Math.max(tilt, -200);
    // limit how far you can look up/down
    float newAngleX = camera.getAngleX() + tilt * angleChange;
    newAngleX = Math.max(newAngleX, (float) -Math.PI / 2);
    newAngleX = Math.min(newAngleX, (float) Math.PI / 2);
    camera.setAngleX(newAngleX);
    // turn (rotate around y)
    int turn = turnLeft.getAmount() - turnRight.getAmount();
    turn = Math.min(turn, 200);
    turn = Math.max(turn, -200);
    camera.rotateAngleY(turn * angleChange);
    // tilet head left/right (rotate around z)
    if (tiltLeft.isPressed()) {
      camera.rotateAngleZ(10 * angleChange);
    }
    if (tiltRight.isPressed()) {
      camera.rotateAngleZ(-10 * angleChange);
    }
  }
  public void draw(Graphics2D g) {
    int viewX1 = viewWindow.getLeftOffset();
    int viewY1 = viewWindow.getTopOffset();
    int viewX2 = viewX1 + viewWindow.getWidth();
    int viewY2 = viewY1 + viewWindow.getHeight();
    if (viewX1 != 0 || viewY1 != 0) {
      g.setColor(Color.BLACK);
      g.fillRect(0, 0, viewX1, screen.getHeight());
      g.fillRect(viewX2, 0, screen.getWidth() - viewX2, screen
          .getHeight());
      g.fillRect(viewX1, 0, viewWindow.getWidth(), viewY1);
      g.fillRect(viewX1, viewY2, viewWindow.getWidth(), screen
          .getHeight()
          - viewY2);
    }
    drawPolygons(g);
    drawText(g);
  }
  public void drawPolygons(Graphics2D g) {
    polygonRenderer.startFrame(g);
    for (int i = 0; i < polygons.size(); i++) {
      polygonRenderer.draw(g, (Polygon3D) polygons.get(i));
    }
    polygonRenderer.endFrame(g);
  }
  public void drawText(Graphics2D g) {
    g.setColor(Color.WHITE);
    // draw text
    if (drawInstructions) {
      g.drawString("Use the mouse/arrow keys to move. "
          + "Press Esc to exit.", 5, fontSize);
    }
    // (you may have to turn off the BufferStrategy in
    // ScreenManager for more accurate tests)
    if (drawFrameRate) {
      calcFrameRate();
      g.drawString(frameRate + " frames/sec", 5, screen.getHeight() - 5);
    }
  }
  public void calcFrameRate() {
    numFrames++;
    long currTime = System.currentTimeMillis();
    // calculate the frame rate every 500 milliseconds
    if (currTime > startTime + 500) {
      frameRate = (float) numFrames * 1000 / (currTime - startTime);
      startTime = currTime;
      numFrames = 0;
    }
  }
}
interface Transformable {
  public void add(Vector3D u);
  public void subtract(Vector3D u);
  public void add(Transform3D xform);
  public void subtract(Transform3D xform);
  public void addRotation(Transform3D xform);
  public void subtractRotation(Transform3D xform);
}
/**
 * The Polygon3D class represents a polygon as a series of vertices.
 */
class Polygon3D implements Transformable {
  // temporary vectors used for calculation
  private static Vector3D temp1 = new Vector3D();
  private static Vector3D temp2 = new Vector3D();
  private Vector3D[] v;
  private int numVertices;
  private Vector3D normal;
  /**
   * Creates an empty polygon that can be used as a "scratch" polygon for
   * transforms, projections, etc.
   */
  public Polygon3D() {
    numVertices = 0;
    v = new Vector3D[0];
    normal = new Vector3D();
  }
  /**
   * Creates a new Polygon3D with the specified vertices.
   */
  public Polygon3D(Vector3D v0, Vector3D v1, Vector3D v2) {
    this(new Vector3D[] { v0, v1, v2 });
  }
  /**
   * Creates a new Polygon3D with the specified vertices. All the vertices are
   * assumed to be in the same plane.
   */
  public Polygon3D(Vector3D v0, Vector3D v1, Vector3D v2, Vector3D v3) {
    this(new Vector3D[] { v0, v1, v2, v3 });
  }
  /**
   * Creates a new Polygon3D with the specified vertices. All the vertices are
   * assumed to be in the same plane.
   */
  public Polygon3D(Vector3D[] vertices) {
    this.v = vertices;
    numVertices = vertices.length;
    calcNormal();
  }
  /**
   * Sets this polygon to the same vertices as the specfied polygon.
   */
  public void setTo(Polygon3D polygon) {
    numVertices = polygon.numVertices;
    normal.setTo(polygon.normal);
    ensureCapacity(numVertices);
    for (int i = 0; i < numVertices; i++) {
      v[i].setTo(polygon.v[i]);
    }
  }
  /**
   * Ensures this polgon has enough capacity to hold the specified number of
   * vertices.
   */
  protected void ensureCapacity(int length) {
    if (v.length < length) {
      Vector3D[] newV = new Vector3D[length];
      System.arraycopy(v, 0, newV, 0, v.length);
      for (int i = v.length; i < newV.length; i++) {
        newV[i] = new Vector3D();
      }
      v = newV;
    }
  }
  /**
   * Gets the number of vertices this polygon has.
   */
  public int getNumVertices() {
    return numVertices;
  }
  /**
   * Gets the vertex at the specified index.
   */
  public Vector3D getVertex(int index) {
    return v[index];
  }
  /**
   * Projects this polygon onto the view window.
   */
  public void project(ViewWindow view) {
    for (int i = 0; i < numVertices; i++) {
      view.project(v[i]);
    }
  }
  // methods from the Transformable interface.
  public void add(Vector3D u) {
    for (int i = 0; i < numVertices; i++) {
      v[i].add(u);
    }
  }
  public void subtract(Vector3D u) {
    for (int i = 0; i < numVertices; i++) {
      v[i].subtract(u);
    }
  }
  public void add(Transform3D xform) {
    addRotation(xform);
    add(xform.getLocation());
  }
  public void subtract(Transform3D xform) {
    subtract(xform.getLocation());
    subtractRotation(xform);
  }
  public void addRotation(Transform3D xform) {
    for (int i = 0; i < numVertices; i++) {
      v[i].addRotation(xform);
    }
    normal.addRotation(xform);
  }
  public void subtractRotation(Transform3D xform) {
    for (int i = 0; i < numVertices; i++) {
      v[i].subtractRotation(xform);
    }
    normal.subtractRotation(xform);
  }
  /**
   * Calculates the unit-vector normal of this polygon. This method uses the
   * first, second, and third vertices to calcuate the normal, so if these
   * vertices are collinear, this method will not work. In this case, you can
   * get the normal from the bounding rectangle. Use setNormal() to explicitly
   * set the normal. This method uses static objects in the Polygon3D class
   * for calculations, so this method is not thread-safe across all instances
   * of Polygon3D.
   */
  public Vector3D calcNormal() {
    if (normal == null) {
      normal = new Vector3D();
    }
    temp1.setTo(v[2]);
    temp1.subtract(v[1]);
    temp2.setTo(v[0]);
    temp2.subtract(v[1]);
    normal.setToCrossProduct(temp1, temp2);
    normal.normalize();
    return normal;
  }
  /**
   * Gets the normal of this polygon. Use calcNormal() if any vertices have
   * changed.
   */
  public Vector3D getNormal() {
    return normal;
  }
  /**
   * Sets the normal of this polygon.
   */
  public void setNormal(Vector3D n) {
    if (normal == null) {
      normal = new Vector3D(n);
    } else {
      normal.setTo(n);
    }
  }
  /**
   * Tests if this polygon is facing the specified location. This method uses
   * static objects in the Polygon3D class for calculations, so this method is
   * not thread-safe across all instances of Polygon3D.
   */
  public boolean isFacing(Vector3D u) {
    temp1.setTo(u);
    temp1.subtract(v[0]);
    return (normal.getDotProduct(temp1) >= 0);
  }
  /**
   * Clips this polygon so that all vertices are in front of the clip plane,
   * clipZ (in other words, all vertices have z <= clipZ). The value of clipZ
   * should not be 0, as this causes divide-by-zero problems. Returns true if
   * the polygon is at least partially in front of the clip plane.
   */
  public boolean clip(float clipZ) {
    ensureCapacity(numVertices * 3);
    boolean isCompletelyHidden = true;
    // insert vertices so all edges are either completly
    // in front or behind the clip plane
    for (int i = 0; i < numVertices; i++) {
      int next = (i + 1) % numVertices;
      Vector3D v1 = v[i];
      Vector3D v2 = v[next];
      if (v1.z < clipZ) {
        isCompletelyHidden = false;
      }
      // ensure v1.z < v2.z
      if (v1.z > v2.z) {
        Vector3D temp = v1;
        v1 = v2;
        v2 = temp;
      }
      if (v1.z < clipZ && v2.z > clipZ) {
        float scale = (clipZ - v1.z) / (v2.z - v1.z);
        insertVertex(next, v1.x + scale * (v2.x - v1.x), v1.y + scale
            * (v2.y - v1.y), clipZ);
        // skip the vertex we just created
        i++;
      }
    }
    if (isCompletelyHidden) {
      return false;
    }
    // delete all vertices that have z > clipZ
    for (int i = numVertices - 1; i >= 0; i--) {
      if (v[i].z > clipZ) {
        deleteVertex(i);
      }
    }
    return (numVertices >= 3);
  }
  /**
   * Inserts a new vertex at the specified index.
   */
  protected void insertVertex(int index, float x, float y, float z) {
    Vector3D newVertex = v[v.length - 1];
    newVertex.x = x;
    newVertex.y = y;
    newVertex.z = z;
    for (int i = v.length - 1; i > index; i--) {
      v[i] = v[i - 1];
    }
    v[index] = newVertex;
    numVertices++;
  }
  /**
   * Delete the vertex at the specified index.
   */
  protected void deleteVertex(int index) {
    Vector3D deleted = v[index];
    for (int i = index; i < v.length - 1; i++) {
      v[i] = v[i + 1];
    }
    v[v.length - 1] = deleted;
    numVertices--;
  }
  /**
   * Inserts a vertex into this polygon at the specified index. The exact
   * vertex in inserted (not a copy).
   */
  public void insertVertex(int index, Vector3D vertex) {
    Vector3D[] newV = new Vector3D[numVertices + 1];
    System.arraycopy(v, 0, newV, 0, index);
    newV[index] = vertex;
    System.arraycopy(v, index, newV, index + 1, numVertices - index);
    v = newV;
    numVertices++;
  }
  /**
   * Calculates and returns the smallest bounding rectangle for this polygon.
   */
  public Rectangle3D calcBoundingRectangle() {
    // the smallest bounding rectangle for a polygon shares
    // at least one edge with the polygon. so, this method
    // finds the bounding rectangle for every edge in the
    // polygon, and returns the smallest one.
    Rectangle3D boundingRect = new Rectangle3D();
    float minimumArea = Float.MAX_VALUE;
    Vector3D u = new Vector3D();
    Vector3D v = new Vector3D();
    Vector3D d = new Vector3D();
    for (int i = 0; i < getNumVertices(); i++) {
      u.setTo(getVertex((i + 1) % getNumVertices()));
      u.subtract(getVertex(i));
      u.normalize();
      v.setToCrossProduct(getNormal(), u);
      v.normalize();
      float uMin = 0;
      float uMax = 0;
      float vMin = 0;
      float vMax = 0;
      for (int j = 0; j < getNumVertices(); j++) {
        if (j != i) {
          d.setTo(getVertex(j));
          d.subtract(getVertex(i));
          float uLength = d.getDotProduct(u);
          float vLength = d.getDotProduct(v);
          uMin = Math.min(uLength, uMin);
          uMax = Math.max(uLength, uMax);
          vMin = Math.min(vLength, vMin);
          vMax = Math.max(vLength, vMax);
        }
      }
      // if this calculated area is the smallest, set
      // the bounding rectangle
      float area = (uMax - uMin) * (vMax - vMin);
      if (area < minimumArea) {
        minimumArea = area;
        Vector3D origin = boundingRect.getOrigin();
        origin.setTo(getVertex(i));
        d.setTo(u);
        d.multiply(uMin);
        origin.add(d);
        d.setTo(v);
        d.multiply(vMin);
        origin.add(d);
        boundingRect.getDirectionU().setTo(u);
        boundingRect.getDirectionV().setTo(v);
        boundingRect.setWidth(uMax - uMin);
        boundingRect.setHeight(vMax - vMin);
      }
    }
    return boundingRect;
  }
}
/**
 * The TexturedPolygon3D class is a Polygon with a texture.
 */
class TexturedPolygon3D extends Polygon3D {
  protected Rectangle3D textureBounds;
  protected Texture texture;
  public TexturedPolygon3D() {
    textureBounds = new Rectangle3D();
  }
  public TexturedPolygon3D(Vector3D v0, Vector3D v1, Vector3D v2) {
    this(new Vector3D[] { v0, v1, v2 });
  }
  public TexturedPolygon3D(Vector3D v0, Vector3D v1, Vector3D v2, Vector3D v3) {
    this(new Vector3D[] { v0, v1, v2, v3 });
  }
  public TexturedPolygon3D(Vector3D[] vertices) {
    super(vertices);
    textureBounds = new Rectangle3D();
  }
  public void setTo(Polygon3D poly) {
    super.setTo(poly);
    if (poly instanceof TexturedPolygon3D) {
      TexturedPolygon3D tPoly = (TexturedPolygon3D) poly;
      textureBounds.setTo(tPoly.textureBounds);
      texture = tPoly.texture;
    }
  }
  /**
   * Gets this polygon"s texture.
   */
  public Texture getTexture() {
    return texture;
  }
  /**
   * Gets this polygon"s texture bounds.
   */
  public Rectangle3D getTextureBounds() {
    return textureBounds;
  }
  /**
   * Sets this polygon"s texture.
   */
  public void setTexture(Texture texture) {
    this.texture = texture;
    textureBounds.setWidth(texture.getWidth());
    textureBounds.setHeight(texture.getHeight());
  }
  /**
   * Sets this polygon"s texture and texture bounds.
   */
  public void setTexture(Texture texture, Rectangle3D bounds) {
    setTexture(texture);
    textureBounds.setTo(bounds);
  }
  public void add(Vector3D u) {
    super.add(u);
    textureBounds.add(u);
  }
  public void subtract(Vector3D u) {
    super.subtract(u);
    textureBounds.subtract(u);
  }
  public void addRotation(Transform3D xform) {
    super.addRotation(xform);
    textureBounds.addRotation(xform);
  }
  public void subtractRotation(Transform3D xform) {
    super.subtractRotation(xform);
    textureBounds.subtractRotation(xform);
  }
  /**
   * Calculates the bounding rectangle for this polygon that is aligned with
   * the texture bounds.
   */
  public Rectangle3D calcBoundingRectangle() {
    Vector3D u = new Vector3D(textureBounds.getDirectionU());
    Vector3D v = new Vector3D(textureBounds.getDirectionV());
    Vector3D d = new Vector3D();
    u.normalize();
    v.normalize();
    float uMin = 0;
    float uMax = 0;
    float vMin = 0;
    float vMax = 0;
    for (int i = 0; i < getNumVertices(); i++) {
      d.setTo(getVertex(i));
      d.subtract(getVertex(0));
      float uLength = d.getDotProduct(u);
      float vLength = d.getDotProduct(v);
      uMin = Math.min(uLength, uMin);
      uMax = Math.max(uLength, uMax);
      vMin = Math.min(vLength, vMin);
      vMax = Math.max(vLength, vMax);
    }
    Rectangle3D boundingRect = new Rectangle3D();
    Vector3D origin = boundingRect.getOrigin();
    origin.setTo(getVertex(0));
    d.setTo(u);
    d.multiply(uMin);
    origin.add(d);
    d.setTo(v);
    d.multiply(vMin);
    origin.add(d);
    boundingRect.getDirectionU().setTo(u);
    boundingRect.getDirectionV().setTo(v);
    boundingRect.setWidth(uMax - uMin);
    boundingRect.setHeight(vMax - vMin);
    // explictly set the normal since the texture directions
    // could create a normal negative to the polygon normal
    boundingRect.setNormal(getNormal());
    return boundingRect;
  }
}
/**
 * The Vector3D class implements a 3D vector with the floating-point values x,
 * y, and z. Vectors can be thought of either as a (x,y,z) point or as a vector
 * from (0,0,0) to (x,y,z).
 */
class Vector3D implements Transformable {
  public float x;
  public float y;
  public float z;
  /**
   * Creates a new Vector3D at (0,0,0).
   */
  public Vector3D() {
    this(0, 0, 0);
  }
  /**
   * Creates a new Vector3D with the same values as the specified Vector3D.
   */
  public Vector3D(Vector3D v) {
    this(v.x, v.y, v.z);
  }
  /**
   * Creates a new Vector3D with the specified (x, y, z) values.
   */
  public Vector3D(float x, float y, float z) {
    setTo(x, y, z);
  }
  /**
   * Checks if this Vector3D is equal to the specified Object. They are equal
   * only if the specified Object is a Vector3D and the two Vector3D"s x, y,
   * and z coordinates are equal.
   */
  public boolean equals(Object obj) {
    Vector3D v = (Vector3D) obj;
    return (v.x == x && v.y == y && v.z == z);
  }
  /**
   * Checks if this Vector3D is equal to the specified x, y, and z
   * coordinates.
   */
  public boolean equals(float x, float y, float z) {
    return (this.x == x && this.y == y && this.z == z);
  }
  /**
   * Sets the vector to the same values as the specified Vector3D.
   */
  public void setTo(Vector3D v) {
    setTo(v.x, v.y, v.z);
  }
  /**
   * Sets this vector to the specified (x, y, z) values.
   */
  public void setTo(float x, float y, float z) {
    this.x = x;
    this.y = y;
    this.z = z;
  }
  /**
   * Adds the specified (x, y, z) values to this vector.
   */
  public void add(float x, float y, float z) {
    this.x += x;
    this.y += y;
    this.z += z;
  }
  /**
   * Subtracts the specified (x, y, z) values to this vector.
   */
  public void subtract(float x, float y, float z) {
    add(-x, -y, -z);
  }
  /**
   * Adds the specified vector to this vector.
   */
  public void add(Vector3D v) {
    add(v.x, v.y, v.z);
  }
  /**
   * Subtracts the specified vector from this vector.
   */
  public void subtract(Vector3D v) {
    add(-v.x, -v.y, -v.z);
  }
  /**
   * Multiplies this vector by the specified value. The new length of this
   * vector will be length()*s.
   */
  public void multiply(float s) {
    x *= s;
    y *= s;
    z *= s;
  }
  /**
   * Divides this vector by the specified value. The new length of this vector
   * will be length()/s.
   */
  public void divide(float s) {
    x /= s;
    y /= s;
    z /= s;
  }
  /**
   * Returns the length of this vector as a float.
   */
  public float length() {
    return (float) Math.sqrt(x * x + y * y + z * z);
  }
  /**
   * Converts this Vector3D to a unit vector, or in other words, a vector of
   * length 1. Same as calling v.divide(v.length()).
   */
  public void normalize() {
    divide(length());
  }
  /**
   * Converts this Vector3D to a String representation.
   */
  public String toString() {
    return "(" + x + ", " + y + ", " + z + ")";
  }
  /**
   * Rotate this vector around the x axis the specified amount. The specified
   * angle is in radians. Use Math.toRadians() to convert from degrees to
   * radians.
   */
  public void rotateX(float angle) {
    rotateX((float) Math.cos(angle), (float) Math.sin(angle));
  }
  /**
   * Rotate this vector around the y axis the specified amount. The specified
   * angle is in radians. Use Math.toRadians() to convert from degrees to
   * radians.
   */
  public void rotateY(float angle) {
    rotateY((float) Math.cos(angle), (float) Math.sin(angle));
  }
  /**
   * Rotate this vector around the z axis the specified amount. The specified
   * angle is in radians. Use Math.toRadians() to convert from degrees to
   * radians.
   */
  public void rotateZ(float angle) {
    rotateZ((float) Math.cos(angle), (float) Math.sin(angle));
  }
  /**
   * Rotate this vector around the x axis the specified amount, using
   * pre-computed cosine and sine values of the angle to rotate.
   */
  public void rotateX(float cosAngle, float sinAngle) {
    float newY = y * cosAngle - z * sinAngle;
    float newZ = y * sinAngle + z * cosAngle;
    y = newY;
    z = newZ;
  }
  /**
   * Rotate this vector around the y axis the specified amount, using
   * pre-computed cosine and sine values of the angle to rotate.
   */
  public void rotateY(float cosAngle, float sinAngle) {
    float newX = z * sinAngle + x * cosAngle;
    float newZ = z * cosAngle - x * sinAngle;
    x = newX;
    z = newZ;
  }
  /**
   * Rotate this vector around the y axis the specified amount, using
   * pre-computed cosine and sine values of the angle to rotate.
   */
  public void rotateZ(float cosAngle, float sinAngle) {
    float newX = x * cosAngle - y * sinAngle;
    float newY = x * sinAngle + y * cosAngle;
    x = newX;
    y = newY;
  }
  /**
   * Adds the specified transform to this vector. This vector is first
   * rotated, then translated.
   */
  public void add(Transform3D xform) {
    // rotate
    addRotation(xform);
    // translate
    add(xform.getLocation());
  }
  /**
   * Subtracts the specified transform to this vector. This vector translated,
   * then rotated.
   */
  public void subtract(Transform3D xform) {
    // translate
    subtract(xform.getLocation());
    // rotate
    subtractRotation(xform);
  }
  /**
   * Rotates this vector with the angle of the specified transform.
   */
  public void addRotation(Transform3D xform) {
    rotateX(xform.getCosAngleX(), xform.getSinAngleX());
    rotateZ(xform.getCosAngleZ(), xform.getSinAngleZ());
    rotateY(xform.getCosAngleY(), xform.getSinAngleY());
  }
  /**
   * Rotates this vector with the opposite angle of the specified transform.
   */
  public void subtractRotation(Transform3D xform) {
    // note that sin(-x) == -sin(x) and cos(-x) == cos(x)
    rotateY(xform.getCosAngleY(), -xform.getSinAngleY());
    rotateZ(xform.getCosAngleZ(), -xform.getSinAngleZ());
    rotateX(xform.getCosAngleX(), -xform.getSinAngleX());
  }
  /**
   * Returns the dot product of this vector and the specified vector.
   */
  public float getDotProduct(Vector3D v) {
    return x * v.x + y * v.y + z * v.z;
  }
  /**
   * Sets this vector to the cross product of the two specified vectors.
   * Either of the specified vectors can be this vector.
   */
  public void setToCrossProduct(Vector3D u, Vector3D v) {
    // assign to local vars first in case u or v is "this"
    float x = u.y * v.z - u.z * v.y;
    float y = u.z * v.x - u.x * v.z;
    float z = u.x * v.y - u.y * v.x;
    this.x = x;
    this.y = y;
    this.z = z;
  }
}
/**
 * A Rectangle3D is a rectangle in 3D space, defined as an origin and vectors
 * pointing in the directions of the base (width) and side (height).
 */
class Rectangle3D implements Transformable {
  private Vector3D origin;
  private Vector3D directionU;
  private Vector3D directionV;
  private Vector3D normal;
  private float width;
  private float height;
  /**
   * Creates a rectangle at the origin with a width and height of zero.
   */
  public Rectangle3D() {
    origin = new Vector3D();
    directionU = new Vector3D(1, 0, 0);
    directionV = new Vector3D(0, 1, 0);
    width = 0;
    height = 0;
  }
  /**
   * Creates a new Rectangle3D with the specified origin, direction of the
   * base (directionU) and direction of the side (directionV).
   */
  public Rectangle3D(Vector3D origin, Vector3D directionU,
      Vector3D directionV, float width, float height) {
    this.origin = new Vector3D(origin);
    this.directionU = new Vector3D(directionU);
    this.directionU.normalize();
    this.directionV = new Vector3D(directionV);
    this.directionV.normalize();
    this.width = width;
    this.height = height;
  }
  /**
   * Sets the values of this Rectangle3D to the specified Rectangle3D.
   */
  public void setTo(Rectangle3D rect) {
    origin.setTo(rect.origin);
    directionU.setTo(rect.directionU);
    directionV.setTo(rect.directionV);
    width = rect.width;
    height = rect.height;
  }
  /**
   * Gets the origin of this Rectangle3D.
   */
  public Vector3D getOrigin() {
    return origin;
  }
  /**
   * Gets the direction of the base of this Rectangle3D.
   */
  public Vector3D getDirectionU() {
    return directionU;
  }
  /**
   * Gets the direction of the side of this Rectangle3D.
   */
  public Vector3D getDirectionV() {
    return directionV;
  }
  /**
   * Gets the width of this Rectangle3D.
   */
  public float getWidth() {
    return width;
  }
  /**
   * Sets the width of this Rectangle3D.
   */
  public void setWidth(float width) {
    this.width = width;
  }
  /**
   * Gets the height of this Rectangle3D.
   */
  public float getHeight() {
    return height;
  }
  /**
   * Sets the height of this Rectangle3D.
   */
  public void setHeight(float height) {
    this.height = height;
  }
  /**
   * Calculates the normal vector of this Rectange3D.
   */
  protected Vector3D calcNormal() {
    if (normal == null) {
      normal = new Vector3D();
    }
    normal.setToCrossProduct(directionU, directionV);
    normal.normalize();
    return normal;
  }
  /**
   * Gets the normal of this Rectangle3D.
   */
  public Vector3D getNormal() {
    if (normal == null) {
      calcNormal();
    }
    return normal;
  }
  /**
   * Sets the normal of this Rectangle3D.
   */
  public void setNormal(Vector3D n) {
    if (normal == null) {
      normal = new Vector3D(n);
    } else {
      normal.setTo(n);
    }
  }
  public void add(Vector3D u) {
    origin.add(u);
    // don"t translate direction vectors or size
  }
  public void subtract(Vector3D u) {
    origin.subtract(u);
    // don"t translate direction vectors or size
  }
  public void add(Transform3D xform) {
    addRotation(xform);
    add(xform.getLocation());
  }
  public void subtract(Transform3D xform) {
    subtract(xform.getLocation());
    subtractRotation(xform);
  }
  public void addRotation(Transform3D xform) {
    origin.addRotation(xform);
    directionU.addRotation(xform);
    directionV.addRotation(xform);
  }
  public void subtractRotation(Transform3D xform) {
    origin.subtractRotation(xform);
    directionU.subtractRotation(xform);
    directionV.subtractRotation(xform);
  }
}
           
       </source>
    
   
  <!-- end source code -->
   




== Texture Map Test 1  ==






   
  <!-- start source code -->
   
    <source lang="java">
       /*
DEVELOPING GAME IN JAVA 
Caracteristiques
Editeur : NEW RIDERS 
Auteur : BRACKEEN 
Parution : 09 2003 
Pages : 972 
Isbn : 1-59273-005-1 
Reliure : Paperback 
Disponibilite : Disponible a la librairie 
*/

import java.awt.AWTException;
import java.awt.Color;
import java.awt.ruponent;
import java.awt.Cursor;
import java.awt.DisplayMode;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Image;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.Window;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.awt.image.DataBuffer;
import java.awt.image.DataBufferByte;
import java.awt.image.DataBufferUShort;
import java.awt.image.IndexColorModel;
import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.ref.SoftReference;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import javax.imageio.ImageIO;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.DataLine;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.Mixer;
import javax.sound.sampled.SourceDataLine;
import javax.sound.sampled.UnsupportedAudioFileException;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
public class TextureMapTest1 extends GameCore3D {
  public static void main(String[] args) {
    new TextureMapTest1().run();
  }
  public void createPolygons() {
    Polygon3D poly;
    // one wall for now
    poly = new Polygon3D(new Vector3D(-128, 256, -1000), new Vector3D(-128,
        0, -1000), new Vector3D(128, 0, -1000), new Vector3D(128, 256,
        -1000));
    polygons.add(poly);
  }
  public void createPolygonRenderer() {
    viewWindow = new ViewWindow(0, 0, screen.getWidth(),
        screen.getHeight(), (float) Math.toRadians(75));
    Transform3D camera = new Transform3D(0, 100, 0);
    polygonRenderer = new SimpleTexturedPolygonRenderer(camera, viewWindow,
        "../images/test_pattern.png");
  }
}
/**
 * The SimpleTexturedPolygonRenderer class demonstrates the fundamentals of
 * perspective-correct texture mapping. It is very slow and maps the same
 * texture for every polygon.
 */
class SimpleTexturedPolygonRenderer extends PolygonRenderer {
  protected Vector3D a = new Vector3D();
  protected Vector3D b = new Vector3D();
  protected Vector3D c = new Vector3D();
  protected Vector3D viewPos = new Vector3D();
  protected Rectangle3D textureBounds = new Rectangle3D();
  protected BufferedImage texture;
  public SimpleTexturedPolygonRenderer(Transform3D camera,
      ViewWindow viewWindow, String textureFile) {
    super(camera, viewWindow);
    texture = loadTexture(textureFile);
  }
  /**
   * Loads the texture image from a file. This image is used for all polygons.
   */
  public BufferedImage loadTexture(String filename) {
    try {
      return ImageIO.read(new File(filename));
    } catch (IOException ex) {
      ex.printStackTrace();
      return null;
    }
  }
  protected void drawCurrentPolygon(Graphics2D g) {
    // Calculate texture bounds.
    // Ideally texture bounds are pre-calculated and stored
    // with the polygon. Coordinates are computed here for
    // demonstration purposes.
    Vector3D textureOrigin = textureBounds.getOrigin();
    Vector3D textureDirectionU = textureBounds.getDirectionU();
    Vector3D textureDirectionV = textureBounds.getDirectionV();
    textureOrigin.setTo(sourcePolygon.getVertex(0));
    textureDirectionU.setTo(sourcePolygon.getVertex(3));
    textureDirectionU.subtract(textureOrigin);
    textureDirectionU.normalize();
    textureDirectionV.setTo(sourcePolygon.getVertex(1));
    textureDirectionV.subtract(textureOrigin);
    textureDirectionV.normalize();
    // transform the texture bounds
    textureBounds.subtract(camera);
    // start texture-mapping calculations
    a.setToCrossProduct(textureBounds.getDirectionV(), textureBounds
        .getOrigin());
    b.setToCrossProduct(textureBounds.getOrigin(), textureBounds
        .getDirectionU());
    c.setToCrossProduct(textureBounds.getDirectionU(), textureBounds
        .getDirectionV());
    int y = scanConverter.getTopBoundary();
    viewPos.z = -viewWindow.getDistance();
    while (y <= scanConverter.getBottomBoundary()) {
      ScanConverter.Scan scan = scanConverter.getScan(y);
      if (scan.isValid()) {
        viewPos.y = viewWindow.convertFromScreenYToViewY(y);
        for (int x = scan.left; x <= scan.right; x++) {
          viewPos.x = viewWindow.convertFromScreenXToViewX(x);
          // compute the texture location
          int tx = (int) (a.getDotProduct(viewPos) / c
              .getDotProduct(viewPos));
          int ty = (int) (b.getDotProduct(viewPos) / c
              .getDotProduct(viewPos));
          // get the color to draw
          try {
            int color = texture.getRGB(tx, ty);
            g.setColor(new Color(color));
          } catch (ArrayIndexOutOfBoundsException ex) {
            g.setColor(Color.red);
          }
          // draw the pixel
          g.drawLine(x, y, x, y);
        }
      }
      y++;
    }
  }
}
/**
 * The FastTexturedPolygonRenderer is a PolygonRenderer that efficiently renders
 * Textures.
 */
class FastTexturedPolygonRenderer extends PolygonRenderer {
  public static final int SCALE_BITS = 12;
  public static final int SCALE = 1 << SCALE_BITS;
  public static final int INTERP_SIZE_BITS = 4;
  public static final int INTERP_SIZE = 1 << INTERP_SIZE_BITS;
  protected Vector3D a = new Vector3D();
  protected Vector3D b = new Vector3D();
  protected Vector3D c = new Vector3D();
  protected Vector3D viewPos = new Vector3D();
  protected BufferedImage doubleBuffer;
  protected short[] doubleBufferData;
  protected HashMap scanRenderers;
  public FastTexturedPolygonRenderer(Transform3D camera, ViewWindow viewWindow) {
    this(camera, viewWindow, true);
  }
  public FastTexturedPolygonRenderer(Transform3D camera,
      ViewWindow viewWindow, boolean clearViewEveryFrame) {
    super(camera, viewWindow, clearViewEveryFrame);
  }
  protected void init() {
    destPolygon = new TexturedPolygon3D();
    scanConverter = new ScanConverter(viewWindow);
    // create renders for each texture (HotSpot optimization)
    scanRenderers = new HashMap();
    scanRenderers.put(PowerOf2Texture.class, new PowerOf2TextureRenderer());
    scanRenderers.put(ShadedTexture.class, new ShadedTextureRenderer());
    scanRenderers.put(ShadedSurface.class, new ShadedSurfaceRenderer());
  }
  public void startFrame(Graphics2D g) {
    // initialize buffer
    if (doubleBuffer == null
        || doubleBuffer.getWidth() != viewWindow.getWidth()
        || doubleBuffer.getHeight() != viewWindow.getHeight()) {
      doubleBuffer = new BufferedImage(viewWindow.getWidth(), viewWindow
          .getHeight(), BufferedImage.TYPE_USHORT_565_RGB);
      //doubleBuffer = g.getDeviceConfiguration().createCompatibleImage(
      //viewWindow.getWidth(), viewWindow.getHeight());
      DataBuffer dest = doubleBuffer.getRaster().getDataBuffer();
      doubleBufferData = ((DataBufferUShort) dest).getData();
    }
    // clear view
    if (clearViewEveryFrame) {
      for (int i = 0; i < doubleBufferData.length; i++) {
        doubleBufferData[i] = 0;
      }
    }
  }
  public void endFrame(Graphics2D g) {
    // draw the double buffer onto the screen
    g.drawImage(doubleBuffer, viewWindow.getLeftOffset(), viewWindow
        .getTopOffset(), null);
  }
  protected void drawCurrentPolygon(Graphics2D g) {
    if (!(sourcePolygon instanceof TexturedPolygon3D)) {
      // not a textured polygon - return
      return;
    }
    TexturedPolygon3D poly = (TexturedPolygon3D) destPolygon;
    Texture texture = poly.getTexture();
    ScanRenderer scanRenderer = (ScanRenderer) scanRenderers.get(texture
        .getClass());
    scanRenderer.setTexture(texture);
    Rectangle3D textureBounds = poly.getTextureBounds();
    a.setToCrossProduct(textureBounds.getDirectionV(), textureBounds
        .getOrigin());
    b.setToCrossProduct(textureBounds.getOrigin(), textureBounds
        .getDirectionU());
    c.setToCrossProduct(textureBounds.getDirectionU(), textureBounds
        .getDirectionV());
    int y = scanConverter.getTopBoundary();
    viewPos.y = viewWindow.convertFromScreenYToViewY(y);
    viewPos.z = -viewWindow.getDistance();
    while (y <= scanConverter.getBottomBoundary()) {
      ScanConverter.Scan scan = scanConverter.getScan(y);
      if (scan.isValid()) {
        viewPos.x = viewWindow.convertFromScreenXToViewX(scan.left);
        int offset = (y - viewWindow.getTopOffset())
            * viewWindow.getWidth()
            + (scan.left - viewWindow.getLeftOffset());
        scanRenderer.render(offset, scan.left, scan.right);
      }
      y++;
      viewPos.y--;
    }
  }
  /**
   * The ScanRenderer class is an abstract inner class of
   * FastTexturedPolygonRenderer that provides an interface for rendering a
   * horizontal scan line.
   */
  public abstract class ScanRenderer {
    protected Texture currentTexture;
    public void setTexture(Texture texture) {
      this.currentTexture = texture;
    }
    public abstract void render(int offset, int left, int right);
  }
  //================================================
  // FASTEST METHOD: no texture (for comparison)
  //================================================
  public class Method0 extends ScanRenderer {
    public void render(int offset, int left, int right) {
      for (int x = left; x <= right; x++) {
        doubleBufferData[offset++] = (short) 0x0007;
      }
    }
  }
  //================================================
  // METHOD 1: access pixel buffers directly
  // and use textures sizes that are a power of 2
  //================================================
  public class Method1 extends ScanRenderer {
    public void render(int offset, int left, int right) {
      for (int x = left; x <= right; x++) {
        int tx = (int) (a.getDotProduct(viewPos) / c
            .getDotProduct(viewPos));
        int ty = (int) (b.getDotProduct(viewPos) / c
            .getDotProduct(viewPos));
        doubleBufferData[offset++] = currentTexture.getColor(tx, ty);
        viewPos.x++;
      }
    }
  }
  //================================================
  // METHOD 2: avoid redundant calculations
  //================================================
  public class Method2 extends ScanRenderer {
    public void render(int offset, int left, int right) {
      float u = a.getDotProduct(viewPos);
      float v = b.getDotProduct(viewPos);
      float z = c.getDotProduct(viewPos);
      float du = a.x;
      float dv = b.x;
      float dz = c.x;
      for (int x = left; x <= right; x++) {
        doubleBufferData[offset++] = currentTexture.getColor(
            (int) (u / z), (int) (v / z));
        u += du;
        v += dv;
        z += dz;
      }
    }
  }
  //================================================
  // METHOD 3: use ints instead of floats
  //================================================
  public class Method3 extends ScanRenderer {
    public void render(int offset, int left, int right) {
      int u = (int) (SCALE * a.getDotProduct(viewPos));
      int v = (int) (SCALE * b.getDotProduct(viewPos));
      int z = (int) (SCALE * c.getDotProduct(viewPos));
      int du = (int) (SCALE * a.x);
      int dv = (int) (SCALE * b.x);
      int dz = (int) (SCALE * c.x);
      for (int x = left; x <= right; x++) {
        doubleBufferData[offset++] = currentTexture.getColor(u / z, v
            / z);
        u += du;
        v += dv;
        z += dz;
      }
    }
  }
  //================================================
  // METHOD 4: reduce the number of divides
  // (interpolate every 16 pixels)
  // Also, apply a VM optimization by referring to
  // the texture"s class rather than it"s parent class.
  //================================================
  // the following three ScanRenderers are the same, but refer
  // to textures explicitly as either a PowerOf2Texture, a
  // ShadedTexture, or a ShadedSurface.
  // This allows HotSpot to do some inlining of the textures"
  // getColor() method, which significantly increases
  // performance.
  public class PowerOf2TextureRenderer extends ScanRenderer {
    public void render(int offset, int left, int right) {
      PowerOf2Texture texture = (PowerOf2Texture) currentTexture;
      float u = SCALE * a.getDotProduct(viewPos);
      float v = SCALE * b.getDotProduct(viewPos);
      float z = c.getDotProduct(viewPos);
      float du = INTERP_SIZE * SCALE * a.x;
      float dv = INTERP_SIZE * SCALE * b.x;
      float dz = INTERP_SIZE * c.x;
      int nextTx = (int) (u / z);
      int nextTy = (int) (v / z);
      int x = left;
      while (x <= right) {
        int tx = nextTx;
        int ty = nextTy;
        int maxLength = right - x + 1;
        if (maxLength > INTERP_SIZE) {
          u += du;
          v += dv;
          z += dz;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) >> INTERP_SIZE_BITS;
          int dty = (nextTy - ty) >> INTERP_SIZE_BITS;
          int endOffset = offset + INTERP_SIZE;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += INTERP_SIZE;
        } else {
          // variable interpolation size
          int interpSize = maxLength;
          u += interpSize * SCALE * a.x;
          v += interpSize * SCALE * b.x;
          z += interpSize * c.x;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) / interpSize;
          int dty = (nextTy - ty) / interpSize;
          int endOffset = offset + interpSize;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += interpSize;
        }
      }
    }
  }
  public class ShadedTextureRenderer extends ScanRenderer {
    public void render(int offset, int left, int right) {
      ShadedTexture texture = (ShadedTexture) currentTexture;
      float u = SCALE * a.getDotProduct(viewPos);
      float v = SCALE * b.getDotProduct(viewPos);
      float z = c.getDotProduct(viewPos);
      float du = INTERP_SIZE * SCALE * a.x;
      float dv = INTERP_SIZE * SCALE * b.x;
      float dz = INTERP_SIZE * c.x;
      int nextTx = (int) (u / z);
      int nextTy = (int) (v / z);
      int x = left;
      while (x <= right) {
        int tx = nextTx;
        int ty = nextTy;
        int maxLength = right - x + 1;
        if (maxLength > INTERP_SIZE) {
          u += du;
          v += dv;
          z += dz;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) >> INTERP_SIZE_BITS;
          int dty = (nextTy - ty) >> INTERP_SIZE_BITS;
          int endOffset = offset + INTERP_SIZE;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += INTERP_SIZE;
        } else {
          // variable interpolation size
          int interpSize = maxLength;
          u += interpSize * SCALE * a.x;
          v += interpSize * SCALE * b.x;
          z += interpSize * c.x;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) / interpSize;
          int dty = (nextTy - ty) / interpSize;
          int endOffset = offset + interpSize;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += interpSize;
        }
      }
    }
  }
  public class ShadedSurfaceRenderer extends ScanRenderer {
    public int checkBounds(int vScaled, int bounds) {
      int v = vScaled >> SCALE_BITS;
      if (v < 0) {
        vScaled = 0;
      } else if (v >= bounds) {
        vScaled = (bounds - 1) << SCALE_BITS;
      }
      return vScaled;
    }
    public void render(int offset, int left, int right) {
      ShadedSurface texture = (ShadedSurface) currentTexture;
      float u = SCALE * a.getDotProduct(viewPos);
      float v = SCALE * b.getDotProduct(viewPos);
      float z = c.getDotProduct(viewPos);
      float du = INTERP_SIZE * SCALE * a.x;
      float dv = INTERP_SIZE * SCALE * b.x;
      float dz = INTERP_SIZE * c.x;
      int nextTx = (int) (u / z);
      int nextTy = (int) (v / z);
      int x = left;
      while (x <= right) {
        int tx = nextTx;
        int ty = nextTy;
        int maxLength = right - x + 1;
        if (maxLength > INTERP_SIZE) {
          u += du;
          v += dv;
          z += dz;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) >> INTERP_SIZE_BITS;
          int dty = (nextTy - ty) >> INTERP_SIZE_BITS;
          int endOffset = offset + INTERP_SIZE;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += INTERP_SIZE;
        } else {
          // variable interpolation size
          int interpSize = maxLength;
          u += interpSize * SCALE * a.x;
          v += interpSize * SCALE * b.x;
          z += interpSize * c.x;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          // make sure tx, ty, nextTx, and nextTy are
          // all within bounds
          tx = checkBounds(tx, texture.getWidth());
          ty = checkBounds(ty, texture.getHeight());
          nextTx = checkBounds(nextTx, texture.getWidth());
          nextTy = checkBounds(nextTy, texture.getHeight());
          int dtx = (nextTx - tx) / interpSize;
          int dty = (nextTy - ty) / interpSize;
          int endOffset = offset + interpSize;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += interpSize;
        }
      }
    }
  }
}
/**
 * A ShadedSurface is a pre-shaded Texture that maps onto a polygon.
 */
final class ShadedSurface extends Texture {
  public static final int SURFACE_BORDER_SIZE = 1;
  public static final int SHADE_RES_BITS = 4;
  public static final int SHADE_RES = 1 << SHADE_RES_BITS;
  public static final int SHADE_RES_MASK = SHADE_RES - 1;
  public static final int SHADE_RES_SQ = SHADE_RES * SHADE_RES;
  public static final int SHADE_RES_SQ_BITS = SHADE_RES_BITS * 2;
  private short[] buffer;
  private SoftReference bufferReference;
  private boolean dirty;
  private ShadedTexture sourceTexture;
  private Rectangle3D sourceTextureBounds;
  private Rectangle3D surfaceBounds;
  private byte[] shadeMap;
  private int shadeMapWidth;
  private int shadeMapHeight;
  // for incrementally calculating shade values
  private int shadeValue;
  private int shadeValueInc;
  /**
   * Creates a ShadedSurface with the specified width and height.
   */
  public ShadedSurface(int width, int height) {
    this(null, width, height);
  }
  /**
   * Creates a ShadedSurface with the specified buffer, width and height.
   */
  public ShadedSurface(short[] buffer, int width, int height) {
    super(width, height);
    this.buffer = buffer;
    bufferReference = new SoftReference(buffer);
    sourceTextureBounds = new Rectangle3D();
    dirty = true;
  }
  /**
   * Creates a ShadedSurface for the specified polygon. The shade map is
   * created from the specified list of point lights and ambient light
   * intensity.
   */
  public static void createShadedSurface(TexturedPolygon3D poly,
      ShadedTexture texture, List lights, float ambientLightIntensity) {
    // create the texture bounds
    Vector3D origin = poly.getVertex(0);
    Vector3D dv = new Vector3D(poly.getVertex(1));
    dv.subtract(origin);
    Vector3D du = new Vector3D();
    du.setToCrossProduct(poly.getNormal(), dv);
    Rectangle3D bounds = new Rectangle3D(origin, du, dv,
        texture.getWidth(), texture.getHeight());
    createShadedSurface(poly, texture, bounds, lights,
        ambientLightIntensity);
  }
  /**
   * Creates a ShadedSurface for the specified polygon. The shade map is
   * created from the specified list of point lights and ambient light
   * intensity.
   */
  public static void createShadedSurface(TexturedPolygon3D poly,
      ShadedTexture texture, Rectangle3D textureBounds, List lights,
      float ambientLightIntensity) {
    // create the surface bounds
    poly.setTexture(texture, textureBounds);
    Rectangle3D surfaceBounds = poly.calcBoundingRectangle();
    // give the surfaceBounds a border to correct for
    // slight errors when texture mapping
    Vector3D du = new Vector3D(surfaceBounds.getDirectionU());
    Vector3D dv = new Vector3D(surfaceBounds.getDirectionV());
    du.multiply(SURFACE_BORDER_SIZE);
    dv.multiply(SURFACE_BORDER_SIZE);
    surfaceBounds.getOrigin().subtract(du);
    surfaceBounds.getOrigin().subtract(dv);
    int width = (int) Math.ceil(surfaceBounds.getWidth()
        + SURFACE_BORDER_SIZE * 2);
    int height = (int) Math.ceil(surfaceBounds.getHeight()
        + SURFACE_BORDER_SIZE * 2);
    surfaceBounds.setWidth(width);
    surfaceBounds.setHeight(height);
    // create the shaded surface texture
    ShadedSurface surface = new ShadedSurface(width, height);
    surface.setTexture(texture, textureBounds);
    surface.setSurfaceBounds(surfaceBounds);
    // create the surface"s shade map
    surface.buildShadeMap(lights, ambientLightIntensity);
    // set the polygon"s surface
    poly.setTexture(surface, surfaceBounds);
  }
  /**
   * Gets the 16-bit color of the pixel at location (x,y) in the bitmap. The x
   * and y values are assumbed to be within the bounds of the surface;
   * otherwise an ArrayIndexOutOfBoundsException occurs.
   */
  public short getColor(int x, int y) {
    //try {
    return buffer[x + y * width];
    //}
    //catch (ArrayIndexOutOfBoundsException ex) {
    //    return -2048;
    //}
  }
  /**
   * Gets the 16-bit color of the pixel at location (x,y) in the bitmap. The x
   * and y values are checked to be within the bounds of the surface, and if
   * not, the pixel on the edge of the texture is returned.
   */
  public short getColorChecked(int x, int y) {
    if (x < 0) {
      x = 0;
    } else if (x >= width) {
      x = width - 1;
    }
    if (y < 0) {
      y = 0;
    } else if (y >= height) {
      y = height - 1;
    }
    return getColor(x, y);
  }
  /**
   * Marks whether this surface is dirty. Surfaces marked as dirty may be
   * cleared externally.
   */
  public void setDirty(boolean dirty) {
    this.dirty = dirty;
  }
  /**
   * Checks wether this surface is dirty. Surfaces marked as dirty may be
   * cleared externally.
   */
  public boolean isDirty() {
    return dirty;
  }
  /**
   * Creates a new surface and add a SoftReference to it.
   */
  protected void newSurface(int width, int height) {
    buffer = new short[width * height];
    bufferReference = new SoftReference(buffer);
  }
  /**
   * Clears this surface, allowing the garbage collector to remove it from
   * memory if needed.
   */
  public void clearSurface() {
    buffer = null;
  }
  /**
   * Checks if the surface has been cleared.
   */
  public boolean isCleared() {
    return (buffer == null);
  }
  /**
   * If the buffer has been previously built and cleared but not yet removed
   * from memory by the garbage collector, then this method attempts to
   * retrieve it. Returns true if successfull.
   */
  public boolean retrieveSurface() {
    if (buffer == null) {
      buffer = (short[]) bufferReference.get();
    }
    return !(buffer == null);
  }
  /**
   * Sets the source texture for this ShadedSurface.
   */
  public void setTexture(ShadedTexture texture) {
    this.sourceTexture = texture;
    sourceTextureBounds.setWidth(texture.getWidth());
    sourceTextureBounds.setHeight(texture.getHeight());
  }
  /**
   * Sets the source texture and source bounds for this ShadedSurface.
   */
  public void setTexture(ShadedTexture texture, Rectangle3D bounds) {
    setTexture(texture);
    sourceTextureBounds.setTo(bounds);
  }
  /**
   * Sets the surface bounds for this ShadedSurface.
   */
  public void setSurfaceBounds(Rectangle3D surfaceBounds) {
    this.surfaceBounds = surfaceBounds;
  }
  /**
   * Gets the surface bounds for this ShadedSurface.
   */
  public Rectangle3D getSurfaceBounds() {
    return surfaceBounds;
  }
  /**
   * Builds the surface. First, this method calls retrieveSurface() to see if
   * the surface needs to be rebuilt. If not, the surface is built by tiling
   * the source texture and apply the shade map.
   */
  public void buildSurface() {
    if (retrieveSurface()) {
      return;
    }
    int width = (int) surfaceBounds.getWidth();
    int height = (int) surfaceBounds.getHeight();
    // create a new surface (buffer)
    newSurface(width, height);
    // builds the surface.
    // assume surface bounds and texture bounds are aligned
    // (possibly with different origins)
    Vector3D origin = sourceTextureBounds.getOrigin();
    Vector3D directionU = sourceTextureBounds.getDirectionU();
    Vector3D directionV = sourceTextureBounds.getDirectionV();
    Vector3D d = new Vector3D(surfaceBounds.getOrigin());
    d.subtract(origin);
    int startU = (int) ((d.getDotProduct(directionU) - SURFACE_BORDER_SIZE));
    int startV = (int) ((d.getDotProduct(directionV) - SURFACE_BORDER_SIZE));
    int offset = 0;
    int shadeMapOffsetU = SHADE_RES - SURFACE_BORDER_SIZE - startU;
    int shadeMapOffsetV = SHADE_RES - SURFACE_BORDER_SIZE - startV;
    for (int v = startV; v < startV + height; v++) {
      sourceTexture.setCurrRow(v);
      int u = startU;
      int amount = SURFACE_BORDER_SIZE;
      while (u < startU + width) {
        getInterpolatedShade(u + shadeMapOffsetU, v + shadeMapOffsetV);
        // keep drawing until we need to recalculate
        // the interpolated shade. (every SHADE_RES pixels)
        int endU = Math.min(startU + width, u + amount);
        while (u < endU) {
          buffer[offset++] = sourceTexture.getColorCurrRow(u,
              shadeValue >> SHADE_RES_SQ_BITS);
          shadeValue += shadeValueInc;
          u++;
        }
        amount = SHADE_RES;
      }
    }
    // if the surface bounds is not aligned with the texture
    // bounds, use this (slower) code.
    /*
     * Vector3D origin = sourceTextureBounds.getOrigin(); Vector3D
     * directionU = sourceTextureBounds.getDirectionU(); Vector3D directionV =
     * sourceTextureBounds.getDirectionV();
     * 
     * Vector3D d = new Vector3D(surfaceBounds.getOrigin());
     * d.subtract(origin); int initTextureU = (int)(SCALE *
     * (d.getDotProduct(directionU) - SURFACE_BORDER_SIZE)); int
     * initTextureV = (int)(SCALE * (d.getDotProduct(directionV) -
     * SURFACE_BORDER_SIZE)); int textureDu1 = (int)(SCALE *
     * directionU.getDotProduct( surfaceBounds.getDirectionV())); int
     * textureDv1 = (int)(SCALE * directionV.getDotProduct(
     * surfaceBounds.getDirectionV())); int textureDu2 = (int)(SCALE *
     * directionU.getDotProduct( surfaceBounds.getDirectionU())); int
     * textureDv2 = (int)(SCALE * directionV.getDotProduct(
     * surfaceBounds.getDirectionU()));
     * 
     * int shadeMapOffset = SHADE_RES - SURFACE_BORDER_SIZE;
     * 
     * for (int v=0; v <height; v++) { int textureU = initTextureU; int
     * textureV = initTextureV;
     * 
     * for (int u=0; u <width; u++) { if (((u + shadeMapOffset) &
     * SHADE_RES_MASK) == 0) { getInterpolatedShade(u + shadeMapOffset, v +
     * shadeMapOffset); } buffer[offset++] = sourceTexture.getColor(
     * textureU >> SCALE_BITS, textureV >> SCALE_BITS, shadeValue >>
     * SHADE_RES_SQ_BITS); textureU+=textureDu2; textureV+=textureDv2;
     * shadeValue+=shadeValueInc; } initTextureU+=textureDu1;
     * initTextureV+=textureDv1; }
     */
  }
  /**
   * Gets the shade (from the shade map) for the specified (u,v) location. The
   * u and v values should be left-shifted by SHADE_RES_BITS, and the extra
   * bits are used to interpolate between values. For an interpolation
   * example, a location halfway between shade values 1 and 3 would return 2.
   */
  public int getInterpolatedShade(int u, int v) {
    int fracU = u & SHADE_RES_MASK;
    int fracV = v & SHADE_RES_MASK;
    int offset = (u >> SHADE_RES_BITS)
        + ((v >> SHADE_RES_BITS) * shadeMapWidth);
    int shade00 = (SHADE_RES - fracV) * shadeMap[offset];
    int shade01 = fracV * shadeMap[offset + shadeMapWidth];
    int shade10 = (SHADE_RES - fracV) * shadeMap[offset + 1];
    int shade11 = fracV * shadeMap[offset + shadeMapWidth + 1];
    shadeValue = SHADE_RES_SQ / 2 + (SHADE_RES - fracU) * shade00
        + (SHADE_RES - fracU) * shade01 + fracU * shade10 + fracU
        * shade11;
    // the value to increment as u increments
    shadeValueInc = -shade00 - shade01 + shade10 + shade11;
    return shadeValue >> SHADE_RES_SQ_BITS;
  }
  /**
   * Gets the shade (from the built shade map) for the specified (u,v)
   * location.
   */
  public int getShade(int u, int v) {
    return shadeMap[u + v * shadeMapWidth];
  }
  /**
   * Builds the shade map for this surface from the specified list of point
   * lights and the ambiant light intensity.
   */
  public void buildShadeMap(List pointLights, float ambientLightIntensity) {
    Vector3D surfaceNormal = surfaceBounds.getNormal();
    int polyWidth = (int) surfaceBounds.getWidth() - SURFACE_BORDER_SIZE
        * 2;
    int polyHeight = (int) surfaceBounds.getHeight() - SURFACE_BORDER_SIZE
        * 2;
    // assume SURFACE_BORDER_SIZE is <= SHADE_RES
    shadeMapWidth = polyWidth / SHADE_RES + 4;
    shadeMapHeight = polyHeight / SHADE_RES + 4;
    shadeMap = new byte[shadeMapWidth * shadeMapHeight];
    // calculate the shade map origin
    Vector3D origin = new Vector3D(surfaceBounds.getOrigin());
    Vector3D du = new Vector3D(surfaceBounds.getDirectionU());
    Vector3D dv = new Vector3D(surfaceBounds.getDirectionV());
    du.multiply(SHADE_RES - SURFACE_BORDER_SIZE);
    dv.multiply(SHADE_RES - SURFACE_BORDER_SIZE);
    origin.subtract(du);
    origin.subtract(dv);
    // calculate the shade for each sample point.
    Vector3D point = new Vector3D();
    du.setTo(surfaceBounds.getDirectionU());
    dv.setTo(surfaceBounds.getDirectionV());
    du.multiply(SHADE_RES);
    dv.multiply(SHADE_RES);
    for (int v = 0; v < shadeMapHeight; v++) {
      point.setTo(origin);
      for (int u = 0; u < shadeMapWidth; u++) {
        shadeMap[u + v * shadeMapWidth] = calcShade(surfaceNormal,
            point, pointLights, ambientLightIntensity);
        point.add(du);
      }
      origin.add(dv);
    }
  }
  /**
   * Determine the shade of a point on the polygon. This computes the
   * Lambertian reflection for a point on the plane. Each point light has an
   * intensity and a distance falloff value, but no specular reflection or
   * shadows from other polygons are computed. The value returned is from 0 to
   * ShadedTexture.MAX_LEVEL.
   */
  protected byte calcShade(Vector3D normal, Vector3D point, List pointLights,
      float ambientLightIntensity) {
    float intensity = 0;
    Vector3D directionToLight = new Vector3D();
    for (int i = 0; i < pointLights.size(); i++) {
      PointLight3D light = (PointLight3D) pointLights.get(i);
      directionToLight.setTo(light);
      directionToLight.subtract(point);
      float distance = directionToLight.length();
      directionToLight.normalize();
      float lightIntensity = light.getIntensity(distance)
          * directionToLight.getDotProduct(normal);
      lightIntensity = Math.min(lightIntensity, 1);
      lightIntensity = Math.max(lightIntensity, 0);
      intensity += lightIntensity;
    }
    intensity = Math.min(intensity, 1);
    intensity = Math.max(intensity, 0);
    intensity += ambientLightIntensity;
    intensity = Math.min(intensity, 1);
    intensity = Math.max(intensity, 0);
    int level = Math.round(intensity * ShadedTexture.MAX_LEVEL);
    return (byte) level;
  }
}
/**
 * A PointLight3D is a point light that has an intensity (between 0 and 1) and
 * optionally a distance falloff value, which causes the light to diminish with
 * distance.
 */
class PointLight3D extends Vector3D {
  public static final float NO_DISTANCE_FALLOFF = -1;
  private float intensity;
  private float distanceFalloff;
  /**
   * Creates a new PointLight3D at (0,0,0) with an intensity of 1 and no
   * distance falloff.
   */
  public PointLight3D() {
    this(0, 0, 0, 1, NO_DISTANCE_FALLOFF);
  }
  /**
   * Creates a copy of the specified PointLight3D.
   */
  public PointLight3D(PointLight3D p) {
    setTo(p);
  }
  /**
   * Creates a new PointLight3D with the specified location and intensity. The
   * created light has no distance falloff.
   */
  public PointLight3D(float x, float y, float z, float intensity) {
    this(x, y, z, intensity, NO_DISTANCE_FALLOFF);
  }
  /**
   * Creates a new PointLight3D with the specified location. intensity, and no
   * distance falloff.
   */
  public PointLight3D(float x, float y, float z, float intensity,
      float distanceFalloff) {
    setTo(x, y, z);
    setIntensity(intensity);
    setDistanceFalloff(distanceFalloff);
  }
  /**
   * Sets this PointLight3D to the same location, intensity, and distance
   * falloff as the specified PointLight3D.
   */
  public void setTo(PointLight3D p) {
    setTo(p.x, p.y, p.z);
    setIntensity(p.getIntensity());
    setDistanceFalloff(p.getDistanceFalloff());
  }
  /**
   * Gets the intensity of this light from the specified distance.
   */
  public float getIntensity(float distance) {
    if (distanceFalloff == NO_DISTANCE_FALLOFF) {
      return intensity;
    } else if (distance >= distanceFalloff) {
      return 0;
    } else {
      return intensity * (distanceFalloff - distance)
          / (distanceFalloff + distance);
    }
  }
  /**
   * Gets the intensity of this light.
   */
  public float getIntensity() {
    return intensity;
  }
  /**
   * Sets the intensity of this light.
   */
  public void setIntensity(float intensity) {
    this.intensity = intensity;
  }
  /**
   * Gets the distances falloff value. The light intensity is zero beyond this
   * distance.
   */
  public float getDistanceFalloff() {
    return distanceFalloff;
  }
  /**
   * Sets the distances falloff value. The light intensity is zero beyond this
   * distance. Set to NO_DISTANCE_FALLOFF if the light does not diminish with
   * distance.
   */
  public void setDistanceFalloff(float distanceFalloff) {
    this.distanceFalloff = distanceFalloff;
  }
}
/**
 * The Transform3D class represents a rotation and translation.
 */
class Transform3D {
  protected Vector3D location;
  private float cosAngleX;
  private float sinAngleX;
  private float cosAngleY;
  private float sinAngleY;
  private float cosAngleZ;
  private float sinAngleZ;
  /**
   * Creates a new Transform3D with no translation or rotation.
   */
  public Transform3D() {
    this(0, 0, 0);
  }
  /**
   * Creates a new Transform3D with the specified translation and no rotation.
   */
  public Transform3D(float x, float y, float z) {
    location = new Vector3D(x, y, z);
    setAngle(0, 0, 0);
  }
  /**
   * Creates a new Transform3D
   */
  public Transform3D(Transform3D v) {
    location = new Vector3D();
    setTo(v);
  }
  public Object clone() {
    return new Transform3D(this);
  }
  /**
   * Sets this Transform3D to the specified Transform3D.
   */
  public void setTo(Transform3D v) {
    location.setTo(v.location);
    this.cosAngleX = v.cosAngleX;
    this.sinAngleX = v.sinAngleX;
    this.cosAngleY = v.cosAngleY;
    this.sinAngleY = v.sinAngleY;
    this.cosAngleZ = v.cosAngleZ;
    this.sinAngleZ = v.sinAngleZ;
  }
  /**
   * Gets the location (translation) of this transform.
   */
  public Vector3D getLocation() {
    return location;
  }
  public float getCosAngleX() {
    return cosAngleX;
  }
  public float getSinAngleX() {
    return sinAngleX;
  }
  public float getCosAngleY() {
    return cosAngleY;
  }
  public float getSinAngleY() {
    return sinAngleY;
  }
  public float getCosAngleZ() {
    return cosAngleZ;
  }
  public float getSinAngleZ() {
    return sinAngleZ;
  }
  public float getAngleX() {
    return (float) Math.atan2(sinAngleX, cosAngleX);
  }
  public float getAngleY() {
    return (float) Math.atan2(sinAngleY, cosAngleY);
  }
  public float getAngleZ() {
    return (float) Math.atan2(sinAngleZ, cosAngleZ);
  }
  public void setAngleX(float angleX) {
    cosAngleX = (float) Math.cos(angleX);
    sinAngleX = (float) Math.sin(angleX);
  }
  public void setAngleY(float angleY) {
    cosAngleY = (float) Math.cos(angleY);
    sinAngleY = (float) Math.sin(angleY);
  }
  public void setAngleZ(float angleZ) {
    cosAngleZ = (float) Math.cos(angleZ);
    sinAngleZ = (float) Math.sin(angleZ);
  }
  public void setAngle(float angleX, float angleY, float angleZ) {
    setAngleX(angleX);
    setAngleY(angleY);
    setAngleZ(angleZ);
  }
  public void rotateAngleX(float angle) {
    if (angle != 0) {
      setAngleX(getAngleX() + angle);
    }
  }
  public void rotateAngleY(float angle) {
    if (angle != 0) {
      setAngleY(getAngleY() + angle);
    }
  }
  public void rotateAngleZ(float angle) {
    if (angle != 0) {
      setAngleZ(getAngleZ() + angle);
    }
  }
  public void rotateAngle(float angleX, float angleY, float angleZ) {
    rotateAngleX(angleX);
    rotateAngleY(angleY);
    rotateAngleZ(angleZ);
  }
}
/**
 * The ViewWindow class represents the geometry of a view window for 3D viewing.
 */
class ViewWindow {
  private Rectangle bounds;
  private float angle;
  private float distanceToCamera;
  /**
   * Creates a new ViewWindow with the specified bounds on the screen and
   * horizontal view angle.
   */
  public ViewWindow(int left, int top, int width, int height, float angle) {
    bounds = new Rectangle();
    this.angle = angle;
    setBounds(left, top, width, height);
  }
  /**
   * Sets the bounds for this ViewWindow on the screen.
   */
  public void setBounds(int left, int top, int width, int height) {
    bounds.x = left;
    bounds.y = top;
    bounds.width = width;
    bounds.height = height;
    distanceToCamera = (bounds.width / 2) / (float) Math.tan(angle / 2);
  }
  /**
   * Sets the horizontal view angle for this ViewWindow.
   */
  public void setAngle(float angle) {
    this.angle = angle;
    distanceToCamera = (bounds.width / 2) / (float) Math.tan(angle / 2);
  }
  /**
   * Gets the horizontal view angle of this view window.
   */
  public float getAngle() {
    return angle;
  }
  /**
   * Gets the width of this view window.
   */
  public int getWidth() {
    return bounds.width;
  }
  /**
   * Gets the height of this view window.
   */
  public int getHeight() {
    return bounds.height;
  }
  /**
   * Gets the y offset of this view window on the screen.
   */
  public int getTopOffset() {
    return bounds.y;
  }
  /**
   * Gets the x offset of this view window on the screen.
   */
  public int getLeftOffset() {
    return bounds.x;
  }
  /**
   * Gets the distance from the camera to to this view window.
   */
  public float getDistance() {
    return distanceToCamera;
  }
  /**
   * Converts an x coordinate on this view window to the corresponding x
   * coordinate on the screen.
   */
  public float convertFromViewXToScreenX(float x) {
    return x + bounds.x + bounds.width / 2;
  }
  /**
   * Converts a y coordinate on this view window to the corresponding y
   * coordinate on the screen.
   */
  public float convertFromViewYToScreenY(float y) {
    return -y + bounds.y + bounds.height / 2;
  }
  /**
   * Converts an x coordinate on the screen to the corresponding x coordinate
   * on this view window.
   */
  public float convertFromScreenXToViewX(float x) {
    return x - bounds.x - bounds.width / 2;
  }
  /**
   * Converts an y coordinate on the screen to the corresponding y coordinate
   * on this view window.
   */
  public float convertFromScreenYToViewY(float y) {
    return -y + bounds.y + bounds.height / 2;
  }
  /**
   * Projects the specified vector to the screen.
   */
  public void project(Vector3D v) {
    // project to view window
    v.x = distanceToCamera * v.x / -v.z;
    v.y = distanceToCamera * v.y / -v.z;
    // convert to screen coordinates
    v.x = convertFromViewXToScreenX(v.x);
    v.y = convertFromViewYToScreenY(v.y);
  }
}
/**
 * The Texture class is an sabstract class that represents a 16-bit color
 * texture.
 */
abstract class Texture {
  protected int width;
  protected int height;
  /**
   * Creates a new Texture with the specified width and height.
   */
  public Texture(int width, int height) {
    this.width = width;
    this.height = height;
  }
  /**
   * Gets the width of this Texture.
   */
  public int getWidth() {
    return width;
  }
  /**
   * Gets the height of this Texture.
   */
  public int getHeight() {
    return height;
  }
  /**
   * Gets the 16-bit color of this Texture at the specified (x,y) location.
   */
  public abstract short getColor(int x, int y);
  /**
   * Creates an unshaded Texture from the specified image file.
   */
  public static Texture createTexture(String filename) {
    return createTexture(filename, false);
  }
  /**
   * Creates an Texture from the specified image file. If shaded is true, then
   * a ShadedTexture is returned.
   */
  public static Texture createTexture(String filename, boolean shaded) {
    try {
      return createTexture(ImageIO.read(new File(filename)), shaded);
    } catch (IOException ex) {
      ex.printStackTrace();
      return null;
    }
  }
  /**
   * Creates an unshaded Texture from the specified image.
   */
  public static Texture createTexture(BufferedImage image) {
    return createTexture(image, false);
  }
  /**
   * Creates an Texture from the specified image. If shaded is true, then a
   * ShadedTexture is returned.
   */
  public static Texture createTexture(BufferedImage image, boolean shaded) {
    int type = image.getType();
    int width = image.getWidth();
    int height = image.getHeight();
    if (!isPowerOfTwo(width) || !isPowerOfTwo(height)) {
      throw new IllegalArgumentException(
          "Size of texture must be a power of two.");
    }
    if (shaded) {
      // convert image to an indexed image
      if (type != BufferedImage.TYPE_BYTE_INDEXED) {
        System.out.println("Warning: image converted to "
            + "256-color indexed image. Some quality may "
            + "be lost.");
        BufferedImage newImage = new BufferedImage(image.getWidth(),
            image.getHeight(), BufferedImage.TYPE_BYTE_INDEXED);
        Graphics2D g = newImage.createGraphics();
        g.drawImage(image, 0, 0, null);
        g.dispose();
        image = newImage;
      }
      DataBuffer dest = image.getRaster().getDataBuffer();
      return new ShadedTexture(((DataBufferByte) dest).getData(),
          countbits(width - 1), countbits(height - 1),
          (IndexColorModel) image.getColorModel());
    } else {
      // convert image to an 16-bit image
      if (type != BufferedImage.TYPE_USHORT_565_RGB) {
        BufferedImage newImage = new BufferedImage(image.getWidth(),
            image.getHeight(), BufferedImage.TYPE_USHORT_565_RGB);
        Graphics2D g = newImage.createGraphics();
        g.drawImage(image, 0, 0, null);
        g.dispose();
        image = newImage;
      }
      DataBuffer dest = image.getRaster().getDataBuffer();
      return new PowerOf2Texture(((DataBufferUShort) dest).getData(),
          countbits(width - 1), countbits(height - 1));
    }
  }
  /**
   * Returns true if the specified number is a power of 2.
   */
  public static boolean isPowerOfTwo(int n) {
    return ((n & (n - 1)) == 0);
  }
  /**
   * Counts the number of "on" bits in an integer.
   */
  public static int countbits(int n) {
    int count = 0;
    while (n > 0) {
      count += (n & 1);
      n >>= 1;
    }
    return count;
  }
}
/**
 * The ShadedTexture class is a Texture that has multiple shades. The texture
 * source image is stored as a 8-bit image with a palette for every shade.
 */
final class ShadedTexture extends Texture {
  public static final int NUM_SHADE_LEVELS = 64;
  public static final int MAX_LEVEL = NUM_SHADE_LEVELS - 1;
  private static final int PALETTE_SIZE_BITS = 8;
  private static final int PALETTE_SIZE = 1 << PALETTE_SIZE_BITS;
  private byte[] buffer;
  private IndexColorModel palette;
  private short[] shadeTable;
  private int defaultShadeLevel;
  private int widthBits;
  private int widthMask;
  private int heightBits;
  private int heightMask;
  // the row set in setCurrRow and used in getColorCurrRow
  private int currRow;
  /**
   * Creates a new ShadedTexture from the specified 8-bit image buffer and
   * palette. The width of the bitmap is 2 to the power of widthBits, or (1 < <
   * widthBits). Likewise, the height of the bitmap is 2 to the power of
   * heightBits, or (1 < < heightBits). The texture is shaded from it"s
   * original color to black.
   */
  public ShadedTexture(byte[] buffer, int widthBits, int heightBits,
      IndexColorModel palette) {
    this(buffer, widthBits, heightBits, palette, Color.BLACK);
  }
  /**
   * Creates a new ShadedTexture from the specified 8-bit image buffer,
   * palette, and target shaded. The width of the bitmap is 2 to the power of
   * widthBits, or (1 < < widthBits). Likewise, the height of the bitmap is 2
   * to the power of heightBits, or (1 < < heightBits). The texture is shaded
   * from it"s original color to the target shade.
   */
  public ShadedTexture(byte[] buffer, int widthBits, int heightBits,
      IndexColorModel palette, Color targetShade) {
    super(1 << widthBits, 1 << heightBits);
    this.buffer = buffer;
    this.widthBits = widthBits;
    this.heightBits = heightBits;
    this.widthMask = getWidth() - 1;
    this.heightMask = getHeight() - 1;
    this.buffer = buffer;
    this.palette = palette;
    defaultShadeLevel = MAX_LEVEL;
    makeShadeTable(targetShade);
  }
  /**
   * Creates the shade table for this ShadedTexture. Each entry in the palette
   * is shaded from the original color to the specified target color.
   */
  public void makeShadeTable(Color targetShade) {
    shadeTable = new short[NUM_SHADE_LEVELS * PALETTE_SIZE];
    for (int level = 0; level < NUM_SHADE_LEVELS; level++) {
      for (int i = 0; i < palette.getMapSize(); i++) {
        int red = calcColor(palette.getRed(i), targetShade.getRed(),
            level);
        int green = calcColor(palette.getGreen(i), targetShade
            .getGreen(), level);
        int blue = calcColor(palette.getBlue(i), targetShade.getBlue(),
            level);
        int index = level * PALETTE_SIZE + i;
        // RGB 5:6:5
        shadeTable[index] = (short) (((red >> 3) << 11)
            | ((green >> 2) << 5) | (blue >> 3));
      }
    }
  }
  private int calcColor(int palColor, int target, int level) {
    return (palColor - target) * (level + 1) / NUM_SHADE_LEVELS + target;
  }
  /**
   * Sets the default shade level that is used when getColor() is called.
   */
  public void setDefaultShadeLevel(int level) {
    defaultShadeLevel = level;
  }
  /**
   * Gets the default shade level that is used when getColor() is called.
   */
  public int getDefaultShadeLevel() {
    return defaultShadeLevel;
  }
  /**
   * Gets the 16-bit color of this Texture at the specified (x,y) location,
   * using the default shade level.
   */
  public short getColor(int x, int y) {
    return getColor(x, y, defaultShadeLevel);
  }
  /**
   * Gets the 16-bit color of this Texture at the specified (x,y) location,
   * using the specified shade level.
   */
  public short getColor(int x, int y, int shadeLevel) {
    return shadeTable[(shadeLevel << PALETTE_SIZE_BITS)
        | (0xff & buffer[(x & widthMask)
            | ((y & heightMask) << widthBits)])];
  }
  /**
   * Sets the current row for getColorCurrRow(). Pre-calculates the offset for
   * this row.
   */
  public void setCurrRow(int y) {
    currRow = (y & heightMask) << widthBits;
  }
  /**
   * Gets the color at the specified x location at the specified shade level.
   * The current row defined in setCurrRow is used.
   */
  public short getColorCurrRow(int x, int shadeLevel) {
    return shadeTable[(shadeLevel << PALETTE_SIZE_BITS)
        | (0xff & buffer[(x & widthMask) | currRow])];
  }
}
/**
 * The PowerOf2Texture class is a Texture with a width and height that are a
 * power of 2 (32, 128, etc.).
 */
final class PowerOf2Texture extends Texture {
  private short[] buffer;
  private int widthBits;
  private int widthMask;
  private int heightBits;
  private int heightMask;
  /**
   * Creates a new PowerOf2Texture with the specified buffer. The width of the
   * bitmap is 2 to the power of widthBits, or (1 < < widthBits). Likewise,
   * the height of the bitmap is 2 to the power of heightBits, or (1 < <
   * heightBits).
   */
  public PowerOf2Texture(short[] buffer, int widthBits, int heightBits) {
    super(1 << widthBits, 1 << heightBits);
    this.buffer = buffer;
    this.widthBits = widthBits;
    this.heightBits = heightBits;
    this.widthMask = getWidth() - 1;
    this.heightMask = getHeight() - 1;
  }
  /**
   * Gets the 16-bit color of the pixel at location (x,y) in the bitmap.
   */
  public short getColor(int x, int y) {
    return buffer[(x & widthMask) + ((y & heightMask) << widthBits)];
  }
}
/**
 * Simple abstract class used for testing. Subclasses should implement the
 * draw() method.
 */
abstract class GameCore {
  protected static final int DEFAULT_FONT_SIZE = 24;
  // various lists of modes, ordered by preference
  protected static final DisplayMode[] MID_RES_MODES = {
      new DisplayMode(800, 600, 16, 0), new DisplayMode(800, 600, 32, 0),
      new DisplayMode(800, 600, 24, 0), new DisplayMode(640, 480, 16, 0),
      new DisplayMode(640, 480, 32, 0), new DisplayMode(640, 480, 24, 0),
      new DisplayMode(1024, 768, 16, 0),
      new DisplayMode(1024, 768, 32, 0),
      new DisplayMode(1024, 768, 24, 0), };
  protected static final DisplayMode[] LOW_RES_MODES = {
      new DisplayMode(640, 480, 16, 0), new DisplayMode(640, 480, 32, 0),
      new DisplayMode(640, 480, 24, 0), new DisplayMode(800, 600, 16, 0),
      new DisplayMode(800, 600, 32, 0), new DisplayMode(800, 600, 24, 0),
      new DisplayMode(1024, 768, 16, 0),
      new DisplayMode(1024, 768, 32, 0),
      new DisplayMode(1024, 768, 24, 0), };
  protected static final DisplayMode[] VERY_LOW_RES_MODES = {
      new DisplayMode(320, 240, 16, 0), new DisplayMode(400, 300, 16, 0),
      new DisplayMode(512, 384, 16, 0), new DisplayMode(640, 480, 16, 0),
      new DisplayMode(800, 600, 16, 0), };
  private boolean isRunning;
  protected ScreenManager screen;
  protected int fontSize = DEFAULT_FONT_SIZE;
  /**
   * Signals the game loop that it"s time to quit
   */
  public void stop() {
    isRunning = false;
  }
  /**
   * Calls init() and gameLoop()
   */
  public void run() {
    try {
      init();
      gameLoop();
    } finally {
      if (screen != null) {
        screen.restoreScreen();
      }
      lazilyExit();
    }
  }
  /**
   * Exits the VM from a daemon thread. The daemon thread waits 2 seconds then
   * calls System.exit(0). Since the VM should exit when only daemon threads
   * are running, this makes sure System.exit(0) is only called if neccesary.
   * It"s neccesary if the Java Sound system is running.
   */
  public void lazilyExit() {
    Thread thread = new Thread() {
      public void run() {
        // first, wait for the VM exit on its own.
        try {
          Thread.sleep(2000);
        } catch (InterruptedException ex) {
        }
        // system is still running, so force an exit
        System.exit(0);
      }
    };
    thread.setDaemon(true);
    thread.start();
  }
  /**
   * Sets full screen mode and initiates and objects.
   */
  public void init() {
    init(MID_RES_MODES);
  }
  /**
   * Sets full screen mode and initiates and objects.
   */
  public void init(DisplayMode[] possibleModes) {
    screen = new ScreenManager();
    DisplayMode displayMode = screen.findFirstCompatibleMode(possibleModes);
    screen.setFullScreen(displayMode);
    Window window = screen.getFullScreenWindow();
    window.setFont(new Font("Dialog", Font.PLAIN, fontSize));
    window.setBackground(Color.blue);
    window.setForeground(Color.white);
    isRunning = true;
  }
  public Image loadImage(String fileName) {
    return new ImageIcon(fileName).getImage();
  }
  /**
   * Runs through the game loop until stop() is called.
   */
  public void gameLoop() {
    long startTime = System.currentTimeMillis();
    long currTime = startTime;
    while (isRunning) {
      long elapsedTime = System.currentTimeMillis() - currTime;
      currTime += elapsedTime;
      // update
      update(elapsedTime);
      // draw the screen
      Graphics2D g = screen.getGraphics();
      draw(g);
      g.dispose();
      screen.update();
      // don"t take a nap! run as fast as possible
      /*
       * try { Thread.sleep(20); } catch (InterruptedException ex) { }
       */
    }
  }
  /**
   * Updates the state of the game/animation based on the amount of elapsed
   * time that has passed.
   */
  public void update(long elapsedTime) {
    // do nothing
  }
  /**
   * Draws to the screen. Subclasses must override this method.
   */
  public abstract void draw(Graphics2D g);
}
/**
 * The ScreenManager class manages initializing and displaying full screen
 * graphics modes.
 */
class ScreenManager {
  private GraphicsDevice device;
  /**
   * Creates a new ScreenManager object.
   */
  public ScreenManager() {
    GraphicsEnvironment environment = GraphicsEnvironment
        .getLocalGraphicsEnvironment();
    device = environment.getDefaultScreenDevice();
  }
  /**
   * Returns a list of compatible display modes for the default device on the
   * system.
   */
  public DisplayMode[] getCompatibleDisplayModes() {
    return device.getDisplayModes();
  }
  /**
   * Returns the first compatible mode in a list of modes. Returns null if no
   * modes are compatible.
   */
  public DisplayMode findFirstCompatibleMode(DisplayMode modes[]) {
    DisplayMode goodModes[] = device.getDisplayModes();
    for (int i = 0; i < modes.length; i++) {
      for (int j = 0; j < goodModes.length; j++) {
        if (displayModesMatch(modes[i], goodModes[j])) {
          return modes[i];
        }
      }
    }
    return null;
  }
  /**
   * Returns the current display mode.
   */
  public DisplayMode getCurrentDisplayMode() {
    return device.getDisplayMode();
  }
  /**
   * Determines if two display modes "match". Two display modes match if they
   * have the same resolution, bit depth, and refresh rate. The bit depth is
   * ignored if one of the modes has a bit depth of
   * DisplayMode.BIT_DEPTH_MULTI. Likewise, the refresh rate is ignored if one
   * of the modes has a refresh rate of DisplayMode.REFRESH_RATE_UNKNOWN.
   */
  public boolean displayModesMatch(DisplayMode mode1, DisplayMode mode2)
  {
    if (mode1.getWidth() != mode2.getWidth()
        || mode1.getHeight() != mode2.getHeight()) {
      return false;
    }
    if (mode1.getBitDepth() != DisplayMode.BIT_DEPTH_MULTI
        && mode2.getBitDepth() != DisplayMode.BIT_DEPTH_MULTI
        && mode1.getBitDepth() != mode2.getBitDepth()) {
      return false;
    }
    if (mode1.getRefreshRate() != DisplayMode.REFRESH_RATE_UNKNOWN
        && mode2.getRefreshRate() != DisplayMode.REFRESH_RATE_UNKNOWN
        && mode1.getRefreshRate() != mode2.getRefreshRate()) {
      return false;
    }
    return true;
  }
  /**
   * Enters full screen mode and changes the display mode. If the specified
   * display mode is null or not compatible with this device, or if the
   * display mode cannot be changed on this system, the current display mode
   * is used.
   * <p>
   * The display uses a BufferStrategy with 2 buffers.
   */
  public void setFullScreen(DisplayMode displayMode) {
    final JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setUndecorated(true);
    frame.setIgnoreRepaint(true);
    frame.setResizable(false);
    device.setFullScreenWindow(frame);
    if (displayMode != null && device.isDisplayChangeSupported()) {
      try {
        device.setDisplayMode(displayMode);
      } catch (IllegalArgumentException ex) {
      }
      // fix for mac os x
      frame.setSize(displayMode.getWidth(), displayMode.getHeight());
    }
    // avoid potential deadlock in 1.4.1_02
    try {
      EventQueue.invokeAndWait(new Runnable() {
        public void run() {
          frame.createBufferStrategy(2);
        }
      });
    } catch (InterruptedException ex) {
      // ignore
    } catch (InvocationTargetException ex) {
      // ignore
    }
  }
  /**
   * Gets the graphics context for the display. The ScreenManager uses double
   * buffering, so applications must call update() to show any graphics drawn.
   * <p>
   * The application must dispose of the graphics object.
   */
  public Graphics2D getGraphics() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      BufferStrategy strategy = window.getBufferStrategy();
      return (Graphics2D) strategy.getDrawGraphics();
    } else {
      return null;
    }
  }
  /**
   * Updates the display.
   */
  public void update() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      BufferStrategy strategy = window.getBufferStrategy();
      if (!strategy.contentsLost()) {
        strategy.show();
      }
    }
    // Sync the display on some systems.
    // (on Linux, this fixes event queue problems)
    //Toolkit.getDefaultToolkit().sync();
  }
  /**
   * Returns the window currently used in full screen mode. Returns null if
   * the device is not in full screen mode.
   */
  public JFrame getFullScreenWindow() {
    return (JFrame) device.getFullScreenWindow();
  }
  /**
   * Returns the width of the window currently used in full screen mode.
   * Returns 0 if the device is not in full screen mode.
   */
  public int getWidth() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      return window.getWidth();
    } else {
      return 0;
    }
  }
  /**
   * Returns the height of the window currently used in full screen mode.
   * Returns 0 if the device is not in full screen mode.
   */
  public int getHeight() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      return window.getHeight();
    } else {
      return 0;
    }
  }
  /**
   * Restores the screen"s display mode.
   */
  public void restoreScreen() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      window.dispose();
    }
    device.setFullScreenWindow(null);
  }
  /**
   * Creates an image compatible with the current display.
   */
  public BufferedImage createCompatibleImage(int w, int h, int transparancy) {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      GraphicsConfiguration gc = window.getGraphicsConfiguration();
      return gc.createCompatibleImage(w, h, transparancy);
    }
    return null;
  }
}
/**
 * A thread pool is a group of a limited number of threads that are used to
 * execute tasks.
 */
class ThreadPool extends ThreadGroup {
  private boolean isAlive;
  private LinkedList taskQueue;
  private int threadID;
  private static int threadPoolID;
  /**
   * Creates a new ThreadPool.
   * 
   * @param numThreads
   *            The number of threads in the pool.
   */
  public ThreadPool(int numThreads) {
    super("ThreadPool-" + (threadPoolID++));
    setDaemon(true);
    isAlive = true;
    taskQueue = new LinkedList();
    for (int i = 0; i < numThreads; i++) {
      new PooledThread().start();
    }
  }
  /**
   * Requests a new task to run. This method returns immediately, and the task
   * executes on the next available idle thread in this ThreadPool.
   * <p>
   * Tasks start execution in the order they are received.
   * 
   * @param task
   *            The task to run. If null, no action is taken.
   * @throws IllegalStateException
   *             if this ThreadPool is already closed.
   */
  public synchronized void runTask(Runnable task) {
    if (!isAlive) {
      throw new IllegalStateException();
    }
    if (task != null) {
      taskQueue.add(task);
      notify();
    }
  }
  protected synchronized Runnable getTask() throws InterruptedException {
    while (taskQueue.size() == 0) {
      if (!isAlive) {
        return null;
      }
      wait();
    }
    return (Runnable) taskQueue.removeFirst();
  }
  /**
   * Closes this ThreadPool and returns immediately. All threads are stopped,
   * and any waiting tasks are not executed. Once a ThreadPool is closed, no
   * more tasks can be run on this ThreadPool.
   */
  public synchronized void close() {
    if (isAlive) {
      isAlive = false;
      taskQueue.clear();
      interrupt();
    }
  }
  /**
   * Closes this ThreadPool and waits for all running threads to finish. Any
   * waiting tasks are executed.
   */
  public void join() {
    // notify all waiting threads that this ThreadPool is no
    // longer alive
    synchronized (this) {
      isAlive = false;
      notifyAll();
    }
    // wait for all threads to finish
    Thread[] threads = new Thread[activeCount()];
    int count = enumerate(threads);
    for (int i = 0; i < count; i++) {
      try {
        threads[i].join();
      } catch (InterruptedException ex) {
      }
    }
  }
  /**
   * Signals that a PooledThread has started. This method does nothing by
   * default; subclasses should override to do any thread-specific startup
   * tasks.
   */
  protected void threadStarted() {
    // do nothing
  }
  /**
   * Signals that a PooledThread has stopped. This method does nothing by
   * default; subclasses should override to do any thread-specific cleanup
   * tasks.
   */
  protected void threadStopped() {
    // do nothing
  }
  /**
   * A PooledThread is a Thread in a ThreadPool group, designed to run tasks
   * (Runnables).
   */
  private class PooledThread extends Thread {
    public PooledThread() {
      super(ThreadPool.this, "PooledThread-" + (threadID++));
    }
    public void run() {
      // signal that this thread has started
      threadStarted();
      while (!isInterrupted()) {
        // get a task to run
        Runnable task = null;
        try {
          task = getTask();
        } catch (InterruptedException ex) {
        }
        // if getTask() returned null or was interrupted,
        // close this thread.
        if (task == null) {
          break;
        }
        // run the task, and eat any exceptions it throws
        try {
          task.run();
        } catch (Throwable t) {
          uncaughtException(this, t);
        }
      }
      // signal that this thread has stopped
      threadStopped();
    }
  }
}
/**
 * The SoundManager class manages sound playback. The SoundManager is a
 * ThreadPool, with each thread playing back one sound at a time. This allows
 * the SoundManager to easily limit the number of simultaneous sounds being
 * played.
 * <p>
 * Possible ideas to extend this class:
 * <ul>
 * <li>add a setMasterVolume() method, which uses Controls to set the volume
 * for each line.
 * <li>don"t play a sound if more than, say, 500ms has passed since the request
 * to play
 * </ul>
 */
class SoundManager extends ThreadPool {
  private AudioFormat playbackFormat;
  private ThreadLocal localLine;
  private ThreadLocal localBuffer;
  private Object pausedLock;
  private boolean paused;
  /**
   * Creates a new SoundManager using the maximum number of simultaneous
   * sounds.
   */
  public SoundManager(AudioFormat playbackFormat) {
    this(playbackFormat, getMaxSimultaneousSounds(playbackFormat));
  }
  /**
   * Creates a new SoundManager with the specified maximum number of
   * simultaneous sounds.
   */
  public SoundManager(AudioFormat playbackFormat, int maxSimultaneousSounds) {
    super(Math.min(maxSimultaneousSounds,
        getMaxSimultaneousSounds(playbackFormat)));
    this.playbackFormat = playbackFormat;
    localLine = new ThreadLocal();
    localBuffer = new ThreadLocal();
    pausedLock = new Object();
    // notify threads in pool it"s ok to start
    synchronized (this) {
      notifyAll();
    }
  }
  /**
   * Gets the maximum number of simultaneous sounds with the specified
   * AudioFormat that the default mixer can play.
   */
  public static int getMaxSimultaneousSounds(AudioFormat playbackFormat) {
    DataLine.Info lineInfo = new DataLine.Info(SourceDataLine.class,
        playbackFormat);
    Mixer mixer = AudioSystem.getMixer(null);
    return mixer.getMaxLines(lineInfo);
  }
  /**
   * Does any clean up before closing.
   */
  protected void cleanUp() {
    // signal to unpause
    setPaused(false);
    // close the mixer (stops any running sounds)
    Mixer mixer = AudioSystem.getMixer(null);
    if (mixer.isOpen()) {
      mixer.close();
    }
  }
  public void close() {
    cleanUp();
    super.close();
  }
  public void join() {
    cleanUp();
    super.join();
  }
  /**
   * Sets the paused state. Sounds may not pause immediately.
   */
  public void setPaused(boolean paused) {
    if (this.paused != paused) {
      synchronized (pausedLock) {
        this.paused = paused;
        if (!paused) {
          // restart sounds
          pausedLock.notifyAll();
        }
      }
    }
  }
  /**
   * Returns the paused state.
   */
  public boolean isPaused() {
    return paused;
  }
  /**
   * Loads a Sound from the file system. Returns null if an error occurs.
   */
  public Sound getSound(String filename) {
    return getSound(getAudioInputStream(filename));
  }
  /**
   * Loads a Sound from an input stream. Returns null if an error occurs.
   */
  public Sound getSound(InputStream is) {
    return getSound(getAudioInputStream(is));
  }
  /**
   * Loads a Sound from an AudioInputStream.
   */
  public Sound getSound(AudioInputStream audioStream) {
    if (audioStream == null) {
      return null;
    }
    // get the number of bytes to read
    int length = (int) (audioStream.getFrameLength() * audioStream
        .getFormat().getFrameSize());
    // read the entire stream
    byte[] samples = new byte[length];
    DataInputStream is = new DataInputStream(audioStream);
    try {
      is.readFully(samples);
      is.close();
    } catch (IOException ex) {
      ex.printStackTrace();
    }
    // return the samples
    return new Sound(samples);
  }
  /**
   * Creates an AudioInputStream from a sound from the file system.
   */
  public AudioInputStream getAudioInputStream(String filename) {
    try {
      return getAudioInputStream(new FileInputStream(filename));
    } catch (IOException ex) {
      ex.printStackTrace();
      return null;
    }
  }
  /**
   * Creates an AudioInputStream from a sound from an input stream
   */
  public AudioInputStream getAudioInputStream(InputStream is) {
    try {
      if (!is.markSupported()) {
        is = new BufferedInputStream(is);
      }
      // open the source stream
      AudioInputStream source = AudioSystem.getAudioInputStream(is);
      // convert to playback format
      return AudioSystem.getAudioInputStream(playbackFormat, source);
    } catch (UnsupportedAudioFileException ex) {
      ex.printStackTrace();
    } catch (IOException ex) {
      ex.printStackTrace();
    } catch (IllegalArgumentException ex) {
      ex.printStackTrace();
    }
    return null;
  }
  /**
   * Plays a sound. This method returns immediately.
   */
  public InputStream play(Sound sound) {
    return play(sound, null, false);
  }
  /**
   * Plays a sound with an optional SoundFilter, and optionally looping. This
   * method returns immediately.
   */
  public InputStream play(Sound sound, SoundFilter filter, boolean loop) {
    InputStream is;
    if (sound != null) {
      if (loop) {
        is = new LoopingByteInputStream(sound.getSamples());
      } else {
        is = new ByteArrayInputStream(sound.getSamples());
      }
      return play(is, filter);
    }
    return null;
  }
  /**
   * Plays a sound from an InputStream. This method returns immediately.
   */
  public InputStream play(InputStream is) {
    return play(is, null);
  }
  /**
   * Plays a sound from an InputStream with an optional sound filter. This
   * method returns immediately.
   */
  public InputStream play(InputStream is, SoundFilter filter) {
    if (is != null) {
      if (filter != null) {
        is = new FilteredSoundStream(is, filter);
      }
      runTask(new SoundPlayer(is));
    }
    return is;
  }
  /**
   * Signals that a PooledThread has started. Creates the Thread"s line and
   * buffer.
   */
  protected void threadStarted() {
    // wait for the SoundManager constructor to finish
    synchronized (this) {
      try {
        wait();
      } catch (InterruptedException ex) {
      }
    }
    // use a short, 100ms (1/10th sec) buffer for filters that
    // change in real-time
    int bufferSize = playbackFormat.getFrameSize()
        * Math.round(playbackFormat.getSampleRate() / 10);
    // create, open, and start the line
    SourceDataLine line;
    DataLine.Info lineInfo = new DataLine.Info(SourceDataLine.class,
        playbackFormat);
    try {
      line = (SourceDataLine) AudioSystem.getLine(lineInfo);
      line.open(playbackFormat, bufferSize);
    } catch (LineUnavailableException ex) {
      // the line is unavailable - signal to end this thread
      Thread.currentThread().interrupt();
      return;
    }
    line.start();
    // create the buffer
    byte[] buffer = new byte[bufferSize];
    // set this thread"s locals
    localLine.set(line);
    localBuffer.set(buffer);
  }
  /**
   * Signals that a PooledThread has stopped. Drains and closes the Thread"s
   * Line.
   */
  protected void threadStopped() {
    SourceDataLine line = (SourceDataLine) localLine.get();
    if (line != null) {
      line.drain();
      line.close();
    }
  }
  /**
   * The SoundPlayer class is a task for the PooledThreads to run. It receives
   * the threads"s Line and byte buffer from the ThreadLocal variables and
   * plays a sound from an InputStream.
   * <p>
   * This class only works when called from a PooledThread.
   */
  protected class SoundPlayer implements Runnable {
    private InputStream source;
    public SoundPlayer(InputStream source) {
      this.source = source;
    }
    public void run() {
      // get line and buffer from ThreadLocals
      SourceDataLine line = (SourceDataLine) localLine.get();
      byte[] buffer = (byte[]) localBuffer.get();
      if (line == null || buffer == null) {
        // the line is unavailable
        return;
      }
      // copy data to the line
      try {
        int numBytesRead = 0;
        while (numBytesRead != -1) {
          // if paused, wait until unpaused
          synchronized (pausedLock) {
            if (paused) {
              try {
                pausedLock.wait();
              } catch (InterruptedException ex) {
                return;
              }
            }
          }
          // copy data
          numBytesRead = source.read(buffer, 0, buffer.length);
          if (numBytesRead != -1) {
            line.write(buffer, 0, numBytesRead);
          }
        }
      } catch (IOException ex) {
        ex.printStackTrace();
      }
    }
  }
}
/**
 * The LoopingByteInputStream is a ByteArrayInputStream that loops indefinitly.
 * The looping stops when the close() method is called.
 * <p>
 * Possible ideas to extend this class:
 * <ul>
 * <li>Add an option to only loop a certain number of times.
 * </ul>
 */
class LoopingByteInputStream extends ByteArrayInputStream {
  private boolean closed;
  /**
   * Creates a new LoopingByteInputStream with the specified byte array. The
   * array is not copied.
   */
  public LoopingByteInputStream(byte[] buffer) {
    super(buffer);
    closed = false;
  }
  /**
   * Reads <code>length</code> bytes from the array. If the end of the array
   * is reached, the reading starts over from the beginning of the array.
   * Returns -1 if the array has been closed.
   */
  public int read(byte[] buffer, int offset, int length) {
    if (closed) {
      return -1;
    }
    int totalBytesRead = 0;
    while (totalBytesRead < length) {
      int numBytesRead = super.read(buffer, offset + totalBytesRead,
          length - totalBytesRead);
      if (numBytesRead > 0) {
        totalBytesRead += numBytesRead;
      } else {
        reset();
      }
    }
    return totalBytesRead;
  }
  /**
   * Closes the stream. Future calls to the read() methods will return 1.
   */
  public void close() throws IOException {
    super.close();
    closed = true;
  }
}
/**
 * A abstract class designed to filter sound samples. Since SoundFilters may use
 * internal buffering of samples, a new SoundFilter object should be created for
 * every sound played. However, SoundFilters can be reused after they are
 * finished by called the reset() method.
 * <p>
 * Assumes all samples are 16-bit, signed, little-endian format.
 * 
 * @see FilteredSoundStream
 */
abstract class SoundFilter {
  /**
   * Resets this SoundFilter. Does nothing by default.
   */
  public void reset() {
    // do nothing
  }
  /**
   * Gets the remaining size, in bytes, that this filter plays after the sound
   * is finished. An example would be an echo that plays longer than it"s
   * original sound. This method returns 0 by default.
   */
  public int getRemainingSize() {
    return 0;
  }
  /**
   * Filters an array of samples. Samples should be in 16-bit, signed,
   * little-endian format.
   */
  public void filter(byte[] samples) {
    filter(samples, 0, samples.length);
  }
  /**
   * Filters an array of samples. Samples should be in 16-bit, signed,
   * little-endian format. This method should be implemented by subclasses.
   */
  public abstract void filter(byte[] samples, int offset, int length);
  /**
   * Convenience method for getting a 16-bit sample from a byte array. Samples
   * should be in 16-bit, signed, little-endian format.
   */
  public static short getSample(byte[] buffer, int position) {
    return (short) (((buffer[position + 1] & 0xff) << 8) | (buffer[position] & 0xff));
  }
  /**
   * Convenience method for setting a 16-bit sample in a byte array. Samples
   * should be in 16-bit, signed, little-endian format.
   */
  public static void setSample(byte[] buffer, int position, short sample) {
    buffer[position] = (byte) (sample & 0xff);
    buffer[position + 1] = (byte) ((sample >> 8) & 0xff);
  }
}
/**
 * The FilteredSoundStream class is a FilterInputStream that applies a
 * SoundFilter to the underlying input stream.
 * 
 * @see SoundFilter
 */
class FilteredSoundStream extends FilterInputStream {
  private static final int REMAINING_SIZE_UNKNOWN = -1;
  private SoundFilter soundFilter;
  private int remainingSize;
  /**
   * Creates a new FilteredSoundStream object with the specified InputStream
   * and SoundFilter.
   */
  public FilteredSoundStream(InputStream in, SoundFilter soundFilter) {
    super(in);
    this.soundFilter = soundFilter;
    remainingSize = REMAINING_SIZE_UNKNOWN;
  }
  /**
   * Overrides the FilterInputStream method to apply this filter whenever
   * bytes are read
   */
  public int read(byte[] samples, int offset, int length) throws IOException {
    // read and filter the sound samples in the stream
    int bytesRead = super.read(samples, offset, length);
    if (bytesRead > 0) {
      soundFilter.filter(samples, offset, bytesRead);
      return bytesRead;
    }
    // if there are no remaining bytes in the sound stream,
    // check if the filter has any remaining bytes ("echoes").
    if (remainingSize == REMAINING_SIZE_UNKNOWN) {
      remainingSize = soundFilter.getRemainingSize();
      // round down to nearest multiple of 4
      // (typical frame size)
      remainingSize = remainingSize / 4 * 4;
    }
    if (remainingSize > 0) {
      length = Math.min(length, remainingSize);
      // clear the buffer
      for (int i = offset; i < offset + length; i++) {
        samples[i] = 0;
      }
      // filter the remaining bytes
      soundFilter.filter(samples, offset, length);
      remainingSize -= length;
      // return
      return length;
    } else {
      // end of stream
      return -1;
    }
  }
}
/**
 * The MoreMath class provides functions not contained in the java.lang.Math or
 * java.lang.StrictMath classes.
 */
class MoreMath {
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(short v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(int v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(long v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(float v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(double v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Faster ceil function to convert a float to an int. Contrary to the
   * java.lang.Math ceil function, this function takes a float as an argument,
   * returns an int instead of a double, and does not consider special cases.
   */
  public static int ceil(float f) {
    if (f > 0) {
      return (int) f + 1;
    } else {
      return (int) f;
    }
  }
  /**
   * Faster floor function to convert a float to an int. Contrary to the
   * java.lang.Math floor function, this function takes a float as an
   * argument, returns an int instead of a double, and does not consider
   * special cases.
   */
  public static int floor(float f) {
    if (f >= 0) {
      return (int) f;
    } else {
      return (int) f - 1;
    }
  }
  /**
   * Returns true if the specified number is a power of 2.
   */
  public static boolean isPowerOfTwo(int n) {
    return ((n & (n - 1)) == 0);
  }
  /**
   * Gets the number of "on" bits in an integer.
   */
  public static int getBitCount(int n) {
    int count = 0;
    while (n > 0) {
      count += (n & 1);
      n >>= 1;
    }
    return count;
  }
}
/**
 * The ScanConverter class converts a projected polygon into a series of
 * horizontal scans for drawing.
 */
class ScanConverter {
  private static final int SCALE_BITS = 16;
  private static final int SCALE = 1 << SCALE_BITS;
  private static final int SCALE_MASK = SCALE - 1;
  protected ViewWindow view;
  protected Scan[] scans;
  protected int top;
  protected int bottom;
  /**
   * A horizontal scan line.
   */
  public static class Scan {
    public int left;
    public int right;
    /**
     * Sets the left and right boundary for this scan if the x value is
     * outside the current boundary.
     */
    public void setBoundary(int x) {
      if (x < left) {
        left = x;
      }
      if (x - 1 > right) {
        right = x - 1;
      }
    }
    /**
     * Clears this scan line.
     */
    public void clear() {
      left = Integer.MAX_VALUE;
      right = Integer.MIN_VALUE;
    }
    /**
     * Determines if this scan is valid (if left <= right).
     */
    public boolean isValid() {
      return (left <= right);
    }
    /**
     * Sets this scan.
     */
    public void setTo(int left, int right) {
      this.left = left;
      this.right = right;
    }
    /**
     * Checks if this scan is equal to the specified values.
     */
    public boolean equals(int left, int right) {
      return (this.left == left && this.right == right);
    }
  }
  /**
   * Creates a new ScanConverter for the specified ViewWindow. The
   * ViewWindow"s properties can change in between scan conversions.
   */
  public ScanConverter(ViewWindow view) {
    this.view = view;
  }
  /**
   * Gets the top boundary of the last scan-converted polygon.
   */
  public int getTopBoundary() {
    return top;
  }
  /**
   * Gets the bottom boundary of the last scan-converted polygon.
   */
  public int getBottomBoundary() {
    return bottom;
  }
  /**
   * Gets the scan line for the specified y value.
   */
  public Scan getScan(int y) {
    return scans[y];
  }
  /**
   * Ensures this ScanConverter has the capacity to scan-convert a polygon to
   * the ViewWindow.
   */
  protected void ensureCapacity() {
    int height = view.getTopOffset() + view.getHeight();
    if (scans == null || scans.length != height) {
      scans = new Scan[height];
      for (int i = 0; i < height; i++) {
        scans[i] = new Scan();
      }
      // set top and bottom so clearCurrentScan clears all
      top = 0;
      bottom = height - 1;
    }
  }
  /**
   * Clears the current scan.
   */
  private void clearCurrentScan() {
    for (int i = top; i <= bottom; i++) {
      scans[i].clear();
    }
    top = Integer.MAX_VALUE;
    bottom = Integer.MIN_VALUE;
  }
  /**
   * Scan-converts a projected polygon. Returns true if the polygon is visible
   * in the view window.
   */
  public boolean convert(Polygon3D polygon) {
    ensureCapacity();
    clearCurrentScan();
    int minX = view.getLeftOffset();
    int maxX = view.getLeftOffset() + view.getWidth() - 1;
    int minY = view.getTopOffset();
    int maxY = view.getTopOffset() + view.getHeight() - 1;
    int numVertices = polygon.getNumVertices();
    for (int i = 0; i < numVertices; i++) {
      Vector3D v1 = polygon.getVertex(i);
      Vector3D v2;
      if (i == numVertices - 1) {
        v2 = polygon.getVertex(0);
      } else {
        v2 = polygon.getVertex(i + 1);
      }
      // ensure v1.y < v2.y
      if (v1.y > v2.y) {
        Vector3D temp = v1;
        v1 = v2;
        v2 = temp;
      }
      float dy = v2.y - v1.y;
      // ignore horizontal lines
      if (dy == 0) {
        continue;
      }
      int startY = Math.max(MoreMath.ceil(v1.y), minY);
      int endY = Math.min(MoreMath.ceil(v2.y) - 1, maxY);
      top = Math.min(top, startY);
      bottom = Math.max(bottom, endY);
      float dx = v2.x - v1.x;
      // special case: vertical line
      if (dx == 0) {
        int x = MoreMath.ceil(v1.x);
        // ensure x within view bounds
        x = Math.min(maxX + 1, Math.max(x, minX));
        for (int y = startY; y <= endY; y++) {
          scans[y].setBoundary(x);
        }
      } else {
        // scan-convert this edge (line equation)
        float gradient = dx / dy;
        // (slower version)
        /*
         * for (int y=startY; y <=endY; y++) { int x =
         * MoreMath.ceil(v1.x + (y - v1.y) * gradient); // ensure x
         * within view bounds x = Math.min(maxX+1, Math.max(x, minX));
         * scans[y].setBoundary(x); }
         */
        // (faster version)
        // trim start of line
        float startX = v1.x + (startY - v1.y) * gradient;
        if (startX < minX) {
          int yInt = (int) (v1.y + (minX - v1.x) / gradient);
          yInt = Math.min(yInt, endY);
          while (startY <= yInt) {
            scans[startY].setBoundary(minX);
            startY++;
          }
        } else if (startX > maxX) {
          int yInt = (int) (v1.y + (maxX - v1.x) / gradient);
          yInt = Math.min(yInt, endY);
          while (startY <= yInt) {
            scans[startY].setBoundary(maxX + 1);
            startY++;
          }
        }
        if (startY > endY) {
          continue;
        }
        // trim back of line
        float endX = v1.x + (endY - v1.y) * gradient;
        if (endX < minX) {
          int yInt = MoreMath.ceil(v1.y + (minX - v1.x) / gradient);
          yInt = Math.max(yInt, startY);
          while (endY >= yInt) {
            scans[endY].setBoundary(minX);
            endY--;
          }
        } else if (endX > maxX) {
          int yInt = MoreMath.ceil(v1.y + (maxX - v1.x) / gradient);
          yInt = Math.max(yInt, startY);
          while (endY >= yInt) {
            scans[endY].setBoundary(maxX + 1);
            endY--;
          }
        }
        if (startY > endY) {
          continue;
        }
        // line equation using integers
        int xScaled = (int) (SCALE * v1.x + SCALE * (startY - v1.y)
            * dx / dy)
            + SCALE_MASK;
        int dxScaled = (int) (dx * SCALE / dy);
        for (int y = startY; y <= endY; y++) {
          scans[y].setBoundary(xScaled >> SCALE_BITS);
          xScaled += dxScaled;
        }
      }
    }
    // check if visible (any valid scans)
    for (int i = top; i <= bottom; i++) {
      if (scans[i].isValid()) {
        return true;
      }
    }
    return false;
  }
}
/**
 * The PolygonRenderer class is an abstract class that transforms and draws
 * polygons onto the screen.
 */
abstract class PolygonRenderer {
  protected ScanConverter scanConverter;
  protected Transform3D camera;
  protected ViewWindow viewWindow;
  protected boolean clearViewEveryFrame;
  protected Polygon3D sourcePolygon;
  protected Polygon3D destPolygon;
  /**
   * Creates a new PolygonRenderer with the specified Transform3D (camera) and
   * ViewWindow. The view is cleared when startFrame() is called.
   */
  public PolygonRenderer(Transform3D camera, ViewWindow viewWindow) {
    this(camera, viewWindow, true);
  }
  /**
   * Creates a new PolygonRenderer with the specified Transform3D (camera) and
   * ViewWindow. If clearViewEveryFrame is true, the view is cleared when
   * startFrame() is called.
   */
  public PolygonRenderer(Transform3D camera, ViewWindow viewWindow,
      boolean clearViewEveryFrame) {
    this.camera = camera;
    this.viewWindow = viewWindow;
    this.clearViewEveryFrame = clearViewEveryFrame;
    init();
  }
  /**
   * Create the scan converter and dest polygon.
   */
  protected void init() {
    destPolygon = new Polygon3D();
    scanConverter = new ScanConverter(viewWindow);
  }
  /**
   * Gets the camera used for this PolygonRenderer.
   */
  public Transform3D getCamera() {
    return camera;
  }
  /**
   * Indicates the start of rendering of a frame. This method should be called
   * every frame before any polygons are drawn.
   */
  public void startFrame(Graphics2D g) {
    if (clearViewEveryFrame) {
      g.setColor(Color.black);
      g.fillRect(viewWindow.getLeftOffset(), viewWindow.getTopOffset(),
          viewWindow.getWidth(), viewWindow.getHeight());
    }
  }
  /**
   * Indicates the end of rendering of a frame. This method should be called
   * every frame after all polygons are drawn.
   */
  public void endFrame(Graphics2D g) {
    // do nothing, for now.
  }
  /**
   * Transforms and draws a polygon.
   */
  public boolean draw(Graphics2D g, Polygon3D poly) {
    if (poly.isFacing(camera.getLocation())) {
      sourcePolygon = poly;
      destPolygon.setTo(poly);
      destPolygon.subtract(camera);
      boolean visible = destPolygon.clip(-1);
      if (visible) {
        destPolygon.project(viewWindow);
        visible = scanConverter.convert(destPolygon);
        if (visible) {
          drawCurrentPolygon(g);
          return true;
        }
      }
    }
    return false;
  }
  /**
   * Draws the current polygon. At this point, the current polygon is
   * transformed, clipped, projected, scan-converted, and visible.
   */
  protected abstract void drawCurrentPolygon(Graphics2D g);
}
/**
 * The Sound class is a container for sound samples. The sound samples are
 * format-agnostic and are stored as a byte array.
 */
class Sound {
  private byte[] samples;
  /**
   * Create a new Sound object with the specified byte array. The array is not
   * copied.
   */
  public Sound(byte[] samples) {
    this.samples = samples;
  }
  /**
   * Returns this Sound"s objects samples as a byte array.
   */
  public byte[] getSamples() {
    return samples;
  }
}
/**
 * The InputManager manages input of key and mouse events. Events are mapped to
 * GameActions.
 */
class InputManager implements KeyListener, MouseListener, MouseMotionListener,
    MouseWheelListener {
  /**
   * An invisible cursor.
   */
  public static final Cursor INVISIBLE_CURSOR = Toolkit.getDefaultToolkit()
      .createCustomCursor(Toolkit.getDefaultToolkit().getImage(""),
          new Point(0, 0), "invisible");
  // mouse codes
  public static final int MOUSE_MOVE_LEFT = 0;
  public static final int MOUSE_MOVE_RIGHT = 1;
  public static final int MOUSE_MOVE_UP = 2;
  public static final int MOUSE_MOVE_DOWN = 3;
  public static final int MOUSE_WHEEL_UP = 4;
  public static final int MOUSE_WHEEL_DOWN = 5;
  public static final int MOUSE_BUTTON_1 = 6;
  public static final int MOUSE_BUTTON_2 = 7;
  public static final int MOUSE_BUTTON_3 = 8;
  private static final int NUM_MOUSE_CODES = 9;
  // key codes are defined in java.awt.KeyEvent.
  // most of the codes (except for some rare ones like
  // "alt graph") are less than 600.
  private static final int NUM_KEY_CODES = 600;
  private GameAction[] keyActions = new GameAction[NUM_KEY_CODES];
  private GameAction[] mouseActions = new GameAction[NUM_MOUSE_CODES];
  private Point mouseLocation;
  private Point centerLocation;
  private Component comp;
  private Robot robot;
  private boolean isRecentering;
  /**
   * Creates a new InputManager that listens to input from the specified
   * component.
   */
  public InputManager(Component comp) {
    this.rup = comp;
    mouseLocation = new Point();
    centerLocation = new Point();
    // register key and mouse listeners
    comp.addKeyListener(this);
    comp.addMouseListener(this);
    comp.addMouseMotionListener(this);
    comp.addMouseWheelListener(this);
    // allow input of the TAB key and other keys normally
    // used for focus traversal
    comp.setFocusTraversalKeysEnabled(false);
  }
  /**
   * Sets the cursor on this InputManager"s input component.
   */
  public void setCursor(Cursor cursor) {
    comp.setCursor(cursor);
  }
  /**
   * Sets whether realtive mouse mode is on or not. For relative mouse mode,
   * the mouse is "locked" in the center of the screen, and only the changed
   * in mouse movement is measured. In normal mode, the mouse is free to move
   * about the screen.
   */
  public void setRelativeMouseMode(boolean mode) {
    if (mode == isRelativeMouseMode()) {
      return;
    }
    if (mode) {
      try {
        robot = new Robot();
        mouseLocation.x = comp.getWidth() / 2;
        mouseLocation.y = comp.getHeight() / 2;
        recenterMouse();
      } catch (AWTException ex) {
        // couldn"t create robot!
        robot = null;
      }
    } else {
      robot = null;
    }
  }
  /**
   * Returns whether or not relative mouse mode is on.
   */
  public boolean isRelativeMouseMode() {
    return (robot != null);
  }
  /**
   * Maps a GameAction to a specific key. The key codes are defined in
   * java.awt.KeyEvent. If the key already has a GameAction mapped to it, the
   * new GameAction overwrites it.
   */
  public void mapToKey(GameAction gameAction, int keyCode) {
    keyActions[keyCode] = gameAction;
  }
  /**
   * Maps a GameAction to a specific mouse action. The mouse codes are defined
   * herer in InputManager (MOUSE_MOVE_LEFT, MOUSE_BUTTON_1, etc). If the
   * mouse action already has a GameAction mapped to it, the new GameAction
   * overwrites it.
   */
  public void mapToMouse(GameAction gameAction, int mouseCode) {
    mouseActions[mouseCode] = gameAction;
  }
  /**
   * Clears all mapped keys and mouse actions to this GameAction.
   */
  public void clearMap(GameAction gameAction) {
    for (int i = 0; i < keyActions.length; i++) {
      if (keyActions[i] == gameAction) {
        keyActions[i] = null;
      }
    }
    for (int i = 0; i < mouseActions.length; i++) {
      if (mouseActions[i] == gameAction) {
        mouseActions[i] = null;
      }
    }
    gameAction.reset();
  }
  /**
   * Gets a List of names of the keys and mouse actions mapped to this
   * GameAction. Each entry in the List is a String.
   */
  public List getMaps(GameAction gameCode) {
    ArrayList list = new ArrayList();
    for (int i = 0; i < keyActions.length; i++) {
      if (keyActions[i] == gameCode) {
        list.add(getKeyName(i));
      }
    }
    for (int i = 0; i < mouseActions.length; i++) {
      if (mouseActions[i] == gameCode) {
        list.add(getMouseName(i));
      }
    }
    return list;
  }
  /**
   * Resets all GameActions so they appear like they haven"t been pressed.
   */
  public void resetAllGameActions() {
    for (int i = 0; i < keyActions.length; i++) {
      if (keyActions[i] != null) {
        keyActions[i].reset();
      }
    }
    for (int i = 0; i < mouseActions.length; i++) {
      if (mouseActions[i] != null) {
        mouseActions[i].reset();
      }
    }
  }
  /**
   * Gets the name of a key code.
   */
  public static String getKeyName(int keyCode) {
    return KeyEvent.getKeyText(keyCode);
  }
  /**
   * Gets the name of a mouse code.
   */
  public static String getMouseName(int mouseCode) {
    switch (mouseCode) {
    case MOUSE_MOVE_LEFT:
      return "Mouse Left";
    case MOUSE_MOVE_RIGHT:
      return "Mouse Right";
    case MOUSE_MOVE_UP:
      return "Mouse Up";
    case MOUSE_MOVE_DOWN:
      return "Mouse Down";
    case MOUSE_WHEEL_UP:
      return "Mouse Wheel Up";
    case MOUSE_WHEEL_DOWN:
      return "Mouse Wheel Down";
    case MOUSE_BUTTON_1:
      return "Mouse Button 1";
    case MOUSE_BUTTON_2:
      return "Mouse Button 2";
    case MOUSE_BUTTON_3:
      return "Mouse Button 3";
    default:
      return "Unknown mouse code " + mouseCode;
    }
  }
  /**
   * Gets the x position of the mouse.
   */
  public int getMouseX() {
    return mouseLocation.x;
  }
  /**
   * Gets the y position of the mouse.
   */
  public int getMouseY() {
    return mouseLocation.y;
  }
  /**
   * Uses the Robot class to try to postion the mouse in the center of the
   * screen.
   * <p>
   * Note that use of the Robot class may not be available on all platforms.
   */
  private synchronized void recenterMouse() {
    if (robot != null && comp.isShowing()) {
      centerLocation.x = comp.getWidth() / 2;
      centerLocation.y = comp.getHeight() / 2;
      SwingUtilities.convertPointToScreen(centerLocation, comp);
      isRecentering = true;
      robot.mouseMove(centerLocation.x, centerLocation.y);
    }
  }
  private GameAction getKeyAction(KeyEvent e) {
    int keyCode = e.getKeyCode();
    if (keyCode < keyActions.length) {
      return keyActions[keyCode];
    } else {
      return null;
    }
  }
  /**
   * Gets the mouse code for the button specified in this MouseEvent.
   */
  public static int getMouseButtonCode(MouseEvent e) {
    switch (e.getButton()) {
    case MouseEvent.BUTTON1:
      return MOUSE_BUTTON_1;
    case MouseEvent.BUTTON2:
      return MOUSE_BUTTON_2;
    case MouseEvent.BUTTON3:
      return MOUSE_BUTTON_3;
    default:
      return -1;
    }
  }
  private GameAction getMouseButtonAction(MouseEvent e) {
    int mouseCode = getMouseButtonCode(e);
    if (mouseCode != -1) {
      return mouseActions[mouseCode];
    } else {
      return null;
    }
  }
  // from the KeyListener interface
  public void keyPressed(KeyEvent e) {
    GameAction gameAction = getKeyAction(e);
    if (gameAction != null) {
      gameAction.press();
    }
    // make sure the key isn"t processed for anything else
    e.consume();
  }
  // from the KeyListener interface
  public void keyReleased(KeyEvent e) {
    GameAction gameAction = getKeyAction(e);
    if (gameAction != null) {
      gameAction.release();
    }
    // make sure the key isn"t processed for anything else
    e.consume();
  }
  // from the KeyListener interface
  public void keyTyped(KeyEvent e) {
    // make sure the key isn"t processed for anything else
    e.consume();
  }
  // from the MouseListener interface
  public void mousePressed(MouseEvent e) {
    GameAction gameAction = getMouseButtonAction(e);
    if (gameAction != null) {
      gameAction.press();
    }
  }
  // from the MouseListener interface
  public void mouseReleased(MouseEvent e) {
    GameAction gameAction = getMouseButtonAction(e);
    if (gameAction != null) {
      gameAction.release();
    }
  }
  // from the MouseListener interface
  public void mouseClicked(MouseEvent e) {
    // do nothing
  }
  // from the MouseListener interface
  public void mouseEntered(MouseEvent e) {
    mouseMoved(e);
  }
  // from the MouseListener interface
  public void mouseExited(MouseEvent e) {
    mouseMoved(e);
  }
  // from the MouseMotionListener interface
  public void mouseDragged(MouseEvent e) {
    mouseMoved(e);
  }
  // from the MouseMotionListener interface
  public synchronized void mouseMoved(MouseEvent e) {
    // this event is from re-centering the mouse - ignore it
    if (isRecentering && centerLocation.x == e.getX()
        && centerLocation.y == e.getY()) {
      isRecentering = false;
    } else {
      int dx = e.getX() - mouseLocation.x;
      int dy = e.getY() - mouseLocation.y;
      mouseHelper(MOUSE_MOVE_LEFT, MOUSE_MOVE_RIGHT, dx);
      mouseHelper(MOUSE_MOVE_UP, MOUSE_MOVE_DOWN, dy);
      if (isRelativeMouseMode()) {
        recenterMouse();
      }
    }
    mouseLocation.x = e.getX();
    mouseLocation.y = e.getY();
  }
  // from the MouseWheelListener interface
  public void mouseWheelMoved(MouseWheelEvent e) {
    mouseHelper(MOUSE_WHEEL_UP, MOUSE_WHEEL_DOWN, e.getWheelRotation());
  }
  private void mouseHelper(int codeNeg, int codePos, int amount) {
    GameAction gameAction;
    if (amount < 0) {
      gameAction = mouseActions[codeNeg];
    } else {
      gameAction = mouseActions[codePos];
    }
    if (gameAction != null) {
      gameAction.press(Math.abs(amount));
      gameAction.release();
    }
  }
}
/**
 * The GameAction class is an abstract to a user-initiated action, like jumping
 * or moving. GameActions can be mapped to keys or the mouse with the
 * InputManager.
 */
class GameAction {
  /**
   * Normal behavior. The isPressed() method returns true as long as the key
   * is held down.
   */
  public static final int NORMAL = 0;
  /**
   * Initial press behavior. The isPressed() method returns true only after
   * the key is first pressed, and not again until the key is released and
   * pressed again.
   */
  public static final int DETECT_INITAL_PRESS_ONLY = 1;
  private static final int STATE_RELEASED = 0;
  private static final int STATE_PRESSED = 1;
  private static final int STATE_WAITING_FOR_RELEASE = 2;
  private String name;
  private int behavior;
  private int amount;
  private int state;
  /**
   * Create a new GameAction with the NORMAL behavior.
   */
  public GameAction(String name) {
    this(name, NORMAL);
  }
  /**
   * Create a new GameAction with the specified behavior.
   */
  public GameAction(String name, int behavior) {
    this.name = name;
    this.behavior = behavior;
    reset();
  }
  /**
   * Gets the name of this GameAction.
   */
  public String getName() {
    return name;
  }
  /**
   * Resets this GameAction so that it appears like it hasn"t been pressed.
   */
  public void reset() {
    state = STATE_RELEASED;
    amount = 0;
  }
  /**
   * Taps this GameAction. Same as calling press() followed by release().
   */
  public synchronized void tap() {
    press();
    release();
  }
  /**
   * Signals that the key was pressed.
   */
  public synchronized void press() {
    press(1);
  }
  /**
   * Signals that the key was pressed a specified number of times, or that the
   * mouse move a spcified distance.
   */
  public synchronized void press(int amount) {
    if (state != STATE_WAITING_FOR_RELEASE) {
      this.amount += amount;
      state = STATE_PRESSED;
    }
  }
  /**
   * Signals that the key was released
   */
  public synchronized void release() {
    state = STATE_RELEASED;
  }
  /**
   * Returns whether the key was pressed or not since last checked.
   */
  public synchronized boolean isPressed() {
    return (getAmount() != 0);
  }
  /**
   * For keys, this is the number of times the key was pressed since it was
   * last checked. For mouse movement, this is the distance moved.
   */
  public synchronized int getAmount() {
    int retVal = amount;
    if (retVal != 0) {
      if (state == STATE_RELEASED) {
        amount = 0;
      } else if (behavior == DETECT_INITAL_PRESS_ONLY) {
        state = STATE_WAITING_FOR_RELEASE;
        amount = 0;
      }
    }
    return retVal;
  }
}
/**
 * The SolidPolygonRenderer class transforms and draws solid-colored polygons
 * onto the screen.
 */
class SolidPolygonRenderer extends PolygonRenderer {
  public SolidPolygonRenderer(Transform3D camera, ViewWindow viewWindow) {
    this(camera, viewWindow, true);
  }
  public SolidPolygonRenderer(Transform3D camera, ViewWindow viewWindow,
      boolean clearViewEveryFrame) {
    super(camera, viewWindow, clearViewEveryFrame);
  }
  /**
   * Draws the current polygon. At this point, the current polygon is
   * transformed, clipped, projected, scan-converted, and visible.
   */
  protected void drawCurrentPolygon(Graphics2D g) {
    // set the color
    if (sourcePolygon instanceof SolidPolygon3D) {
      g.setColor(((SolidPolygon3D) sourcePolygon).getColor());
    } else {
      g.setColor(Color.GREEN);
    }
    // draw the scans
    int y = scanConverter.getTopBoundary();
    while (y <= scanConverter.getBottomBoundary()) {
      ScanConverter.Scan scan = scanConverter.getScan(y);
      if (scan.isValid()) {
        g.drawLine(scan.left, y, scan.right, y);
      }
      y++;
    }
  }
}
/**
 * The SolidPolygon3D class is a Polygon with a color.
 */
class SolidPolygon3D extends Polygon3D {
  private Color color = Color.GREEN;
  public SolidPolygon3D() {
    super();
  }
  public SolidPolygon3D(Vector3D v0, Vector3D v1, Vector3D v2) {
    this(new Vector3D[] { v0, v1, v2 });
  }
  public SolidPolygon3D(Vector3D v0, Vector3D v1, Vector3D v2, Vector3D v3) {
    this(new Vector3D[] { v0, v1, v2, v3 });
  }
  public SolidPolygon3D(Vector3D[] vertices) {
    super(vertices);
  }
  public void setTo(Polygon3D polygon) {
    super.setTo(polygon);
    if (polygon instanceof SolidPolygon3D) {
      color = ((SolidPolygon3D) polygon).color;
    }
  }
  /**
   * Gets the color of this solid-colored polygon used for rendering this
   * polygon.
   */
  public Color getColor() {
    return color;
  }
  /**
   * Sets the color of this solid-colored polygon used for rendering this
   * polygon.
   */
  public void setColor(Color color) {
    this.color = color;
  }
}
abstract class GameCore3D extends GameCore {
  protected PolygonRenderer polygonRenderer;
  protected ViewWindow viewWindow;
  protected List polygons;
  private boolean drawFrameRate = false;
  private boolean drawInstructions = true;
  // for calculating frame rate
  private int numFrames;
  private long startTime;
  private float frameRate;
  protected InputManager inputManager;
  private GameAction exit = new GameAction("exit");
  private GameAction smallerView = new GameAction("smallerView",
      GameAction.DETECT_INITAL_PRESS_ONLY);
  private GameAction largerView = new GameAction("largerView",
      GameAction.DETECT_INITAL_PRESS_ONLY);
  private GameAction frameRateToggle = new GameAction("frameRateToggle",
      GameAction.DETECT_INITAL_PRESS_ONLY);
  protected GameAction goForward = new GameAction("goForward");
  protected GameAction goBackward = new GameAction("goBackward");
  protected GameAction goUp = new GameAction("goUp");
  protected GameAction goDown = new GameAction("goDown");
  protected GameAction goLeft = new GameAction("goLeft");
  protected GameAction goRight = new GameAction("goRight");
  protected GameAction turnLeft = new GameAction("turnLeft");
  protected GameAction turnRight = new GameAction("turnRight");
  protected GameAction tiltUp = new GameAction("tiltUp");
  protected GameAction tiltDown = new GameAction("tiltDown");
  protected GameAction tiltLeft = new GameAction("tiltLeft");
  protected GameAction tiltRight = new GameAction("tiltRight");
  public void init(DisplayMode[] modes) {
    super.init(modes);
    inputManager = new InputManager(screen.getFullScreenWindow());
    inputManager.setRelativeMouseMode(true);
    inputManager.setCursor(InputManager.INVISIBLE_CURSOR);
    inputManager.mapToKey(exit, KeyEvent.VK_ESCAPE);
    inputManager.mapToKey(goForward, KeyEvent.VK_W);
    inputManager.mapToKey(goForward, KeyEvent.VK_UP);
    inputManager.mapToKey(goBackward, KeyEvent.VK_S);
    inputManager.mapToKey(goBackward, KeyEvent.VK_DOWN);
    inputManager.mapToKey(goLeft, KeyEvent.VK_A);
    inputManager.mapToKey(goLeft, KeyEvent.VK_LEFT);
    inputManager.mapToKey(goRight, KeyEvent.VK_D);
    inputManager.mapToKey(goRight, KeyEvent.VK_RIGHT);
    inputManager.mapToKey(goUp, KeyEvent.VK_PAGE_UP);
    inputManager.mapToKey(goDown, KeyEvent.VK_PAGE_DOWN);
    inputManager.mapToMouse(turnLeft, InputManager.MOUSE_MOVE_LEFT);
    inputManager.mapToMouse(turnRight, InputManager.MOUSE_MOVE_RIGHT);
    inputManager.mapToMouse(tiltUp, InputManager.MOUSE_MOVE_UP);
    inputManager.mapToMouse(tiltDown, InputManager.MOUSE_MOVE_DOWN);
    inputManager.mapToKey(tiltLeft, KeyEvent.VK_INSERT);
    inputManager.mapToKey(tiltRight, KeyEvent.VK_DELETE);
    inputManager.mapToKey(smallerView, KeyEvent.VK_SUBTRACT);
    inputManager.mapToKey(smallerView, KeyEvent.VK_MINUS);
    inputManager.mapToKey(largerView, KeyEvent.VK_ADD);
    inputManager.mapToKey(largerView, KeyEvent.VK_PLUS);
    inputManager.mapToKey(largerView, KeyEvent.VK_EQUALS);
    inputManager.mapToKey(frameRateToggle, KeyEvent.VK_R);
    // create the polygon renderer
    createPolygonRenderer();
    // create polygons
    polygons = new ArrayList();
    createPolygons();
  }
  public abstract void createPolygons();
  public void createPolygonRenderer() {
    // make the view window the entire screen
    viewWindow = new ViewWindow(0, 0, screen.getWidth(),
        screen.getHeight(), (float) Math.toRadians(75));
    Transform3D camera = new Transform3D(0, 100, 0);
    polygonRenderer = new SolidPolygonRenderer(camera, viewWindow);
  }
  /**
   * Sets the view bounds, centering the view on the screen.
   */
  public void setViewBounds(int width, int height) {
    width = Math.min(width, screen.getWidth());
    height = Math.min(height, screen.getHeight());
    width = Math.max(64, width);
    height = Math.max(48, height);
    viewWindow.setBounds((screen.getWidth() - width) / 2, (screen
        .getHeight() - height) / 2, width, height);
    // clear the screen if view size changed
    // (clear both buffers)
    for (int i = 0; i < 2; i++) {
      Graphics2D g = screen.getGraphics();
      g.setColor(Color.BLACK);
      g.fillRect(0, 0, screen.getWidth(), screen.getHeight());
      screen.update();
    }
  }
  public void update(long elapsedTime) {
    // check options
    if (exit.isPressed()) {
      stop();
      return;
    }
    if (largerView.isPressed()) {
      setViewBounds(viewWindow.getWidth() + 64,
          viewWindow.getHeight() + 48);
    } else if (smallerView.isPressed()) {
      setViewBounds(viewWindow.getWidth() - 64,
          viewWindow.getHeight() - 48);
    }
    if (frameRateToggle.isPressed()) {
      drawFrameRate = !drawFrameRate;
    }
    updateWorld(elapsedTime);
  }
  public void updateWorld(long elapsedTime) {
    // cap elapsedTime
    elapsedTime = Math.min(elapsedTime, 100);
    float angleChange = 0.0002f * elapsedTime;
    float distanceChange = .5f * elapsedTime;
    Transform3D camera = polygonRenderer.getCamera();
    Vector3D cameraLoc = camera.getLocation();
    // apply movement
    if (goForward.isPressed()) {
      cameraLoc.x -= distanceChange * camera.getSinAngleY();
      cameraLoc.z -= distanceChange * camera.getCosAngleY();
    }
    if (goBackward.isPressed()) {
      cameraLoc.x += distanceChange * camera.getSinAngleY();
      cameraLoc.z += distanceChange * camera.getCosAngleY();
    }
    if (goLeft.isPressed()) {
      cameraLoc.x -= distanceChange * camera.getCosAngleY();
      cameraLoc.z += distanceChange * camera.getSinAngleY();
    }
    if (goRight.isPressed()) {
      cameraLoc.x += distanceChange * camera.getCosAngleY();
      cameraLoc.z -= distanceChange * camera.getSinAngleY();
    }
    if (goUp.isPressed()) {
      cameraLoc.y += distanceChange;
    }
    if (goDown.isPressed()) {
      cameraLoc.y -= distanceChange;
    }
    // look up/down (rotate around x)
    int tilt = tiltUp.getAmount() - tiltDown.getAmount();
    tilt = Math.min(tilt, 200);
    tilt = Math.max(tilt, -200);
    // limit how far you can look up/down
    float newAngleX = camera.getAngleX() + tilt * angleChange;
    newAngleX = Math.max(newAngleX, (float) -Math.PI / 2);
    newAngleX = Math.min(newAngleX, (float) Math.PI / 2);
    camera.setAngleX(newAngleX);
    // turn (rotate around y)
    int turn = turnLeft.getAmount() - turnRight.getAmount();
    turn = Math.min(turn, 200);
    turn = Math.max(turn, -200);
    camera.rotateAngleY(turn * angleChange);
    // tilet head left/right (rotate around z)
    if (tiltLeft.isPressed()) {
      camera.rotateAngleZ(10 * angleChange);
    }
    if (tiltRight.isPressed()) {
      camera.rotateAngleZ(-10 * angleChange);
    }
  }
  public void draw(Graphics2D g) {
    int viewX1 = viewWindow.getLeftOffset();
    int viewY1 = viewWindow.getTopOffset();
    int viewX2 = viewX1 + viewWindow.getWidth();
    int viewY2 = viewY1 + viewWindow.getHeight();
    if (viewX1 != 0 || viewY1 != 0) {
      g.setColor(Color.BLACK);
      g.fillRect(0, 0, viewX1, screen.getHeight());
      g.fillRect(viewX2, 0, screen.getWidth() - viewX2, screen
          .getHeight());
      g.fillRect(viewX1, 0, viewWindow.getWidth(), viewY1);
      g.fillRect(viewX1, viewY2, viewWindow.getWidth(), screen
          .getHeight()
          - viewY2);
    }
    drawPolygons(g);
    drawText(g);
  }
  public void drawPolygons(Graphics2D g) {
    polygonRenderer.startFrame(g);
    for (int i = 0; i < polygons.size(); i++) {
      polygonRenderer.draw(g, (Polygon3D) polygons.get(i));
    }
    polygonRenderer.endFrame(g);
  }
  public void drawText(Graphics2D g) {
    g.setColor(Color.WHITE);
    // draw text
    if (drawInstructions) {
      g.drawString("Use the mouse/arrow keys to move. "
          + "Press Esc to exit.", 5, fontSize);
    }
    // (you may have to turn off the BufferStrategy in
    // ScreenManager for more accurate tests)
    if (drawFrameRate) {
      calcFrameRate();
      g.drawString(frameRate + " frames/sec", 5, screen.getHeight() - 5);
    }
  }
  public void calcFrameRate() {
    numFrames++;
    long currTime = System.currentTimeMillis();
    // calculate the frame rate every 500 milliseconds
    if (currTime > startTime + 500) {
      frameRate = (float) numFrames * 1000 / (currTime - startTime);
      startTime = currTime;
      numFrames = 0;
    }
  }
}
interface Transformable {
  public void add(Vector3D u);
  public void subtract(Vector3D u);
  public void add(Transform3D xform);
  public void subtract(Transform3D xform);
  public void addRotation(Transform3D xform);
  public void subtractRotation(Transform3D xform);
}
/**
 * The Polygon3D class represents a polygon as a series of vertices.
 */
class Polygon3D implements Transformable {
  // temporary vectors used for calculation
  private static Vector3D temp1 = new Vector3D();
  private static Vector3D temp2 = new Vector3D();
  private Vector3D[] v;
  private int numVertices;
  private Vector3D normal;
  /**
   * Creates an empty polygon that can be used as a "scratch" polygon for
   * transforms, projections, etc.
   */
  public Polygon3D() {
    numVertices = 0;
    v = new Vector3D[0];
    normal = new Vector3D();
  }
  /**
   * Creates a new Polygon3D with the specified vertices.
   */
  public Polygon3D(Vector3D v0, Vector3D v1, Vector3D v2) {
    this(new Vector3D[] { v0, v1, v2 });
  }
  /**
   * Creates a new Polygon3D with the specified vertices. All the vertices are
   * assumed to be in the same plane.
   */
  public Polygon3D(Vector3D v0, Vector3D v1, Vector3D v2, Vector3D v3) {
    this(new Vector3D[] { v0, v1, v2, v3 });
  }
  /**
   * Creates a new Polygon3D with the specified vertices. All the vertices are
   * assumed to be in the same plane.
   */
  public Polygon3D(Vector3D[] vertices) {
    this.v = vertices;
    numVertices = vertices.length;
    calcNormal();
  }
  /**
   * Sets this polygon to the same vertices as the specfied polygon.
   */
  public void setTo(Polygon3D polygon) {
    numVertices = polygon.numVertices;
    normal.setTo(polygon.normal);
    ensureCapacity(numVertices);
    for (int i = 0; i < numVertices; i++) {
      v[i].setTo(polygon.v[i]);
    }
  }
  /**
   * Ensures this polgon has enough capacity to hold the specified number of
   * vertices.
   */
  protected void ensureCapacity(int length) {
    if (v.length < length) {
      Vector3D[] newV = new Vector3D[length];
      System.arraycopy(v, 0, newV, 0, v.length);
      for (int i = v.length; i < newV.length; i++) {
        newV[i] = new Vector3D();
      }
      v = newV;
    }
  }
  /**
   * Gets the number of vertices this polygon has.
   */
  public int getNumVertices() {
    return numVertices;
  }
  /**
   * Gets the vertex at the specified index.
   */
  public Vector3D getVertex(int index) {
    return v[index];
  }
  /**
   * Projects this polygon onto the view window.
   */
  public void project(ViewWindow view) {
    for (int i = 0; i < numVertices; i++) {
      view.project(v[i]);
    }
  }
  // methods from the Transformable interface.
  public void add(Vector3D u) {
    for (int i = 0; i < numVertices; i++) {
      v[i].add(u);
    }
  }
  public void subtract(Vector3D u) {
    for (int i = 0; i < numVertices; i++) {
      v[i].subtract(u);
    }
  }
  public void add(Transform3D xform) {
    addRotation(xform);
    add(xform.getLocation());
  }
  public void subtract(Transform3D xform) {
    subtract(xform.getLocation());
    subtractRotation(xform);
  }
  public void addRotation(Transform3D xform) {
    for (int i = 0; i < numVertices; i++) {
      v[i].addRotation(xform);
    }
    normal.addRotation(xform);
  }
  public void subtractRotation(Transform3D xform) {
    for (int i = 0; i < numVertices; i++) {
      v[i].subtractRotation(xform);
    }
    normal.subtractRotation(xform);
  }
  /**
   * Calculates the unit-vector normal of this polygon. This method uses the
   * first, second, and third vertices to calcuate the normal, so if these
   * vertices are collinear, this method will not work. In this case, you can
   * get the normal from the bounding rectangle. Use setNormal() to explicitly
   * set the normal. This method uses static objects in the Polygon3D class
   * for calculations, so this method is not thread-safe across all instances
   * of Polygon3D.
   */
  public Vector3D calcNormal() {
    if (normal == null) {
      normal = new Vector3D();
    }
    temp1.setTo(v[2]);
    temp1.subtract(v[1]);
    temp2.setTo(v[0]);
    temp2.subtract(v[1]);
    normal.setToCrossProduct(temp1, temp2);
    normal.normalize();
    return normal;
  }
  /**
   * Gets the normal of this polygon. Use calcNormal() if any vertices have
   * changed.
   */
  public Vector3D getNormal() {
    return normal;
  }
  /**
   * Sets the normal of this polygon.
   */
  public void setNormal(Vector3D n) {
    if (normal == null) {
      normal = new Vector3D(n);
    } else {
      normal.setTo(n);
    }
  }
  /**
   * Tests if this polygon is facing the specified location. This method uses
   * static objects in the Polygon3D class for calculations, so this method is
   * not thread-safe across all instances of Polygon3D.
   */
  public boolean isFacing(Vector3D u) {
    temp1.setTo(u);
    temp1.subtract(v[0]);
    return (normal.getDotProduct(temp1) >= 0);
  }
  /**
   * Clips this polygon so that all vertices are in front of the clip plane,
   * clipZ (in other words, all vertices have z <= clipZ). The value of clipZ
   * should not be 0, as this causes divide-by-zero problems. Returns true if
   * the polygon is at least partially in front of the clip plane.
   */
  public boolean clip(float clipZ) {
    ensureCapacity(numVertices * 3);
    boolean isCompletelyHidden = true;
    // insert vertices so all edges are either completly
    // in front or behind the clip plane
    for (int i = 0; i < numVertices; i++) {
      int next = (i + 1) % numVertices;
      Vector3D v1 = v[i];
      Vector3D v2 = v[next];
      if (v1.z < clipZ) {
        isCompletelyHidden = false;
      }
      // ensure v1.z < v2.z
      if (v1.z > v2.z) {
        Vector3D temp = v1;
        v1 = v2;
        v2 = temp;
      }
      if (v1.z < clipZ && v2.z > clipZ) {
        float scale = (clipZ - v1.z) / (v2.z - v1.z);
        insertVertex(next, v1.x + scale * (v2.x - v1.x), v1.y + scale
            * (v2.y - v1.y), clipZ);
        // skip the vertex we just created
        i++;
      }
    }
    if (isCompletelyHidden) {
      return false;
    }
    // delete all vertices that have z > clipZ
    for (int i = numVertices - 1; i >= 0; i--) {
      if (v[i].z > clipZ) {
        deleteVertex(i);
      }
    }
    return (numVertices >= 3);
  }
  /**
   * Inserts a new vertex at the specified index.
   */
  protected void insertVertex(int index, float x, float y, float z) {
    Vector3D newVertex = v[v.length - 1];
    newVertex.x = x;
    newVertex.y = y;
    newVertex.z = z;
    for (int i = v.length - 1; i > index; i--) {
      v[i] = v[i - 1];
    }
    v[index] = newVertex;
    numVertices++;
  }
  /**
   * Delete the vertex at the specified index.
   */
  protected void deleteVertex(int index) {
    Vector3D deleted = v[index];
    for (int i = index; i < v.length - 1; i++) {
      v[i] = v[i + 1];
    }
    v[v.length - 1] = deleted;
    numVertices--;
  }
  /**
   * Inserts a vertex into this polygon at the specified index. The exact
   * vertex in inserted (not a copy).
   */
  public void insertVertex(int index, Vector3D vertex) {
    Vector3D[] newV = new Vector3D[numVertices + 1];
    System.arraycopy(v, 0, newV, 0, index);
    newV[index] = vertex;
    System.arraycopy(v, index, newV, index + 1, numVertices - index);
    v = newV;
    numVertices++;
  }
  /**
   * Calculates and returns the smallest bounding rectangle for this polygon.
   */
  public Rectangle3D calcBoundingRectangle() {
    // the smallest bounding rectangle for a polygon shares
    // at least one edge with the polygon. so, this method
    // finds the bounding rectangle for every edge in the
    // polygon, and returns the smallest one.
    Rectangle3D boundingRect = new Rectangle3D();
    float minimumArea = Float.MAX_VALUE;
    Vector3D u = new Vector3D();
    Vector3D v = new Vector3D();
    Vector3D d = new Vector3D();
    for (int i = 0; i < getNumVertices(); i++) {
      u.setTo(getVertex((i + 1) % getNumVertices()));
      u.subtract(getVertex(i));
      u.normalize();
      v.setToCrossProduct(getNormal(), u);
      v.normalize();
      float uMin = 0;
      float uMax = 0;
      float vMin = 0;
      float vMax = 0;
      for (int j = 0; j < getNumVertices(); j++) {
        if (j != i) {
          d.setTo(getVertex(j));
          d.subtract(getVertex(i));
          float uLength = d.getDotProduct(u);
          float vLength = d.getDotProduct(v);
          uMin = Math.min(uLength, uMin);
          uMax = Math.max(uLength, uMax);
          vMin = Math.min(vLength, vMin);
          vMax = Math.max(vLength, vMax);
        }
      }
      // if this calculated area is the smallest, set
      // the bounding rectangle
      float area = (uMax - uMin) * (vMax - vMin);
      if (area < minimumArea) {
        minimumArea = area;
        Vector3D origin = boundingRect.getOrigin();
        origin.setTo(getVertex(i));
        d.setTo(u);
        d.multiply(uMin);
        origin.add(d);
        d.setTo(v);
        d.multiply(vMin);
        origin.add(d);
        boundingRect.getDirectionU().setTo(u);
        boundingRect.getDirectionV().setTo(v);
        boundingRect.setWidth(uMax - uMin);
        boundingRect.setHeight(vMax - vMin);
      }
    }
    return boundingRect;
  }
}
/**
 * The TexturedPolygon3D class is a Polygon with a texture.
 */
class TexturedPolygon3D extends Polygon3D {
  protected Rectangle3D textureBounds;
  protected Texture texture;
  public TexturedPolygon3D() {
    textureBounds = new Rectangle3D();
  }
  public TexturedPolygon3D(Vector3D v0, Vector3D v1, Vector3D v2) {
    this(new Vector3D[] { v0, v1, v2 });
  }
  public TexturedPolygon3D(Vector3D v0, Vector3D v1, Vector3D v2, Vector3D v3) {
    this(new Vector3D[] { v0, v1, v2, v3 });
  }
  public TexturedPolygon3D(Vector3D[] vertices) {
    super(vertices);
    textureBounds = new Rectangle3D();
  }
  public void setTo(Polygon3D poly) {
    super.setTo(poly);
    if (poly instanceof TexturedPolygon3D) {
      TexturedPolygon3D tPoly = (TexturedPolygon3D) poly;
      textureBounds.setTo(tPoly.textureBounds);
      texture = tPoly.texture;
    }
  }
  /**
   * Gets this polygon"s texture.
   */
  public Texture getTexture() {
    return texture;
  }
  /**
   * Gets this polygon"s texture bounds.
   */
  public Rectangle3D getTextureBounds() {
    return textureBounds;
  }
  /**
   * Sets this polygon"s texture.
   */
  public void setTexture(Texture texture) {
    this.texture = texture;
    textureBounds.setWidth(texture.getWidth());
    textureBounds.setHeight(texture.getHeight());
  }
  /**
   * Sets this polygon"s texture and texture bounds.
   */
  public void setTexture(Texture texture, Rectangle3D bounds) {
    setTexture(texture);
    textureBounds.setTo(bounds);
  }
  public void add(Vector3D u) {
    super.add(u);
    textureBounds.add(u);
  }
  public void subtract(Vector3D u) {
    super.subtract(u);
    textureBounds.subtract(u);
  }
  public void addRotation(Transform3D xform) {
    super.addRotation(xform);
    textureBounds.addRotation(xform);
  }
  public void subtractRotation(Transform3D xform) {
    super.subtractRotation(xform);
    textureBounds.subtractRotation(xform);
  }
  /**
   * Calculates the bounding rectangle for this polygon that is aligned with
   * the texture bounds.
   */
  public Rectangle3D calcBoundingRectangle() {
    Vector3D u = new Vector3D(textureBounds.getDirectionU());
    Vector3D v = new Vector3D(textureBounds.getDirectionV());
    Vector3D d = new Vector3D();
    u.normalize();
    v.normalize();
    float uMin = 0;
    float uMax = 0;
    float vMin = 0;
    float vMax = 0;
    for (int i = 0; i < getNumVertices(); i++) {
      d.setTo(getVertex(i));
      d.subtract(getVertex(0));
      float uLength = d.getDotProduct(u);
      float vLength = d.getDotProduct(v);
      uMin = Math.min(uLength, uMin);
      uMax = Math.max(uLength, uMax);
      vMin = Math.min(vLength, vMin);
      vMax = Math.max(vLength, vMax);
    }
    Rectangle3D boundingRect = new Rectangle3D();
    Vector3D origin = boundingRect.getOrigin();
    origin.setTo(getVertex(0));
    d.setTo(u);
    d.multiply(uMin);
    origin.add(d);
    d.setTo(v);
    d.multiply(vMin);
    origin.add(d);
    boundingRect.getDirectionU().setTo(u);
    boundingRect.getDirectionV().setTo(v);
    boundingRect.setWidth(uMax - uMin);
    boundingRect.setHeight(vMax - vMin);
    // explictly set the normal since the texture directions
    // could create a normal negative to the polygon normal
    boundingRect.setNormal(getNormal());
    return boundingRect;
  }
}
/**
 * The Vector3D class implements a 3D vector with the floating-point values x,
 * y, and z. Vectors can be thought of either as a (x,y,z) point or as a vector
 * from (0,0,0) to (x,y,z).
 */
class Vector3D implements Transformable {
  public float x;
  public float y;
  public float z;
  /**
   * Creates a new Vector3D at (0,0,0).
   */
  public Vector3D() {
    this(0, 0, 0);
  }
  /**
   * Creates a new Vector3D with the same values as the specified Vector3D.
   */
  public Vector3D(Vector3D v) {
    this(v.x, v.y, v.z);
  }
  /**
   * Creates a new Vector3D with the specified (x, y, z) values.
   */
  public Vector3D(float x, float y, float z) {
    setTo(x, y, z);
  }
  /**
   * Checks if this Vector3D is equal to the specified Object. They are equal
   * only if the specified Object is a Vector3D and the two Vector3D"s x, y,
   * and z coordinates are equal.
   */
  public boolean equals(Object obj) {
    Vector3D v = (Vector3D) obj;
    return (v.x == x && v.y == y && v.z == z);
  }
  /**
   * Checks if this Vector3D is equal to the specified x, y, and z
   * coordinates.
   */
  public boolean equals(float x, float y, float z) {
    return (this.x == x && this.y == y && this.z == z);
  }
  /**
   * Sets the vector to the same values as the specified Vector3D.
   */
  public void setTo(Vector3D v) {
    setTo(v.x, v.y, v.z);
  }
  /**
   * Sets this vector to the specified (x, y, z) values.
   */
  public void setTo(float x, float y, float z) {
    this.x = x;
    this.y = y;
    this.z = z;
  }
  /**
   * Adds the specified (x, y, z) values to this vector.
   */
  public void add(float x, float y, float z) {
    this.x += x;
    this.y += y;
    this.z += z;
  }
  /**
   * Subtracts the specified (x, y, z) values to this vector.
   */
  public void subtract(float x, float y, float z) {
    add(-x, -y, -z);
  }
  /**
   * Adds the specified vector to this vector.
   */
  public void add(Vector3D v) {
    add(v.x, v.y, v.z);
  }
  /**
   * Subtracts the specified vector from this vector.
   */
  public void subtract(Vector3D v) {
    add(-v.x, -v.y, -v.z);
  }
  /**
   * Multiplies this vector by the specified value. The new length of this
   * vector will be length()*s.
   */
  public void multiply(float s) {
    x *= s;
    y *= s;
    z *= s;
  }
  /**
   * Divides this vector by the specified value. The new length of this vector
   * will be length()/s.
   */
  public void divide(float s) {
    x /= s;
    y /= s;
    z /= s;
  }
  /**
   * Returns the length of this vector as a float.
   */
  public float length() {
    return (float) Math.sqrt(x * x + y * y + z * z);
  }
  /**
   * Converts this Vector3D to a unit vector, or in other words, a vector of
   * length 1. Same as calling v.divide(v.length()).
   */
  public void normalize() {
    divide(length());
  }
  /**
   * Converts this Vector3D to a String representation.
   */
  public String toString() {
    return "(" + x + ", " + y + ", " + z + ")";
  }
  /**
   * Rotate this vector around the x axis the specified amount. The specified
   * angle is in radians. Use Math.toRadians() to convert from degrees to
   * radians.
   */
  public void rotateX(float angle) {
    rotateX((float) Math.cos(angle), (float) Math.sin(angle));
  }
  /**
   * Rotate this vector around the y axis the specified amount. The specified
   * angle is in radians. Use Math.toRadians() to convert from degrees to
   * radians.
   */
  public void rotateY(float angle) {
    rotateY((float) Math.cos(angle), (float) Math.sin(angle));
  }
  /**
   * Rotate this vector around the z axis the specified amount. The specified
   * angle is in radians. Use Math.toRadians() to convert from degrees to
   * radians.
   */
  public void rotateZ(float angle) {
    rotateZ((float) Math.cos(angle), (float) Math.sin(angle));
  }
  /**
   * Rotate this vector around the x axis the specified amount, using
   * pre-computed cosine and sine values of the angle to rotate.
   */
  public void rotateX(float cosAngle, float sinAngle) {
    float newY = y * cosAngle - z * sinAngle;
    float newZ = y * sinAngle + z * cosAngle;
    y = newY;
    z = newZ;
  }
  /**
   * Rotate this vector around the y axis the specified amount, using
   * pre-computed cosine and sine values of the angle to rotate.
   */
  public void rotateY(float cosAngle, float sinAngle) {
    float newX = z * sinAngle + x * cosAngle;
    float newZ = z * cosAngle - x * sinAngle;
    x = newX;
    z = newZ;
  }
  /**
   * Rotate this vector around the y axis the specified amount, using
   * pre-computed cosine and sine values of the angle to rotate.
   */
  public void rotateZ(float cosAngle, float sinAngle) {
    float newX = x * cosAngle - y * sinAngle;
    float newY = x * sinAngle + y * cosAngle;
    x = newX;
    y = newY;
  }
  /**
   * Adds the specified transform to this vector. This vector is first
   * rotated, then translated.
   */
  public void add(Transform3D xform) {
    // rotate
    addRotation(xform);
    // translate
    add(xform.getLocation());
  }
  /**
   * Subtracts the specified transform to this vector. This vector translated,
   * then rotated.
   */
  public void subtract(Transform3D xform) {
    // translate
    subtract(xform.getLocation());
    // rotate
    subtractRotation(xform);
  }
  /**
   * Rotates this vector with the angle of the specified transform.
   */
  public void addRotation(Transform3D xform) {
    rotateX(xform.getCosAngleX(), xform.getSinAngleX());
    rotateZ(xform.getCosAngleZ(), xform.getSinAngleZ());
    rotateY(xform.getCosAngleY(), xform.getSinAngleY());
  }
  /**
   * Rotates this vector with the opposite angle of the specified transform.
   */
  public void subtractRotation(Transform3D xform) {
    // note that sin(-x) == -sin(x) and cos(-x) == cos(x)
    rotateY(xform.getCosAngleY(), -xform.getSinAngleY());
    rotateZ(xform.getCosAngleZ(), -xform.getSinAngleZ());
    rotateX(xform.getCosAngleX(), -xform.getSinAngleX());
  }
  /**
   * Returns the dot product of this vector and the specified vector.
   */
  public float getDotProduct(Vector3D v) {
    return x * v.x + y * v.y + z * v.z;
  }
  /**
   * Sets this vector to the cross product of the two specified vectors.
   * Either of the specified vectors can be this vector.
   */
  public void setToCrossProduct(Vector3D u, Vector3D v) {
    // assign to local vars first in case u or v is "this"
    float x = u.y * v.z - u.z * v.y;
    float y = u.z * v.x - u.x * v.z;
    float z = u.x * v.y - u.y * v.x;
    this.x = x;
    this.y = y;
    this.z = z;
  }
}
/**
 * A Rectangle3D is a rectangle in 3D space, defined as an origin and vectors
 * pointing in the directions of the base (width) and side (height).
 */
class Rectangle3D implements Transformable {
  private Vector3D origin;
  private Vector3D directionU;
  private Vector3D directionV;
  private Vector3D normal;
  private float width;
  private float height;
  /**
   * Creates a rectangle at the origin with a width and height of zero.
   */
  public Rectangle3D() {
    origin = new Vector3D();
    directionU = new Vector3D(1, 0, 0);
    directionV = new Vector3D(0, 1, 0);
    width = 0;
    height = 0;
  }
  /**
   * Creates a new Rectangle3D with the specified origin, direction of the
   * base (directionU) and direction of the side (directionV).
   */
  public Rectangle3D(Vector3D origin, Vector3D directionU,
      Vector3D directionV, float width, float height) {
    this.origin = new Vector3D(origin);
    this.directionU = new Vector3D(directionU);
    this.directionU.normalize();
    this.directionV = new Vector3D(directionV);
    this.directionV.normalize();
    this.width = width;
    this.height = height;
  }
  /**
   * Sets the values of this Rectangle3D to the specified Rectangle3D.
   */
  public void setTo(Rectangle3D rect) {
    origin.setTo(rect.origin);
    directionU.setTo(rect.directionU);
    directionV.setTo(rect.directionV);
    width = rect.width;
    height = rect.height;
  }
  /**
   * Gets the origin of this Rectangle3D.
   */
  public Vector3D getOrigin() {
    return origin;
  }
  /**
   * Gets the direction of the base of this Rectangle3D.
   */
  public Vector3D getDirectionU() {
    return directionU;
  }
  /**
   * Gets the direction of the side of this Rectangle3D.
   */
  public Vector3D getDirectionV() {
    return directionV;
  }
  /**
   * Gets the width of this Rectangle3D.
   */
  public float getWidth() {
    return width;
  }
  /**
   * Sets the width of this Rectangle3D.
   */
  public void setWidth(float width) {
    this.width = width;
  }
  /**
   * Gets the height of this Rectangle3D.
   */
  public float getHeight() {
    return height;
  }
  /**
   * Sets the height of this Rectangle3D.
   */
  public void setHeight(float height) {
    this.height = height;
  }
  /**
   * Calculates the normal vector of this Rectange3D.
   */
  protected Vector3D calcNormal() {
    if (normal == null) {
      normal = new Vector3D();
    }
    normal.setToCrossProduct(directionU, directionV);
    normal.normalize();
    return normal;
  }
  /**
   * Gets the normal of this Rectangle3D.
   */
  public Vector3D getNormal() {
    if (normal == null) {
      calcNormal();
    }
    return normal;
  }
  /**
   * Sets the normal of this Rectangle3D.
   */
  public void setNormal(Vector3D n) {
    if (normal == null) {
      normal = new Vector3D(n);
    } else {
      normal.setTo(n);
    }
  }
  public void add(Vector3D u) {
    origin.add(u);
    // don"t translate direction vectors or size
  }
  public void subtract(Vector3D u) {
    origin.subtract(u);
    // don"t translate direction vectors or size
  }
  public void add(Transform3D xform) {
    addRotation(xform);
    add(xform.getLocation());
  }
  public void subtract(Transform3D xform) {
    subtract(xform.getLocation());
    subtractRotation(xform);
  }
  public void addRotation(Transform3D xform) {
    origin.addRotation(xform);
    directionU.addRotation(xform);
    directionV.addRotation(xform);
  }
  public void subtractRotation(Transform3D xform) {
    origin.subtractRotation(xform);
    directionU.subtractRotation(xform);
    directionV.subtractRotation(xform);
  }
}
           
       </source>
    
   
  <!-- end source code -->
   




== Texture Map Test 2 ==






   
  <!-- start source code -->
   
    <source lang="java">
       /*
DEVELOPING GAME IN JAVA 
Caracteristiques
Editeur : NEW RIDERS 
Auteur : BRACKEEN 
Parution : 09 2003 
Pages : 972 
Isbn : 1-59273-005-1 
Reliure : Paperback 
Disponibilite : Disponible a la librairie 
*/
         
import java.awt.AWTException;
import java.awt.Color;
import java.awt.ruponent;
import java.awt.Cursor;
import java.awt.DisplayMode;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Image;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.Window;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.awt.image.DataBuffer;
import java.awt.image.DataBufferByte;
import java.awt.image.DataBufferUShort;
import java.awt.image.IndexColorModel;
import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.ref.SoftReference;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import javax.imageio.ImageIO;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.DataLine;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.Mixer;
import javax.sound.sampled.SourceDataLine;
import javax.sound.sampled.UnsupportedAudioFileException;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
public class TextureMapTest2 extends GameCore3D {
  public static void main(String[] args) {
    new TextureMapTest2().run();
  }
  public void init() {
    init(LOW_RES_MODES);
  }
  // create a house (convex polyhedra)
  public void createPolygons() {
    // create Textures
    Texture wall = loadTexture("../images/wall1.png");
    Texture roof = loadTexture("../images/roof1.png");
    TexturedPolygon3D poly;
    // walls
    poly = new TexturedPolygon3D(new Vector3D(-200, 250, -1000),
        new Vector3D(-200, 0, -1000), new Vector3D(200, 0, -1000),
        new Vector3D(200, 250, -1000));
    setTexture(poly, wall);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(200, 250, -1400),
        new Vector3D(200, 0, -1400), new Vector3D(-200, 0, -1400),
        new Vector3D(-200, 250, -1400));
    setTexture(poly, wall);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(-200, 250, -1400),
        new Vector3D(-200, 0, -1400), new Vector3D(-200, 0, -1000),
        new Vector3D(-200, 250, -1000));
    setTexture(poly, wall);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(200, 250, -1000),
        new Vector3D(200, 0, -1000), new Vector3D(200, 0, -1400),
        new Vector3D(200, 250, -1400));
    setTexture(poly, wall);
    polygons.add(poly);
    // roof
    poly = new TexturedPolygon3D(new Vector3D(-200, 250, -1000),
        new Vector3D(200, 250, -1000), new Vector3D(75, 400, -1200),
        new Vector3D(-75, 400, -1200));
    setTexture(poly, roof);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(-200, 250, -1400),
        new Vector3D(-200, 250, -1000), new Vector3D(-75, 400, -1200));
    setTexture(poly, roof);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(200, 250, -1400),
        new Vector3D(-200, 250, -1400), new Vector3D(-75, 400, -1200),
        new Vector3D(75, 400, -1200));
    setTexture(poly, roof);
    polygons.add(poly);
    poly = new TexturedPolygon3D(new Vector3D(200, 250, -1000),
        new Vector3D(200, 250, -1400), new Vector3D(75, 400, -1200));
    setTexture(poly, roof);
    polygons.add(poly);
  }
  public void setTexture(TexturedPolygon3D poly, Texture texture) {
    Vector3D origin = poly.getVertex(0);
    Vector3D dv = new Vector3D(poly.getVertex(1));
    dv.subtract(origin);
    Vector3D du = new Vector3D();
    du.setToCrossProduct(poly.getNormal(), dv);
    Rectangle3D textureBounds = new Rectangle3D(origin, du, dv, texture
        .getWidth(), texture.getHeight());
    poly.setTexture(texture, textureBounds);
  }
  public Texture loadTexture(String imageName) {
    return Texture.createTexture(imageName);
  }
  public void createPolygonRenderer() {
    viewWindow = new ViewWindow(0, 0, screen.getWidth(),
        screen.getHeight(), (float) Math.toRadians(75));
    Transform3D camera = new Transform3D(0, 100, 0);
    polygonRenderer = new FastTexturedPolygonRenderer(camera, viewWindow);
  }
}
/**
 * The FastTexturedPolygonRenderer is a PolygonRenderer that efficiently renders
 * Textures.
 */
class FastTexturedPolygonRenderer extends PolygonRenderer {
  public static final int SCALE_BITS = 12;
  public static final int SCALE = 1 << SCALE_BITS;
  public static final int INTERP_SIZE_BITS = 4;
  public static final int INTERP_SIZE = 1 << INTERP_SIZE_BITS;
  protected Vector3D a = new Vector3D();
  protected Vector3D b = new Vector3D();
  protected Vector3D c = new Vector3D();
  protected Vector3D viewPos = new Vector3D();
  protected BufferedImage doubleBuffer;
  protected short[] doubleBufferData;
  protected HashMap scanRenderers;
  public FastTexturedPolygonRenderer(Transform3D camera, ViewWindow viewWindow) {
    this(camera, viewWindow, true);
  }
  public FastTexturedPolygonRenderer(Transform3D camera,
      ViewWindow viewWindow, boolean clearViewEveryFrame) {
    super(camera, viewWindow, clearViewEveryFrame);
  }
  protected void init() {
    destPolygon = new TexturedPolygon3D();
    scanConverter = new ScanConverter(viewWindow);
    // create renders for each texture (HotSpot optimization)
    scanRenderers = new HashMap();
    scanRenderers.put(PowerOf2Texture.class, new PowerOf2TextureRenderer());
    scanRenderers.put(ShadedTexture.class, new ShadedTextureRenderer());
    scanRenderers.put(ShadedSurface.class, new ShadedSurfaceRenderer());
  }
  public void startFrame(Graphics2D g) {
    // initialize buffer
    if (doubleBuffer == null
        || doubleBuffer.getWidth() != viewWindow.getWidth()
        || doubleBuffer.getHeight() != viewWindow.getHeight()) {
      doubleBuffer = new BufferedImage(viewWindow.getWidth(), viewWindow
          .getHeight(), BufferedImage.TYPE_USHORT_565_RGB);
      //doubleBuffer = g.getDeviceConfiguration().createCompatibleImage(
      //viewWindow.getWidth(), viewWindow.getHeight());
      DataBuffer dest = doubleBuffer.getRaster().getDataBuffer();
      doubleBufferData = ((DataBufferUShort) dest).getData();
    }
    // clear view
    if (clearViewEveryFrame) {
      for (int i = 0; i < doubleBufferData.length; i++) {
        doubleBufferData[i] = 0;
      }
    }
  }
  public void endFrame(Graphics2D g) {
    // draw the double buffer onto the screen
    g.drawImage(doubleBuffer, viewWindow.getLeftOffset(), viewWindow
        .getTopOffset(), null);
  }
  protected void drawCurrentPolygon(Graphics2D g) {
    if (!(sourcePolygon instanceof TexturedPolygon3D)) {
      // not a textured polygon - return
      return;
    }
    TexturedPolygon3D poly = (TexturedPolygon3D) destPolygon;
    Texture texture = poly.getTexture();
    ScanRenderer scanRenderer = (ScanRenderer) scanRenderers.get(texture
        .getClass());
    scanRenderer.setTexture(texture);
    Rectangle3D textureBounds = poly.getTextureBounds();
    a.setToCrossProduct(textureBounds.getDirectionV(), textureBounds
        .getOrigin());
    b.setToCrossProduct(textureBounds.getOrigin(), textureBounds
        .getDirectionU());
    c.setToCrossProduct(textureBounds.getDirectionU(), textureBounds
        .getDirectionV());
    int y = scanConverter.getTopBoundary();
    viewPos.y = viewWindow.convertFromScreenYToViewY(y);
    viewPos.z = -viewWindow.getDistance();
    while (y <= scanConverter.getBottomBoundary()) {
      ScanConverter.Scan scan = scanConverter.getScan(y);
      if (scan.isValid()) {
        viewPos.x = viewWindow.convertFromScreenXToViewX(scan.left);
        int offset = (y - viewWindow.getTopOffset())
            * viewWindow.getWidth()
            + (scan.left - viewWindow.getLeftOffset());
        scanRenderer.render(offset, scan.left, scan.right);
      }
      y++;
      viewPos.y--;
    }
  }
  /**
   * The ScanRenderer class is an abstract inner class of
   * FastTexturedPolygonRenderer that provides an interface for rendering a
   * horizontal scan line.
   */
  public abstract class ScanRenderer {
    protected Texture currentTexture;
    public void setTexture(Texture texture) {
      this.currentTexture = texture;
    }
    public abstract void render(int offset, int left, int right);
  }
  //================================================
  // FASTEST METHOD: no texture (for comparison)
  //================================================
  public class Method0 extends ScanRenderer {
    public void render(int offset, int left, int right) {
      for (int x = left; x <= right; x++) {
        doubleBufferData[offset++] = (short) 0x0007;
      }
    }
  }
  //================================================
  // METHOD 1: access pixel buffers directly
  // and use textures sizes that are a power of 2
  //================================================
  public class Method1 extends ScanRenderer {
    public void render(int offset, int left, int right) {
      for (int x = left; x <= right; x++) {
        int tx = (int) (a.getDotProduct(viewPos) / c
            .getDotProduct(viewPos));
        int ty = (int) (b.getDotProduct(viewPos) / c
            .getDotProduct(viewPos));
        doubleBufferData[offset++] = currentTexture.getColor(tx, ty);
        viewPos.x++;
      }
    }
  }
  //================================================
  // METHOD 2: avoid redundant calculations
  //================================================
  public class Method2 extends ScanRenderer {
    public void render(int offset, int left, int right) {
      float u = a.getDotProduct(viewPos);
      float v = b.getDotProduct(viewPos);
      float z = c.getDotProduct(viewPos);
      float du = a.x;
      float dv = b.x;
      float dz = c.x;
      for (int x = left; x <= right; x++) {
        doubleBufferData[offset++] = currentTexture.getColor(
            (int) (u / z), (int) (v / z));
        u += du;
        v += dv;
        z += dz;
      }
    }
  }
  //================================================
  // METHOD 3: use ints instead of floats
  //================================================
  public class Method3 extends ScanRenderer {
    public void render(int offset, int left, int right) {
      int u = (int) (SCALE * a.getDotProduct(viewPos));
      int v = (int) (SCALE * b.getDotProduct(viewPos));
      int z = (int) (SCALE * c.getDotProduct(viewPos));
      int du = (int) (SCALE * a.x);
      int dv = (int) (SCALE * b.x);
      int dz = (int) (SCALE * c.x);
      for (int x = left; x <= right; x++) {
        doubleBufferData[offset++] = currentTexture.getColor(u / z, v
            / z);
        u += du;
        v += dv;
        z += dz;
      }
    }
  }
  //================================================
  // METHOD 4: reduce the number of divides
  // (interpolate every 16 pixels)
  // Also, apply a VM optimization by referring to
  // the texture"s class rather than it"s parent class.
  //================================================
  // the following three ScanRenderers are the same, but refer
  // to textures explicitly as either a PowerOf2Texture, a
  // ShadedTexture, or a ShadedSurface.
  // This allows HotSpot to do some inlining of the textures"
  // getColor() method, which significantly increases
  // performance.
  public class PowerOf2TextureRenderer extends ScanRenderer {
    public void render(int offset, int left, int right) {
      PowerOf2Texture texture = (PowerOf2Texture) currentTexture;
      float u = SCALE * a.getDotProduct(viewPos);
      float v = SCALE * b.getDotProduct(viewPos);
      float z = c.getDotProduct(viewPos);
      float du = INTERP_SIZE * SCALE * a.x;
      float dv = INTERP_SIZE * SCALE * b.x;
      float dz = INTERP_SIZE * c.x;
      int nextTx = (int) (u / z);
      int nextTy = (int) (v / z);
      int x = left;
      while (x <= right) {
        int tx = nextTx;
        int ty = nextTy;
        int maxLength = right - x + 1;
        if (maxLength > INTERP_SIZE) {
          u += du;
          v += dv;
          z += dz;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) >> INTERP_SIZE_BITS;
          int dty = (nextTy - ty) >> INTERP_SIZE_BITS;
          int endOffset = offset + INTERP_SIZE;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += INTERP_SIZE;
        } else {
          // variable interpolation size
          int interpSize = maxLength;
          u += interpSize * SCALE * a.x;
          v += interpSize * SCALE * b.x;
          z += interpSize * c.x;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) / interpSize;
          int dty = (nextTy - ty) / interpSize;
          int endOffset = offset + interpSize;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += interpSize;
        }
      }
    }
  }
  public class ShadedTextureRenderer extends ScanRenderer {
    public void render(int offset, int left, int right) {
      ShadedTexture texture = (ShadedTexture) currentTexture;
      float u = SCALE * a.getDotProduct(viewPos);
      float v = SCALE * b.getDotProduct(viewPos);
      float z = c.getDotProduct(viewPos);
      float du = INTERP_SIZE * SCALE * a.x;
      float dv = INTERP_SIZE * SCALE * b.x;
      float dz = INTERP_SIZE * c.x;
      int nextTx = (int) (u / z);
      int nextTy = (int) (v / z);
      int x = left;
      while (x <= right) {
        int tx = nextTx;
        int ty = nextTy;
        int maxLength = right - x + 1;
        if (maxLength > INTERP_SIZE) {
          u += du;
          v += dv;
          z += dz;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) >> INTERP_SIZE_BITS;
          int dty = (nextTy - ty) >> INTERP_SIZE_BITS;
          int endOffset = offset + INTERP_SIZE;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += INTERP_SIZE;
        } else {
          // variable interpolation size
          int interpSize = maxLength;
          u += interpSize * SCALE * a.x;
          v += interpSize * SCALE * b.x;
          z += interpSize * c.x;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) / interpSize;
          int dty = (nextTy - ty) / interpSize;
          int endOffset = offset + interpSize;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += interpSize;
        }
      }
    }
  }
  public class ShadedSurfaceRenderer extends ScanRenderer {
    public int checkBounds(int vScaled, int bounds) {
      int v = vScaled >> SCALE_BITS;
      if (v < 0) {
        vScaled = 0;
      } else if (v >= bounds) {
        vScaled = (bounds - 1) << SCALE_BITS;
      }
      return vScaled;
    }
    public void render(int offset, int left, int right) {
      ShadedSurface texture = (ShadedSurface) currentTexture;
      float u = SCALE * a.getDotProduct(viewPos);
      float v = SCALE * b.getDotProduct(viewPos);
      float z = c.getDotProduct(viewPos);
      float du = INTERP_SIZE * SCALE * a.x;
      float dv = INTERP_SIZE * SCALE * b.x;
      float dz = INTERP_SIZE * c.x;
      int nextTx = (int) (u / z);
      int nextTy = (int) (v / z);
      int x = left;
      while (x <= right) {
        int tx = nextTx;
        int ty = nextTy;
        int maxLength = right - x + 1;
        if (maxLength > INTERP_SIZE) {
          u += du;
          v += dv;
          z += dz;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          int dtx = (nextTx - tx) >> INTERP_SIZE_BITS;
          int dty = (nextTy - ty) >> INTERP_SIZE_BITS;
          int endOffset = offset + INTERP_SIZE;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += INTERP_SIZE;
        } else {
          // variable interpolation size
          int interpSize = maxLength;
          u += interpSize * SCALE * a.x;
          v += interpSize * SCALE * b.x;
          z += interpSize * c.x;
          nextTx = (int) (u / z);
          nextTy = (int) (v / z);
          // make sure tx, ty, nextTx, and nextTy are
          // all within bounds
          tx = checkBounds(tx, texture.getWidth());
          ty = checkBounds(ty, texture.getHeight());
          nextTx = checkBounds(nextTx, texture.getWidth());
          nextTy = checkBounds(nextTy, texture.getHeight());
          int dtx = (nextTx - tx) / interpSize;
          int dty = (nextTy - ty) / interpSize;
          int endOffset = offset + interpSize;
          while (offset < endOffset) {
            doubleBufferData[offset++] = texture.getColor(
                tx >> SCALE_BITS, ty >> SCALE_BITS);
            tx += dtx;
            ty += dty;
          }
          x += interpSize;
        }
      }
    }
  }
}
/**
 * A ShadedSurface is a pre-shaded Texture that maps onto a polygon.
 */
final class ShadedSurface extends Texture {
  public static final int SURFACE_BORDER_SIZE = 1;
  public static final int SHADE_RES_BITS = 4;
  public static final int SHADE_RES = 1 << SHADE_RES_BITS;
  public static final int SHADE_RES_MASK = SHADE_RES - 1;
  public static final int SHADE_RES_SQ = SHADE_RES * SHADE_RES;
  public static final int SHADE_RES_SQ_BITS = SHADE_RES_BITS * 2;
  private short[] buffer;
  private SoftReference bufferReference;
  private boolean dirty;
  private ShadedTexture sourceTexture;
  private Rectangle3D sourceTextureBounds;
  private Rectangle3D surfaceBounds;
  private byte[] shadeMap;
  private int shadeMapWidth;
  private int shadeMapHeight;
  // for incrementally calculating shade values
  private int shadeValue;
  private int shadeValueInc;
  /**
   * Creates a ShadedSurface with the specified width and height.
   */
  public ShadedSurface(int width, int height) {
    this(null, width, height);
  }
  /**
   * Creates a ShadedSurface with the specified buffer, width and height.
   */
  public ShadedSurface(short[] buffer, int width, int height) {
    super(width, height);
    this.buffer = buffer;
    bufferReference = new SoftReference(buffer);
    sourceTextureBounds = new Rectangle3D();
    dirty = true;
  }
  /**
   * Creates a ShadedSurface for the specified polygon. The shade map is
   * created from the specified list of point lights and ambient light
   * intensity.
   */
  public static void createShadedSurface(TexturedPolygon3D poly,
      ShadedTexture texture, List lights, float ambientLightIntensity) {
    // create the texture bounds
    Vector3D origin = poly.getVertex(0);
    Vector3D dv = new Vector3D(poly.getVertex(1));
    dv.subtract(origin);
    Vector3D du = new Vector3D();
    du.setToCrossProduct(poly.getNormal(), dv);
    Rectangle3D bounds = new Rectangle3D(origin, du, dv,
        texture.getWidth(), texture.getHeight());
    createShadedSurface(poly, texture, bounds, lights,
        ambientLightIntensity);
  }
  /**
   * Creates a ShadedSurface for the specified polygon. The shade map is
   * created from the specified list of point lights and ambient light
   * intensity.
   */
  public static void createShadedSurface(TexturedPolygon3D poly,
      ShadedTexture texture, Rectangle3D textureBounds, List lights,
      float ambientLightIntensity) {
    // create the surface bounds
    poly.setTexture(texture, textureBounds);
    Rectangle3D surfaceBounds = poly.calcBoundingRectangle();
    // give the surfaceBounds a border to correct for
    // slight errors when texture mapping
    Vector3D du = new Vector3D(surfaceBounds.getDirectionU());
    Vector3D dv = new Vector3D(surfaceBounds.getDirectionV());
    du.multiply(SURFACE_BORDER_SIZE);
    dv.multiply(SURFACE_BORDER_SIZE);
    surfaceBounds.getOrigin().subtract(du);
    surfaceBounds.getOrigin().subtract(dv);
    int width = (int) Math.ceil(surfaceBounds.getWidth()
        + SURFACE_BORDER_SIZE * 2);
    int height = (int) Math.ceil(surfaceBounds.getHeight()
        + SURFACE_BORDER_SIZE * 2);
    surfaceBounds.setWidth(width);
    surfaceBounds.setHeight(height);
    // create the shaded surface texture
    ShadedSurface surface = new ShadedSurface(width, height);
    surface.setTexture(texture, textureBounds);
    surface.setSurfaceBounds(surfaceBounds);
    // create the surface"s shade map
    surface.buildShadeMap(lights, ambientLightIntensity);
    // set the polygon"s surface
    poly.setTexture(surface, surfaceBounds);
  }
  /**
   * Gets the 16-bit color of the pixel at location (x,y) in the bitmap. The x
   * and y values are assumbed to be within the bounds of the surface;
   * otherwise an ArrayIndexOutOfBoundsException occurs.
   */
  public short getColor(int x, int y) {
    //try {
    return buffer[x + y * width];
    //}
    //catch (ArrayIndexOutOfBoundsException ex) {
    //    return -2048;
    //}
  }
  /**
   * Gets the 16-bit color of the pixel at location (x,y) in the bitmap. The x
   * and y values are checked to be within the bounds of the surface, and if
   * not, the pixel on the edge of the texture is returned.
   */
  public short getColorChecked(int x, int y) {
    if (x < 0) {
      x = 0;
    } else if (x >= width) {
      x = width - 1;
    }
    if (y < 0) {
      y = 0;
    } else if (y >= height) {
      y = height - 1;
    }
    return getColor(x, y);
  }
  /**
   * Marks whether this surface is dirty. Surfaces marked as dirty may be
   * cleared externally.
   */
  public void setDirty(boolean dirty) {
    this.dirty = dirty;
  }
  /**
   * Checks wether this surface is dirty. Surfaces marked as dirty may be
   * cleared externally.
   */
  public boolean isDirty() {
    return dirty;
  }
  /**
   * Creates a new surface and add a SoftReference to it.
   */
  protected void newSurface(int width, int height) {
    buffer = new short[width * height];
    bufferReference = new SoftReference(buffer);
  }
  /**
   * Clears this surface, allowing the garbage collector to remove it from
   * memory if needed.
   */
  public void clearSurface() {
    buffer = null;
  }
  /**
   * Checks if the surface has been cleared.
   */
  public boolean isCleared() {
    return (buffer == null);
  }
  /**
   * If the buffer has been previously built and cleared but not yet removed
   * from memory by the garbage collector, then this method attempts to
   * retrieve it. Returns true if successfull.
   */
  public boolean retrieveSurface() {
    if (buffer == null) {
      buffer = (short[]) bufferReference.get();
    }
    return !(buffer == null);
  }
  /**
   * Sets the source texture for this ShadedSurface.
   */
  public void setTexture(ShadedTexture texture) {
    this.sourceTexture = texture;
    sourceTextureBounds.setWidth(texture.getWidth());
    sourceTextureBounds.setHeight(texture.getHeight());
  }
  /**
   * Sets the source texture and source bounds for this ShadedSurface.
   */
  public void setTexture(ShadedTexture texture, Rectangle3D bounds) {
    setTexture(texture);
    sourceTextureBounds.setTo(bounds);
  }
  /**
   * Sets the surface bounds for this ShadedSurface.
   */
  public void setSurfaceBounds(Rectangle3D surfaceBounds) {
    this.surfaceBounds = surfaceBounds;
  }
  /**
   * Gets the surface bounds for this ShadedSurface.
   */
  public Rectangle3D getSurfaceBounds() {
    return surfaceBounds;
  }
  /**
   * Builds the surface. First, this method calls retrieveSurface() to see if
   * the surface needs to be rebuilt. If not, the surface is built by tiling
   * the source texture and apply the shade map.
   */
  public void buildSurface() {
    if (retrieveSurface()) {
      return;
    }
    int width = (int) surfaceBounds.getWidth();
    int height = (int) surfaceBounds.getHeight();
    // create a new surface (buffer)
    newSurface(width, height);
    // builds the surface.
    // assume surface bounds and texture bounds are aligned
    // (possibly with different origins)
    Vector3D origin = sourceTextureBounds.getOrigin();
    Vector3D directionU = sourceTextureBounds.getDirectionU();
    Vector3D directionV = sourceTextureBounds.getDirectionV();
    Vector3D d = new Vector3D(surfaceBounds.getOrigin());
    d.subtract(origin);
    int startU = (int) ((d.getDotProduct(directionU) - SURFACE_BORDER_SIZE));
    int startV = (int) ((d.getDotProduct(directionV) - SURFACE_BORDER_SIZE));
    int offset = 0;
    int shadeMapOffsetU = SHADE_RES - SURFACE_BORDER_SIZE - startU;
    int shadeMapOffsetV = SHADE_RES - SURFACE_BORDER_SIZE - startV;
    for (int v = startV; v < startV + height; v++) {
      sourceTexture.setCurrRow(v);
      int u = startU;
      int amount = SURFACE_BORDER_SIZE;
      while (u < startU + width) {
        getInterpolatedShade(u + shadeMapOffsetU, v + shadeMapOffsetV);
        // keep drawing until we need to recalculate
        // the interpolated shade. (every SHADE_RES pixels)
        int endU = Math.min(startU + width, u + amount);
        while (u < endU) {
          buffer[offset++] = sourceTexture.getColorCurrRow(u,
              shadeValue >> SHADE_RES_SQ_BITS);
          shadeValue += shadeValueInc;
          u++;
        }
        amount = SHADE_RES;
      }
    }
    // if the surface bounds is not aligned with the texture
    // bounds, use this (slower) code.
    /*
     * Vector3D origin = sourceTextureBounds.getOrigin(); Vector3D
     * directionU = sourceTextureBounds.getDirectionU(); Vector3D directionV =
     * sourceTextureBounds.getDirectionV();
     * 
     * Vector3D d = new Vector3D(surfaceBounds.getOrigin());
     * d.subtract(origin); int initTextureU = (int)(SCALE *
     * (d.getDotProduct(directionU) - SURFACE_BORDER_SIZE)); int
     * initTextureV = (int)(SCALE * (d.getDotProduct(directionV) -
     * SURFACE_BORDER_SIZE)); int textureDu1 = (int)(SCALE *
     * directionU.getDotProduct( surfaceBounds.getDirectionV())); int
     * textureDv1 = (int)(SCALE * directionV.getDotProduct(
     * surfaceBounds.getDirectionV())); int textureDu2 = (int)(SCALE *
     * directionU.getDotProduct( surfaceBounds.getDirectionU())); int
     * textureDv2 = (int)(SCALE * directionV.getDotProduct(
     * surfaceBounds.getDirectionU()));
     * 
     * int shadeMapOffset = SHADE_RES - SURFACE_BORDER_SIZE;
     * 
     * for (int v=0; v <height; v++) { int textureU = initTextureU; int
     * textureV = initTextureV;
     * 
     * for (int u=0; u <width; u++) { if (((u + shadeMapOffset) &
     * SHADE_RES_MASK) == 0) { getInterpolatedShade(u + shadeMapOffset, v +
     * shadeMapOffset); } buffer[offset++] = sourceTexture.getColor(
     * textureU >> SCALE_BITS, textureV >> SCALE_BITS, shadeValue >>
     * SHADE_RES_SQ_BITS); textureU+=textureDu2; textureV+=textureDv2;
     * shadeValue+=shadeValueInc; } initTextureU+=textureDu1;
     * initTextureV+=textureDv1; }
     */
  }
  /**
   * Gets the shade (from the shade map) for the specified (u,v) location. The
   * u and v values should be left-shifted by SHADE_RES_BITS, and the extra
   * bits are used to interpolate between values. For an interpolation
   * example, a location halfway between shade values 1 and 3 would return 2.
   */
  public int getInterpolatedShade(int u, int v) {
    int fracU = u & SHADE_RES_MASK;
    int fracV = v & SHADE_RES_MASK;
    int offset = (u >> SHADE_RES_BITS)
        + ((v >> SHADE_RES_BITS) * shadeMapWidth);
    int shade00 = (SHADE_RES - fracV) * shadeMap[offset];
    int shade01 = fracV * shadeMap[offset + shadeMapWidth];
    int shade10 = (SHADE_RES - fracV) * shadeMap[offset + 1];
    int shade11 = fracV * shadeMap[offset + shadeMapWidth + 1];
    shadeValue = SHADE_RES_SQ / 2 + (SHADE_RES - fracU) * shade00
        + (SHADE_RES - fracU) * shade01 + fracU * shade10 + fracU
        * shade11;
    // the value to increment as u increments
    shadeValueInc = -shade00 - shade01 + shade10 + shade11;
    return shadeValue >> SHADE_RES_SQ_BITS;
  }
  /**
   * Gets the shade (from the built shade map) for the specified (u,v)
   * location.
   */
  public int getShade(int u, int v) {
    return shadeMap[u + v * shadeMapWidth];
  }
  /**
   * Builds the shade map for this surface from the specified list of point
   * lights and the ambiant light intensity.
   */
  public void buildShadeMap(List pointLights, float ambientLightIntensity) {
    Vector3D surfaceNormal = surfaceBounds.getNormal();
    int polyWidth = (int) surfaceBounds.getWidth() - SURFACE_BORDER_SIZE
        * 2;
    int polyHeight = (int) surfaceBounds.getHeight() - SURFACE_BORDER_SIZE
        * 2;
    // assume SURFACE_BORDER_SIZE is <= SHADE_RES
    shadeMapWidth = polyWidth / SHADE_RES + 4;
    shadeMapHeight = polyHeight / SHADE_RES + 4;
    shadeMap = new byte[shadeMapWidth * shadeMapHeight];
    // calculate the shade map origin
    Vector3D origin = new Vector3D(surfaceBounds.getOrigin());
    Vector3D du = new Vector3D(surfaceBounds.getDirectionU());
    Vector3D dv = new Vector3D(surfaceBounds.getDirectionV());
    du.multiply(SHADE_RES - SURFACE_BORDER_SIZE);
    dv.multiply(SHADE_RES - SURFACE_BORDER_SIZE);
    origin.subtract(du);
    origin.subtract(dv);
    // calculate the shade for each sample point.
    Vector3D point = new Vector3D();
    du.setTo(surfaceBounds.getDirectionU());
    dv.setTo(surfaceBounds.getDirectionV());
    du.multiply(SHADE_RES);
    dv.multiply(SHADE_RES);
    for (int v = 0; v < shadeMapHeight; v++) {
      point.setTo(origin);
      for (int u = 0; u < shadeMapWidth; u++) {
        shadeMap[u + v * shadeMapWidth] = calcShade(surfaceNormal,
            point, pointLights, ambientLightIntensity);
        point.add(du);
      }
      origin.add(dv);
    }
  }
  /**
   * Determine the shade of a point on the polygon. This computes the
   * Lambertian reflection for a point on the plane. Each point light has an
   * intensity and a distance falloff value, but no specular reflection or
   * shadows from other polygons are computed. The value returned is from 0 to
   * ShadedTexture.MAX_LEVEL.
   */
  protected byte calcShade(Vector3D normal, Vector3D point, List pointLights,
      float ambientLightIntensity) {
    float intensity = 0;
    Vector3D directionToLight = new Vector3D();
    for (int i = 0; i < pointLights.size(); i++) {
      PointLight3D light = (PointLight3D) pointLights.get(i);
      directionToLight.setTo(light);
      directionToLight.subtract(point);
      float distance = directionToLight.length();
      directionToLight.normalize();
      float lightIntensity = light.getIntensity(distance)
          * directionToLight.getDotProduct(normal);
      lightIntensity = Math.min(lightIntensity, 1);
      lightIntensity = Math.max(lightIntensity, 0);
      intensity += lightIntensity;
    }
    intensity = Math.min(intensity, 1);
    intensity = Math.max(intensity, 0);
    intensity += ambientLightIntensity;
    intensity = Math.min(intensity, 1);
    intensity = Math.max(intensity, 0);
    int level = Math.round(intensity * ShadedTexture.MAX_LEVEL);
    return (byte) level;
  }
}
/**
 * A PointLight3D is a point light that has an intensity (between 0 and 1) and
 * optionally a distance falloff value, which causes the light to diminish with
 * distance.
 */
class PointLight3D extends Vector3D {
  public static final float NO_DISTANCE_FALLOFF = -1;
  private float intensity;
  private float distanceFalloff;
  /**
   * Creates a new PointLight3D at (0,0,0) with an intensity of 1 and no
   * distance falloff.
   */
  public PointLight3D() {
    this(0, 0, 0, 1, NO_DISTANCE_FALLOFF);
  }
  /**
   * Creates a copy of the specified PointLight3D.
   */
  public PointLight3D(PointLight3D p) {
    setTo(p);
  }
  /**
   * Creates a new PointLight3D with the specified location and intensity. The
   * created light has no distance falloff.
   */
  public PointLight3D(float x, float y, float z, float intensity) {
    this(x, y, z, intensity, NO_DISTANCE_FALLOFF);
  }
  /**
   * Creates a new PointLight3D with the specified location. intensity, and no
   * distance falloff.
   */
  public PointLight3D(float x, float y, float z, float intensity,
      float distanceFalloff) {
    setTo(x, y, z);
    setIntensity(intensity);
    setDistanceFalloff(distanceFalloff);
  }
  /**
   * Sets this PointLight3D to the same location, intensity, and distance
   * falloff as the specified PointLight3D.
   */
  public void setTo(PointLight3D p) {
    setTo(p.x, p.y, p.z);
    setIntensity(p.getIntensity());
    setDistanceFalloff(p.getDistanceFalloff());
  }
  /**
   * Gets the intensity of this light from the specified distance.
   */
  public float getIntensity(float distance) {
    if (distanceFalloff == NO_DISTANCE_FALLOFF) {
      return intensity;
    } else if (distance >= distanceFalloff) {
      return 0;
    } else {
      return intensity * (distanceFalloff - distance)
          / (distanceFalloff + distance);
    }
  }
  /**
   * Gets the intensity of this light.
   */
  public float getIntensity() {
    return intensity;
  }
  /**
   * Sets the intensity of this light.
   */
  public void setIntensity(float intensity) {
    this.intensity = intensity;
  }
  /**
   * Gets the distances falloff value. The light intensity is zero beyond this
   * distance.
   */
  public float getDistanceFalloff() {
    return distanceFalloff;
  }
  /**
   * Sets the distances falloff value. The light intensity is zero beyond this
   * distance. Set to NO_DISTANCE_FALLOFF if the light does not diminish with
   * distance.
   */
  public void setDistanceFalloff(float distanceFalloff) {
    this.distanceFalloff = distanceFalloff;
  }
}
/**
 * The Transform3D class represents a rotation and translation.
 */
class Transform3D {
  protected Vector3D location;
  private float cosAngleX;
  private float sinAngleX;
  private float cosAngleY;
  private float sinAngleY;
  private float cosAngleZ;
  private float sinAngleZ;
  /**
   * Creates a new Transform3D with no translation or rotation.
   */
  public Transform3D() {
    this(0, 0, 0);
  }
  /**
   * Creates a new Transform3D with the specified translation and no rotation.
   */
  public Transform3D(float x, float y, float z) {
    location = new Vector3D(x, y, z);
    setAngle(0, 0, 0);
  }
  /**
   * Creates a new Transform3D
   */
  public Transform3D(Transform3D v) {
    location = new Vector3D();
    setTo(v);
  }
  public Object clone() {
    return new Transform3D(this);
  }
  /**
   * Sets this Transform3D to the specified Transform3D.
   */
  public void setTo(Transform3D v) {
    location.setTo(v.location);
    this.cosAngleX = v.cosAngleX;
    this.sinAngleX = v.sinAngleX;
    this.cosAngleY = v.cosAngleY;
    this.sinAngleY = v.sinAngleY;
    this.cosAngleZ = v.cosAngleZ;
    this.sinAngleZ = v.sinAngleZ;
  }
  /**
   * Gets the location (translation) of this transform.
   */
  public Vector3D getLocation() {
    return location;
  }
  public float getCosAngleX() {
    return cosAngleX;
  }
  public float getSinAngleX() {
    return sinAngleX;
  }
  public float getCosAngleY() {
    return cosAngleY;
  }
  public float getSinAngleY() {
    return sinAngleY;
  }
  public float getCosAngleZ() {
    return cosAngleZ;
  }
  public float getSinAngleZ() {
    return sinAngleZ;
  }
  public float getAngleX() {
    return (float) Math.atan2(sinAngleX, cosAngleX);
  }
  public float getAngleY() {
    return (float) Math.atan2(sinAngleY, cosAngleY);
  }
  public float getAngleZ() {
    return (float) Math.atan2(sinAngleZ, cosAngleZ);
  }
  public void setAngleX(float angleX) {
    cosAngleX = (float) Math.cos(angleX);
    sinAngleX = (float) Math.sin(angleX);
  }
  public void setAngleY(float angleY) {
    cosAngleY = (float) Math.cos(angleY);
    sinAngleY = (float) Math.sin(angleY);
  }
  public void setAngleZ(float angleZ) {
    cosAngleZ = (float) Math.cos(angleZ);
    sinAngleZ = (float) Math.sin(angleZ);
  }
  public void setAngle(float angleX, float angleY, float angleZ) {
    setAngleX(angleX);
    setAngleY(angleY);
    setAngleZ(angleZ);
  }
  public void rotateAngleX(float angle) {
    if (angle != 0) {
      setAngleX(getAngleX() + angle);
    }
  }
  public void rotateAngleY(float angle) {
    if (angle != 0) {
      setAngleY(getAngleY() + angle);
    }
  }
  public void rotateAngleZ(float angle) {
    if (angle != 0) {
      setAngleZ(getAngleZ() + angle);
    }
  }
  public void rotateAngle(float angleX, float angleY, float angleZ) {
    rotateAngleX(angleX);
    rotateAngleY(angleY);
    rotateAngleZ(angleZ);
  }
}
/**
 * The ViewWindow class represents the geometry of a view window for 3D viewing.
 */
class ViewWindow {
  private Rectangle bounds;
  private float angle;
  private float distanceToCamera;
  /**
   * Creates a new ViewWindow with the specified bounds on the screen and
   * horizontal view angle.
   */
  public ViewWindow(int left, int top, int width, int height, float angle) {
    bounds = new Rectangle();
    this.angle = angle;
    setBounds(left, top, width, height);
  }
  /**
   * Sets the bounds for this ViewWindow on the screen.
   */
  public void setBounds(int left, int top, int width, int height) {
    bounds.x = left;
    bounds.y = top;
    bounds.width = width;
    bounds.height = height;
    distanceToCamera = (bounds.width / 2) / (float) Math.tan(angle / 2);
  }
  /**
   * Sets the horizontal view angle for this ViewWindow.
   */
  public void setAngle(float angle) {
    this.angle = angle;
    distanceToCamera = (bounds.width / 2) / (float) Math.tan(angle / 2);
  }
  /**
   * Gets the horizontal view angle of this view window.
   */
  public float getAngle() {
    return angle;
  }
  /**
   * Gets the width of this view window.
   */
  public int getWidth() {
    return bounds.width;
  }
  /**
   * Gets the height of this view window.
   */
  public int getHeight() {
    return bounds.height;
  }
  /**
   * Gets the y offset of this view window on the screen.
   */
  public int getTopOffset() {
    return bounds.y;
  }
  /**
   * Gets the x offset of this view window on the screen.
   */
  public int getLeftOffset() {
    return bounds.x;
  }
  /**
   * Gets the distance from the camera to to this view window.
   */
  public float getDistance() {
    return distanceToCamera;
  }
  /**
   * Converts an x coordinate on this view window to the corresponding x
   * coordinate on the screen.
   */
  public float convertFromViewXToScreenX(float x) {
    return x + bounds.x + bounds.width / 2;
  }
  /**
   * Converts a y coordinate on this view window to the corresponding y
   * coordinate on the screen.
   */
  public float convertFromViewYToScreenY(float y) {
    return -y + bounds.y + bounds.height / 2;
  }
  /**
   * Converts an x coordinate on the screen to the corresponding x coordinate
   * on this view window.
   */
  public float convertFromScreenXToViewX(float x) {
    return x - bounds.x - bounds.width / 2;
  }
  /**
   * Converts an y coordinate on the screen to the corresponding y coordinate
   * on this view window.
   */
  public float convertFromScreenYToViewY(float y) {
    return -y + bounds.y + bounds.height / 2;
  }
  /**
   * Projects the specified vector to the screen.
   */
  public void project(Vector3D v) {
    // project to view window
    v.x = distanceToCamera * v.x / -v.z;
    v.y = distanceToCamera * v.y / -v.z;
    // convert to screen coordinates
    v.x = convertFromViewXToScreenX(v.x);
    v.y = convertFromViewYToScreenY(v.y);
  }
}
/**
 * The Texture class is an sabstract class that represents a 16-bit color
 * texture.
 */
abstract class Texture {
  protected int width;
  protected int height;
  /**
   * Creates a new Texture with the specified width and height.
   */
  public Texture(int width, int height) {
    this.width = width;
    this.height = height;
  }
  /**
   * Gets the width of this Texture.
   */
  public int getWidth() {
    return width;
  }
  /**
   * Gets the height of this Texture.
   */
  public int getHeight() {
    return height;
  }
  /**
   * Gets the 16-bit color of this Texture at the specified (x,y) location.
   */
  public abstract short getColor(int x, int y);
  /**
   * Creates an unshaded Texture from the specified image file.
   */
  public static Texture createTexture(String filename) {
    return createTexture(filename, false);
  }
  /**
   * Creates an Texture from the specified image file. If shaded is true, then
   * a ShadedTexture is returned.
   */
  public static Texture createTexture(String filename, boolean shaded) {
    try {
      return createTexture(ImageIO.read(new File(filename)), shaded);
    } catch (IOException ex) {
      ex.printStackTrace();
      return null;
    }
  }
  /**
   * Creates an unshaded Texture from the specified image.
   */
  public static Texture createTexture(BufferedImage image) {
    return createTexture(image, false);
  }
  /**
   * Creates an Texture from the specified image. If shaded is true, then a
   * ShadedTexture is returned.
   */
  public static Texture createTexture(BufferedImage image, boolean shaded) {
    int type = image.getType();
    int width = image.getWidth();
    int height = image.getHeight();
    if (!isPowerOfTwo(width) || !isPowerOfTwo(height)) {
      throw new IllegalArgumentException(
          "Size of texture must be a power of two.");
    }
    if (shaded) {
      // convert image to an indexed image
      if (type != BufferedImage.TYPE_BYTE_INDEXED) {
        System.out.println("Warning: image converted to "
            + "256-color indexed image. Some quality may "
            + "be lost.");
        BufferedImage newImage = new BufferedImage(image.getWidth(),
            image.getHeight(), BufferedImage.TYPE_BYTE_INDEXED);
        Graphics2D g = newImage.createGraphics();
        g.drawImage(image, 0, 0, null);
        g.dispose();
        image = newImage;
      }
      DataBuffer dest = image.getRaster().getDataBuffer();
      return new ShadedTexture(((DataBufferByte) dest).getData(),
          countbits(width - 1), countbits(height - 1),
          (IndexColorModel) image.getColorModel());
    } else {
      // convert image to an 16-bit image
      if (type != BufferedImage.TYPE_USHORT_565_RGB) {
        BufferedImage newImage = new BufferedImage(image.getWidth(),
            image.getHeight(), BufferedImage.TYPE_USHORT_565_RGB);
        Graphics2D g = newImage.createGraphics();
        g.drawImage(image, 0, 0, null);
        g.dispose();
        image = newImage;
      }
      DataBuffer dest = image.getRaster().getDataBuffer();
      return new PowerOf2Texture(((DataBufferUShort) dest).getData(),
          countbits(width - 1), countbits(height - 1));
    }
  }
  /**
   * Returns true if the specified number is a power of 2.
   */
  public static boolean isPowerOfTwo(int n) {
    return ((n & (n - 1)) == 0);
  }
  /**
   * Counts the number of "on" bits in an integer.
   */
  public static int countbits(int n) {
    int count = 0;
    while (n > 0) {
      count += (n & 1);
      n >>= 1;
    }
    return count;
  }
}
/**
 * The ShadedTexture class is a Texture that has multiple shades. The texture
 * source image is stored as a 8-bit image with a palette for every shade.
 */
final class ShadedTexture extends Texture {
  public static final int NUM_SHADE_LEVELS = 64;
  public static final int MAX_LEVEL = NUM_SHADE_LEVELS - 1;
  private static final int PALETTE_SIZE_BITS = 8;
  private static final int PALETTE_SIZE = 1 << PALETTE_SIZE_BITS;
  private byte[] buffer;
  private IndexColorModel palette;
  private short[] shadeTable;
  private int defaultShadeLevel;
  private int widthBits;
  private int widthMask;
  private int heightBits;
  private int heightMask;
  // the row set in setCurrRow and used in getColorCurrRow
  private int currRow;
  /**
   * Creates a new ShadedTexture from the specified 8-bit image buffer and
   * palette. The width of the bitmap is 2 to the power of widthBits, or (1 < <
   * widthBits). Likewise, the height of the bitmap is 2 to the power of
   * heightBits, or (1 < < heightBits). The texture is shaded from it"s
   * original color to black.
   */
  public ShadedTexture(byte[] buffer, int widthBits, int heightBits,
      IndexColorModel palette) {
    this(buffer, widthBits, heightBits, palette, Color.BLACK);
  }
  /**
   * Creates a new ShadedTexture from the specified 8-bit image buffer,
   * palette, and target shaded. The width of the bitmap is 2 to the power of
   * widthBits, or (1 < < widthBits). Likewise, the height of the bitmap is 2
   * to the power of heightBits, or (1 < < heightBits). The texture is shaded
   * from it"s original color to the target shade.
   */
  public ShadedTexture(byte[] buffer, int widthBits, int heightBits,
      IndexColorModel palette, Color targetShade) {
    super(1 << widthBits, 1 << heightBits);
    this.buffer = buffer;
    this.widthBits = widthBits;
    this.heightBits = heightBits;
    this.widthMask = getWidth() - 1;
    this.heightMask = getHeight() - 1;
    this.buffer = buffer;
    this.palette = palette;
    defaultShadeLevel = MAX_LEVEL;
    makeShadeTable(targetShade);
  }
  /**
   * Creates the shade table for this ShadedTexture. Each entry in the palette
   * is shaded from the original color to the specified target color.
   */
  public void makeShadeTable(Color targetShade) {
    shadeTable = new short[NUM_SHADE_LEVELS * PALETTE_SIZE];
    for (int level = 0; level < NUM_SHADE_LEVELS; level++) {
      for (int i = 0; i < palette.getMapSize(); i++) {
        int red = calcColor(palette.getRed(i), targetShade.getRed(),
            level);
        int green = calcColor(palette.getGreen(i), targetShade
            .getGreen(), level);
        int blue = calcColor(palette.getBlue(i), targetShade.getBlue(),
            level);
        int index = level * PALETTE_SIZE + i;
        // RGB 5:6:5
        shadeTable[index] = (short) (((red >> 3) << 11)
            | ((green >> 2) << 5) | (blue >> 3));
      }
    }
  }
  private int calcColor(int palColor, int target, int level) {
    return (palColor - target) * (level + 1) / NUM_SHADE_LEVELS + target;
  }
  /**
   * Sets the default shade level that is used when getColor() is called.
   */
  public void setDefaultShadeLevel(int level) {
    defaultShadeLevel = level;
  }
  /**
   * Gets the default shade level that is used when getColor() is called.
   */
  public int getDefaultShadeLevel() {
    return defaultShadeLevel;
  }
  /**
   * Gets the 16-bit color of this Texture at the specified (x,y) location,
   * using the default shade level.
   */
  public short getColor(int x, int y) {
    return getColor(x, y, defaultShadeLevel);
  }
  /**
   * Gets the 16-bit color of this Texture at the specified (x,y) location,
   * using the specified shade level.
   */
  public short getColor(int x, int y, int shadeLevel) {
    return shadeTable[(shadeLevel << PALETTE_SIZE_BITS)
        | (0xff & buffer[(x & widthMask)
            | ((y & heightMask) << widthBits)])];
  }
  /**
   * Sets the current row for getColorCurrRow(). Pre-calculates the offset for
   * this row.
   */
  public void setCurrRow(int y) {
    currRow = (y & heightMask) << widthBits;
  }
  /**
   * Gets the color at the specified x location at the specified shade level.
   * The current row defined in setCurrRow is used.
   */
  public short getColorCurrRow(int x, int shadeLevel) {
    return shadeTable[(shadeLevel << PALETTE_SIZE_BITS)
        | (0xff & buffer[(x & widthMask) | currRow])];
  }
}
/**
 * The PowerOf2Texture class is a Texture with a width and height that are a
 * power of 2 (32, 128, etc.).
 */
final class PowerOf2Texture extends Texture {
  private short[] buffer;
  private int widthBits;
  private int widthMask;
  private int heightBits;
  private int heightMask;
  /**
   * Creates a new PowerOf2Texture with the specified buffer. The width of the
   * bitmap is 2 to the power of widthBits, or (1 < < widthBits). Likewise,
   * the height of the bitmap is 2 to the power of heightBits, or (1 < <
   * heightBits).
   */
  public PowerOf2Texture(short[] buffer, int widthBits, int heightBits) {
    super(1 << widthBits, 1 << heightBits);
    this.buffer = buffer;
    this.widthBits = widthBits;
    this.heightBits = heightBits;
    this.widthMask = getWidth() - 1;
    this.heightMask = getHeight() - 1;
  }
  /**
   * Gets the 16-bit color of the pixel at location (x,y) in the bitmap.
   */
  public short getColor(int x, int y) {
    return buffer[(x & widthMask) + ((y & heightMask) << widthBits)];
  }
}
/**
 * Simple abstract class used for testing. Subclasses should implement the
 * draw() method.
 */
abstract class GameCore {
  protected static final int DEFAULT_FONT_SIZE = 24;
  // various lists of modes, ordered by preference
  protected static final DisplayMode[] MID_RES_MODES = {
      new DisplayMode(800, 600, 16, 0), new DisplayMode(800, 600, 32, 0),
      new DisplayMode(800, 600, 24, 0), new DisplayMode(640, 480, 16, 0),
      new DisplayMode(640, 480, 32, 0), new DisplayMode(640, 480, 24, 0),
      new DisplayMode(1024, 768, 16, 0),
      new DisplayMode(1024, 768, 32, 0),
      new DisplayMode(1024, 768, 24, 0), };
  protected static final DisplayMode[] LOW_RES_MODES = {
      new DisplayMode(640, 480, 16, 0), new DisplayMode(640, 480, 32, 0),
      new DisplayMode(640, 480, 24, 0), new DisplayMode(800, 600, 16, 0),
      new DisplayMode(800, 600, 32, 0), new DisplayMode(800, 600, 24, 0),
      new DisplayMode(1024, 768, 16, 0),
      new DisplayMode(1024, 768, 32, 0),
      new DisplayMode(1024, 768, 24, 0), };
  protected static final DisplayMode[] VERY_LOW_RES_MODES = {
      new DisplayMode(320, 240, 16, 0), new DisplayMode(400, 300, 16, 0),
      new DisplayMode(512, 384, 16, 0), new DisplayMode(640, 480, 16, 0),
      new DisplayMode(800, 600, 16, 0), };
  private boolean isRunning;
  protected ScreenManager screen;
  protected int fontSize = DEFAULT_FONT_SIZE;
  /**
   * Signals the game loop that it"s time to quit
   */
  public void stop() {
    isRunning = false;
  }
  /**
   * Calls init() and gameLoop()
   */
  public void run() {
    try {
      init();
      gameLoop();
    } finally {
      if (screen != null) {
        screen.restoreScreen();
      }
      lazilyExit();
    }
  }
  /**
   * Exits the VM from a daemon thread. The daemon thread waits 2 seconds then
   * calls System.exit(0). Since the VM should exit when only daemon threads
   * are running, this makes sure System.exit(0) is only called if neccesary.
   * It"s neccesary if the Java Sound system is running.
   */
  public void lazilyExit() {
    Thread thread = new Thread() {
      public void run() {
        // first, wait for the VM exit on its own.
        try {
          Thread.sleep(2000);
        } catch (InterruptedException ex) {
        }
        // system is still running, so force an exit
        System.exit(0);
      }
    };
    thread.setDaemon(true);
    thread.start();
  }
  /**
   * Sets full screen mode and initiates and objects.
   */
  public void init() {
    init(MID_RES_MODES);
  }
  /**
   * Sets full screen mode and initiates and objects.
   */
  public void init(DisplayMode[] possibleModes) {
    screen = new ScreenManager();
    DisplayMode displayMode = screen.findFirstCompatibleMode(possibleModes);
    screen.setFullScreen(displayMode);
    Window window = screen.getFullScreenWindow();
    window.setFont(new Font("Dialog", Font.PLAIN, fontSize));
    window.setBackground(Color.blue);
    window.setForeground(Color.white);
    isRunning = true;
  }
  public Image loadImage(String fileName) {
    return new ImageIcon(fileName).getImage();
  }
  /**
   * Runs through the game loop until stop() is called.
   */
  public void gameLoop() {
    long startTime = System.currentTimeMillis();
    long currTime = startTime;
    while (isRunning) {
      long elapsedTime = System.currentTimeMillis() - currTime;
      currTime += elapsedTime;
      // update
      update(elapsedTime);
      // draw the screen
      Graphics2D g = screen.getGraphics();
      draw(g);
      g.dispose();
      screen.update();
      // don"t take a nap! run as fast as possible
      /*
       * try { Thread.sleep(20); } catch (InterruptedException ex) { }
       */
    }
  }
  /**
   * Updates the state of the game/animation based on the amount of elapsed
   * time that has passed.
   */
  public void update(long elapsedTime) {
    // do nothing
  }
  /**
   * Draws to the screen. Subclasses must override this method.
   */
  public abstract void draw(Graphics2D g);
}
/**
 * The ScreenManager class manages initializing and displaying full screen
 * graphics modes.
 */
class ScreenManager {
  private GraphicsDevice device;
  /**
   * Creates a new ScreenManager object.
   */
  public ScreenManager() {
    GraphicsEnvironment environment = GraphicsEnvironment
        .getLocalGraphicsEnvironment();
    device = environment.getDefaultScreenDevice();
  }
  /**
   * Returns a list of compatible display modes for the default device on the
   * system.
   */
  public DisplayMode[] getCompatibleDisplayModes() {
    return device.getDisplayModes();
  }
  /**
   * Returns the first compatible mode in a list of modes. Returns null if no
   * modes are compatible.
   */
  public DisplayMode findFirstCompatibleMode(DisplayMode modes[]) {
    DisplayMode goodModes[] = device.getDisplayModes();
    for (int i = 0; i < modes.length; i++) {
      for (int j = 0; j < goodModes.length; j++) {
        if (displayModesMatch(modes[i], goodModes[j])) {
          return modes[i];
        }
      }
    }
    return null;
  }
  /**
   * Returns the current display mode.
   */
  public DisplayMode getCurrentDisplayMode() {
    return device.getDisplayMode();
  }
  /**
   * Determines if two display modes "match". Two display modes match if they
   * have the same resolution, bit depth, and refresh rate. The bit depth is
   * ignored if one of the modes has a bit depth of
   * DisplayMode.BIT_DEPTH_MULTI. Likewise, the refresh rate is ignored if one
   * of the modes has a refresh rate of DisplayMode.REFRESH_RATE_UNKNOWN.
   */
  public boolean displayModesMatch(DisplayMode mode1, DisplayMode mode2)
  {
    if (mode1.getWidth() != mode2.getWidth()
        || mode1.getHeight() != mode2.getHeight()) {
      return false;
    }
    if (mode1.getBitDepth() != DisplayMode.BIT_DEPTH_MULTI
        && mode2.getBitDepth() != DisplayMode.BIT_DEPTH_MULTI
        && mode1.getBitDepth() != mode2.getBitDepth()) {
      return false;
    }
    if (mode1.getRefreshRate() != DisplayMode.REFRESH_RATE_UNKNOWN
        && mode2.getRefreshRate() != DisplayMode.REFRESH_RATE_UNKNOWN
        && mode1.getRefreshRate() != mode2.getRefreshRate()) {
      return false;
    }
    return true;
  }
  /**
   * Enters full screen mode and changes the display mode. If the specified
   * display mode is null or not compatible with this device, or if the
   * display mode cannot be changed on this system, the current display mode
   * is used.
   * <p>
   * The display uses a BufferStrategy with 2 buffers.
   */
  public void setFullScreen(DisplayMode displayMode) {
    final JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setUndecorated(true);
    frame.setIgnoreRepaint(true);
    frame.setResizable(false);
    device.setFullScreenWindow(frame);
    if (displayMode != null && device.isDisplayChangeSupported()) {
      try {
        device.setDisplayMode(displayMode);
      } catch (IllegalArgumentException ex) {
      }
      // fix for mac os x
      frame.setSize(displayMode.getWidth(), displayMode.getHeight());
    }
    // avoid potential deadlock in 1.4.1_02
    try {
      EventQueue.invokeAndWait(new Runnable() {
        public void run() {
          frame.createBufferStrategy(2);
        }
      });
    } catch (InterruptedException ex) {
      // ignore
    } catch (InvocationTargetException ex) {
      // ignore
    }
  }
  /**
   * Gets the graphics context for the display. The ScreenManager uses double
   * buffering, so applications must call update() to show any graphics drawn.
   * <p>
   * The application must dispose of the graphics object.
   */
  public Graphics2D getGraphics() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      BufferStrategy strategy = window.getBufferStrategy();
      return (Graphics2D) strategy.getDrawGraphics();
    } else {
      return null;
    }
  }
  /**
   * Updates the display.
   */
  public void update() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      BufferStrategy strategy = window.getBufferStrategy();
      if (!strategy.contentsLost()) {
        strategy.show();
      }
    }
    // Sync the display on some systems.
    // (on Linux, this fixes event queue problems)
    //Toolkit.getDefaultToolkit().sync();
  }
  /**
   * Returns the window currently used in full screen mode. Returns null if
   * the device is not in full screen mode.
   */
  public JFrame getFullScreenWindow() {
    return (JFrame) device.getFullScreenWindow();
  }
  /**
   * Returns the width of the window currently used in full screen mode.
   * Returns 0 if the device is not in full screen mode.
   */
  public int getWidth() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      return window.getWidth();
    } else {
      return 0;
    }
  }
  /**
   * Returns the height of the window currently used in full screen mode.
   * Returns 0 if the device is not in full screen mode.
   */
  public int getHeight() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      return window.getHeight();
    } else {
      return 0;
    }
  }
  /**
   * Restores the screen"s display mode.
   */
  public void restoreScreen() {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      window.dispose();
    }
    device.setFullScreenWindow(null);
  }
  /**
   * Creates an image compatible with the current display.
   */
  public BufferedImage createCompatibleImage(int w, int h, int transparancy) {
    Window window = device.getFullScreenWindow();
    if (window != null) {
      GraphicsConfiguration gc = window.getGraphicsConfiguration();
      return gc.createCompatibleImage(w, h, transparancy);
    }
    return null;
  }
}
/**
 * A thread pool is a group of a limited number of threads that are used to
 * execute tasks.
 */
class ThreadPool extends ThreadGroup {
  private boolean isAlive;
  private LinkedList taskQueue;
  private int threadID;
  private static int threadPoolID;
  /**
   * Creates a new ThreadPool.
   * 
   * @param numThreads
   *            The number of threads in the pool.
   */
  public ThreadPool(int numThreads) {
    super("ThreadPool-" + (threadPoolID++));
    setDaemon(true);
    isAlive = true;
    taskQueue = new LinkedList();
    for (int i = 0; i < numThreads; i++) {
      new PooledThread().start();
    }
  }
  /**
   * Requests a new task to run. This method returns immediately, and the task
   * executes on the next available idle thread in this ThreadPool.
   * <p>
   * Tasks start execution in the order they are received.
   * 
   * @param task
   *            The task to run. If null, no action is taken.
   * @throws IllegalStateException
   *             if this ThreadPool is already closed.
   */
  public synchronized void runTask(Runnable task) {
    if (!isAlive) {
      throw new IllegalStateException();
    }
    if (task != null) {
      taskQueue.add(task);
      notify();
    }
  }
  protected synchronized Runnable getTask() throws InterruptedException {
    while (taskQueue.size() == 0) {
      if (!isAlive) {
        return null;
      }
      wait();
    }
    return (Runnable) taskQueue.removeFirst();
  }
  /**
   * Closes this ThreadPool and returns immediately. All threads are stopped,
   * and any waiting tasks are not executed. Once a ThreadPool is closed, no
   * more tasks can be run on this ThreadPool.
   */
  public synchronized void close() {
    if (isAlive) {
      isAlive = false;
      taskQueue.clear();
      interrupt();
    }
  }
  /**
   * Closes this ThreadPool and waits for all running threads to finish. Any
   * waiting tasks are executed.
   */
  public void join() {
    // notify all waiting threads that this ThreadPool is no
    // longer alive
    synchronized (this) {
      isAlive = false;
      notifyAll();
    }
    // wait for all threads to finish
    Thread[] threads = new Thread[activeCount()];
    int count = enumerate(threads);
    for (int i = 0; i < count; i++) {
      try {
        threads[i].join();
      } catch (InterruptedException ex) {
      }
    }
  }
  /**
   * Signals that a PooledThread has started. This method does nothing by
   * default; subclasses should override to do any thread-specific startup
   * tasks.
   */
  protected void threadStarted() {
    // do nothing
  }
  /**
   * Signals that a PooledThread has stopped. This method does nothing by
   * default; subclasses should override to do any thread-specific cleanup
   * tasks.
   */
  protected void threadStopped() {
    // do nothing
  }
  /**
   * A PooledThread is a Thread in a ThreadPool group, designed to run tasks
   * (Runnables).
   */
  private class PooledThread extends Thread {
    public PooledThread() {
      super(ThreadPool.this, "PooledThread-" + (threadID++));
    }
    public void run() {
      // signal that this thread has started
      threadStarted();
      while (!isInterrupted()) {
        // get a task to run
        Runnable task = null;
        try {
          task = getTask();
        } catch (InterruptedException ex) {
        }
        // if getTask() returned null or was interrupted,
        // close this thread.
        if (task == null) {
          break;
        }
        // run the task, and eat any exceptions it throws
        try {
          task.run();
        } catch (Throwable t) {
          uncaughtException(this, t);
        }
      }
      // signal that this thread has stopped
      threadStopped();
    }
  }
}
/**
 * The SoundManager class manages sound playback. The SoundManager is a
 * ThreadPool, with each thread playing back one sound at a time. This allows
 * the SoundManager to easily limit the number of simultaneous sounds being
 * played.
 * <p>
 * Possible ideas to extend this class:
 * <ul>
 * <li>add a setMasterVolume() method, which uses Controls to set the volume
 * for each line.
 * <li>don"t play a sound if more than, say, 500ms has passed since the request
 * to play
 * </ul>
 */
class SoundManager extends ThreadPool {
  private AudioFormat playbackFormat;
  private ThreadLocal localLine;
  private ThreadLocal localBuffer;
  private Object pausedLock;
  private boolean paused;
  /**
   * Creates a new SoundManager using the maximum number of simultaneous
   * sounds.
   */
  public SoundManager(AudioFormat playbackFormat) {
    this(playbackFormat, getMaxSimultaneousSounds(playbackFormat));
  }
  /**
   * Creates a new SoundManager with the specified maximum number of
   * simultaneous sounds.
   */
  public SoundManager(AudioFormat playbackFormat, int maxSimultaneousSounds) {
    super(Math.min(maxSimultaneousSounds,
        getMaxSimultaneousSounds(playbackFormat)));
    this.playbackFormat = playbackFormat;
    localLine = new ThreadLocal();
    localBuffer = new ThreadLocal();
    pausedLock = new Object();
    // notify threads in pool it"s ok to start
    synchronized (this) {
      notifyAll();
    }
  }
  /**
   * Gets the maximum number of simultaneous sounds with the specified
   * AudioFormat that the default mixer can play.
   */
  public static int getMaxSimultaneousSounds(AudioFormat playbackFormat) {
    DataLine.Info lineInfo = new DataLine.Info(SourceDataLine.class,
        playbackFormat);
    Mixer mixer = AudioSystem.getMixer(null);
    return mixer.getMaxLines(lineInfo);
  }
  /**
   * Does any clean up before closing.
   */
  protected void cleanUp() {
    // signal to unpause
    setPaused(false);
    // close the mixer (stops any running sounds)
    Mixer mixer = AudioSystem.getMixer(null);
    if (mixer.isOpen()) {
      mixer.close();
    }
  }
  public void close() {
    cleanUp();
    super.close();
  }
  public void join() {
    cleanUp();
    super.join();
  }
  /**
   * Sets the paused state. Sounds may not pause immediately.
   */
  public void setPaused(boolean paused) {
    if (this.paused != paused) {
      synchronized (pausedLock) {
        this.paused = paused;
        if (!paused) {
          // restart sounds
          pausedLock.notifyAll();
        }
      }
    }
  }
  /**
   * Returns the paused state.
   */
  public boolean isPaused() {
    return paused;
  }
  /**
   * Loads a Sound from the file system. Returns null if an error occurs.
   */
  public Sound getSound(String filename) {
    return getSound(getAudioInputStream(filename));
  }
  /**
   * Loads a Sound from an input stream. Returns null if an error occurs.
   */
  public Sound getSound(InputStream is) {
    return getSound(getAudioInputStream(is));
  }
  /**
   * Loads a Sound from an AudioInputStream.
   */
  public Sound getSound(AudioInputStream audioStream) {
    if (audioStream == null) {
      return null;
    }
    // get the number of bytes to read
    int length = (int) (audioStream.getFrameLength() * audioStream
        .getFormat().getFrameSize());
    // read the entire stream
    byte[] samples = new byte[length];
    DataInputStream is = new DataInputStream(audioStream);
    try {
      is.readFully(samples);
      is.close();
    } catch (IOException ex) {
      ex.printStackTrace();
    }
    // return the samples
    return new Sound(samples);
  }
  /**
   * Creates an AudioInputStream from a sound from the file system.
   */
  public AudioInputStream getAudioInputStream(String filename) {
    try {
      return getAudioInputStream(new FileInputStream(filename));
    } catch (IOException ex) {
      ex.printStackTrace();
      return null;
    }
  }
  /**
   * Creates an AudioInputStream from a sound from an input stream
   */
  public AudioInputStream getAudioInputStream(InputStream is) {
    try {
      if (!is.markSupported()) {
        is = new BufferedInputStream(is);
      }
      // open the source stream
      AudioInputStream source = AudioSystem.getAudioInputStream(is);
      // convert to playback format
      return AudioSystem.getAudioInputStream(playbackFormat, source);
    } catch (UnsupportedAudioFileException ex) {
      ex.printStackTrace();
    } catch (IOException ex) {
      ex.printStackTrace();
    } catch (IllegalArgumentException ex) {
      ex.printStackTrace();
    }
    return null;
  }
  /**
   * Plays a sound. This method returns immediately.
   */
  public InputStream play(Sound sound) {
    return play(sound, null, false);
  }
  /**
   * Plays a sound with an optional SoundFilter, and optionally looping. This
   * method returns immediately.
   */
  public InputStream play(Sound sound, SoundFilter filter, boolean loop) {
    InputStream is;
    if (sound != null) {
      if (loop) {
        is = new LoopingByteInputStream(sound.getSamples());
      } else {
        is = new ByteArrayInputStream(sound.getSamples());
      }
      return play(is, filter);
    }
    return null;
  }
  /**
   * Plays a sound from an InputStream. This method returns immediately.
   */
  public InputStream play(InputStream is) {
    return play(is, null);
  }
  /**
   * Plays a sound from an InputStream with an optional sound filter. This
   * method returns immediately.
   */
  public InputStream play(InputStream is, SoundFilter filter) {
    if (is != null) {
      if (filter != null) {
        is = new FilteredSoundStream(is, filter);
      }
      runTask(new SoundPlayer(is));
    }
    return is;
  }
  /**
   * Signals that a PooledThread has started. Creates the Thread"s line and
   * buffer.
   */
  protected void threadStarted() {
    // wait for the SoundManager constructor to finish
    synchronized (this) {
      try {
        wait();
      } catch (InterruptedException ex) {
      }
    }
    // use a short, 100ms (1/10th sec) buffer for filters that
    // change in real-time
    int bufferSize = playbackFormat.getFrameSize()
        * Math.round(playbackFormat.getSampleRate() / 10);
    // create, open, and start the line
    SourceDataLine line;
    DataLine.Info lineInfo = new DataLine.Info(SourceDataLine.class,
        playbackFormat);
    try {
      line = (SourceDataLine) AudioSystem.getLine(lineInfo);
      line.open(playbackFormat, bufferSize);
    } catch (LineUnavailableException ex) {
      // the line is unavailable - signal to end this thread
      Thread.currentThread().interrupt();
      return;
    }
    line.start();
    // create the buffer
    byte[] buffer = new byte[bufferSize];
    // set this thread"s locals
    localLine.set(line);
    localBuffer.set(buffer);
  }
  /**
   * Signals that a PooledThread has stopped. Drains and closes the Thread"s
   * Line.
   */
  protected void threadStopped() {
    SourceDataLine line = (SourceDataLine) localLine.get();
    if (line != null) {
      line.drain();
      line.close();
    }
  }
  /**
   * The SoundPlayer class is a task for the PooledThreads to run. It receives
   * the threads"s Line and byte buffer from the ThreadLocal variables and
   * plays a sound from an InputStream.
   * <p>
   * This class only works when called from a PooledThread.
   */
  protected class SoundPlayer implements Runnable {
    private InputStream source;
    public SoundPlayer(InputStream source) {
      this.source = source;
    }
    public void run() {
      // get line and buffer from ThreadLocals
      SourceDataLine line = (SourceDataLine) localLine.get();
      byte[] buffer = (byte[]) localBuffer.get();
      if (line == null || buffer == null) {
        // the line is unavailable
        return;
      }
      // copy data to the line
      try {
        int numBytesRead = 0;
        while (numBytesRead != -1) {
          // if paused, wait until unpaused
          synchronized (pausedLock) {
            if (paused) {
              try {
                pausedLock.wait();
              } catch (InterruptedException ex) {
                return;
              }
            }
          }
          // copy data
          numBytesRead = source.read(buffer, 0, buffer.length);
          if (numBytesRead != -1) {
            line.write(buffer, 0, numBytesRead);
          }
        }
      } catch (IOException ex) {
        ex.printStackTrace();
      }
    }
  }
}
/**
 * The LoopingByteInputStream is a ByteArrayInputStream that loops indefinitly.
 * The looping stops when the close() method is called.
 * <p>
 * Possible ideas to extend this class:
 * <ul>
 * <li>Add an option to only loop a certain number of times.
 * </ul>
 */
class LoopingByteInputStream extends ByteArrayInputStream {
  private boolean closed;
  /**
   * Creates a new LoopingByteInputStream with the specified byte array. The
   * array is not copied.
   */
  public LoopingByteInputStream(byte[] buffer) {
    super(buffer);
    closed = false;
  }
  /**
   * Reads <code>length</code> bytes from the array. If the end of the array
   * is reached, the reading starts over from the beginning of the array.
   * Returns -1 if the array has been closed.
   */
  public int read(byte[] buffer, int offset, int length) {
    if (closed) {
      return -1;
    }
    int totalBytesRead = 0;
    while (totalBytesRead < length) {
      int numBytesRead = super.read(buffer, offset + totalBytesRead,
          length - totalBytesRead);
      if (numBytesRead > 0) {
        totalBytesRead += numBytesRead;
      } else {
        reset();
      }
    }
    return totalBytesRead;
  }
  /**
   * Closes the stream. Future calls to the read() methods will return 1.
   */
  public void close() throws IOException {
    super.close();
    closed = true;
  }
}
/**
 * A abstract class designed to filter sound samples. Since SoundFilters may use
 * internal buffering of samples, a new SoundFilter object should be created for
 * every sound played. However, SoundFilters can be reused after they are
 * finished by called the reset() method.
 * <p>
 * Assumes all samples are 16-bit, signed, little-endian format.
 * 
 * @see FilteredSoundStream
 */
abstract class SoundFilter {
  /**
   * Resets this SoundFilter. Does nothing by default.
   */
  public void reset() {
    // do nothing
  }
  /**
   * Gets the remaining size, in bytes, that this filter plays after the sound
   * is finished. An example would be an echo that plays longer than it"s
   * original sound. This method returns 0 by default.
   */
  public int getRemainingSize() {
    return 0;
  }
  /**
   * Filters an array of samples. Samples should be in 16-bit, signed,
   * little-endian format.
   */
  public void filter(byte[] samples) {
    filter(samples, 0, samples.length);
  }
  /**
   * Filters an array of samples. Samples should be in 16-bit, signed,
   * little-endian format. This method should be implemented by subclasses.
   */
  public abstract void filter(byte[] samples, int offset, int length);
  /**
   * Convenience method for getting a 16-bit sample from a byte array. Samples
   * should be in 16-bit, signed, little-endian format.
   */
  public static short getSample(byte[] buffer, int position) {
    return (short) (((buffer[position + 1] & 0xff) << 8) | (buffer[position] & 0xff));
  }
  /**
   * Convenience method for setting a 16-bit sample in a byte array. Samples
   * should be in 16-bit, signed, little-endian format.
   */
  public static void setSample(byte[] buffer, int position, short sample) {
    buffer[position] = (byte) (sample & 0xff);
    buffer[position + 1] = (byte) ((sample >> 8) & 0xff);
  }
}
/**
 * The FilteredSoundStream class is a FilterInputStream that applies a
 * SoundFilter to the underlying input stream.
 * 
 * @see SoundFilter
 */
class FilteredSoundStream extends FilterInputStream {
  private static final int REMAINING_SIZE_UNKNOWN = -1;
  private SoundFilter soundFilter;
  private int remainingSize;
  /**
   * Creates a new FilteredSoundStream object with the specified InputStream
   * and SoundFilter.
   */
  public FilteredSoundStream(InputStream in, SoundFilter soundFilter) {
    super(in);
    this.soundFilter = soundFilter;
    remainingSize = REMAINING_SIZE_UNKNOWN;
  }
  /**
   * Overrides the FilterInputStream method to apply this filter whenever
   * bytes are read
   */
  public int read(byte[] samples, int offset, int length) throws IOException {
    // read and filter the sound samples in the stream
    int bytesRead = super.read(samples, offset, length);
    if (bytesRead > 0) {
      soundFilter.filter(samples, offset, bytesRead);
      return bytesRead;
    }
    // if there are no remaining bytes in the sound stream,
    // check if the filter has any remaining bytes ("echoes").
    if (remainingSize == REMAINING_SIZE_UNKNOWN) {
      remainingSize = soundFilter.getRemainingSize();
      // round down to nearest multiple of 4
      // (typical frame size)
      remainingSize = remainingSize / 4 * 4;
    }
    if (remainingSize > 0) {
      length = Math.min(length, remainingSize);
      // clear the buffer
      for (int i = offset; i < offset + length; i++) {
        samples[i] = 0;
      }
      // filter the remaining bytes
      soundFilter.filter(samples, offset, length);
      remainingSize -= length;
      // return
      return length;
    } else {
      // end of stream
      return -1;
    }
  }
}
/**
 * The MoreMath class provides functions not contained in the java.lang.Math or
 * java.lang.StrictMath classes.
 */
class MoreMath {
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(short v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(int v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(long v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(float v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Returns the sign of the number. Returns -1 for negative, 1 for positive,
   * and 0 otherwise.
   */
  public static int sign(double v) {
    return (v > 0) ? 1 : (v < 0) ? -1 : 0;
  }
  /**
   * Faster ceil function to convert a float to an int. Contrary to the
   * java.lang.Math ceil function, this function takes a float as an argument,
   * returns an int instead of a double, and does not consider special cases.
   */
  public static int ceil(float f) {
    if (f > 0) {
      return (int) f + 1;
    } else {
      return (int) f;
    }
  }
  /**
   * Faster floor function to convert a float to an int. Contrary to the
   * java.lang.Math floor function, this function takes a float as an
   * argument, returns an int instead of a double, and does not consider
   * special cases.
   */
  public static int floor(float f) {
    if (f >= 0) {
      return (int) f;
    } else {
      return (int) f - 1;
    }
  }
  /**
   * Returns true if the specified number is a power of 2.
   */
  public static boolean isPowerOfTwo(int n) {
    return ((n & (n - 1)) == 0);
  }
  /**
   * Gets the number of "on" bits in an integer.
   */
  public static int getBitCount(int n) {
    int count = 0;
    while (n > 0) {
      count += (n & 1);
      n >>= 1;
    }
    return count;
  }
}
/**
 * The ScanConverter class converts a projected polygon into a series of
 * horizontal scans for drawing.
 */
class ScanConverter {
  private static final int SCALE_BITS = 16;
  private static final int SCALE = 1 << SCALE_BITS;
  private static final int SCALE_MASK = SCALE - 1;
  protected ViewWindow view;
  protected Scan[] scans;
  protected int top;
  protected int bottom;
  /**
   * A horizontal scan line.
   */
  public static class Scan {
    public int left;
    public int right;
    /**
     * Sets the left and right boundary for this scan if the x value is
     * outside the current boundary.
     */
    public void setBoundary(int x) {
      if (x < left) {
        left = x;
      }
      if (x - 1 > right) {
        right = x - 1;
      }
    }
    /**
     * Clears this scan line.
     */
    public void clear() {
      left = Integer.MAX_VALUE;
      right = Integer.MIN_VALUE;
    }
    /**
     * Determines if this scan is valid (if left <= right).
     */
    public boolean isValid() {
      return (left <= right);
    }
    /**
     * Sets this scan.
     */
    public void setTo(int left, int right) {
      this.left = left;
      this.right = right;
    }
    /**
     * Checks if this scan is equal to the specified values.
     */
    public boolean equals(int left, int right) {
      return (this.left == left && this.right == right);
    }
  }
  /**
   * Creates a new ScanConverter for the specified ViewWindow. The
   * ViewWindow"s properties can change in between scan conversions.
   */
  public ScanConverter(ViewWindow view) {
    this.view = view;
  }
  /**
   * Gets the top boundary of the last scan-converted polygon.
   */
  public int getTopBoundary() {
    return top;
  }
  /**
   * Gets the bottom boundary of the last scan-converted polygon.
   */
  public int getBottomBoundary() {
    return bottom;
  }
  /**
   * Gets the scan line for the specified y value.
   */
  public Scan getScan(int y) {
    return scans[y];
  }
  /**
   * Ensures this ScanConverter has the capacity to scan-convert a polygon to
   * the ViewWindow.
   */
  protected void ensureCapacity() {
    int height = view.getTopOffset() + view.getHeight();
    if (scans == null || scans.length != height) {
      scans = new Scan[height];
      for (int i = 0; i < height; i++) {
        scans[i] = new Scan();
      }
      // set top and bottom so clearCurrentScan clears all
      top = 0;
      bottom = height - 1;
    }
  }
  /**
   * Clears the current scan.
   */
  private void clearCurrentScan() {
    for (int i = top; i <= bottom; i++) {
      scans[i].clear();
    }
    top = Integer.MAX_VALUE;
    bottom = Integer.MIN_VALUE;
  }
  /**
   * Scan-converts a projected polygon. Returns true if the polygon is visible
   * in the view window.
   */
  public boolean convert(Polygon3D polygon) {
    ensureCapacity();
    clearCurrentScan();
    int minX = view.getLeftOffset();
    int maxX = view.getLeftOffset() + view.getWidth() - 1;
    int minY = view.getTopOffset();
    int maxY = view.getTopOffset() + view.getHeight() - 1;
    int numVertices = polygon.getNumVertices();
    for (int i = 0; i < numVertices; i++) {
      Vector3D v1 = polygon.getVertex(i);
      Vector3D v2;
      if (i == numVertices - 1) {
        v2 = polygon.getVertex(0);
      } else {
        v2 = polygon.getVertex(i + 1);
      }
      // ensure v1.y < v2.y
      if (v1.y > v2.y) {
        Vector3D temp = v1;
        v1 = v2;
        v2 = temp;
      }
      float dy = v2.y - v1.y;
      // ignore horizontal lines
      if (dy == 0) {
        continue;
      }
      int startY = Math.max(MoreMath.ceil(v1.y), minY);
      int endY = Math.min(MoreMath.ceil(v2.y) - 1, maxY);
      top = Math.min(top, startY);
      bottom = Math.max(bottom, endY);
      float dx = v2.x - v1.x;
      // special case: vertical line
      if (dx == 0) {
        int x = MoreMath.ceil(v1.x);
        // ensure x within view bounds
        x = Math.min(maxX + 1, Math.max(x, minX));
        for (int y = startY; y <= endY; y++) {
          scans[y].setBoundary(x);
        }
      } else {
        // scan-convert this edge (line equation)
        float gradient = dx / dy;
        // (slower version)
        /*
         * for (int y=startY; y <=endY; y++) { int x =
         * MoreMath.ceil(v1.x + (y - v1.y) * gradient); // ensure x
         * within view bounds x = Math.min(maxX+1, Math.max(x, minX));
         * scans[y].setBoundary(x); }
         */
        // (faster version)
        // trim start of line
        float startX = v1.x + (startY - v1.y) * gradient;
        if (startX < minX) {
          int yInt = (int) (v1.y + (minX - v1.x) / gradient);
          yInt = Math.min(yInt, endY);
          while (startY <= yInt) {
            scans[startY].setBoundary(minX);
            startY++;
          }
        } else if (startX > maxX) {
          int yInt = (int) (v1.y + (maxX - v1.x) / gradient);
          yInt = Math.min(yInt, endY);
          while (startY <= yInt) {
            scans[startY].setBoundary(maxX + 1);
            startY++;
          }
        }
        if (startY > endY) {
          continue;
        }
        // trim back of line
        float endX = v1.x + (endY - v1.y) * gradient;
        if (endX < minX) {
          int yInt = MoreMath.ceil(v1.y + (minX - v1.x) / gradient);
          yInt = Math.max(yInt, startY);
          while (endY >= yInt) {
            scans[endY].setBoundary(minX);
            endY--;
          }
        } else if (endX > maxX) {
          int yInt = MoreMath.ceil(v1.y + (maxX - v1.x) / gradient);
          yInt = Math.max(yInt, startY);
          while (endY >= yInt) {
            scans[endY].setBoundary(maxX + 1);
            endY--;
          }
        }
        if (startY > endY) {
          continue;
        }
        // line equation using integers
        int xScaled = (int) (SCALE * v1.x + SCALE * (startY - v1.y)
            * dx / dy)
            + SCALE_MASK;
        int dxScaled = (int) (dx * SCALE / dy);
        for (int y = startY; y <= endY; y++) {
          scans[y].setBoundary(xScaled >> SCALE_BITS);
          xScaled += dxScaled;
        }
      }
    }
    // check if visible (any valid scans)
    for (int i = top; i <= bottom; i++) {
      if (scans[i].isValid()) {
        return true;
      }
    }
    return false;
  }
}
/**
 * The PolygonRenderer class is an abstract class that transforms and draws
 * polygons onto the screen.
 */
abstract class PolygonRenderer {
  protected ScanConverter scanConverter;
  protected Transform3D camera;
  protected ViewWindow viewWindow;
  protected boolean clearViewEveryFrame;
  protected Polygon3D sourcePolygon;
  protected Polygon3D destPolygon;
  /**
   * Creates a new PolygonRenderer with the specified Transform3D (camera) and
   * ViewWindow. The view is cleared when startFrame() is called.
   */
  public PolygonRenderer(Transform3D camera, ViewWindow viewWindow) {
    this(camera, viewWindow, true);
  }
  /**
   * Creates a new PolygonRenderer with the specified Transform3D (camera) and
   * ViewWindow. If clearViewEveryFrame is true, the view is cleared when
   * startFrame() is called.
   */
  public PolygonRenderer(Transform3D camera, ViewWindow viewWindow,
      boolean clearViewEveryFrame) {
    this.camera = camera;
    this.viewWindow = viewWindow;
    this.clearViewEveryFrame = clearViewEveryFrame;
    init();
  }
  /**
   * Create the scan converter and dest polygon.
   */
  protected void init() {
    destPolygon = new Polygon3D();
    scanConverter = new ScanConverter(viewWindow);
  }
  /**
   * Gets the camera used for this PolygonRenderer.
   */
  public Transform3D getCamera() {
    return camera;
  }
  /**
   * Indicates the start of rendering of a frame. This method should be called
   * every frame before any polygons are drawn.
   */
  public void startFrame(Graphics2D g) {
    if (clearViewEveryFrame) {
      g.setColor(Color.black);
      g.fillRect(viewWindow.getLeftOffset(), viewWindow.getTopOffset(),
          viewWindow.getWidth(), viewWindow.getHeight());
    }
  }
  /**
   * Indicates the end of rendering of a frame. This method should be called
   * every frame after all polygons are drawn.
   */
  public void endFrame(Graphics2D g) {
    // do nothing, for now.
  }
  /**
   * Transforms and draws a polygon.
   */
  public boolean draw(Graphics2D g, Polygon3D poly) {
    if (poly.isFacing(camera.getLocation())) {
      sourcePolygon = poly;
      destPolygon.setTo(poly);
      destPolygon.subtract(camera);
      boolean visible = destPolygon.clip(-1);
      if (visible) {
        destPolygon.project(viewWindow);
        visible = scanConverter.convert(destPolygon);
        if (visible) {
          drawCurrentPolygon(g);
          return true;
        }
      }
    }
    return false;
  }
  /**
   * Draws the current polygon. At this point, the current polygon is
   * transformed, clipped, projected, scan-converted, and visible.
   */
  protected abstract void drawCurrentPolygon(Graphics2D g);
}
/**
 * The Sound class is a container for sound samples. The sound samples are
 * format-agnostic and are stored as a byte array.
 */
class Sound {
  private byte[] samples;
  /**
   * Create a new Sound object with the specified byte array. The array is not
   * copied.
   */
  public Sound(byte[] samples) {
    this.samples = samples;
  }
  /**
   * Returns this Sound"s objects samples as a byte array.
   */
  public byte[] getSamples() {
    return samples;
  }
}
/**
 * The InputManager manages input of key and mouse events. Events are mapped to
 * GameActions.
 */
class InputManager implements KeyListener, MouseListener, MouseMotionListener,
    MouseWheelListener {
  /**
   * An invisible cursor.
   */
  public static final Cursor INVISIBLE_CURSOR = Toolkit.getDefaultToolkit()
      .createCustomCursor(Toolkit.getDefaultToolkit().getImage(""),
          new Point(0, 0), "invisible");
  // mouse codes
  public static final int MOUSE_MOVE_LEFT = 0;
  public static final int MOUSE_MOVE_RIGHT = 1;
  public static final int MOUSE_MOVE_UP = 2;
  public static final int MOUSE_MOVE_DOWN = 3;
  public static final int MOUSE_WHEEL_UP = 4;
  public static final int MOUSE_WHEEL_DOWN = 5;
  public static final int MOUSE_BUTTON_1 = 6;
  public static final int MOUSE_BUTTON_2 = 7;
  public static final int MOUSE_BUTTON_3 = 8;
  private static final int NUM_MOUSE_CODES = 9;
  // key codes are defined in java.awt.KeyEvent.
  // most of the codes (except for some rare ones like
  // "alt graph") are less than 600.
  private static final int NUM_KEY_CODES = 600;
  private GameAction[] keyActions = new GameAction[NUM_KEY_CODES];
  private GameAction[] mouseActions = new GameAction[NUM_MOUSE_CODES];
  private Point mouseLocation;
  private Point centerLocation;
  private Component comp;
  private Robot robot;
  private boolean isRecentering;
  /**
   * Creates a new InputManager that listens to input from the specified
   * component.
   */
  public InputManager(Component comp) {
    this.rup = comp;
    mouseLocation = new Point();
    centerLocation = new Point();
    // register key and mouse listeners
    comp.addKeyListener(this);
    comp.addMouseListener(this);
    comp.addMouseMotionListener(this);
    comp.addMouseWheelListener(this);
    // allow input of the TAB key and other keys normally
    // used for focus traversal
    comp.setFocusTraversalKeysEnabled(false);
  }
  /**
   * Sets the cursor on this InputManager"s input component.
   */
  public void setCursor(Cursor cursor) {
    comp.setCursor(cursor);
  }
  /**
   * Sets whether realtive mouse mode is on or not. For relative mouse mode,
   * the mouse is "locked" in the center of the screen, and only the changed
   * in mouse movement is measured. In normal mode, the mouse is free to move
   * about the screen.
   */
  public void setRelativeMouseMode(boolean mode) {
    if (mode == isRelativeMouseMode()) {
      return;
    }
    if (mode) {
      try {
        robot = new Robot();
        mouseLocation.x = comp.getWidth() / 2;
        mouseLocation.y = comp.getHeight() / 2;
        recenterMouse();
      } catch (AWTException ex) {
        // couldn"t create robot!
        robot = null;
      }
    } else {
      robot = null;
    }
  }
  /**
   * Returns whether or not relative mouse mode is on.
   */
  public boolean isRelativeMouseMode() {
    return (robot != null);
  }
  /**
   * Maps a GameAction to a specific key. The key codes are defined in
   * java.awt.KeyEvent. If the key already has a GameAction mapped to it, the
   * new GameAction overwrites it.
   */
  public void mapToKey(GameAction gameAction, int keyCode) {
    keyActions[keyCode] = gameAction;
  }
  /**
   * Maps a GameAction to a specific mouse action. The mouse codes are defined
   * herer in InputManager (MOUSE_MOVE_LEFT, MOUSE_BUTTON_1, etc). If the
   * mouse action already has a GameAction mapped to it, the new GameAction
   * overwrites it.
   */
  public void mapToMouse(GameAction gameAction, int mouseCode) {
    mouseActions[mouseCode] = gameAction;
  }
  /**
   * Clears all mapped keys and mouse actions to this GameAction.
   */
  public void clearMap(GameAction gameAction) {
    for (int i = 0; i < keyActions.length; i++) {
      if (keyActions[i] == gameAction) {
        keyActions[i] = null;
      }
    }
    for (int i = 0; i < mouseActions.length; i++) {
      if (mouseActions[i] == gameAction) {
        mouseActions[i] = null;
      }
    }
    gameAction.reset();
  }
  /**
   * Gets a List of names of the keys and mouse actions mapped to this
   * GameAction. Each entry in the List is a String.
   */
  public List getMaps(GameAction gameCode) {
    ArrayList list = new ArrayList();
    for (int i = 0; i < keyActions.length; i++) {
      if (keyActions[i] == gameCode) {
        list.add(getKeyName(i));
      }
    }
    for (int i = 0; i < mouseActions.length; i++) {
      if (mouseActions[i] == gameCode) {
        list.add(getMouseName(i));
      }
    }
    return list;
  }
  /**
   * Resets all GameActions so they appear like they haven"t been pressed.
   */
  public void resetAllGameActions() {
    for (int i = 0; i < keyActions.length; i++) {
      if (keyActions[i] != null) {
        keyActions[i].reset();
      }
    }
    for (int i = 0; i < mouseActions.length; i++) {
      if (mouseActions[i] != null) {
        mouseActions[i].reset();
      }
    }
  }
  /**
   * Gets the name of a key code.
   */
  public static String getKeyName(int keyCode) {
    return KeyEvent.getKeyText(keyCode);
  }
  /**
   * Gets the name of a mouse code.
   */
  public static String getMouseName(int mouseCode) {
    switch (mouseCode) {
    case MOUSE_MOVE_LEFT:
      return "Mouse Left";
    case MOUSE_MOVE_RIGHT:
      return "Mouse Right";
    case MOUSE_MOVE_UP:
      return "Mouse Up";
    case MOUSE_MOVE_DOWN:
      return "Mouse Down";
    case MOUSE_WHEEL_UP:
      return "Mouse Wheel Up";
    case MOUSE_WHEEL_DOWN:
      return "Mouse Wheel Down";
    case MOUSE_BUTTON_1:
      return "Mouse Button 1";
    case MOUSE_BUTTON_2:
      return "Mouse Button 2";
    case MOUSE_BUTTON_3:
      return "Mouse Button 3";
    default:
      return "Unknown mouse code " + mouseCode;
    }
  }
  /**
   * Gets the x position of the mouse.
   */
  public int getMouseX() {
    return mouseLocation.x;
  }
  /**
   * Gets the y position of the mouse.
   */
  public int getMouseY() {
    return mouseLocation.y;
  }
  /**
   * Uses the Robot class to try to postion the mouse in the center of the
   * screen.
   * <p>
   * Note that use of the Robot class may not be available on all platforms.
   */
  private synchronized void recenterMouse() {
    if (robot != null && comp.isShowing()) {
      centerLocation.x = comp.getWidth() / 2;
      centerLocation.y = comp.getHeight() / 2;
      SwingUtilities.convertPointToScreen(centerLocation, comp);
      isRecentering = true;
      robot.mouseMove(centerLocation.x, centerLocation.y);
    }
  }
  private GameAction getKeyAction(KeyEvent e) {
    int keyCode = e.getKeyCode();
    if (keyCode < keyActions.length) {
      return keyActions[keyCode];
    } else {
      return null;
    }
  }
  /**
   * Gets the mouse code for the button specified in this MouseEvent.
   */
  public static int getMouseButtonCode(MouseEvent e) {
    switch (e.getButton()) {
    case MouseEvent.BUTTON1:
      return MOUSE_BUTTON_1;
    case MouseEvent.BUTTON2:
      return MOUSE_BUTTON_2;
    case MouseEvent.BUTTON3:
      return MOUSE_BUTTON_3;
    default:
      return -1;
    }
  }
  private GameAction getMouseButtonAction(MouseEvent e) {
    int mouseCode = getMouseButtonCode(e);
    if (mouseCode != -1) {
      return mouseActions[mouseCode];
    } else {
      return null;
    }
  }
  // from the KeyListener interface
  public void keyPressed(KeyEvent e) {
    GameAction gameAction = getKeyAction(e);
    if (gameAction != null) {
      gameAction.press();
    }
    // make sure the key isn"t processed for anything else
    e.consume();
  }
  // from the KeyListener interface
  public void keyReleased(KeyEvent e) {
    GameAction gameAction = getKeyAction(e);
    if (gameAction != null) {
      gameAction.release();
    }
    // make sure the key isn"t processed for anything else
    e.consume();
  }
  // from the KeyListener interface
  public void keyTyped(KeyEvent e) {
    // make sure the key isn"t processed for anything else
    e.consume();
  }
  // from the MouseListener interface
  public void mousePressed(MouseEvent e) {
    GameAction gameAction = getMouseButtonAction(e);
    if (gameAction != null) {
      gameAction.press();
    }
  }
  // from the MouseListener interface
  public void mouseReleased(MouseEvent e) {
    GameAction gameAction = getMouseButtonAction(e);
    if (gameAction != null) {
      gameAction.release();
    }
  }
  // from the MouseListener interface
  public void mouseClicked(MouseEvent e) {
    // do nothing
  }
  // from the MouseListener interface
  public void mouseEntered(MouseEvent e) {
    mouseMoved(e);
  }
  // from the MouseListener interface
  public void mouseExited(MouseEvent e) {
    mouseMoved(e);
  }
  // from the MouseMotionListener interface
  public void mouseDragged(MouseEvent e) {
    mouseMoved(e);
  }
  // from the MouseMotionListener interface
  public synchronized void mouseMoved(MouseEvent e) {
    // this event is from re-centering the mouse - ignore it
    if (isRecentering && centerLocation.x == e.getX()
        && centerLocation.y == e.getY()) {
      isRecentering = false;
    } else {
      int dx = e.getX() - mouseLocation.x;
      int dy = e.getY() - mouseLocation.y;
      mouseHelper(MOUSE_MOVE_LEFT, MOUSE_MOVE_RIGHT, dx);
      mouseHelper(MOUSE_MOVE_UP, MOUSE_MOVE_DOWN, dy);
      if (isRelativeMouseMode()) {
        recenterMouse();
      }
    }
    mouseLocation.x = e.getX();
    mouseLocation.y = e.getY();
  }
  // from the MouseWheelListener interface
  public void mouseWheelMoved(MouseWheelEvent e) {
    mouseHelper(MOUSE_WHEEL_UP, MOUSE_WHEEL_DOWN, e.getWheelRotation());
  }
  private void mouseHelper(int codeNeg, int codePos, int amount) {
    GameAction gameAction;
    if (amount < 0) {
      gameAction = mouseActions[codeNeg];
    } else {
      gameAction = mouseActions[codePos];
    }
    if (gameAction != null) {
      gameAction.press(Math.abs(amount));
      gameAction.release();
    }
  }
}
/**
 * The GameAction class is an abstract to a user-initiated action, like jumping
 * or moving. GameActions can be mapped to keys or the mouse with the
 * InputManager.
 */
class GameAction {
  /**
   * Normal behavior. The isPressed() method returns true as long as the key
   * is held down.
   */
  public static final int NORMAL = 0;
  /**
   * Initial press behavior. The isPressed() method returns true only after
   * the key is first pressed, and not again until the key is released and
   * pressed again.
   */
  public static final int DETECT_INITAL_PRESS_ONLY = 1;
  private static final int STATE_RELEASED = 0;
  private static final int STATE_PRESSED = 1;
  private static final int STATE_WAITING_FOR_RELEASE = 2;
  private String name;
  private int behavior;
  private int amount;
  private int state;
  /**
   * Create a new GameAction with the NORMAL behavior.
   */
  public GameAction(String name) {
    this(name, NORMAL);
  }
  /**
   * Create a new GameAction with the specified behavior.
   */
  public GameAction(String name, int behavior) {
    this.name = name;
    this.behavior = behavior;
    reset();
  }
  /**
   * Gets the name of this GameAction.
   */
  public String getName() {
    return name;
  }
  /**
   * Resets this GameAction so that it appears like it hasn"t been pressed.
   */
  public void reset() {
    state = STATE_RELEASED;
    amount = 0;
  }
  /**
   * Taps this GameAction. Same as calling press() followed by release().
   */
  public synchronized void tap() {
    press();
    release();
  }
  /**
   * Signals that the key was pressed.
   */
  public synchronized void press() {
    press(1);
  }
  /**
   * Signals that the key was pressed a specified number of times, or that the
   * mouse move a spcified distance.
   */
  public synchronized void press(int amount) {
    if (state != STATE_WAITING_FOR_RELEASE) {
      this.amount += amount;
      state = STATE_PRESSED;
    }
  }
  /**
   * Signals that the key was released
   */
  public synchronized void release() {
    state = STATE_RELEASED;
  }
  /**
   * Returns whether the key was pressed or not since last checked.
   */
  public synchronized boolean isPressed() {
    return (getAmount() != 0);
  }
  /**
   * For keys, this is the number of times the key was pressed since it was
   * last checked. For mouse movement, this is the distance moved.
   */
  public synchronized int getAmount() {
    int retVal = amount;
    if (retVal != 0) {
      if (state == STATE_RELEASED) {
        amount = 0;
      } else if (behavior == DETECT_INITAL_PRESS_ONLY) {
        state = STATE_WAITING_FOR_RELEASE;
        amount = 0;
      }
    }
    return retVal;
  }
}
/**
 * The SolidPolygonRenderer class transforms and draws solid-colored polygons
 * onto the screen.
 */
class SolidPolygonRenderer extends PolygonRenderer {
  public SolidPolygonRenderer(Transform3D camera, ViewWindow viewWindow) {
    this(camera, viewWindow, true);
  }
  public SolidPolygonRenderer(Transform3D camera, ViewWindow viewWindow,
      boolean clearViewEveryFrame) {
    super(camera, viewWindow, clearViewEveryFrame);
  }
  /**
   * Draws the current polygon. At this point, the current polygon is
   * transformed, clipped, projected, scan-converted, and visible.
   */
  protected void drawCurrentPolygon(Graphics2D g) {
    // set the color
    if (sourcePolygon instanceof SolidPolygon3D) {
      g.setColor(((SolidPolygon3D) sourcePolygon).getColor());
    } else {
      g.setColor(Color.GREEN);
    }
    // draw the scans
    int y = scanConverter.getTopBoundary();
    while (y <= scanConverter.getBottomBoundary()) {
      ScanConverter.Scan scan = scanConverter.getScan(y);
      if (scan.isValid()) {
        g.drawLine(scan.left, y, scan.right, y);
      }
      y++;
    }
  }
}
/**
 * The SolidPolygon3D class is a Polygon with a color.
 */
class SolidPolygon3D extends Polygon3D {
  private Color color = Color.GREEN;
  public SolidPolygon3D() {
    super();
  }
  public SolidPolygon3D(Vector3D v0, Vector3D v1, Vector3D v2) {
    this(new Vector3D[] { v0, v1, v2 });
  }
  public SolidPolygon3D(Vector3D v0, Vector3D v1, Vector3D v2, Vector3D v3) {
    this(new Vector3D[] { v0, v1, v2, v3 });
  }
  public SolidPolygon3D(Vector3D[] vertices) {
    super(vertices);
  }
  public void setTo(Polygon3D polygon) {
    super.setTo(polygon);
    if (polygon instanceof SolidPolygon3D) {
      color = ((SolidPolygon3D) polygon).color;
    }
  }
  /**
   * Gets the color of this solid-colored polygon used for rendering this
   * polygon.
   */
  public Color getColor() {
    return color;
  }
  /**
   * Sets the color of this solid-colored polygon used for rendering this
   * polygon.
   */
  public void setColor(Color color) {
    this.color = color;
  }
}
abstract class GameCore3D extends GameCore {
  protected PolygonRenderer polygonRenderer;
  protected ViewWindow viewWindow;
  protected List polygons;
  private boolean drawFrameRate = false;
  private boolean drawInstructions = true;
  // for calculating frame rate
  private int numFrames;
  private long startTime;
  private float frameRate;
  protected InputManager inputManager;
  private GameAction exit = new GameAction("exit");
  private GameAction smallerView = new GameAction("smallerView",
      GameAction.DETECT_INITAL_PRESS_ONLY);
  private GameAction largerView = new GameAction("largerView",
      GameAction.DETECT_INITAL_PRESS_ONLY);
  private GameAction frameRateToggle = new GameAction("frameRateToggle",
      GameAction.DETECT_INITAL_PRESS_ONLY);
  protected GameAction goForward = new GameAction("goForward");
  protected GameAction goBackward = new GameAction("goBackward");
  protected GameAction goUp = new GameAction("goUp");
  protected GameAction goDown = new GameAction("goDown");
  protected GameAction goLeft = new GameAction("goLeft");
  protected GameAction goRight = new GameAction("goRight");
  protected GameAction turnLeft = new GameAction("turnLeft");
  protected GameAction turnRight = new GameAction("turnRight");
  protected GameAction tiltUp = new GameAction("tiltUp");
  protected GameAction tiltDown = new GameAction("tiltDown");
  protected GameAction tiltLeft = new GameAction("tiltLeft");
  protected GameAction tiltRight = new GameAction("tiltRight");
  public void init(DisplayMode[] modes) {
    super.init(modes);
    inputManager = new InputManager(screen.getFullScreenWindow());
    inputManager.setRelativeMouseMode(true);
    inputManager.setCursor(InputManager.INVISIBLE_CURSOR);
    inputManager.mapToKey(exit, KeyEvent.VK_ESCAPE);
    inputManager.mapToKey(goForward, KeyEvent.VK_W);
    inputManager.mapToKey(goForward, KeyEvent.VK_UP);
    inputManager.mapToKey(goBackward, KeyEvent.VK_S);
    inputManager.mapToKey(goBackward, KeyEvent.VK_DOWN);
    inputManager.mapToKey(goLeft, KeyEvent.VK_A);
    inputManager.mapToKey(goLeft, KeyEvent.VK_LEFT);
    inputManager.mapToKey(goRight, KeyEvent.VK_D);
    inputManager.mapToKey(goRight, KeyEvent.VK_RIGHT);
    inputManager.mapToKey(goUp, KeyEvent.VK_PAGE_UP);
    inputManager.mapToKey(goDown, KeyEvent.VK_PAGE_DOWN);
    inputManager.mapToMouse(turnLeft, InputManager.MOUSE_MOVE_LEFT);
    inputManager.mapToMouse(turnRight, InputManager.MOUSE_MOVE_RIGHT);
    inputManager.mapToMouse(tiltUp, InputManager.MOUSE_MOVE_UP);
    inputManager.mapToMouse(tiltDown, InputManager.MOUSE_MOVE_DOWN);
    inputManager.mapToKey(tiltLeft, KeyEvent.VK_INSERT);
    inputManager.mapToKey(tiltRight, KeyEvent.VK_DELETE);
    inputManager.mapToKey(smallerView, KeyEvent.VK_SUBTRACT);
    inputManager.mapToKey(smallerView, KeyEvent.VK_MINUS);
    inputManager.mapToKey(largerView, KeyEvent.VK_ADD);
    inputManager.mapToKey(largerView, KeyEvent.VK_PLUS);
    inputManager.mapToKey(largerView, KeyEvent.VK_EQUALS);
    inputManager.mapToKey(frameRateToggle, KeyEvent.VK_R);
    // create the polygon renderer
    createPolygonRenderer();
    // create polygons
    polygons = new ArrayList();
    createPolygons();
  }
  public abstract void createPolygons();
  public void createPolygonRenderer() {
    // make the view window the entire screen
    viewWindow = new ViewWindow(0, 0, screen.getWidth(),
        screen.getHeight(), (float) Math.toRadians(75));
    Transform3D camera = new Transform3D(0, 100, 0);
    polygonRenderer = new SolidPolygonRenderer(camera, viewWindow);
  }
  /**
   * Sets the view bounds, centering the view on the screen.
   */
  public void setViewBounds(int width, int height) {
    width = Math.min(width, screen.getWidth());
    height = Math.min(height, screen.getHeight());
    width = Math.max(64, width);
    height = Math.max(48, height);
    viewWindow.setBounds((screen.getWidth() - width) / 2, (screen
        .getHeight() - height) / 2, width, height);
    // clear the screen if view size changed
    // (clear both buffers)
    for (int i = 0; i < 2; i++) {
      Graphics2D g = screen.getGraphics();
      g.setColor(Color.BLACK);
      g.fillRect(0, 0, screen.getWidth(), screen.getHeight());
      screen.update();
    }
  }
  public void update(long elapsedTime) {
    // check options
    if (exit.isPressed()) {
      stop();
      return;
    }
    if (largerView.isPressed()) {
      setViewBounds(viewWindow.getWidth() + 64,
          viewWindow.getHeight() + 48);
    } else if (smallerView.isPressed()) {
      setViewBounds(viewWindow.getWidth() - 64,
          viewWindow.getHeight() - 48);
    }
    if (frameRateToggle.isPressed()) {
      drawFrameRate = !drawFrameRate;
    }
    updateWorld(elapsedTime);
  }
  public void updateWorld(long elapsedTime) {
    // cap elapsedTime
    elapsedTime = Math.min(elapsedTime, 100);
    float angleChange = 0.0002f * elapsedTime;
    float distanceChange = .5f * elapsedTime;
    Transform3D camera = polygonRenderer.getCamera();
    Vector3D cameraLoc = camera.getLocation();
    // apply movement
    if (goForward.isPressed()) {
      cameraLoc.x -= distanceChange * camera.getSinAngleY();
      cameraLoc.z -= distanceChange * camera.getCosAngleY();
    }
    if (goBackward.isPressed()) {
      cameraLoc.x += distanceChange * camera.getSinAngleY();
      cameraLoc.z += distanceChange * camera.getCosAngleY();
    }
    if (goLeft.isPressed()) {
      cameraLoc.x -= distanceChange * camera.getCosAngleY();
      cameraLoc.z += distanceChange * camera.getSinAngleY();
    }
    if (goRight.isPressed()) {
      cameraLoc.x += distanceChange * camera.getCosAngleY();
      cameraLoc.z -= distanceChange * camera.getSinAngleY();
    }
    if (goUp.isPressed()) {
      cameraLoc.y += distanceChange;
    }
    if (goDown.isPressed()) {
      cameraLoc.y -= distanceChange;
    }
    // look up/down (rotate around x)
    int tilt = tiltUp.getAmount() - tiltDown.getAmount();
    tilt = Math.min(tilt, 200);
    tilt = Math.max(tilt, -200);
    // limit how far you can look up/down
    float newAngleX = camera.getAngleX() + tilt * angleChange;
    newAngleX = Math.max(newAngleX, (float) -Math.PI / 2);
    newAngleX = Math.min(newAngleX, (float) Math.PI / 2);
    camera.setAngleX(newAngleX);
    // turn (rotate around y)
    int turn = turnLeft.getAmount() - turnRight.getAmount();
    turn = Math.min(turn, 200);
    turn = Math.max(turn, -200);
    camera.rotateAngleY(turn * angleChange);
    // tilet head left/right (rotate around z)
    if (tiltLeft.isPressed()) {
      camera.rotateAngleZ(10 * angleChange);
    }
    if (tiltRight.isPressed()) {
      camera.rotateAngleZ(-10 * angleChange);
    }
  }
  public void draw(Graphics2D g) {
    int viewX1 = viewWindow.getLeftOffset();
    int viewY1 = viewWindow.getTopOffset();
    int viewX2 = viewX1 + viewWindow.getWidth();
    int viewY2 = viewY1 + viewWindow.getHeight();
    if (viewX1 != 0 || viewY1 != 0) {
      g.setColor(Color.BLACK);
      g.fillRect(0, 0, viewX1, screen.getHeight());
      g.fillRect(viewX2, 0, screen.getWidth() - viewX2, screen
          .getHeight());
      g.fillRect(viewX1, 0, viewWindow.getWidth(), viewY1);
      g.fillRect(viewX1, viewY2, viewWindow.getWidth(), screen
          .getHeight()
          - viewY2);
    }
    drawPolygons(g);
    drawText(g);
  }
  public void drawPolygons(Graphics2D g) {
    polygonRenderer.startFrame(g);
    for (int i = 0; i < polygons.size(); i++) {
      polygonRenderer.draw(g, (Polygon3D) polygons.get(i));
    }
    polygonRenderer.endFrame(g);
  }
  public void drawText(Graphics2D g) {
    g.setColor(Color.WHITE);
    // draw text
    if (drawInstructions) {
      g.drawString("Use the mouse/arrow keys to move. "
          + "Press Esc to exit.", 5, fontSize);
    }
    // (you may have to turn off the BufferStrategy in
    // ScreenManager for more accurate tests)
    if (drawFrameRate) {
      calcFrameRate();
      g.drawString(frameRate + " frames/sec", 5, screen.getHeight() - 5);
    }
  }
  public void calcFrameRate() {
    numFrames++;
    long currTime = System.currentTimeMillis();
    // calculate the frame rate every 500 milliseconds
    if (currTime > startTime + 500) {
      frameRate = (float) numFrames * 1000 / (currTime - startTime);
      startTime = currTime;
      numFrames = 0;
    }
  }
}
interface Transformable {
  public void add(Vector3D u);
  public void subtract(Vector3D u);
  public void add(Transform3D xform);
  public void subtract(Transform3D xform);
  public void addRotation(Transform3D xform);
  public void subtractRotation(Transform3D xform);
}
/**
 * The Polygon3D class represents a polygon as a series of vertices.
 */
class Polygon3D implements Transformable {
  // temporary vectors used for calculation
  private static Vector3D temp1 = new Vector3D();
  private static Vector3D temp2 = new Vector3D();
  private Vector3D[] v;
  private int numVertices;
  private Vector3D normal;
  /**
   * Creates an empty polygon that can be used as a "scratch" polygon for
   * transforms, projections, etc.
   */
  public Polygon3D() {
    numVertices = 0;
    v = new Vector3D[0];
    normal = new Vector3D();
  }
  /**
   * Creates a new Polygon3D with the specified vertices.
   */
  public Polygon3D(Vector3D v0, Vector3D v1, Vector3D v2) {
    this(new Vector3D[] { v0, v1, v2 });
  }
  /**
   * Creates a new Polygon3D with the specified vertices. All the vertices are
   * assumed to be in the same plane.
   */
  public Polygon3D(Vector3D v0, Vector3D v1, Vector3D v2, Vector3D v3) {
    this(new Vector3D[] { v0, v1, v2, v3 });
  }
  /**
   * Creates a new Polygon3D with the specified vertices. All the vertices are
   * assumed to be in the same plane.
   */
  public Polygon3D(Vector3D[] vertices) {
    this.v = vertices;
    numVertices = vertices.length;
    calcNormal();
  }
  /**
   * Sets this polygon to the same vertices as the specfied polygon.
   */
  public void setTo(Polygon3D polygon) {
    numVertices = polygon.numVertices;
    normal.setTo(polygon.normal);
    ensureCapacity(numVertices);
    for (int i = 0; i < numVertices; i++) {
      v[i].setTo(polygon.v[i]);
    }
  }
  /**
   * Ensures this polgon has enough capacity to hold the specified number of
   * vertices.
   */
  protected void ensureCapacity(int length) {
    if (v.length < length) {
      Vector3D[] newV = new Vector3D[length];
      System.arraycopy(v, 0, newV, 0, v.length);
      for (int i = v.length; i < newV.length; i++) {
        newV[i] = new Vector3D();
      }
      v = newV;
    }
  }
  /**
   * Gets the number of vertices this polygon has.
   */
  public int getNumVertices() {
    return numVertices;
  }
  /**
   * Gets the vertex at the specified index.
   */
  public Vector3D getVertex(int index) {
    return v[index];
  }
  /**
   * Projects this polygon onto the view window.
   */
  public void project(ViewWindow view) {
    for (int i = 0; i < numVertices; i++) {
      view.project(v[i]);
    }
  }
  // methods from the Transformable interface.
  public void add(Vector3D u) {
    for (int i = 0; i < numVertices; i++) {
      v[i].add(u);
    }
  }
  public void subtract(Vector3D u) {
    for (int i = 0; i < numVertices; i++) {
      v[i].subtract(u);
    }
  }
  public void add(Transform3D xform) {
    addRotation(xform);
    add(xform.getLocation());
  }
  public void subtract(Transform3D xform) {
    subtract(xform.getLocation());
    subtractRotation(xform);
  }
  public void addRotation(Transform3D xform) {
    for (int i = 0; i < numVertices; i++) {
      v[i].addRotation(xform);
    }
    normal.addRotation(xform);
  }
  public void subtractRotation(Transform3D xform) {
    for (int i = 0; i < numVertices; i++) {
      v[i].subtractRotation(xform);
    }
    normal.subtractRotation(xform);
  }
  /**
   * Calculates the unit-vector normal of this polygon. This method uses the
   * first, second, and third vertices to calcuate the normal, so if these
   * vertices are collinear, this method will not work. In this case, you can
   * get the normal from the bounding rectangle. Use setNormal() to explicitly
   * set the normal. This method uses static objects in the Polygon3D class
   * for calculations, so this method is not thread-safe across all instances
   * of Polygon3D.
   */
  public Vector3D calcNormal() {
    if (normal == null) {
      normal = new Vector3D();
    }
    temp1.setTo(v[2]);
    temp1.subtract(v[1]);
    temp2.setTo(v[0]);
    temp2.subtract(v[1]);
    normal.setToCrossProduct(temp1, temp2);
    normal.normalize();
    return normal;
  }
  /**
   * Gets the normal of this polygon. Use calcNormal() if any vertices have
   * changed.
   */
  public Vector3D getNormal() {
    return normal;
  }
  /**
   * Sets the normal of this polygon.
   */
  public void setNormal(Vector3D n) {
    if (normal == null) {
      normal = new Vector3D(n);
    } else {
      normal.setTo(n);
    }
  }
  /**
   * Tests if this polygon is facing the specified location. This method uses
   * static objects in the Polygon3D class for calculations, so this method is
   * not thread-safe across all instances of Polygon3D.
   */
  public boolean isFacing(Vector3D u) {
    temp1.setTo(u);
    temp1.subtract(v[0]);
    return (normal.getDotProduct(temp1) >= 0);
  }
  /**
   * Clips this polygon so that all vertices are in front of the clip plane,
   * clipZ (in other words, all vertices have z <= clipZ). The value of clipZ
   * should not be 0, as this causes divide-by-zero problems. Returns true if
   * the polygon is at least partially in front of the clip plane.
   */
  public boolean clip(float clipZ) {
    ensureCapacity(numVertices * 3);
    boolean isCompletelyHidden = true;
    // insert vertices so all edges are either completly
    // in front or behind the clip plane
    for (int i = 0; i < numVertices; i++) {
      int next = (i + 1) % numVertices;
      Vector3D v1 = v[i];
      Vector3D v2 = v[next];
      if (v1.z < clipZ) {
        isCompletelyHidden = false;
      }
      // ensure v1.z < v2.z
      if (v1.z > v2.z) {
        Vector3D temp = v1;
        v1 = v2;
        v2 = temp;
      }
      if (v1.z < clipZ && v2.z > clipZ) {
        float scale = (clipZ - v1.z) / (v2.z - v1.z);
        insertVertex(next, v1.x + scale * (v2.x - v1.x), v1.y + scale
            * (v2.y - v1.y), clipZ);
        // skip the vertex we just created
        i++;
      }
    }
    if (isCompletelyHidden) {
      return false;
    }
    // delete all vertices that have z > clipZ
    for (int i = numVertices - 1; i >= 0; i--) {
      if (v[i].z > clipZ) {
        deleteVertex(i);
      }
    }
    return (numVertices >= 3);
  }
  /**
   * Inserts a new vertex at the specified index.
   */
  protected void insertVertex(int index, float x, float y, float z) {
    Vector3D newVertex = v[v.length - 1];
    newVertex.x = x;
    newVertex.y = y;
    newVertex.z = z;
    for (int i = v.length - 1; i > index; i--) {
      v[i] = v[i - 1];
    }
    v[index] = newVertex;
    numVertices++;
  }
  /**
   * Delete the vertex at the specified index.
   */
  protected void deleteVertex(int index) {
    Vector3D deleted = v[index];
    for (int i = index; i < v.length - 1; i++) {
      v[i] = v[i + 1];
    }
    v[v.length - 1] = deleted;
    numVertices--;
  }
  /**
   * Inserts a vertex into this polygon at the specified index. The exact
   * vertex in inserted (not a copy).
   */
  public void insertVertex(int index, Vector3D vertex) {
    Vector3D[] newV = new Vector3D[numVertices + 1];
    System.arraycopy(v, 0, newV, 0, index);
    newV[index] = vertex;
    System.arraycopy(v, index, newV, index + 1, numVertices - index);
    v = newV;
    numVertices++;
  }
  /**
   * Calculates and returns the smallest bounding rectangle for this polygon.
   */
  public Rectangle3D calcBoundingRectangle() {
    // the smallest bounding rectangle for a polygon shares
    // at least one edge with the polygon. so, this method
    // finds the bounding rectangle for every edge in the
    // polygon, and returns the smallest one.
    Rectangle3D boundingRect = new Rectangle3D();
    float minimumArea = Float.MAX_VALUE;
    Vector3D u = new Vector3D();
    Vector3D v = new Vector3D();
    Vector3D d = new Vector3D();
    for (int i = 0; i < getNumVertices(); i++) {
      u.setTo(getVertex((i + 1) % getNumVertices()));
      u.subtract(getVertex(i));
      u.normalize();
      v.setToCrossProduct(getNormal(), u);
      v.normalize();
      float uMin = 0;
      float uMax = 0;
      float vMin = 0;
      float vMax = 0;
      for (int j = 0; j < getNumVertices(); j++) {
        if (j != i) {
          d.setTo(getVertex(j));
          d.subtract(getVertex(i));
          float uLength = d.getDotProduct(u);
          float vLength = d.getDotProduct(v);
          uMin = Math.min(uLength, uMin);
          uMax = Math.max(uLength, uMax);
          vMin = Math.min(vLength, vMin);
          vMax = Math.max(vLength, vMax);
        }
      }
      // if this calculated area is the smallest, set
      // the bounding rectangle
      float area = (uMax - uMin) * (vMax - vMin);
      if (area < minimumArea) {
        minimumArea = area;
        Vector3D origin = boundingRect.getOrigin();
        origin.setTo(getVertex(i));
        d.setTo(u);
        d.multiply(uMin);
        origin.add(d);
        d.setTo(v);
        d.multiply(vMin);
        origin.add(d);
        boundingRect.getDirectionU().setTo(u);
        boundingRect.getDirectionV().setTo(v);
        boundingRect.setWidth(uMax - uMin);
        boundingRect.setHeight(vMax - vMin);
      }
    }
    return boundingRect;
  }
}
/**
 * The TexturedPolygon3D class is a Polygon with a texture.
 */
class TexturedPolygon3D extends Polygon3D {
  protected Rectangle3D textureBounds;
  protected Texture texture;
  public TexturedPolygon3D() {
    textureBounds = new Rectangle3D();
  }
  public TexturedPolygon3D(Vector3D v0, Vector3D v1, Vector3D v2) {
    this(new Vector3D[] { v0, v1, v2 });
  }
  public TexturedPolygon3D(Vector3D v0, Vector3D v1, Vector3D v2, Vector3D v3) {
    this(new Vector3D[] { v0, v1, v2, v3 });
  }
  public TexturedPolygon3D(Vector3D[] vertices) {
    super(vertices);
    textureBounds = new Rectangle3D();
  }
  public void setTo(Polygon3D poly) {
    super.setTo(poly);
    if (poly instanceof TexturedPolygon3D) {
      TexturedPolygon3D tPoly = (TexturedPolygon3D) poly;
      textureBounds.setTo(tPoly.textureBounds);
      texture = tPoly.texture;
    }
  }
  /**
   * Gets this polygon"s texture.
   */
  public Texture getTexture() {
    return texture;
  }
  /**
   * Gets this polygon"s texture bounds.
   */
  public Rectangle3D getTextureBounds() {
    return textureBounds;
  }
  /**
   * Sets this polygon"s texture.
   */
  public void setTexture(Texture texture) {
    this.texture = texture;
    textureBounds.setWidth(texture.getWidth());
    textureBounds.setHeight(texture.getHeight());
  }
  /**
   * Sets this polygon"s texture and texture bounds.
   */
  public void setTexture(Texture texture, Rectangle3D bounds) {
    setTexture(texture);
    textureBounds.setTo(bounds);
  }
  public void add(Vector3D u) {
    super.add(u);
    textureBounds.add(u);
  }
  public void subtract(Vector3D u) {
    super.subtract(u);
    textureBounds.subtract(u);
  }
  public void addRotation(Transform3D xform) {
    super.addRotation(xform);
    textureBounds.addRotation(xform);
  }
  public void subtractRotation(Transform3D xform) {
    super.subtractRotation(xform);
    textureBounds.subtractRotation(xform);
  }
  /**
   * Calculates the bounding rectangle for this polygon that is aligned with
   * the texture bounds.
   */
  public Rectangle3D calcBoundingRectangle() {
    Vector3D u = new Vector3D(textureBounds.getDirectionU());
    Vector3D v = new Vector3D(textureBounds.getDirectionV());
    Vector3D d = new Vector3D();
    u.normalize();
    v.normalize();
    float uMin = 0;
    float uMax = 0;
    float vMin = 0;
    float vMax = 0;
    for (int i = 0; i < getNumVertices(); i++) {
      d.setTo(getVertex(i));
      d.subtract(getVertex(0));
      float uLength = d.getDotProduct(u);
      float vLength = d.getDotProduct(v);
      uMin = Math.min(uLength, uMin);
      uMax = Math.max(uLength, uMax);
      vMin = Math.min(vLength, vMin);
      vMax = Math.max(vLength, vMax);
    }
    Rectangle3D boundingRect = new Rectangle3D();
    Vector3D origin = boundingRect.getOrigin();
    origin.setTo(getVertex(0));
    d.setTo(u);
    d.multiply(uMin);
    origin.add(d);
    d.setTo(v);
    d.multiply(vMin);
    origin.add(d);
    boundingRect.getDirectionU().setTo(u);
    boundingRect.getDirectionV().setTo(v);
    boundingRect.setWidth(uMax - uMin);
    boundingRect.setHeight(vMax - vMin);
    // explictly set the normal since the texture directions
    // could create a normal negative to the polygon normal
    boundingRect.setNormal(getNormal());
    return boundingRect;
  }
}
/**
 * The Vector3D class implements a 3D vector with the floating-point values x,
 * y, and z. Vectors can be thought of either as a (x,y,z) point or as a vector
 * from (0,0,0) to (x,y,z).
 */
class Vector3D implements Transformable {
  public float x;
  public float y;
  public float z;
  /**
   * Creates a new Vector3D at (0,0,0).
   */
  public Vector3D() {
    this(0, 0, 0);
  }
  /**
   * Creates a new Vector3D with the same values as the specified Vector3D.
   */
  public Vector3D(Vector3D v) {
    this(v.x, v.y, v.z);
  }
  /**
   * Creates a new Vector3D with the specified (x, y, z) values.
   */
  public Vector3D(float x, float y, float z) {
    setTo(x, y, z);
  }
  /**
   * Checks if this Vector3D is equal to the specified Object. They are equal
   * only if the specified Object is a Vector3D and the two Vector3D"s x, y,
   * and z coordinates are equal.
   */
  public boolean equals(Object obj) {
    Vector3D v = (Vector3D) obj;
    return (v.x == x && v.y == y && v.z == z);
  }
  /**
   * Checks if this Vector3D is equal to the specified x, y, and z
   * coordinates.
   */
  public boolean equals(float x, float y, float z) {
    return (this.x == x && this.y == y && this.z == z);
  }
  /**
   * Sets the vector to the same values as the specified Vector3D.
   */
  public void setTo(Vector3D v) {
    setTo(v.x, v.y, v.z);
  }
  /**
   * Sets this vector to the specified (x, y, z) values.
   */
  public void setTo(float x, float y, float z) {
    this.x = x;
    this.y = y;
    this.z = z;
  }
  /**
   * Adds the specified (x, y, z) values to this vector.
   */
  public void add(float x, float y, float z) {
    this.x += x;
    this.y += y;
    this.z += z;
  }
  /**
   * Subtracts the specified (x, y, z) values to this vector.
   */
  public void subtract(float x, float y, float z) {
    add(-x, -y, -z);
  }
  /**
   * Adds the specified vector to this vector.
   */
  public void add(Vector3D v) {
    add(v.x, v.y, v.z);
  }
  /**
   * Subtracts the specified vector from this vector.
   */
  public void subtract(Vector3D v) {
    add(-v.x, -v.y, -v.z);
  }
  /**
   * Multiplies this vector by the specified value. The new length of this
   * vector will be length()*s.
   */
  public void multiply(float s) {
    x *= s;
    y *= s;
    z *= s;
  }
  /**
   * Divides this vector by the specified value. The new length of this vector
   * will be length()/s.
   */
  public void divide(float s) {
    x /= s;
    y /= s;
    z /= s;
  }
  /**
   * Returns the length of this vector as a float.
   */
  public float length() {
    return (float) Math.sqrt(x * x + y * y + z * z);
  }
  /**
   * Converts this Vector3D to a unit vector, or in other words, a vector of
   * length 1. Same as calling v.divide(v.length()).
   */
  public void normalize() {
    divide(length());
  }
  /**
   * Converts this Vector3D to a String representation.
   */
  public String toString() {
    return "(" + x + ", " + y + ", " + z + ")";
  }
  /**
   * Rotate this vector around the x axis the specified amount. The specified
   * angle is in radians. Use Math.toRadians() to convert from degrees to
   * radians.
   */
  public void rotateX(float angle) {
    rotateX((float) Math.cos(angle), (float) Math.sin(angle));
  }
  /**
   * Rotate this vector around the y axis the specified amount. The specified
   * angle is in radians. Use Math.toRadians() to convert from degrees to
   * radians.
   */
  public void rotateY(float angle) {
    rotateY((float) Math.cos(angle), (float) Math.sin(angle));
  }
  /**
   * Rotate this vector around the z axis the specified amount. The specified
   * angle is in radians. Use Math.toRadians() to convert from degrees to
   * radians.
   */
  public void rotateZ(float angle) {
    rotateZ((float) Math.cos(angle), (float) Math.sin(angle));
  }
  /**
   * Rotate this vector around the x axis the specified amount, using
   * pre-computed cosine and sine values of the angle to rotate.
   */
  public void rotateX(float cosAngle, float sinAngle) {
    float newY = y * cosAngle - z * sinAngle;
    float newZ = y * sinAngle + z * cosAngle;
    y = newY;
    z = newZ;
  }
  /**
   * Rotate this vector around the y axis the specified amount, using
   * pre-computed cosine and sine values of the angle to rotate.
   */
  public void rotateY(float cosAngle, float sinAngle) {
    float newX = z * sinAngle + x * cosAngle;
    float newZ = z * cosAngle - x * sinAngle;
    x = newX;
    z = newZ;
  }
  /**
   * Rotate this vector around the y axis the specified amount, using
   * pre-computed cosine and sine values of the angle to rotate.
   */
  public void rotateZ(float cosAngle, float sinAngle) {
    float newX = x * cosAngle - y * sinAngle;
    float newY = x * sinAngle + y * cosAngle;
    x = newX;
    y = newY;
  }
  /**
   * Adds the specified transform to this vector. This vector is first
   * rotated, then translated.
   */
  public void add(Transform3D xform) {
    // rotate
    addRotation(xform);
    // translate
    add(xform.getLocation());
  }
  /**
   * Subtracts the specified transform to this vector. This vector translated,
   * then rotated.
   */
  public void subtract(Transform3D xform) {
    // translate
    subtract(xform.getLocation());
    // rotate
    subtractRotation(xform);
  }
  /**
   * Rotates this vector with the angle of the specified transform.
   */
  public void addRotation(Transform3D xform) {
    rotateX(xform.getCosAngleX(), xform.getSinAngleX());
    rotateZ(xform.getCosAngleZ(), xform.getSinAngleZ());
    rotateY(xform.getCosAngleY(), xform.getSinAngleY());
  }
  /**
   * Rotates this vector with the opposite angle of the specified transform.
   */
  public void subtractRotation(Transform3D xform) {
    // note that sin(-x) == -sin(x) and cos(-x) == cos(x)
    rotateY(xform.getCosAngleY(), -xform.getSinAngleY());
    rotateZ(xform.getCosAngleZ(), -xform.getSinAngleZ());
    rotateX(xform.getCosAngleX(), -xform.getSinAngleX());
  }
  /**
   * Returns the dot product of this vector and the specified vector.
   */
  public float getDotProduct(Vector3D v) {
    return x * v.x + y * v.y + z * v.z;
  }
  /**
   * Sets this vector to the cross product of the two specified vectors.
   * Either of the specified vectors can be this vector.
   */
  public void setToCrossProduct(Vector3D u, Vector3D v) {
    // assign to local vars first in case u or v is "this"
    float x = u.y * v.z - u.z * v.y;
    float y = u.z * v.x - u.x * v.z;
    float z = u.x * v.y - u.y * v.x;
    this.x = x;
    this.y = y;
    this.z = z;
  }
}
/**
 * A Rectangle3D is a rectangle in 3D space, defined as an origin and vectors
 * pointing in the directions of the base (width) and side (height).
 */
class Rectangle3D implements Transformable {
  private Vector3D origin;
  private Vector3D directionU;
  private Vector3D directionV;
  private Vector3D normal;
  private float width;
  private float height;
  /**
   * Creates a rectangle at the origin with a width and height of zero.
   */
  public Rectangle3D() {
    origin = new Vector3D();
    directionU = new Vector3D(1, 0, 0);
    directionV = new Vector3D(0, 1, 0);
    width = 0;
    height = 0;
  }
  /**
   * Creates a new Rectangle3D with the specified origin, direction of the
   * base (directionU) and direction of the side (directionV).
   */
  public Rectangle3D(Vector3D origin, Vector3D directionU,
      Vector3D directionV, float width, float height) {
    this.origin = new Vector3D(origin);
    this.directionU = new Vector3D(directionU);
    this.directionU.normalize();
    this.directionV = new Vector3D(directionV);
    this.directionV.normalize();
    this.width = width;
    this.height = height;
  }
  /**
   * Sets the values of this Rectangle3D to the specified Rectangle3D.
   */
  public void setTo(Rectangle3D rect) {
    origin.setTo(rect.origin);
    directionU.setTo(rect.directionU);
    directionV.setTo(rect.directionV);
    width = rect.width;
    height = rect.height;
  }
  /**
   * Gets the origin of this Rectangle3D.
   */
  public Vector3D getOrigin() {
    return origin;
  }
  /**
   * Gets the direction of the base of this Rectangle3D.
   */
  public Vector3D getDirectionU() {
    return directionU;
  }
  /**
   * Gets the direction of the side of this Rectangle3D.
   */
  public Vector3D getDirectionV() {
    return directionV;
  }
  /**
   * Gets the width of this Rectangle3D.
   */
  public float getWidth() {
    return width;
  }
  /**
   * Sets the width of this Rectangle3D.
   */
  public void setWidth(float width) {
    this.width = width;
  }
  /**
   * Gets the height of this Rectangle3D.
   */
  public float getHeight() {
    return height;
  }
  /**
   * Sets the height of this Rectangle3D.
   */
  public void setHeight(float height) {
    this.height = height;
  }
  /**
   * Calculates the normal vector of this Rectange3D.
   */
  protected Vector3D calcNormal() {
    if (normal == null) {
      normal = new Vector3D();
    }
    normal.setToCrossProduct(directionU, directionV);
    normal.normalize();
    return normal;
  }
  /**
   * Gets the normal of this Rectangle3D.
   */
  public Vector3D getNormal() {
    if (normal == null) {
      calcNormal();
    }
    return normal;
  }
  /**
   * Sets the normal of this Rectangle3D.
   */
  public void setNormal(Vector3D n) {
    if (normal == null) {
      normal = new Vector3D(n);
    } else {
      normal.setTo(n);
    }
  }
  public void add(Vector3D u) {
    origin.add(u);
    // don"t translate direction vectors or size
  }
  public void subtract(Vector3D u) {
    origin.subtract(u);
    // don"t translate direction vectors or size
  }
  public void add(Transform3D xform) {
    addRotation(xform);
    add(xform.getLocation());
  }
  public void subtract(Transform3D xform) {
    subtract(xform.getLocation());
    subtractRotation(xform);
  }
  public void addRotation(Transform3D xform) {
    origin.addRotation(xform);
    directionU.addRotation(xform);
    directionV.addRotation(xform);
  }
  public void subtractRotation(Transform3D xform) {
    origin.subtractRotation(xform);
    directionU.subtractRotation(xform);
    directionV.subtractRotation(xform);
  }
}         
           
       </source>
    
   
  <!-- end source code -->