Java Tutorial/2D Graphics/AlphaComposite

AlphaComposite.DST_IN

import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.ruponent;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Ellipse2D;
import java.awt.image.BufferedImage;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class AlphaCompositeDSTIN extends JFrame {
  public AlphaCompositeDSTIN() {
    getContentPane().add(new DrawingCanvas());
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(500,500);
    setVisible(true);
  }
  public static void main(String arg[]) {
    new AlphaCompositeDSTIN();
  }
}
class DrawingCanvas extends JPanel{
  float alphaValue = 1.0f;
  int compositeRule = AlphaComposite.DST_IN;
  AlphaComposite ac;
  DrawingCanvas() {
    setSize(300, 300);
    setBackground(Color.white);
  }
  public void paint(Graphics g) {
    Graphics2D g2D = (Graphics2D) g;
    int w = getSize().width;
    int h = getSize().height;
    BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
    Graphics2D big = bi.createGraphics();
    ac = AlphaComposite.getInstance(compositeRule, alphaValue);
    big.setColor(Color.red);
    big.drawString("Destination", w / 4, h / 4);
    big.fill(new Ellipse2D.Double(0, h / 3, 2 * w / 3, h / 3));
    big.setColor(Color.blue);
    big.drawString("Source", 3 * w / 4, h / 4);
    big.setComposite(ac);
    big.fill(new Ellipse2D.Double(w / 3, h / 3, 2 * w / 3, h / 3));
    g2D.drawImage(bi, null, 0, 0);
  }
}

AlphaComposite.DST_OUT

import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.ruponent;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Ellipse2D;
import java.awt.image.BufferedImage;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class AlphaCompositeDSTOUT extends JFrame {
  public AlphaCompositeDSTOUT() {
    getContentPane().add(new DrawingCanvas());
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(500,500);
    setVisible(true);
  }
  public static void main(String arg[]) {
    new AlphaCompositeDSTOUT();
  }
}
class DrawingCanvas extends JPanel{
  float alphaValue = 1.0f;
  int compositeRule = AlphaComposite.DST_OUT;
  AlphaComposite ac;
  DrawingCanvas() {
    setSize(300, 300);
    setBackground(Color.white);
  }
  public void paint(Graphics g) {
    Graphics2D g2D = (Graphics2D) g;
    int w = getSize().width;
    int h = getSize().height;
    BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
    Graphics2D big = bi.createGraphics();
    ac = AlphaComposite.getInstance(compositeRule, alphaValue);
    big.setColor(Color.red);
    big.drawString("Destination", w / 4, h / 4);
    big.fill(new Ellipse2D.Double(0, h / 3, 2 * w / 3, h / 3));
    big.setColor(Color.blue);
    big.drawString("Source", 3 * w / 4, h / 4);
    big.setComposite(ac);
    big.fill(new Ellipse2D.Double(w / 3, h / 3, 2 * w / 3, h / 3));
    g2D.drawImage(bi, null, 0, 0);
  }
}

AlphaComposite.DST_OVER

import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.ruponent;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Ellipse2D;
import java.awt.image.BufferedImage;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class AlphaCompositeDSTOVER extends JFrame {
  public AlphaCompositeDSTOVER() {
    getContentPane().add(new DrawingCanvas());
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(500,500);
    setVisible(true);
  }
  public static void main(String arg[]) {
    new AlphaCompositeDSTOVER();
  }
}
class DrawingCanvas extends JPanel{
  float alphaValue = 1.0f;
  int compositeRule = AlphaComposite.DST_OVER;
  AlphaComposite ac;
  DrawingCanvas() {
    setSize(300, 300);
    setBackground(Color.white);
  }
  public void paint(Graphics g) {
    Graphics2D g2D = (Graphics2D) g;
    int w = getSize().width;
    int h = getSize().height;
    BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
    Graphics2D big = bi.createGraphics();
    ac = AlphaComposite.getInstance(compositeRule, alphaValue);
    big.setColor(Color.red);
    big.drawString("Destination", w / 4, h / 4);
    big.fill(new Ellipse2D.Double(0, h / 3, 2 * w / 3, h / 3));
    big.setColor(Color.blue);
    big.drawString("Source", 3 * w / 4, h / 4);
    big.setComposite(ac);
    big.fill(new Ellipse2D.Double(w / 3, h / 3, 2 * w / 3, h / 3));
    g2D.drawImage(bi, null, 0, 0);
  }
}

AlphaComposite.SRC

import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.ruponent;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Ellipse2D;
import java.awt.image.BufferedImage;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class AlphaCompositeSRC extends JFrame {
  public AlphaCompositeSRC() {
    getContentPane().add(new DrawingCanvas());
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(500,500);
    setVisible(true);
  }
  public static void main(String arg[]) {
    new AlphaCompositeSRC();
  }
}
class DrawingCanvas extends JPanel{
  float alphaValue = 1.0f;
  int compositeRule = AlphaComposite.SRC;
  AlphaComposite ac;
  DrawingCanvas() {
    setSize(300, 300);
    setBackground(Color.white);
  }
  public void paint(Graphics g) {
    Graphics2D g2D = (Graphics2D) g;
    int w = getSize().width;
    int h = getSize().height;
    BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
    Graphics2D big = bi.createGraphics();
    ac = AlphaComposite.getInstance(compositeRule, alphaValue);
    big.setColor(Color.red);
    big.drawString("Destination", w / 4, h / 4);
    big.fill(new Ellipse2D.Double(0, h / 3, 2 * w / 3, h / 3));
    big.setColor(Color.blue);
    big.drawString("Source", 3 * w / 4, h / 4);
    big.setComposite(ac);
    big.fill(new Ellipse2D.Double(w / 3, h / 3, 2 * w / 3, h / 3));
    g2D.drawImage(bi, null, 0, 0);
  }
}

AlphaComposite.SRC_IN

import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.ruponent;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Ellipse2D;
import java.awt.image.BufferedImage;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class AlphaCompositeSRCIN extends JFrame {
  public AlphaCompositeSRCIN() {
    getContentPane().add(new DrawingCanvas());
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(500,500);
    setVisible(true);
  }
  public static void main(String arg[]) {
    new AlphaCompositeSRCIN();
  }
}
class DrawingCanvas extends JPanel{
  float alphaValue = 1.0f;
  int compositeRule = AlphaComposite.SRC_IN;
  AlphaComposite ac;
  DrawingCanvas() {
    setSize(300, 300);
    setBackground(Color.white);
  }
  public void paint(Graphics g) {
    Graphics2D g2D = (Graphics2D) g;
    int w = getSize().width;
    int h = getSize().height;
    BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
    Graphics2D big = bi.createGraphics();
    ac = AlphaComposite.getInstance(compositeRule, alphaValue);
    big.setColor(Color.red);
    big.drawString("Destination", w / 4, h / 4);
    big.fill(new Ellipse2D.Double(0, h / 3, 2 * w / 3, h / 3));
    big.setColor(Color.blue);
    big.drawString("Source", 3 * w / 4, h / 4);
    big.setComposite(ac);
    big.fill(new Ellipse2D.Double(w / 3, h / 3, 2 * w / 3, h / 3));
    g2D.drawImage(bi, null, 0, 0);
  }
}

AlphaComposite.SRC_OUT

import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.ruponent;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Ellipse2D;
import java.awt.image.BufferedImage;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class AlphaCompositeSRCOUT extends JFrame {
  public AlphaCompositeSRCOUT() {
    getContentPane().add(new DrawingCanvas());
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(500,500);
    setVisible(true);
  }
  public static void main(String arg[]) {
    new AlphaCompositeSRCOUT();
  }
}
class DrawingCanvas extends JPanel{
  float alphaValue = 1.0f;
  int compositeRule = AlphaComposite.SRC_OUT;
  AlphaComposite ac;
  DrawingCanvas() {
    setSize(300, 300);
    setBackground(Color.white);
  }
  public void paint(Graphics g) {
    Graphics2D g2D = (Graphics2D) g;
    int w = getSize().width;
    int h = getSize().height;
    BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
    Graphics2D big = bi.createGraphics();
    ac = AlphaComposite.getInstance(compositeRule, alphaValue);
    big.setColor(Color.red);
    big.drawString("Destination", w / 4, h / 4);
    big.fill(new Ellipse2D.Double(0, h / 3, 2 * w / 3, h / 3));
    big.setColor(Color.blue);
    big.drawString("Source", 3 * w / 4, h / 4);
    big.setComposite(ac);
    big.fill(new Ellipse2D.Double(w / 3, h / 3, 2 * w / 3, h / 3));
    g2D.drawImage(bi, null, 0, 0);
  }
}

AlphaComposite.SRC_OVER

import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.ruponent;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Ellipse2D;
import java.awt.image.BufferedImage;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class AlphaCompositeSRCOVER extends JFrame {
  public AlphaCompositeSRCOVER() {
    getContentPane().add(new DrawingCanvas());
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(500,500);
    setVisible(true);
  }
  public static void main(String arg[]) {
    new AlphaCompositeSRCOVER();
  }
}
class DrawingCanvas extends JPanel{
  float alphaValue = 1.0f;
  int compositeRule = AlphaComposite.SRC_OVER;
  AlphaComposite ac;
  DrawingCanvas() {
    setSize(300, 300);
    setBackground(Color.white);
  }
  public void paint(Graphics g) {
    Graphics2D g2D = (Graphics2D) g;
    int w = getSize().width;
    int h = getSize().height;
    BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
    Graphics2D big = bi.createGraphics();
    ac = AlphaComposite.getInstance(compositeRule, alphaValue);
    big.setColor(Color.red);
    big.drawString("Destination", w / 4, h / 4);
    big.fill(new Ellipse2D.Double(0, h / 3, 2 * w / 3, h / 3));
    big.setColor(Color.blue);
    big.drawString("Source", 3 * w / 4, h / 4);
    big.setComposite(ac);
    big.fill(new Ellipse2D.Double(w / 3, h / 3, 2 * w / 3, h / 3));
    g2D.drawImage(bi, null, 0, 0);
  }
}

Alpha Composite with BufferedImage

import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.Ellipse2D;
import java.awt.image.BufferedImage;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class AlphaCompositeCLEAR extends JFrame {
  public AlphaCompositeCLEAR() {
    getContentPane().add(new DrawingCanvas());
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(300,300);
    setVisible(true);
  }
  public static void main(String arg[]) {
    new AlphaCompositeCLEAR();
  }
}
class DrawingCanvas extends JPanel{
  float alphaValue = 1.0f;
  int compositeRule = AlphaComposite.CLEAR;
  AlphaComposite ac;
  DrawingCanvas() {
    setSize(300, 300);
    setBackground(Color.white);
  }
  public void paint(Graphics g) {
    Graphics2D g2D = (Graphics2D) g;
    int w = getSize().width;
    int h = getSize().height;
    BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
    Graphics2D big = bi.createGraphics();
    ac = AlphaComposite.getInstance(compositeRule, alphaValue);
    big.setColor(Color.red);
    big.drawString("Destination", w / 4, h / 4);
    big.fill(new Ellipse2D.Double(0, h / 3, 2 * w / 3, h / 3));
    big.setColor(Color.blue);
    big.drawString("Source", 3 * w / 4, h / 4);
    big.setComposite(ac);
    big.fill(new Ellipse2D.Double(w / 3, h / 3, 2 * w / 3, h / 3));
    g2D.drawImage(bi, null, 0, 0);
  }
}

Composite Demo

import java.awt.AlphaComposite;
import java.awt.Canvas;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Toolkit;
import javax.swing.JFrame;
public class MainClass extends JFrame {
  public static void main(String args[]) {
    MainClass app = new MainClass();
  }
  public MainClass() {
    super("Draw2D");
    add("Center", new MyCanvas());
    setSize(400, 400);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setVisible(true);
  }
  class MyCanvas extends Canvas {
    public void paint(Graphics graphics) {
      Graphics2D g = (Graphics2D) graphics;
      float alpha = 0.5f;
      AlphaComposite composite = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, alpha);
      g.setComposite(composite);
      Toolkit toolkit = Toolkit.getDefaultToolkit();
      Image image0 = toolkit.getImage("image0.gif");
      Image image1 = toolkit.getImage("image1.gif");
      g.drawImage(image0, 200, 100, this);
      g.drawImage(image1, 100, 150, this);
    }
  }
}

Compositing is the combining of elements from separate sources into single images

import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class CompositingDST extends JPanel {
  public void paint(Graphics g) {
    Graphics2D g2d = (Graphics2D) g;
    AlphaComposite ac = AlphaComposite.getInstance(AlphaComposite.DST, 0.5f);
    BufferedImage buffImg = new BufferedImage(60, 60, BufferedImage.TYPE_INT_ARGB);
    Graphics2D gbi = buffImg.createGraphics();
    gbi.setPaint(Color.red);
    gbi.fillRect(0, 0, 40, 40);
    gbi.setComposite(ac);
    gbi.setPaint(Color.green);
    gbi.fillRect(5, 5, 40, 40);
    g2d.drawImage(buffImg, 20, 20, null);
  }
  public static void main(String[] args) {
    JFrame frame = new JFrame("Composition");
    frame.add(new CompositingDST());
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(400, 120);
    frame.setVisible(true);
  }
}

Composition technique in this animation.

import java.awt.AlphaComposite;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
public class ImageComposite extends JPanel implements ActionListener {
  Image a = new ImageIcon(this.getClass().getResource("a.png")).getImage();
  Image b = new ImageIcon(this.getClass().getResource("b.png")).getImage();
  Timer timer = new Timer(800, this);
  float alpha = 1f;
  public ImageComposite() {
    timer.start();
  }
  public void paint(Graphics g) {
    super.paint(g);
    Graphics2D g2d = (Graphics2D) g;
    BufferedImage buffImg = new BufferedImage(200, 100, BufferedImage.TYPE_INT_ARGB);
    Graphics2D gbi = buffImg.createGraphics();
    AlphaComposite ac = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, alpha);
    gbi.drawImage(a, 40, 30, null);
    gbi.setComposite(ac);
    gbi.drawImage(b, 0, 0, null);
    g2d.drawImage(buffImg, 20, 20, null);
  }
  public void actionPerformed(ActionEvent e) {
    alpha -= 0.1;
    if (alpha <= 0) {
      alpha = 0;
      timer.stop();
    }
    repaint();
  }
  public static void main(String[] args) {
    JFrame frame = new JFrame();
    frame.add(new ImageComposite());
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(300, 210);
    frame.setVisible(true);
  }
}

Draw ten rectangles with different levels of transparency

import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class TransparentRectangles extends JPanel {
  public void paint(Graphics g) {
    super.paint(g);
    Graphics2D g2d = (Graphics2D) g;
    for (int i = 1; i <= 10; i++) {
      g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, i * 0.1f));
      g2d.fillRect(50 * i, 20, 50, 50);
    }
  }
  public static void main(String[] args) {
    JFrame frame = new JFrame("Transparent Rectangles");
    frame.add(new TransparentRectangles());
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(600, 100);
    frame.setVisible(true);
  }
}