import java.awt.*;
import java.awt.image.*;
import java.util.*;
import javax.swing.*;

public class EABlitTest extends Frame {        
    protected void test() {
	BufferedImage srcImg = createSrcImage();
	Image dstImg = getGraphicsConfiguration().createCompatibleVolatileImage(20, 50);    
	
	//be over-cautious and render twice to avoid BI caching issues
	renderToVI(srcImg, dstImg);
	renderToVI(srcImg, dstImg);	
	
	BufferedImage validationImg = new BufferedImage(20, 50, BufferedImage.TYPE_INT_RGB);
	Graphics2D valG = (Graphics2D) validationImg.getGraphics();
	valG.drawImage(dstImg, 0, 0, null);

	//Loop over all pixel, and count the different pixel values encountered.
	TreeSet<Integer> colorCntSet = new TreeSet<>();
	for(int x=0; x < validationImg.getWidth(); x++) {
	    for(int y=0; y < validationImg.getHeight(); y++) {
		    int rgb = validationImg.getRGB(x, y);
		    colorCntSet.add(rgb);
	    }  
	}
	
	if(colorCntSet.size() == 3) {
	    System.out.println("Passed!");
	}else {
	    throw new RuntimeException("Test FAILED!");
	}
    }
    
    protected void renderToVI(BufferedImage src, Image dst) {
	Graphics2D g = (Graphics2D) dst.getGraphics();
	
	g.setColor(Color.WHITE);
	g.fillRect(0, 0, 50, 50);
	g.rotate(0.5f);
	g.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
	
	g.setComposite(AlphaComposite.SrcOver.derive(1f));
	g.drawImage(src, 10, 10, null);
	
	g.setComposite(AlphaComposite.SrcOver.derive(0.5f));
	g.drawImage(src, 20, 20, null);
    }
    
    protected BufferedImage createSrcImage() {
	BufferedImage bi = new BufferedImage(10, 10, BufferedImage.TYPE_INT_RGB);
	Graphics2D g = (Graphics2D) bi.getGraphics();
	g.setColor(Color.YELLOW);
	g.fillRect(0, 0, 10, 10);
	return bi;
    }
    
    public static void main(String[] args) {
	SwingUtilities.invokeLater(new Runnable() {
	    public void run() {
		new EABlitTest().test();
	    }
	});
    }
    
}