Copy Graphics2D data to a BufferedImage

Java 2D
#1

I have a Graphics2D object obtained from the BufferStrategy that I am drawing to. If I want to take the image data from the Graphics2D and store it off in a BufferedImage somewhere (say for a screenshot, or something like that), how would I go about doing that?
Thanks.

#2

java.awt.Robot may work - I havn’t tried it.

Another solution, is to write your own Composite class, that, instead of doing a Composite with the destination pixels, writes the destination pixel to a BufferedImage.

Something like :-


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

import java.awt.event.*;
public class ScreenCapture      implements Composite, CompositeContext
{
      private BufferedImage screenShot;
      private ColorModel screenColorModel;

      private ScreenCapture()
      {
      }

      public CompositeContext      createContext(ColorModel srcColorModel, ColorModel      dstColorModel,      RenderingHints      hints)
      {
            screenColorModel = dstColorModel;
            return this;
      }
      
      public void      compose(Raster      src, Raster      dstIn, WritableRaster dstOut)
      {
            screenShot = new BufferedImage(screenColorModel,dstOut,false,(Hashtable)null);
      }
      
      public void      dispose()
      {
      }

      public static BufferedImage screenShot(Graphics2D g2d, Rectangle bounds)
      {
            Composite oldComposite = g2d.getComposite();
            ScreenCapture ssc      = new      ScreenCapture();
            g2d.setComposite(ssc);
            g2d.fillRect(bounds.x,bounds.y,bounds.width,bounds.height);
            g2d.setComposite(oldComposite);
            return ssc.screenShot;
      }
      
      public static void main(String [] args)
      {
            final      Frame      f = new Frame();
            f.addKeyListener(new      KeyAdapter()
            {
                  public void      keyPressed(KeyEvent ke)
                  {
                        if(ke.getKeyCode()==KeyEvent.VK_ESCAPE)
                        {
                              f.dispose();
                        }
                  }
            });
            GraphicsDevice      gd      = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice();
            
            gd.setFullScreenWindow(f);
            gd.setDisplayMode(new DisplayMode(800,600,32,60));
            
            f.createBufferStrategy(2);
            
            BufferStrategy      bs      = f.getBufferStrategy();
            Graphics2D g2d      = (Graphics2D)bs.getDrawGraphics();
            
            g2d.setColor(Color.black);
            g2d.fillRect(0,0,800,600);
            g2d.setColor(Color.red);
            g2d.drawString("If the Capture worked,      you should see      this :-",50,50);
            BufferedImage screenShot =      ScreenCapture.screenShot(g2d,new      Rectangle(0,0,800,600));
            
            g2d.setColor(Color.black);
            g2d.fillRect(0,0,800,600);
            g2d.drawImage(screenShot,0,0,null);
            bs.show();
      }
}

:edit:

hahahahahaha, well… that idea should work.

But ofcourse like all good ideas… it doesn’t :-


java.lang.InternalError: not implemented yet
      at sun.awt.windows.Win32OffScreenSurfaceData.getRaster(Win32OffScreenSurfaceData.java:249)
      at sun.java2d.pipe.GeneralCompositePipe.renderPathTile(GeneralCompositePipe.java:82)
      at sun.java2d.pipe.SpanShapeRenderer$Composite.renderBox(SpanShapeRenderer.java:42)
      at sun.java2d.pipe.SpanShapeRenderer.renderRect(SpanShapeRenderer.java:171)
      at sun.java2d.pipe.SpanShapeRenderer.fill(SpanShapeRenderer.java:122)
      at sun.java2d.pipe.PixelToShapeConverter.fillRect(PixelToShapeConverter.java:44)
      at sun.java2d.pipe.ValidatePipe.fillRect(ValidatePipe.java:58)
      at sun.java2d.SunGraphics2D.fillRect(SunGraphics2D.java:2142)
      at ScreenCapture.screenShot(ScreenCapture.java:35)
      at ScreenCapture.main(ScreenCapture.java:67)

How easy it is to find bugs in Java2D =D

flibble!

#3

yeah, this is a long-standing bug, fixed in 1.5 for accelerated offscreen surfaces, but not for the screen ones.