canvas/source/java/BackBuffer.java

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  30
  31 // Java AWT
  32 import java.awt.*;
  33 import java.awt.image.*;
  34
  35 public class BackBuffer
  36 {
  37     private BufferedImage                                       backBuffer;
  38     //private VolatileImage                                     backBuffer;
  39     private Graphics2D                                          backBufferGraphics;
  40     private Graphics2D                                          referenceDevice;
  41
  42     public BackBuffer( Graphics2D _referenceDevice,
  43                        int width,
  44                        int height )
  45     {
  46         referenceDevice = _referenceDevice;
  47         setSize( width, height );
  48     }
  49
  50     public Graphics2D getGraphics()
  51     {
  52         return backBufferGraphics;
  53     }
  54
  55     public void setSize( int width,
  56                          int height )
  57     {
  58         if( backBuffer != null &&
  59             width == backBuffer.getWidth() &&
  60             height == backBuffer.getHeight() )
  61         {
  62             return;
  63         }
  64
  65         if( backBufferGraphics != null )
  66             backBufferGraphics.dispose();
  67
  68         if( backBuffer != null )
  69             backBuffer.flush();
  70
  71         // TODO: Maybe VolatileImage with another BufferedImage as a backup is
  72         // a tad faster here.
  73         backBuffer = referenceDevice.getDeviceConfiguration().createCompatibleImage(width,
  74                                                                                     height);
  75 //        backBuffer = referenceDevice.getDeviceConfiguration().createCompatibleVolatileImage(width,
  76 //                                                                                            height);
  77
  78         backBufferGraphics = backBuffer.createGraphics();
  79         CanvasUtils.initGraphics( backBufferGraphics );
  80
  81         // clear the buffer to white (to have a defined state here)
  82         backBufferGraphics.setColor( java.awt.Color.white );
  83         backBufferGraphics.fillRect( 0,0,width,height );
  84     }
  85
  86     public void redraw( Graphics2D graph )
  87     {
  88         if( graph != null &&
  89             backBuffer != null )
  90         {
  91             CanvasUtils.printLog("BackBuffer.redraw(): using buffer of size (" +
  92                                   backBuffer.getWidth() + "," + backBuffer.getHeight() + ")" );
  93
  94             graph.drawImage(backBuffer, 0, 0, null);
  95
  96             // TODO: this is just twiddled to work. I cannot be sure
  97             // that this volatile backbuffer will survive in the first
  98             // place, nor that it wise to leave it in VRAM.
  99
 100             // only flush non-volatile images
 101             // CanvasUtils.postRenderImageTreatment( backBuffer );
 102         }
 103     }
 104
 105     public java.awt.Image getBackBuffer()
 106     {
 107         return backBuffer;
 108     }
 109
 110     public void dispose()
 111     {
 112         backBufferGraphics.dispose();
 113         backBuffer.flush();
 114     }
 115 }