Merged JSR-231 branch on to the main JOGL trunk. The main trunk now

contains the evolving JSR-231 Reference Implementation and the JSR-231
branch is permanently closed.


git-svn-id: file:///usr/local/projects/SUN/JOGL/git-svn/svn-server-sync/jogl/trunk@401 232f8b59-042b-4e1e-8c03-345bb8c30851

1 files changed, 877 insertions, 0 deletions

diff --git a/src/classes/javax/media/opengl/GLJPanel.java b/src/classes/javax/media/opengl/GLJPanel.java
new file mode 100644
index 000000000..3d6f4e831
--- /dev/null
+++ b/src/classes/javax/media/opengl/GLJPanel.java
@@ -0,0 +1,877 @@
+/*
+ * Copyright (c) 2003 Sun Microsystems, Inc. All Rights Reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ * 
+ * - Redistribution of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * 
+ * - Redistribution in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * 
+ * Neither the name of Sun Microsystems, Inc. or the names of
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ * 
+ * This software is provided "AS IS," without a warranty of any kind. ALL
+ * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
+ * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
+ * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN
+ * MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR
+ * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
+ * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR
+ * ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR
+ * DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE
+ * DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY,
+ * ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF
+ * SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
+ * 
+ * You acknowledge that this software is not designed or intended for use
+ * in the design, construction, operation or maintenance of any nuclear
+ * facility.
+ * 
+ * Sun gratefully acknowledges that this software was originally authored
+ * and developed by Kenneth Bradley Russell and Christopher John Kline.
+ */
+
+package javax.media.opengl;
+
+import java.awt.*;
+import java.awt.geom.*;
+import java.awt.image.*;
+import javax.swing.*;
+import java.nio.*;
+import java.security.*;
+import javax.swing.JComponent;
+import javax.swing.JPanel;
+import com.sun.opengl.impl.*;
+
+// FIXME: Subclasses need to call resetGLFunctionAvailability() on their
+// context whenever the displayChanged() function is called on their
+// GLEventListeners
+
+/** A lightweight Swing component which provides OpenGL rendering
+    support. Provided for compatibility with Swing user interfaces
+    when adding a heavyweight doesn't work either because of
+    Z-ordering or LayoutManager problems. This component attempts to
+    use hardware-accelerated rendering via pbuffers and falls back on
+    to software rendering if problems occur. This class can not be
+    instantiated directly; use {@link GLDrawableFactory} to construct
+    them. <P>
+
+    Note that because this component attempts to use pbuffers for
+    rendering, and because pbuffers can not be resized, somewhat
+    surprising behavior may occur during resize operations; the {@link
+    GLEventListener#init} method may be called multiple times as the
+    pbuffer is resized to be able to cover the size of the GLJPanel.
+    This behavior is correct, as the textures and display lists for
+    the GLJPanel will have been lost during the resize operation. The
+    application should attempt to make its GLEventListener.init()
+    methods as side-effect-free as possible. <P>
+
+    The GLJPanel can be made transparent by creating it with a
+    GLCapabilities object with alpha bits specified and calling {@link
+    #setOpaque}(false). Pixels with resulting OpenGL alpha values less
+    than 1.0 will be overlaid on any underlying Java2D rendering.
+*/
+
+public class GLJPanel extends JPanel implements GLAutoDrawable {
+  private static final boolean DEBUG = Debug.debug("GLJPanel");
+  private static final boolean VERBOSE = Debug.verbose();
+
+  private GLDrawableHelper drawableHelper = new GLDrawableHelper();
+  private volatile boolean isInitialized;
+  private volatile boolean shouldInitialize = false;
+
+  // Data used for either pbuffers or pixmap-based offscreen surfaces
+  private GLCapabilities        offscreenCaps;
+  private GLCapabilitiesChooser chooser;
+  private GLContext             shareWith;
+  // This image is exactly the correct size to render into the panel
+  private BufferedImage         offscreenImage;
+  // One of these is used to store the read back pixels before storing
+  // in the BufferedImage
+  private ByteBuffer            readBackBytes;
+  private IntBuffer             readBackInts;
+  private int                   readBackWidthInPixels;
+  private int                   readBackHeightInPixels;
+  // Width of the actual GLJPanel
+  private int panelWidth   = 0;
+  private int panelHeight  = 0;
+  private Updater updater;
+  private int awtFormat;
+  private int glFormat;
+  private int glType;
+  // Lazy reshape notification
+  private boolean handleReshape = false;
+  private boolean sendReshape = true;
+
+  // Implementation using pbuffers
+  private static boolean hardwareAccelerationDisabled =
+    Debug.isPropertyDefined("jogl.gljpanel.nohw");
+  private static boolean softwareRenderingDisabled =
+    Debug.isPropertyDefined("jogl.gljpanel.nosw");
+  private GLPbuffer pbuffer;
+  private int       pbufferWidth  = 256;
+  private int       pbufferHeight = 256;
+
+  // Implementation using software rendering
+  private GLDrawableImpl offscreenDrawable;
+  private GLContextImpl offscreenContext;
+
+  // For handling reshape events lazily
+  private int reshapeX;
+  private int reshapeY;
+  private int reshapeWidth;
+  private int reshapeHeight;
+
+  // For saving/restoring of OpenGL state during ReadPixels
+  private int[] swapbytes    = new int[1];
+  private int[] rowlength    = new int[1];
+  private int[] skiprows     = new int[1];
+  private int[] skippixels   = new int[1];
+  private int[] alignment    = new int[1];
+
+  // Implementation using Java2D OpenGL pipeline's back buffer
+  private static boolean swingBufferPerWindow =
+    Debug.isPropertyDefined("swing.bufferPerWindow") ?
+    Debug.getBooleanProperty("swing.bufferPerWindow") :
+      true;
+  private boolean oglPipelineEnabled =
+    Java2D.isOGLPipelineActive() &&
+    !Debug.isPropertyDefined("jogl.gljpanel.noogl");
+  // Opaque Object identifier representing the Java2D surface we are
+  // drawing to; used to determine when to destroy and recreate JOGL
+  // context
+  private Object j2dSurface;
+  // Graphics object being used during Java2D update action
+  // (absolutely essential to cache this)
+  private Graphics cached2DGraphics;
+  // No-op context representing the Java2D OpenGL context
+  private GLContext j2dContext;
+  // Context associated with no-op drawable representing the JOGL
+  // OpenGL context
+  private GLDrawable joglDrawable;
+  // The real OpenGL context JOGL uses to render
+  private GLContext  joglContext;
+  // State captured from Java2D OpenGL context necessary in order to
+  // properly render into Java2D back buffer
+  private int[] drawBuffer   = new int[1];
+  private int[] readBuffer   = new int[1];
+  // These are always set to (0, 0) except when the Java2D / OpenGL
+  // pipeline is active
+  private int   viewportX;
+  private int   viewportY;
+
+  /** Creates a new GLJPanel component. The passed GLCapabilities must
+      be non-null and specifies the OpenGL capabilities for the
+      component. The GLCapabilitiesChooser must be non-null and
+      specifies the algorithm for selecting one of the available
+      GLCapabilities for the component; the GLDrawableFactory uses a
+      DefaultGLCapabilitiesChooser if the user does not provide
+      one. The passed GLContext may be null and specifies an OpenGL
+      context with which to share textures, display lists and other
+      OpenGL state. */
+  protected GLJPanel(GLCapabilities capabilities, GLCapabilitiesChooser chooser, GLContext shareWith) {
+    super();
+
+    // Works around problems on many vendors' cards; we don't need a
+    // back buffer for the offscreen surface anyway
+    if (capabilities != null) {
+        offscreenCaps = (GLCapabilities) capabilities.clone();
+    } else {
+        offscreenCaps = new GLCapabilities();
+    }
+    offscreenCaps.setDoubleBuffered(false);
+    this.chooser = ((chooser != null) ? chooser : new DefaultGLCapabilitiesChooser());
+    this.shareWith = shareWith;
+  }
+
+  public void display() {
+    if (EventQueue.isDispatchThread()) {
+      // Want display() to be synchronous, so call paintImmediately()
+      paintImmediately(0, 0, getWidth(), getHeight());
+    } else {
+      // Multithreaded redrawing of Swing components is not allowed,
+      // so do everything on the event dispatch thread
+      try {
+        EventQueue.invokeAndWait(paintImmediatelyAction);
+      } catch (Exception e) {
+        throw new GLException(e);
+      }
+    }
+  }
+
+  private void captureJ2DState(GL gl) {
+    gl.glGetIntegerv(GL.GL_DRAW_BUFFER, drawBuffer, 0);
+    gl.glGetIntegerv(GL.GL_READ_BUFFER, readBuffer, 0);
+  }
+
+  private boolean preGL(Graphics g) {
+    GL gl = joglContext.getGL();
+    // Set up needed state in JOGL context from Java2D context
+    gl.glEnable(GL.GL_SCISSOR_TEST);
+    Rectangle r = Java2D.getOGLScissorBox(g);
+    if (r == null) {
+      return false;
+    }
+    gl.glScissor(r.x, r.y, r.width, r.height);
+    Rectangle oglViewport = Java2D.getOGLViewport(g, panelWidth, panelHeight);
+    // If the viewport X or Y changes, in addition to the panel's
+    // width or height, we need to send a reshape operation to the
+    // client
+    if ((viewportX != oglViewport.x) ||
+        (viewportY != oglViewport.y)) {
+      sendReshape = true;
+      if (DEBUG) {
+        System.err.println("Sending reshape because viewport changed");
+        System.err.println("  viewportX (" + viewportX + ") ?= oglViewport.x (" + oglViewport.x + ")");
+        System.err.println("  viewportY (" + viewportY + ") ?= oglViewport.y (" + oglViewport.y + ")");
+      }
+    }
+    viewportX = oglViewport.x;
+    viewportY = oglViewport.y;
+
+    gl.glDrawBuffer(drawBuffer[0]);
+    gl.glReadBuffer(readBuffer[0]);
+    return true;
+  }
+
+  /** Overridden from JComponent; calls event listeners' {@link
+      GLEventListener#display display} methods. Should not be invoked
+      by applications directly. */
+  public void paintComponent(final Graphics g) {
+    if (shouldInitialize) {
+      initialize();
+    }
+
+    if (!isInitialized) {
+      return;
+    }
+
+    // NOTE: must do this when the context is not current as it may
+    // involve destroying the pbuffer (current context) and
+    // re-creating it -- tricky to do properly while the context is
+    // current
+    if (handleReshape) {
+      handleReshape();
+    }
+
+    updater.setGraphics(g);
+
+    if (oglPipelineEnabled) {
+      Java2D.invokeWithOGLContextCurrent(g, new Runnable() {
+          public void run() {
+            // Create no-op context representing Java2D context
+            if (j2dContext == null) {
+              j2dContext = GLDrawableFactory.getFactory().createExternalGLContext();
+
+              // Check to see whether we can support the requested
+              // capabilities or need to fall back to a pbuffer
+              // FIXME: add more checks?
+
+              GL gl = j2dContext.getGL();
+              if ((getGLInteger(gl, GL.GL_RED_BITS)         < offscreenCaps.getRedBits())        ||
+                  (getGLInteger(gl, GL.GL_GREEN_BITS)       < offscreenCaps.getGreenBits())      ||
+                  (getGLInteger(gl, GL.GL_BLUE_BITS)        < offscreenCaps.getBlueBits())       ||
+                  //                  (getGLInteger(gl, GL.GL_ALPHA_BITS)       < offscreenCaps.getAlphaBits())      ||
+                  (getGLInteger(gl, GL.GL_ACCUM_RED_BITS)   < offscreenCaps.getAccumRedBits())   ||
+                  (getGLInteger(gl, GL.GL_ACCUM_GREEN_BITS) < offscreenCaps.getAccumGreenBits()) ||
+                  (getGLInteger(gl, GL.GL_ACCUM_BLUE_BITS)  < offscreenCaps.getAccumBlueBits())  ||
+                  (getGLInteger(gl, GL.GL_ACCUM_ALPHA_BITS) < offscreenCaps.getAccumAlphaBits()) ||
+                  //          (getGLInteger(gl, GL.GL_DEPTH_BITS)       < offscreenCaps.getDepthBits())      ||
+                  (getGLInteger(gl, GL.GL_STENCIL_BITS)     < offscreenCaps.getStencilBits())) {
+                if (DEBUG) {
+                  System.err.println("GLJPanel: Falling back to pbuffer-based support because Java2D context insufficient");
+                  System.err.println("                    Available              Required");
+                  System.err.println("GL_RED_BITS         " + getGLInteger(gl, GL.GL_RED_BITS)         + "              " + offscreenCaps.getRedBits());
+                  System.err.println("GL_GREEN_BITS       " + getGLInteger(gl, GL.GL_GREEN_BITS)       + "              " + offscreenCaps.getGreenBits());
+                  System.err.println("GL_BLUE_BITS        " + getGLInteger(gl, GL.GL_BLUE_BITS)        + "              " + offscreenCaps.getBlueBits());
+                  System.err.println("GL_ALPHA_BITS       " + getGLInteger(gl, GL.GL_ALPHA_BITS)       + "              " + offscreenCaps.getAlphaBits());
+                  System.err.println("GL_ACCUM_RED_BITS   " + getGLInteger(gl, GL.GL_ACCUM_RED_BITS)   + "              " + offscreenCaps.getAccumRedBits());
+                  System.err.println("GL_ACCUM_GREEN_BITS " + getGLInteger(gl, GL.GL_ACCUM_GREEN_BITS) + "              " + offscreenCaps.getAccumGreenBits());
+                  System.err.println("GL_ACCUM_BLUE_BITS  " + getGLInteger(gl, GL.GL_ACCUM_BLUE_BITS)  + "              " + offscreenCaps.getAccumBlueBits());
+                  System.err.println("GL_ACCUM_ALPHA_BITS " + getGLInteger(gl, GL.GL_ACCUM_ALPHA_BITS) + "              " + offscreenCaps.getAccumAlphaBits());
+                  System.err.println("GL_DEPTH_BITS       " + getGLInteger(gl, GL.GL_DEPTH_BITS)       + "              " + offscreenCaps.getDepthBits());
+                  System.err.println("GL_STENCIL_BITS     " + getGLInteger(gl, GL.GL_STENCIL_BITS)     + "              " + offscreenCaps.getStencilBits());
+                }
+                isInitialized = false;
+                shouldInitialize = true;
+                oglPipelineEnabled = false;
+                handleReshape = true;
+                j2dContext.destroy();
+                j2dContext = null;
+                return;
+              }
+            }
+
+            j2dContext.makeCurrent();
+            try {
+              captureJ2DState(j2dContext.getGL());
+              Object curSurface = Java2D.getOGLSurfaceIdentifier(g);
+              if (curSurface != null) {
+                if (j2dSurface != curSurface) {
+                  if (joglContext != null) {
+                    joglContext.destroy();
+                    joglContext = null;
+                    joglDrawable = null;
+                    sendReshape = true;
+                    if (DEBUG) {
+                      System.err.println("Sending reshape because surface changed");
+                      System.err.println("New surface = " + curSurface);
+                    }
+                  }
+                  j2dSurface = curSurface;
+                }
+                if (joglContext == null) {
+                  joglDrawable = GLDrawableFactory.getFactory().createExternalGLDrawable();
+                  joglContext = joglDrawable.createContext(shareWith);
+                }
+                drawableHelper.invokeGL(joglDrawable, joglContext, displayAction, initAction);
+              }
+            } finally {
+              j2dContext.release();
+            }
+          }
+        });
+    } else {
+      if (!hardwareAccelerationDisabled) {
+        pbuffer.display();
+      } else {
+        drawableHelper.invokeGL(offscreenDrawable, offscreenContext, displayAction, initAction);
+      }
+    }
+  }
+
+  /** Overridden from JPanel; used to indicate that an OpenGL context
+      may be created for the component. */
+  public void addNotify() {
+    super.addNotify();
+    shouldInitialize = true;
+    if (DEBUG) {
+      System.err.println("GLJPanel.addNotify()");
+    }
+  }
+
+  /** Overridden from JPanel; used to indicate that it's no longer
+      safe to have an OpenGL context for the component. */
+  public void removeNotify() {
+    if (DEBUG) {
+      System.err.println("GLJPanel.removeNotify()");
+    }
+    if (oglPipelineEnabled) {
+      Java2D.invokeWithOGLContextCurrent(null, new Runnable() {
+          public void run() {
+            if (joglContext != null) {
+              joglContext.destroy();
+              joglContext = null;
+            }
+            joglDrawable = null;
+            if (j2dContext != null) {
+              j2dContext.destroy();
+              j2dContext = null;
+            }
+          }
+        });
+    } else {
+      if (!hardwareAccelerationDisabled) {
+        if (pbuffer != null) {
+          pbuffer.destroy();
+          pbuffer = null;
+        }
+      } else {
+        if (offscreenContext != null) {
+          offscreenContext.destroy();
+          offscreenContext = null;
+        }
+        if (offscreenDrawable != null) {
+          offscreenDrawable.destroy();
+          offscreenDrawable = null;
+        }
+      }
+    }
+    isInitialized = false;
+    super.removeNotify();
+  }
+
+  /** Overridden from Canvas; causes {@link GLEventListener#reshape
+      reshape} to be called on all registered {@link
+      GLEventListener}s. Called automatically by the AWT; should not
+      be invoked by applications directly. */
+  public void reshape(int x, int y, int width, int height) {
+    super.reshape(x, y, width, height);
+
+    reshapeX = x;
+    reshapeY = y;
+    reshapeWidth = width;
+    reshapeHeight = height;
+    handleReshape = true;
+  }
+
+  public void setOpaque(boolean opaque) {
+    if (opaque != isOpaque()) {
+      if (offscreenImage != null) {
+        offscreenImage.flush();
+        offscreenImage = null;
+      }
+    }
+    super.setOpaque(opaque);
+  }
+
+  public void addGLEventListener(GLEventListener listener) {
+    drawableHelper.addGLEventListener(listener);
+  }
+
+  public void removeGLEventListener(GLEventListener listener) {
+    drawableHelper.removeGLEventListener(listener);
+  }
+
+  public GLContext createContext(GLContext shareWith) {
+    if (!hardwareAccelerationDisabled) {
+      return pbuffer.createContext(shareWith);
+    } else {
+      return offscreenDrawable.createContext(shareWith);
+    }
+  }
+
+  public void setRealized(boolean realized) {
+  }
+
+  public GLContext getContext() {
+    if (oglPipelineEnabled) {
+      return joglContext;
+    } else {
+      if (!hardwareAccelerationDisabled) {
+        return pbuffer.getContext();
+      } else {
+        return offscreenContext;
+      }
+    }
+  }
+
+  public GL getGL() {
+    GLContext context = getContext();
+    return (context == null) ? null : context.getGL();
+  }
+
+  public void setGL(GL gl) {
+    GLContext context = getContext();
+    if (context != null) {
+      context.setGL(gl);
+    }
+  }
+
+  public void setAutoSwapBufferMode(boolean onOrOff) {
+    if (!hardwareAccelerationDisabled) {
+      pbuffer.setAutoSwapBufferMode(onOrOff);
+    } else {
+      drawableHelper.setAutoSwapBufferMode(onOrOff);
+    }
+  }
+
+  public boolean getAutoSwapBufferMode() {
+    if (!hardwareAccelerationDisabled) {
+      return pbuffer.getAutoSwapBufferMode();
+    } else {
+      return drawableHelper.getAutoSwapBufferMode();
+    }
+  }
+
+  public void swapBuffers() {
+    if (!hardwareAccelerationDisabled) {
+      pbuffer.swapBuffers();
+    } else {
+      drawableHelper.invokeGL(offscreenDrawable, offscreenContext, swapBuffersAction, initAction);
+    }
+  }
+
+  /** For a translucent GLJPanel (one for which {@link #setOpaque
+      setOpaque}(false) has been called), indicates whether the
+      application should preserve the OpenGL color buffer
+      (GL_COLOR_BUFFER_BIT) for correct rendering of the GLJPanel and
+      underlying widgets which may show through portions of the
+      GLJPanel with alpha values less than 1.  Most Swing
+      implementations currently expect the GLJPanel to be completely
+      cleared (e.g., by <code>glClear(GL_COLOR_BUFFER_BIT |
+      GL_DEPTH_BUFFER_BIT)</code>), but for certain optimized Java2D
+      and Swing implementations which use OpenGL internally, it may be
+      possible to perform OpenGL rendering using the GLJPanel into the
+      same OpenGL drawable as the Java2D implementation. */
+  public boolean shouldPreserveColorBufferIfTranslucent() {
+    return oglPipelineEnabled;
+  }
+
+  //----------------------------------------------------------------------
+  // Internals only below this point
+  //
+
+  private void initialize() {
+    if (panelWidth == 0 ||
+        panelHeight == 0) {
+      // See whether we have a non-zero size yet and can go ahead with
+      // initialization
+      if (reshapeWidth == 0 ||
+          reshapeHeight == 0) {
+        return;
+      }
+
+      // Pull down reshapeWidth and reshapeHeight into panelWidth and
+      // panelHeight eagerly in order to complete initialization, and
+      // force a reshape later
+      panelWidth = reshapeWidth;
+      panelHeight = reshapeHeight;
+    }
+
+    if (!oglPipelineEnabled) {
+      // Initialize either the hardware-accelerated rendering path or
+      // the lightweight rendering path
+      if (!hardwareAccelerationDisabled) {
+        if (GLDrawableFactory.getFactory().canCreateGLPbuffer()) {
+          if (pbuffer != null) {
+            throw new InternalError("Creating pbuffer twice without destroying it (memory leak / correctness bug)");
+          }
+          try {
+            pbuffer = GLDrawableFactory.getFactory().createGLPbuffer(offscreenCaps,
+                                                                     pbufferWidth,
+                                                                     pbufferHeight,
+                                                                     shareWith);
+            updater = new Updater();
+            pbuffer.addGLEventListener(updater);
+            shouldInitialize = false;
+            isInitialized = true;
+            return;
+          } catch (GLException e) {
+            if (DEBUG) {
+              e.printStackTrace();
+              System.err.println("GLJPanel: Falling back on software rendering because of problems creating pbuffer");
+            }
+            hardwareAccelerationDisabled = true;
+          }
+        } else {
+          if (DEBUG) {
+            System.err.println("GLJPanel: Falling back on software rendering because no pbuffer support");
+          }
+
+          // If the factory reports that it can't create a pbuffer,
+          // don't try again the next time, and fall through to the
+          // software rendering path
+          hardwareAccelerationDisabled = true;
+        }
+      }
+
+      if (softwareRenderingDisabled) {
+        throw new GLException("Fallback to software rendering disabled by user");
+      }
+
+      // Fall-through path: create an offscreen context instead
+      offscreenDrawable = GLDrawableFactoryImpl.getFactoryImpl().createOffscreenDrawable(offscreenCaps, chooser);
+      offscreenDrawable.setSize(Math.max(1, panelWidth), Math.max(1, panelHeight));
+      offscreenContext = (GLContextImpl) offscreenDrawable.createContext(shareWith);
+      offscreenContext.setSynchronized(true);
+    }
+    updater = new Updater();
+    shouldInitialize = false;
+    isInitialized = true;
+  }
+
+  private void handleReshape() {
+    readBackWidthInPixels = 0;
+    readBackHeightInPixels = 0;
+
+    panelWidth  = reshapeWidth;
+    panelHeight = reshapeHeight;
+
+    if (DEBUG) {
+      System.err.println("GLJPanel.handleReshape: (w,h) = (" +
+                         panelWidth + "," + panelHeight + ")");
+    }
+
+    sendReshape = true;
+
+    if (!oglPipelineEnabled) {
+      if (!hardwareAccelerationDisabled) {
+        // Use factor larger than 2 during shrinks for some hysteresis
+        float shrinkFactor = 2.5f;
+        if ((panelWidth > pbufferWidth           )       || (panelHeight > pbufferHeight) ||
+            (panelWidth < (pbufferWidth / shrinkFactor)) || (panelHeight < (pbufferWidth / shrinkFactor))) {
+          if (DEBUG) {
+            System.err.println("Resizing pbuffer from (" + pbufferWidth + ", " + pbufferHeight + ") " +
+                               " to fit (" + panelWidth + ", " + panelHeight + ")");
+          }
+          // Must destroy and recreate pbuffer to fit
+          if (pbuffer != null) {
+            pbuffer.destroy();
+          }
+          pbuffer = null;
+          isInitialized = false;
+          pbufferWidth = getNextPowerOf2(panelWidth);
+          pbufferHeight = getNextPowerOf2(panelHeight);
+          if (DEBUG) {
+            System.err.println("New pbuffer size is (" + pbufferWidth + ", " + pbufferHeight + ")");
+          }
+          initialize();
+        }
+
+        // It looks like NVidia's drivers (at least the ones on my
+        // notebook) are buggy and don't allow a rectangle of less than
+        // the pbuffer's width to be read...this doesn't really matter
+        // because it's the Graphics.drawImage() calls that are the
+        // bottleneck. Should probably make the size of the offscreen
+        // image be the exact size of the pbuffer to save some work on
+        // resize operations...
+        readBackWidthInPixels  = pbufferWidth;
+        readBackHeightInPixels = panelHeight;
+      } else {
+        offscreenContext.destroy();
+        offscreenDrawable.setSize(Math.max(1, panelWidth), Math.max(1, panelHeight));
+        readBackWidthInPixels  = Math.max(1, panelWidth);
+        readBackHeightInPixels = Math.max(1, panelHeight);
+      }
+
+      if (offscreenImage != null) {
+        offscreenImage.flush();
+        offscreenImage = null;
+      }
+    }
+
+    handleReshape = false;
+  }
+
+  // FIXME: it isn't clear whether this works any more given that
+  // we're accessing the GLDrawable inside of the GLPbuffer directly
+  // up in reshape() -- need to rethink and clean this up
+  class Updater implements GLEventListener {
+    private Graphics g;
+
+    public void setGraphics(Graphics g) {
+      this.g = g;
+    }
+
+    public void init(GLAutoDrawable drawable) {
+      if (oglPipelineEnabled) {
+        if (!preGL(g)) {
+          return;
+        }
+      }
+      drawableHelper.init(GLJPanel.this);
+    }
+
+    public void display(GLAutoDrawable drawable) {
+      if (oglPipelineEnabled) {
+        if (!preGL(g)) {
+          return;
+        }
+      }
+
+      if (sendReshape) {
+        if (DEBUG) {
+          System.err.println("glViewport(" + viewportX + ", " + viewportY + ", " + panelWidth + ", " + panelHeight + ")");
+        }
+        getGL().glViewport(viewportX, viewportY, panelWidth, panelHeight);
+        drawableHelper.reshape(GLJPanel.this, viewportX, viewportY, panelWidth, panelHeight);
+        sendReshape = false;
+      }
+
+      drawableHelper.display(GLJPanel.this);
+
+      if (!oglPipelineEnabled) {
+        // Must now copy pixels from offscreen context into surface
+        if (offscreenImage == null) {
+          if (panelWidth > 0 && panelHeight > 0) {
+            // It looks like NVidia's drivers (at least the ones on my
+            // notebook) are buggy and don't allow a sub-rectangle to be
+            // read from a pbuffer...this doesn't really matter because
+            // it's the Graphics.drawImage() calls that are the
+            // bottleneck
+
+            int awtFormat = 0;
+            int hwGLFormat = 0;
+            if (!hardwareAccelerationDisabled) {
+              // This seems to be a good choice on all platforms
+              hwGLFormat = GL.GL_UNSIGNED_INT_8_8_8_8_REV;
+            }
+
+            // Should be more flexible in these BufferedImage formats;
+            // perhaps see what the preferred image types are on the
+            // given platform
+            if (isOpaque()) {
+              awtFormat = BufferedImage.TYPE_INT_RGB;
+            } else {
+              awtFormat = BufferedImage.TYPE_INT_ARGB;
+            }
+
+            offscreenImage = new BufferedImage(panelWidth,
+                                               panelHeight,
+                                               awtFormat);
+            switch (awtFormat) {
+            case BufferedImage.TYPE_3BYTE_BGR:
+              glFormat = GL.GL_BGR;
+              glType   = GL.GL_UNSIGNED_BYTE;
+              readBackBytes = ByteBuffer.allocate(readBackWidthInPixels * readBackHeightInPixels * 3);
+              break;
+
+            case BufferedImage.TYPE_INT_RGB:
+            case BufferedImage.TYPE_INT_ARGB:
+              glFormat = GL.GL_BGRA;
+              glType   = (hardwareAccelerationDisabled
+                          ? offscreenContext.getOffscreenContextPixelDataType()
+                          : hwGLFormat);
+              readBackInts = IntBuffer.allocate(readBackWidthInPixels * readBackHeightInPixels);
+              break;
+
+            default:
+              // FIXME: Support more off-screen image types (current
+              // offscreen context implementations don't use others, and
+              // some of the OpenGL formats aren't supported in the 1.1
+              // headers, which we're currently using)
+              throw new GLException("Unsupported offscreen image type " + awtFormat);
+            }
+          }
+        }
+
+        if (offscreenImage != null) {
+          GL gl = getGL();
+          // Save current modes
+          gl.glGetIntegerv(GL.GL_PACK_SWAP_BYTES,    swapbytes, 0);
+          gl.glGetIntegerv(GL.GL_PACK_ROW_LENGTH,    rowlength, 0);
+          gl.glGetIntegerv(GL.GL_PACK_SKIP_ROWS,     skiprows, 0);
+          gl.glGetIntegerv(GL.GL_PACK_SKIP_PIXELS,   skippixels, 0);
+          gl.glGetIntegerv(GL.GL_PACK_ALIGNMENT,     alignment, 0);
+
+          gl.glPixelStorei(GL.GL_PACK_SWAP_BYTES,    GL.GL_FALSE);
+          gl.glPixelStorei(GL.GL_PACK_ROW_LENGTH,    readBackWidthInPixels);
+          gl.glPixelStorei(GL.GL_PACK_SKIP_ROWS,     0);
+          gl.glPixelStorei(GL.GL_PACK_SKIP_PIXELS,   0);
+          gl.glPixelStorei(GL.GL_PACK_ALIGNMENT,     1);
+
+          // Actually read the pixels.
+          gl.glReadBuffer(GL.GL_FRONT);
+          if (readBackBytes != null) {
+            gl.glReadPixels(0, 0, readBackWidthInPixels, readBackHeightInPixels, glFormat, glType, readBackBytes);
+          } else if (readBackInts != null) {
+            gl.glReadPixels(0, 0, readBackWidthInPixels, readBackHeightInPixels, glFormat, glType, readBackInts);
+          }
+
+          // Restore saved modes.
+          gl.glPixelStorei(GL.GL_PACK_SWAP_BYTES,  swapbytes[0]);
+          gl.glPixelStorei(GL.GL_PACK_ROW_LENGTH,  rowlength[0]);
+          gl.glPixelStorei(GL.GL_PACK_SKIP_ROWS,   skiprows[0]);
+          gl.glPixelStorei(GL.GL_PACK_SKIP_PIXELS, skippixels[0]);
+          gl.glPixelStorei(GL.GL_PACK_ALIGNMENT,   alignment[0]);
+
+          if (readBackBytes != null || readBackInts != null) {
+            // Copy temporary data into raster of BufferedImage for faster
+            // blitting Note that we could avoid this copy in the cases
+            // where !offscreenContext.offscreenImageNeedsVerticalFlip(),
+            // but that's the software rendering path which is very slow
+            // anyway
+            Object src  = null;
+            Object dest = null;
+            int    srcIncr  = 0;
+            int    destIncr = 0;
+
+            if (readBackBytes != null) {
+              src = readBackBytes.array();
+              dest = ((DataBufferByte) offscreenImage.getRaster().getDataBuffer()).getData();
+              srcIncr = readBackWidthInPixels * 3;
+              destIncr = offscreenImage.getWidth() * 3;
+            } else {
+              src = readBackInts.array();
+              dest = ((DataBufferInt) offscreenImage.getRaster().getDataBuffer()).getData();
+              srcIncr = readBackWidthInPixels;
+              destIncr = offscreenImage.getWidth();
+            }
+
+            if (!hardwareAccelerationDisabled ||
+                offscreenContext.offscreenImageNeedsVerticalFlip()) {
+              int srcPos = 0;
+              int destPos = (offscreenImage.getHeight() - 1) * destIncr;
+              for (; destPos >= 0; srcPos += srcIncr, destPos -= destIncr) {
+                System.arraycopy(src, srcPos, dest, destPos, destIncr);
+              }
+            } else {
+              int srcPos = 0;
+              int destEnd = destIncr * offscreenImage.getHeight();
+              for (int destPos = 0; destPos < destEnd; srcPos += srcIncr, destPos += destIncr) {
+                System.arraycopy(src, srcPos, dest, destPos, destIncr);
+              }
+            }
+
+            // Draw resulting image in one shot
+            g.drawImage(offscreenImage, 0, 0, offscreenImage.getWidth(), offscreenImage.getHeight(), GLJPanel.this);
+          }
+        }
+      } else {
+        // Cause OpenGL pipeline to flush its results because
+        // otherwise it's possible we will buffer up multiple frames'
+        // rendering results, resulting in apparent mouse lag
+        GL gl = getGL();
+        gl.glFinish();
+      }
+    }
+
+    public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height) {
+      // This is handled above and dispatched directly to the appropriate context
+    }
+
+    public void displayChanged(GLAutoDrawable drawable, boolean modeChanged, boolean deviceChanged) {
+    }
+  }
+
+  class InitAction implements Runnable {
+    public void run() {
+      updater.init(GLJPanel.this);
+    }
+  }
+  private InitAction initAction = new InitAction();
+
+  class DisplayAction implements Runnable {
+    public void run() {
+      updater.display(GLJPanel.this);
+    }
+  }
+  private DisplayAction displayAction = new DisplayAction();
+
+  // This one is used exclusively in the non-hardware-accelerated case
+  class SwapBuffersAction implements Runnable {
+    public void run() {
+      offscreenDrawable.swapBuffers();
+    }
+  }
+  private SwapBuffersAction swapBuffersAction = new SwapBuffersAction();
+
+  class PaintImmediatelyAction implements Runnable {
+    public void run() {
+      paintImmediately(0, 0, getWidth(), getHeight());
+    }
+  }
+  private PaintImmediatelyAction paintImmediatelyAction = new PaintImmediatelyAction();
+
+  private int getNextPowerOf2(int number) {
+    // Workaround for problems where 0 width or height are transiently
+    // seen during layout
+    if (number == 0) {
+      return 2;
+    }
+
+    if (((number-1) & number) == 0) {
+      //ex: 8 -> 0b1000; 8-1=7 -> 0b0111; 0b1000&0b0111 == 0
+      return number;
+    }
+    int power = 0;
+    while (number > 0) {
+      number = number>>1;
+      power++;
+    }
+    return (1<<power);
+  }
+
+  private int getGLInteger(GL gl, int which) {
+    int[] tmp = new int[1];
+    gl.glGetIntegerv(which, tmp, 0);
+    return tmp[0];
+  }
+}