JOGL/OSX: Properly utilize NSOpenGLContext update() via ContextUpdater, which only holds the 'update' state now.

Avoid calling updater() for every makeCurrent(), but if view's frame has changed only.
This solves the pixel flickering experienced on OSX.

- GLContextImpl:update() -> drawableUpdatedNotify() w/ comments

- ContextUpdater holds context, view, old view frame and the update state.
  It doesn't issue NSOpenGLContext update() by itself, but allows querying and clearing the update flag.

- MacOSXOnscreenCGLContext impl drawableUpdatedNotify()
   - register via ContextUpdater, and use it if available.

2 files changed, 50 insertions, 14 deletions

diff --git a/src/jogl/classes/jogamp/opengl/GLContextImpl.java b/src/jogl/classes/jogamp/opengl/GLContextImpl.java
index 99693aabe..283b0c751 100644
--- a/src/jogl/classes/jogamp/opengl/GLContextImpl.java
+++ b/src/jogl/classes/jogamp/opengl/GLContextImpl.java
@@ -196,8 +196,18 @@ public abstract class GLContextImpl extends GLContext {
     return gl;
   }
 
-  // This is only needed for Mac OS X on-screen contexts
-  protected void update() throws GLException { }
+  /**
+   * Call this method to notify the OpenGL context
+   * that the drawable has changed (size or position).
+   * 
+   * <p>
+   * This is currently being used and overridden by Mac OSX, 
+   * which issues the {@link jogamp.opengl.macosx.cgl.CGL#updateContext(long) NSOpenGLContext update()} call.
+   * </p>
+   *  
+   * @throws GLException
+   */
+  protected void drawableUpdatedNotify() throws GLException { }
 
   boolean lockFailFast = true;
   Object lockFailFastSync = new Object();
@@ -362,7 +372,7 @@ public abstract class GLContextImpl extends GLContext {
       if (current == this) {
         // Assume we don't need to make this context current again
         // For Mac OS X, however, we need to update the context to track resizes
-        update();
+        drawableUpdatedNotify();
         return CONTEXT_CURRENT;
       } else {
         current.release();
diff --git a/src/jogl/classes/jogamp/opengl/macosx/cgl/MacOSXOnscreenCGLContext.java b/src/jogl/classes/jogamp/opengl/macosx/cgl/MacOSXOnscreenCGLContext.java
index 55d3a0853..393bd398b 100644
--- a/src/jogl/classes/jogamp/opengl/macosx/cgl/MacOSXOnscreenCGLContext.java
+++ b/src/jogl/classes/jogamp/opengl/macosx/cgl/MacOSXOnscreenCGLContext.java
@@ -49,41 +49,67 @@ public class MacOSXOnscreenCGLContext extends MacOSXCGLContext {
     super(drawable, shareWith);
   }
 
-    @Override
+  @Override
   protected void makeCurrentImpl(boolean newCreated) throws GLException {
       super.makeCurrentImpl(newCreated);
-      CGL.updateContext(contextHandle);
+      drawableUpdatedNotify();  
   }
     
-    @Override
+  @Override
   protected void releaseImpl() throws GLException {
     super.releaseImpl();
   }
 
-    @Override
+  @Override
   protected void swapBuffers() {
     if (!CGL.flushBuffer(contextHandle)) {
       throw new GLException("Error swapping buffers");
     }
   }
 
-    @Override
-  protected void update() throws GLException {
-    if (contextHandle == 0) {
-      throw new GLException("Context not created");
+  @Override
+  protected void drawableUpdatedNotify() throws GLException {
+    if(0==updateHandle || CGL.updateContextNeedsUpdate(updateHandle)) {
+        if (contextHandle == 0) {
+          throw new GLException("Context not created");
+        }
+        CGL.updateContext(contextHandle);
     }
-    CGL.updateContext(contextHandle);
   }
-
+  
+  protected long updateHandle = 0;
+  
+  @Override
   protected boolean createImpl() {
-    return create(false, false);
+    boolean res = create(false, false);
+    if(res && isNSContext) {
+        if(0 != updateHandle) {
+            throw new InternalError("XXX1");
+        }
+        updateHandle = CGL.updateContextRegister(contextHandle, drawable.getHandle());
+        if(0 == updateHandle) {
+            throw new InternalError("XXX2");
+        }
+    }
+    return res;
   }
 
+  @Override
+  protected void destroyImpl() throws GLException {
+    if ( 0 != updateHandle ) {
+        CGL.updateContextUnregister(updateHandle);
+        updateHandle = 0;
+    }
+    super.destroyImpl();
+  }
+  
+  @Override
   public void setOpenGLMode(int mode) {
     if (mode != MacOSXCGLDrawable.NSOPENGL_MODE)
       throw new GLException("OpenGL mode switching not supported for on-screen GLContexts");
   }
     
+  @Override
   public int  getOpenGLMode() {
     return MacOSXCGLDrawable.NSOPENGL_MODE;
   }