Bug 776 GLContext Sharing: Refine API for relaxed and lazy GLContext sharing ; Fix GLContext memory contract (volatile)

(Unit test remarks see below)

- Add shared GLContext queries
  - Refined GLContextShareSet:
    - Use IdentityHashMap since GLContext's can only be identical w/ same reference (footprint, performance)
    - Add API doc for clarification
    - Add methods:
       - ArrayList<GLContext> getCreatedShares(final GLContext context)
       - ArrayList<GLContext> getDestroyedShares(final GLContext context)
    - Use 'final' where possible

  - Add GLContext methods:
      - boolean isShared()
      - List<GLContext> getCreatedShares()
      - List<GLContext> getDestroyedShares()

- Add GLSharedContextSetter interface defining setting a shared GLContext
  directly (GLContext) or via a GLAutoDrawable:
  - setSharedContext(GLContext)
  - setSharedAutoDrawable(GLAutoDrawable)

  Both cause initialization/creation of GLAutoDrawable's drawable/context to be postponed,
  if the shared GLContext is not yet created natively or
  the shared GLAutoDrawable's GLContext does not yet exist.

  Most of impl. resides in GLDrawableHelper

  Implemented in:
    - GLAutoDrawableBase, GLOffscreenAutoDrawable
    - GLWindow
    - AWT GLCanvas

  TODO:
    - GLJPanel
    - SWT GLCanvas

- GLDrawableFactory:
   - Add 'GLOffscreenAutoDrawable createOffscreenAutoDrawable(..)' variant w/o passing the
     optional shared GLContext _and_ specifying lazy GLContext
     creation. This allows to benefit from GLSharedContextSetter contract.
     Lazy GLContext creation is performed at 2st display() call at the latest.

     All JOGL code and unit tests use this new method now.

  - Mark 'createOffscreenAutoDrawable(..)' w/ shared GLContext argument
    and immediate GLContext creation deprecated - shall be removed in 2.2.0

- Make reference to GLContext and it's native handle volatile
  Since we rely on the query 'GLContext.isCreated()' to properly allow GLAutoDrawable's to query whether
  a shared GLContext is natively created (already), the handle must be volatile
  since such query and the actual creation may operate on different threads.

+++++

- Add/Refine shared GLContext unit tests demonstrating diff. sharing methods.

  All variants of using shared GLContext:
      com.jogamp.opengl.test.junit.jogl.acore.TestSharedContextVBO*

  Most convenient way to share via setSharedAutoDrawable(GLAutoDrawable):
      com.jogamp.opengl.test.junit.jogl.acore.TestSharedContextVBOES2[NEWT|AWT]3

  AWT use w/ JTabbedPane using setSharedAutoDrawable(GLAutoDrawable):
      com.jogamp.opengl.test.junit.jogl.acore.TestSharedContextWithJTabbedPaneAWT

1 files changed, 59 insertions, 1 deletions

diff --git a/src/jogl/classes/jogamp/opengl/GLDrawableHelper.java b/src/jogl/classes/jogamp/opengl/GLDrawableHelper.java
index 4ce6a7121..cf5d7a206 100644
--- a/src/jogl/classes/jogamp/opengl/GLDrawableHelper.java
+++ b/src/jogl/classes/jogamp/opengl/GLDrawableHelper.java
@@ -82,6 +82,10 @@ public class GLDrawableHelper {
   private GLAnimatorControl animatorCtrl;
   private static Runnable nop = new Runnable() { @Override public void run() {} };
 
+  private GLContext sharedContext;
+  private GLAutoDrawable sharedAutoDrawable;
+
+
   public GLDrawableHelper() {
     reset();
   }
@@ -98,6 +102,60 @@ public class GLDrawableHelper {
         glRunnables.clear();
     }
     animatorCtrl = null;
+    sharedContext = null;
+    sharedAutoDrawable = null;
+  }
+
+  public final void setSharedContext(GLContext thisContext, GLContext sharedContext) throws IllegalStateException {
+      if( null == sharedContext ) {
+          throw new IllegalStateException("Null shared GLContext");
+      }
+      if( thisContext == sharedContext ) {
+          throw new IllegalStateException("Shared GLContext same as local");
+      }
+      if( null != this.sharedContext ) {
+          throw new IllegalStateException("Shared GLContext already set");
+      }
+      if( null != this.sharedAutoDrawable ) {
+          throw new IllegalStateException("Shared GLAutoDrawable already set");
+      }
+      this.sharedContext = sharedContext;
+  }
+
+  public final void setSharedAutoDrawable(GLAutoDrawable thisAutoDrawable, GLAutoDrawable sharedAutoDrawable) throws IllegalStateException {
+      if( null == sharedAutoDrawable ) {
+          throw new IllegalStateException("Null shared GLAutoDrawable");
+      }
+      if( thisAutoDrawable == sharedAutoDrawable ) {
+          throw new IllegalStateException("Shared GLAutoDrawable same as this");
+      }
+      if( null != this.sharedContext ) {
+          throw new IllegalStateException("Shared GLContext already set");
+      }
+      if( null != this.sharedAutoDrawable ) {
+          throw new IllegalStateException("Shared GLAutoDrawable already set");
+      }
+      this.sharedAutoDrawable = sharedAutoDrawable;
+  }
+
+  /**
+   * @param shared returns the shared GLContext, based on set shared GLAutoDrawable
+   *               or GLContext. Maybe null if none is set.
+   * @return true if initialization is pending due to a set shared GLAutoDrawable or GLContext
+   *         which is not ready yet. Otherwise false.
+   */
+  public boolean isSharedGLContextPending(GLContext[] shared) {
+      final GLContext shareWith;
+      final boolean pending;
+      if ( null != sharedAutoDrawable ) {
+          shareWith = sharedAutoDrawable.getContext();
+          pending = null == shareWith || !shareWith.isCreated();
+      } else {
+          shareWith = sharedContext;
+          pending = null != shareWith && !shareWith.isCreated();
+      }
+      shared[0] = shareWith;
+      return pending;
   }
 
   @Override
@@ -612,7 +670,7 @@ public class GLDrawableHelper {
   public final void reshape(GLAutoDrawable drawable, int x, int y, int width, int height) {
     synchronized(listenersLock) {
         for (int i=0; i < listeners.size(); i++) {
-          reshape((GLEventListener) listeners.get(i), drawable, x, y, width, height, 0==i /* setViewport */, true /* checkInit */);
+          reshape(listeners.get(i), drawable, x, y, width, height, 0==i /* setViewport */, true /* checkInit */);
         }
     }
   }