GLRendererQuirks: Add RequiresBoundVAO (w/ impl.), GLSLBuggyDiscard (todo) ; GLContextImpl: Bind default VAO if having quirk RequiresBoundVAO.

OSX w/ OpenGL >= 3 core context implementation requires a bound VAO for vertex attribute operations,
i.e. VertexAttributePointer(..). This has been experienced on OSX 10.7.5, OpenGL 3.2 core w/ Nvidia GPU
and in several forum posts. Such 'behavior' violates the GL 3.2 core specification,
which does not state this requirement, hence it is a bug. (Please correct me if I am wrong!)

GLContextImpl works around this quirk, by generating a default VAO and binds it at 1st makeCurrent (@creation)
and deletes it at destroy. This is minimal invasive since no action is required for subsequent makeCurrent or release.
We assume if a user uses and binds a VAO herself, she will mind this quirk.

Note: We could enhance this workaround by quering for a currently bound VAO at makeCurrent() and bind our default if none.
However, we refrain from this operation to minimize the workaround and complexity.

2 files changed, 34 insertions, 6 deletions

diff --git a/src/jogl/classes/com/jogamp/opengl/GLRendererQuirks.java b/src/jogl/classes/com/jogamp/opengl/GLRendererQuirks.java
index 82799bf67..51944cb71 100644
--- a/src/jogl/classes/com/jogamp/opengl/GLRendererQuirks.java
+++ b/src/jogl/classes/com/jogamp/opengl/GLRendererQuirks.java
@@ -58,12 +58,19 @@ public class GLRendererQuirks {
     
     /** SIGSEGV on setSwapInterval() after changing the context's drawable w/ 'Mesa 8.0.4' dri2SetSwapInterval/DRI2 (soft & intel) */
     public static final int NoSetSwapIntervalPostRetarget = 4;
+
+    /** Requires a bound VAO for vertex attribute operations, i.e. GL impl. uses no default VAO. Violates GL 3.2. On OSX OpenGL 3.2 context. FIXME: Constrain version. */
+    public static final int RequiresBoundVAO = 5;
+    
+    /** GLSL <code>discard</code> command leads to undefined behavior or won't get compiled if being used. Appears to happen on Nvidia Tegra2. FIXME: Constrain version. */
+    public static final int GLSLBuggyDiscard = 6;
     
     /** Number of quirks known. */
-    public static final int COUNT                   = 5;
+    public static final int COUNT = 7;
     
     private static final String[] _names = new String[] { "NoDoubleBufferedPBuffer", "NoDoubleBufferedBitmap", "NoSetSwapInterval",
-                                                          "NoOffscreenBitmap", "NoSetSwapIntervalPostRetarget" 
+                                                          "NoOffscreenBitmap", "NoSetSwapIntervalPostRetarget", "RequiresBoundVAO",
+                                                          "GLSLBuggyDiscard"
                                                         };
 
     private final int _bitmask;
diff --git a/src/jogl/classes/jogamp/opengl/GLContextImpl.java b/src/jogl/classes/jogamp/opengl/GLContextImpl.java
index d2e0bb407..48184119b 100644
--- a/src/jogl/classes/jogamp/opengl/GLContextImpl.java
+++ b/src/jogl/classes/jogamp/opengl/GLContextImpl.java
@@ -98,7 +98,8 @@ public abstract class GLContextImpl extends GLContext {
   private final GLStateTracker glStateTracker = new GLStateTracker();
   private GLDebugMessageHandler glDebugHandler = null;
   private final int[] boundFBOTarget = new int[] { 0, 0 }; // { draw, read }
-
+  private int defaultVAO = 0; 
+  
   protected GLDrawableImpl drawable;
   protected GLDrawableImpl drawableRead;
   
@@ -347,6 +348,12 @@ public abstract class GLContextImpl extends GLContext {
                   } catch (Throwable t) {
                       drawableContextRealizedException = t;
                   }
+                  if(0 != defaultVAO) {
+                      int[] tmp = new int[] { defaultVAO };
+                      gl.getGL2GL3().glBindVertexArray(0);
+                      gl.getGL2GL3().glDeleteVertexArrays(1, tmp, 0);
+                      defaultVAO = 0;
+                  }
                   glDebugHandler.enable(false);
                   if(lock.getHoldCount() > 1) {
                       // pending release() after makeCurrent()
@@ -563,6 +570,13 @@ public abstract class GLContextImpl extends GLContext {
         final boolean created;
         try {
             created = createImpl(shareWith); // may throws exception if fails!
+            if( created && glRendererQuirks.exist(GLRendererQuirks.RequiresBoundVAO) ) {
+                // Workaround: Create a default VAO to be used per default on makeCurrent
+                final int[] tmp = new int[1];
+                gl.getGL2GL3().glGenVertexArrays(1, tmp, 0);
+                defaultVAO = tmp[0];
+                gl.getGL2GL3().glBindVertexArray(defaultVAO);
+            }
         } finally {
             if (null != shareWith) {
                 shareWith.getDrawableImpl().unlockSurface();
@@ -1292,11 +1306,18 @@ public abstract class GLContextImpl extends GLContext {
     
     // OS related quirks
     if( Platform.getOSType() == Platform.OSType.MACOS ) {
-        final int quirk = GLRendererQuirks.NoOffscreenBitmap;
+        final int quirk1 = GLRendererQuirks.NoOffscreenBitmap;
         if(DEBUG) {
-            System.err.println("Quirk: "+GLRendererQuirks.toString(quirk)+": cause: OS "+Platform.getOSType());
+            System.err.println("Quirk: "+GLRendererQuirks.toString(quirk1)+": cause: OS "+Platform.getOSType());
+        }
+        quirks[i++] = quirk1;
+        if( 3 <= ctxMajorVersion ) {
+            final int quirk2 = GLRendererQuirks.RequiresBoundVAO;
+            if(DEBUG) {
+                System.err.println("Quirk: "+GLRendererQuirks.toString(quirk2)+": cause: OS "+Platform.getOSType());
+            }
+            quirks[i++] = quirk2;
         }
-        quirks[i++] = quirk;
     } else if( Platform.getOSType() == Platform.OSType.WINDOWS ) {
         final int quirk = GLRendererQuirks.NoDoubleBufferedBitmap;
         if(DEBUG) {