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.

3 files changed, 61 insertions, 27 deletions

diff --git a/src/jogl/native/macosx/ContextUpdater.h b/src/jogl/native/macosx/ContextUpdater.h
index f8ce93def..2483ec403 100644
--- a/src/jogl/native/macosx/ContextUpdater.h
+++ b/src/jogl/native/macosx/ContextUpdater.h
@@ -22,10 +22,13 @@ This notification is sent whenever an NSView that has an attached NSSurface chan
     #define UNLOCK_GL(func, line) [ContextUpdater unlock];
 #endif
 
-// gznote: OpenGL NOT thread safe - need to sync on update and paints
-
 @interface ContextUpdater : NSObject
 {
+@protected
+    NSView * view;
+    NSRect viewRect;
+    NSOpenGLContext *ctx;
+    BOOL viewUpdated;
 }
 
 + (void) lock;
@@ -33,8 +36,10 @@ This notification is sent whenever an NSView that has an attached NSSurface chan
 + (void) unlock;
 + (void) unlockInFunction:(char *)func atLine:(int)line;
 
-- (void) registerFor:(NSOpenGLContext *)context with: (NSView *)window;
+- (id) initWithContext:(NSOpenGLContext *)context view: (NSView *)nsView;
 
 - (void) update:(NSNotification *)notification;
 
+- (BOOL) needsUpdate;
+
 @end
diff --git a/src/jogl/native/macosx/ContextUpdater.m b/src/jogl/native/macosx/ContextUpdater.m
index 859697722..64d5ef1f9 100644
--- a/src/jogl/native/macosx/ContextUpdater.m
+++ b/src/jogl/native/macosx/ContextUpdater.m
@@ -5,18 +5,17 @@
 {
 }
 
-static NSOpenGLContext *theContext;
 static pthread_mutex_t resourceLock = PTHREAD_MUTEX_INITIALIZER;
 
 static void printLockDebugInfo(char *message, char *func, int line)
 {
     fprintf(stderr, "%s in function: \"%s\" at line: %d\n", message, func, line);
-    fflush(stderr);
+    fflush(NULL);
 }
 
 + (void) lock
 {
-    if (theContext != NULL)
+    if (ctx != NULL)
     {
         pthread_mutex_lock(&resourceLock);
     }
@@ -24,7 +23,7 @@ static void printLockDebugInfo(char *message, char *func, int line)
 
 + (void) lockInFunction:(char *)func atLine:(int)line
 {
-    if (theContext != NULL)
+    if (ctx != NULL)
     {
         printLockDebugInfo("locked  ", func, line);
         [self lock];
@@ -33,7 +32,7 @@ static void printLockDebugInfo(char *message, char *func, int line)
 
 + (void) unlock
 {
-    if (theContext != NULL)
+    if (ctx != NULL)
     {
         pthread_mutex_unlock(&resourceLock);
     }
@@ -41,43 +40,62 @@ static void printLockDebugInfo(char *message, char *func, int line)
 
 + (void) unlockInFunction:(char *)func atLine:(int)line
 {
-    if (theContext != NULL)
+    if (ctx != NULL)
     {
         printLockDebugInfo("unlocked", func, line);
         [self unlock];
     }
 }
 
-- (void) registerFor:(NSOpenGLContext *)context with: (NSView *)view
+- (void) update:(NSNotification *)notification
 {
-    if (view != NULL)
-    {
-        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(update:) name:NSViewGlobalFrameDidChangeNotification object: view];
-        theContext = context;
+    [ContextUpdater lock];
+    
+    NSRect r = [view frame];
+    if(viewRect.origin.x != r.origin.x || 
+       viewRect.origin.y != r.origin.y || 
+       viewRect.size.width != r.size.width ||
+       viewRect.size.height != r.size.height) {
+        viewUpdated = TRUE;
+        viewRect = r;
     }
+    
+    [ContextUpdater unlock];
 }
 
-- (void) update:(NSNotification *)notification
+- (BOOL) needsUpdate
 {
+    BOOL r;
     [ContextUpdater lock];
     
-    [theContext update];
+    r = viewUpdated;
+    viewUpdated = FALSE;
     
     [ContextUpdater unlock];
+
+    return r;
 }
 
-- (id) init
-{    
-    theContext = NULL;
-    
+- (id) initWithContext:(NSOpenGLContext *)context view: (NSView *)nsView
+{
+    ctx = context;
+    view = nsView;
+    [ctx retain];
+    [view retain];
+    viewRect = [view frame];
+    viewUpdated = FALSE;
+    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(update:) name:NSViewGlobalFrameDidChangeNotification object: view];
+
     return [super init];
 }
 
 - (void) dealloc
 {
     [[NSNotificationCenter defaultCenter] removeObserver:self];
+    [view release];
+    [ctx release];
     
     [super dealloc];
 }
 
-@end
\ No newline at end of file
+@end
diff --git a/src/jogl/native/macosx/MacOSXWindowSystemInterface.m b/src/jogl/native/macosx/MacOSXWindowSystemInterface.m
index 86d875502..aab70791c 100644
--- a/src/jogl/native/macosx/MacOSXWindowSystemInterface.m
+++ b/src/jogl/native/macosx/MacOSXWindowSystemInterface.m
@@ -590,7 +590,8 @@ Bool deleteContext(void* nsJContext) {
     
   NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
   [nsContext clearDrawable];
-  [nsContext release]; // freezes for a few seconds if ctx is shared
+  // [nsContext release]; // FIXME: JAU: freezes for a few seconds if ctx is shared
+  // [nsContext dealloc];
   [pool release];
   return true;
 }
@@ -624,15 +625,25 @@ void copyContext(void* destContext, void* srcContext, int mask) {
   [dst copyAttributesFromContext: src withMask: mask];
 }
 
-void* updateContextRegister(void* nsJContext, void* view) {
+void* updateContextRegister(void* nsJContext, void* nsJView) {
   NSOpenGLContext *nsContext = (NSOpenGLContext*)nsJContext;
-  NSView *nsView = (NSView*)view;
+  NSView *nsView = (NSView*)nsJView;
     
   NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
-  ContextUpdater *contextUpdater = [[ContextUpdater alloc] init];
-  [contextUpdater registerFor:nsContext with:nsView];
+  ContextUpdater *contextUpdater = [[ContextUpdater alloc] initWithContext: nsContext view: nsView];
   [pool release];
-  return NULL;
+  return contextUpdater;
+}
+
+Bool updateContextNeedsUpdate(void* updater) {
+  ContextUpdater *contextUpdater = (ContextUpdater *)updater;
+  BOOL res;
+    
+  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
+  res = [contextUpdater needsUpdate];
+  [pool release];
+
+  return ( res == TRUE ) ? true : false;
 }
 
 void updateContextUnregister(void* updater) {