From Stephan Huber, "attached you'll find a small enhancement for GraphicsWindowCocoa to

implement the recently introduced setSyncToVBlank-method.

Additionally I added a ToggleSyncToVBlank-eventhandler to osgViewer. I
used it to test the code, perhaps you'll find it useful and include it
in the distribution."

src/osgViewer/GraphicsWindowCocoa.mm

@@ -1048,7 +1048,7 @@ bool GraphicsWindowCocoa::realizeImplementation()
     
     useCursor(_traits->useCursor);
     setWindowName(_traits->windowName);
-    setVSync(_traits->vsync);
+    setSyncToVBlank(_traits->vsync);
     
     MenubarController::instance()->update();
     
@@ -1419,11 +1419,12 @@ void GraphicsWindowCocoa::setCursor(MouseCursor mouseCursor)
 
 
 // ----------------------------------------------------------------------------------------------------------
-// setVSync
+// setSyncToVBlank
 // ----------------------------------------------------------------------------------------------------------
 
-void GraphicsWindowCocoa::setVSync(bool f) 
+void GraphicsWindowCocoa::setSyncToVBlank(bool f) 
 {
+    if (_traits.valid()) _traits->vsync = f;
     GLint VBL(f?1:0);
     [_context setValues:&VBL forParameter:NSOpenGLCPSwapInterval];
 }

src/osgViewer/ViewerEventHandlers.cpp

@@ -626,6 +626,66 @@ void LODScaleHandler::getUsage(osg::ApplicationUsage& usage) const
     }
 }
 
+ToggleSyncToVBlankHandler::ToggleSyncToVBlankHandler():
+    _keyEventToggleSyncToVBlank('v')
+{
+}
+
+bool ToggleSyncToVBlankHandler::handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa)
+{
+    osgViewer::View* view = dynamic_cast<osgViewer::View*>(&aa);
+    if (!view) return false;
+    
+    osgViewer::ViewerBase* viewer = view->getViewerBase();
+
+    if (viewer == NULL)
+    {
+        return false;
+    }
+    
+    if (ea.getHandled()) return false;
+
+    switch(ea.getEventType())
+    {
+        case(osgGA::GUIEventAdapter::KEYUP):
+        {
+            if (ea.getKey() == _keyEventToggleSyncToVBlank)
+            {
+                // Increase resolution
+                osgViewer::Viewer::Windows    windows;
+
+                viewer->getWindows(windows);
+                for(osgViewer::Viewer::Windows::iterator itr = windows.begin();
+                    itr != windows.end();
+                    ++itr)
+                {
+                    (*itr)->setSyncToVBlank( !(*itr)->getSyncToVBlank() );
+                }
+
+                aa.requestRedraw();
+                return true;
+            }
+
+            break;
+        }
+    default:
+        break;
+    }
+
+    return false;
+}
+
+
+void ToggleSyncToVBlankHandler::getUsage(osg::ApplicationUsage& usage) const
+{
+    {
+        std::ostringstream ostr;
+        ostr<<char(_keyEventToggleSyncToVBlank);
+        usage.addKeyboardMouseBinding(ostr.str(),"Toggle SyncToVBlank.");
+    }
+}
+
+
 InteractiveImageHandler::InteractiveImageHandler(osg::Image* image) :
     _image(image),
     _texture(0),