From Andre Garneau,"Please find attached changes to have the GraphicsWindowWin32 class

selectively set the pixel format for windows that are inherited, following
some discussions on the mailing list last week.

This is implemented through a new traits flag
(setInheritedWindowPixelFormat) with a default state of false (to avoid
breaking existing applications). When set to true, the pixel format of the
inherited window will be set according to the traits specifications.
"

include/osg/GraphicsContext

@@ -77,7 +77,8 @@ class OSG_EXPORT GraphicsContext : public Object
                 vsync(true),
                 useMultiThreadedOpenGLEngine(false),
                 useCursor(true),
-                sharedContext(0) {}
+                sharedContext(0),
+                setInheritedWindowPixelFormat(false) {}
                             
             // graphics context orginal and size
             int x;
@@ -126,6 +127,9 @@ class OSG_EXPORT GraphicsContext : public Object
             GraphicsContext* sharedContext;
             
             osg::ref_ptr<osg::Referenced> inheritedWindowData;
+            
+            // ask the GraphicsWindow implementation to set the pixel format of an inherited window
+            bool setInheritedWindowPixelFormat;
         };