Added more comprehensive releaseGLObjects(State*=0) throughout Nodes,

Drawables,StateSet, and osgDB::Registry.

Added cleanup_frame() from to osgProducer::OsgCamerGroup to help with proper
clean of OpenGL objects before exit, and modified osgviewer, osghangglider,
osgwindows examples to do the extra frame call to cleanup_frame() before exit.

include/osg/Drawable

@@ -238,10 +238,9 @@ class OSG_EXPORT Drawable : public Object
         */
         virtual void compileGLObjects(State& state) const;
 
-        /**
-            if osg::State object is supplied: release any OpenGL display lists associated with graphics context specified
-            or
-            if state pointer is NULL: release all display lists for all graphics contexts */
+        /** If State is non-zero, this function releases OpenGL objects for
+          * the specified graphics context. Otherwise, releases OpenGL objexts
+          * for all graphics contexts. */
         virtual void releaseGLObjects(State* state=0) const;
 
         struct UpdateCallback : public virtual osg::Object

include/osg/Geode

@@ -132,6 +132,11 @@ class OSG_EXPORT Geode : public Node
             return _bbox;
         }
 
+        /** If State is non-zero, this function releases any associated OpenGL objects for
+           * the specified graphics context. Otherwise, releases OpenGL objexts
+           * for all graphics contexts. */
+        virtual void releaseGLObjects(osg::State* = 0) const;
+
     protected:
 
         virtual ~Geode();

include/osg/Group

@@ -120,6 +120,12 @@ class OSG_EXPORT Group : public Node
             return _children.size(); // node not found.
         }
 
+        /** If State is non-zero, this function releases any associated OpenGL objects for
+           * the specified graphics context. Otherwise, releases OpenGL objexts
+           * for all graphics contexts. */
+        virtual void releaseGLObjects(osg::State* = 0) const;
+
+
     protected:
 
         virtual ~Group();

include/osg/Node

@@ -248,6 +248,12 @@ class OSG_EXPORT Node : public Object
         void dirtyBound();
 
 
+        /** If State is non-zero, this function releases any associated OpenGL objects for
+           * the specified graphics context. Otherwise, releases OpenGL objexts
+           * for all graphics contexts. */
+        virtual void releaseGLObjects(osg::State* = 0) const;
+
+
     protected:
 
         /** Node destructor. Note, is protected so that Nodes cannot

include/osg/Object

@@ -20,6 +20,9 @@
 
 namespace osg {
 
+// forward declare
+class State;
+
 /** META_Object macro define the standard clone, isSameKindAs and className methods.
   * Use when subclassing from Object to make it more convenient to define 
   * the standard pure virtual clone, isSameKindAs and className methods 
@@ -102,6 +105,11 @@ class OSG_EXPORT Object : public Referenced
         inline const Referenced* getUserData() const { return _userData.get(); }
 
 
+        /** If State is non-zero, this function releases any associated OpenGL objects for
+           * the specified graphics context. Otherwise, releases OpenGL objexts
+           * for all graphics contexts. */
+        virtual void releaseGLObjects(osg::State* = 0) const {}
+
     protected:
 
         /** Object destructor. Note, is protected so that Objects cannot