Introduced use of MarkerObject to IncrmentalCompileOperation/DatabasePager as a way of marking objects that have already been processed and compiled,

thus avoid potential threading conflicts when paged subgraphs are reused.


git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@14470 16af8721-9629-0410-8352-f15c8da7e697

include/osg/Object

@@ -269,6 +269,19 @@ T* cloneType(const T* t)
     }
 }
 
+/** DummyObject that can be used as placeholder but otherwise has no other functionality.*/
+class DummyObject : public osg::Object
+{
+public:
+    DummyObject() {}
+    DummyObject(const DummyObject& dummy, const osg::CopyOp& copyop) {}
+    META_Object(osg, DummyObject)
+protected:
+    virtual ~DummyObject() {}
+};
+
+
+
 }
 
 #endif