Added new statc prototype() and create() methods to CullVisitor and DatabasePager to allow overriding of the default implementations

include/osgDB/DatabasePager

@@ -45,6 +45,19 @@ class OSGDB_EXPORT DatabasePager : public osg::NodeVisitor::DatabaseRequestHandl
 
         DatabasePager();
 
+        DatabasePager(const DatabasePager& rhs);
+        
+        /** Create a shallow copy on the DatabasePager.*/
+        virtual DatabasePager* clone() const { return new DatabasePager(*this); }
+
+        /** get the prototype singleton used by DatabasePager::create().*/
+        static osg::ref_ptr<DatabasePager>& prototype();
+        
+        /** create a DatabasePager by cloning DatabasePager::prototype().*/
+        static DatabasePager* create();
+
+        
+
         /** Add a request to load a node file to end the the database request list.*/
         virtual void requestNodeFile(const std::string& fileName,osg::Group* group,
                                      float priority, const osg::FrameStamp* framestamp);

include/osgUtil/CullVisitor

@@ -53,9 +53,18 @@ class OSGUTIL_EXPORT CullVisitor : public osg::NodeVisitor, public osg::CullStac
     
 
         CullVisitor();
-        virtual ~CullVisitor();
+        
+        /// Copy constructor that does a shallow copy.
+        CullVisitor(const CullVisitor&);
 
-        virtual CullVisitor* cloneType() const { return new CullVisitor(); }
+        /** Create a shallow copy on the CullVisitor.*/
+        virtual CullVisitor* clone() const { return new CullVisitor(*this); }
+
+        /** get the prototype singleton used by CullVisitor::create().*/
+        static osg::ref_ptr<CullVisitor>& prototype();
+        
+        /** create a CullVisitor by cloning CullVisitor::prototype().*/
+        static CullVisitor* create();
 
         virtual void reset();
 
@@ -258,6 +267,8 @@ class OSGUTIL_EXPORT CullVisitor : public osg::NodeVisitor, public osg::CullStac
 
     protected:
 
+        virtual ~CullVisitor();
+
         /** Prevent unwanted copy operator.*/
         CullVisitor& operator = (const CullVisitor&) { return *this; }