From Farshid Lashkari, "As discussed, I've added the ability to handle Drawable objects within the NodeVisitor class. Here is an overview of the changes:

- Added apply(Drawable) and apply(Geometry) to NodeVisitor

- Added accept(NodeVisitor) method to Drawable/Geometry

- Added traverse(NodeVisitor) to Geode which calls accept(NodeVisitor) on all Drawables

- Updated CullVisitor to use new apply(Drawable) to handle drawables. The apply(Billboard) method still manually handles the drawables since it is depends on the billboard settings. I needed to disable the traverse within billboard to prevent duplicate traversal of drawables.

- Update other osgUtil node visitors (GLObjectsVisitor, IncrementalCompileOperation, ..) to use new apply(Drawable) method.
"

include/osg/Drawable

@@ -115,6 +115,8 @@ class OSG_EXPORT Drawable : public Object
           * Equivalent to dynamic_cast<const Geometry*>(this).*/
         virtual const Geometry* asGeometry() const { return 0; }
 
+        /** Visitor Pattern : calls the apply method of a NodeVisitor with this drawable's type.*/
+        virtual void accept(NodeVisitor& nv);
 
         /** Compute the DataVariance based on an assessment of callback etc.*/
         virtual void computeDataVariance();

include/osg/Geode

@@ -41,6 +41,8 @@ class OSG_EXPORT Geode : public Node
         virtual Geode* asGeode() { return this; }
         virtual const Geode* asGeode() const { return this; }
 
+        virtual void traverse(NodeVisitor& nv);
+
         /** Add a \c Drawable to the \c Geode.
           * If \c drawable is not \c NULL and is not contained in the \c Geode
           * then increment its reference count, add it to the drawables list and

include/osg/Geometry

@@ -44,6 +44,8 @@ class OSG_EXPORT Geometry : public Drawable
         virtual Geometry* asGeometry() { return this; }
         virtual const Geometry* asGeometry() const { return this; }
 
+        virtual void accept(NodeVisitor& nv) { nv.apply(*this); }
+
         bool empty() const;
 
         typedef std::vector< osg::ref_ptr<osg::Array> >  ArrayList;

include/osg/NodeVisitor

@@ -41,6 +41,8 @@ class TexGenNode;
 class Transform;
 class Camera;
 class CameraView;
+class Drawable;
+class Geometry;
 
 const unsigned int UNINITIALIZED_FRAME_NUMBER=0xffffffff;
 
@@ -89,7 +91,7 @@ class OSG_EXPORT NodeVisitor : public virtual Object
 
         NodeVisitor(const NodeVisitor& nv, const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);
 
-	virtual ~NodeVisitor();
+    virtual ~NodeVisitor();
         
         META_Object(osg, NodeVisitor)
 
@@ -237,6 +239,8 @@ class OSG_EXPORT NodeVisitor : public virtual Object
           * If the getDistanceToViewPoint(pos) is not implemented then a default value of 0.0 is returned.*/
         virtual float getDistanceToViewPoint(const Vec3& /*pos*/, bool /*useLODScale*/) const { return 0.0f; }
 
+        virtual void apply(Drawable& drawable);
+        virtual void apply(Geometry& drawable);
 
         virtual void apply(Node& node);
 

include/osgUtil/CullVisitor

@@ -90,6 +90,7 @@ class OSGUTIL_EXPORT CullVisitor : public osg::NodeVisitor, public osg::CullStac
 
         virtual void apply(osg::Node&);
         virtual void apply(osg::Geode& node);
+        virtual void apply(osg::Drawable& drawable);
         virtual void apply(osg::Billboard& node);
         virtual void apply(osg::LightSource& node);
         virtual void apply(osg::ClipNode& node);

include/osgUtil/IncrementalCompileOperation

@@ -44,7 +44,6 @@ class OSGUTIL_EXPORT StateToCompile : public osg::NodeVisitor
         bool empty() const { return _textures.empty() &&  _programs.empty() && _drawables.empty(); }
 
         virtual void apply(osg::Node& node);
-        virtual void apply(osg::Geode& node);
 
         virtual void apply(osg::Drawable& drawable);
         virtual void apply(osg::StateSet& stateset);

src/osg/Drawable.cpp

@@ -272,6 +272,11 @@ Drawable::~Drawable()
     dirtyDisplayList();
 }
 
+void Drawable::accept(NodeVisitor& nv)
+{
+    nv.apply(*this);
+}
+
 osg::MatrixList Drawable::getWorldMatrices(const osg::Node* haltTraversalAtNode) const
 {
     osg::MatrixList matrices;

src/osg/Geode.cpp

@@ -48,6 +48,16 @@ Geode::~Geode()
     }
 }
 
+void Geode::traverse(NodeVisitor& nv)
+{
+    for(DrawableList::iterator itr=_drawables.begin();
+        itr!=_drawables.end();
+        ++itr)
+    {
+        (*itr)->accept(nv);
+    }
+}
+
 bool Geode::addDrawable( Drawable *drawable )
 {
     if (drawable /* && !containsDrawable(drawable)*/)

src/osg/NodeVisitor.cpp

@@ -33,6 +33,7 @@
 #include <osg/Transform>
 #include <osg/Camera>
 #include <osg/CameraView>
+#include <osg/Geometry>
 
 #include <stdlib.h>
 
@@ -75,6 +76,16 @@ NodeVisitor::~NodeVisitor()
     // if (_traversalVisitor) detach from _traversalVisitor;
 }
 
+void NodeVisitor::apply(Drawable& drawable)
+{
+    // It all ends here...
+}
+
+void NodeVisitor::apply(Geometry& drawable)
+{
+    apply(static_cast<Drawable&>(drawable));
+}
+
 void NodeVisitor::apply(Node& node)
 {
     traverse(node);

src/osgUtil/CullVisitor.cpp

@@ -961,91 +961,94 @@ void CullVisitor::apply(Geode& node)
 {
     if (isCulled(node)) return;
 
+    // push the culling mode.
+    pushCurrentMask();
+
     // push the node's state.
     StateSet* node_state = node.getStateSet();
     if (node_state) pushStateSet(node_state);
 
-    // traverse any call callbacks and traverse any children.
     handle_cull_callbacks_and_traverse(node);
 
-    RefMatrix& matrix = *getModelViewMatrix();
-    for(unsigned int i=0;i<node.getNumDrawables();++i)
-    {
-        Drawable* drawable = node.getDrawable(i);
-        const BoundingBox &bb =drawable->getBound();
-
-        if( drawable->getCullCallback() )
-        {
-            if( drawable->getCullCallback()->cull( this, drawable, &_renderInfo ) == true )
-            continue;
-        }
-
-        //else
-        {
-            if (node.isCullingActive() && isCulled(bb)) continue;
-        }
-
-
-        if (_computeNearFar && bb.valid())
-        {
-            if (!updateCalculatedNearFar(matrix,*drawable,false)) continue;
-        }
-
-        // need to track how push/pops there are, so we can unravel the stack correctly.
-        unsigned int numPopStateSetRequired = 0;
-
-        // push the geoset's state on the geostate stack.
-        StateSet* stateset = drawable->getStateSet();
-        if (stateset)
-        {
-            ++numPopStateSetRequired;
-            pushStateSet(stateset);
-        }
-
-        CullingSet& cs = getCurrentCullingSet();
-        if (!cs.getStateFrustumList().empty())
-        {
-            osg::CullingSet::StateFrustumList& sfl = cs.getStateFrustumList();
-            for(osg::CullingSet::StateFrustumList::iterator itr = sfl.begin();
-                itr != sfl.end();
-                ++itr)
-            {
-                if (itr->second.contains(bb))
-                {
-                    ++numPopStateSetRequired;
-                    pushStateSet(itr->first.get());
-                }
-            }
-        }
-
-        float depth = bb.valid() ? distance(bb.center(),matrix) : 0.0f;
-
-        if (osg::isNaN(depth))
-        {
-            OSG_NOTICE<<"CullVisitor::apply(Geode&) detected NaN,"<<std::endl
-                                    <<"    depth="<<depth<<", center=("<<bb.center()<<"),"<<std::endl
-                                    <<"    matrix="<<matrix<<std::endl;
-            OSG_DEBUG << "    NodePath:" << std::endl;
-            for (NodePath::const_iterator i = getNodePath().begin(); i != getNodePath().end(); ++i)
-            {
-                OSG_DEBUG << "        \"" << (*i)->getName() << "\"" << std::endl;
-            }
-        }
-        else
-        {
-            addDrawableAndDepth(drawable,&matrix,depth);
-        }
-
-        for(unsigned int i=0;i< numPopStateSetRequired; ++i)
-        {
-            popStateSet();
-        }
-
-    }
-
     // pop the node's state off the geostate stack.
     if (node_state) popStateSet();
 
+    // pop the culling mode.
+    popCurrentMask();
+}
+
+void CullVisitor::apply(osg::Drawable& drawable)
+{
+    RefMatrix& matrix = *getModelViewMatrix();
+
+    const BoundingBox &bb =drawable.getBound();
+
+    if( drawable.getCullCallback() )
+    {
+        if( drawable.getCullCallback()->cull( this, &drawable, &_renderInfo ) == true )
+        return;
+    }
+
+    //else
+    {
+        if (getNodePath().back()->isCullingActive() && isCulled(bb)) return;
+    }
+
+
+    if (_computeNearFar && bb.valid())
+    {
+        if (!updateCalculatedNearFar(matrix,drawable,false)) return;
+    }
+
+    // need to track how push/pops there are, so we can unravel the stack correctly.
+    unsigned int numPopStateSetRequired = 0;
+
+    // push the geoset's state on the geostate stack.
+    StateSet* stateset = drawable.getStateSet();
+    if (stateset)
+    {
+        ++numPopStateSetRequired;
+        pushStateSet(stateset);
+    }
+
+    CullingSet& cs = getCurrentCullingSet();
+    if (!cs.getStateFrustumList().empty())
+    {
+        osg::CullingSet::StateFrustumList& sfl = cs.getStateFrustumList();
+        for(osg::CullingSet::StateFrustumList::iterator itr = sfl.begin();
+            itr != sfl.end();
+            ++itr)
+        {
+            if (itr->second.contains(bb))
+            {
+                ++numPopStateSetRequired;
+                pushStateSet(itr->first.get());
+            }
+        }
+    }
+
+    float depth = bb.valid() ? distance(bb.center(),matrix) : 0.0f;
+
+    if (osg::isNaN(depth))
+    {
+        OSG_NOTICE<<"CullVisitor::apply(Geode&) detected NaN,"<<std::endl
+                                <<"    depth="<<depth<<", center=("<<bb.center()<<"),"<<std::endl
+                                <<"    matrix="<<matrix<<std::endl;
+        OSG_DEBUG << "    NodePath:" << std::endl;
+        for (NodePath::const_iterator i = getNodePath().begin(); i != getNodePath().end(); ++i)
+        {
+            OSG_DEBUG << "        \"" << (*i)->getName() << "\"" << std::endl;
+        }
+    }
+    else
+    {
+        addDrawableAndDepth(&drawable,&matrix,depth);
+    }
+
+    for(unsigned int i=0;i< numPopStateSetRequired; ++i)
+    {
+        popStateSet();
+    }
 }
 
 
@@ -1057,8 +1060,8 @@ void CullVisitor::apply(Billboard& node)
     StateSet* node_state = node.getStateSet();
     if (node_state) pushStateSet(node_state);
 
-    // traverse any call callbacks and traverse any children.
+    // Don't traverse billboard, since drawables are handled manually below
-    handle_cull_callbacks_and_traverse(node);
+    //handle_cull_callbacks_and_traverse(node);
 
     const Vec3& eye_local = getEyeLocal();
     const RefMatrix& modelview = *getModelViewMatrix();

src/osgUtil/GLObjectsVisitor.cpp

@@ -61,18 +61,7 @@ void GLObjectsVisitor::apply(osg::Geode& node)
         apply(*(node.getStateSet()));
     }
 
-    for(unsigned int i=0;i<node.getNumDrawables();++i)
+    traverse(node);
-    {
-        osg::Drawable* drawable = node.getDrawable(i);
-        if (drawable)
-        {
-            apply(*drawable);
-            if (drawable->getStateSet())
-            {
-                apply(*(drawable->getStateSet()));
-            }
-        }
-    }
 
     bool programSetAfter = _lastCompiledProgram.valid();
     if (!programSetBefore && programSetAfter)
@@ -120,6 +109,11 @@ void GLObjectsVisitor::apply(osg::Drawable& drawable)
     {
         drawable.releaseGLObjects(_renderInfo.getState());
     }
+
+    if (drawable.getStateSet())
+    {
+        apply(*(drawable.getStateSet()));
+    }
 }
 
 void GLObjectsVisitor::apply(osg::StateSet& stateset)

src/osgUtil/IncrementalCompileOperation.cpp

@@ -70,27 +70,6 @@ void StateToCompile::apply(osg::Node& node)
     traverse(node);
 }
 
-void StateToCompile::apply(osg::Geode& node)
-{
-    if (node.getStateSet())
-    {
-        apply(*(node.getStateSet()));
-    }
-
-    for(unsigned int i=0;i<node.getNumDrawables();++i)
-    {
-        osg::Drawable* drawable = node.getDrawable(i);
-        if (drawable)
-        {
-            apply(*drawable);
-            if (drawable->getStateSet())
-            {
-                apply(*(drawable->getStateSet()));
-            }
-        }
-    }
-}
-
 void StateToCompile::apply(osg::Drawable& drawable)
 {
     if (_drawablesHandled.count(&drawable)!=0) return;
@@ -122,6 +101,11 @@ void StateToCompile::apply(osg::Drawable& drawable)
     {
         _drawables.insert(&drawable);
     }
+
+    if (drawable.getStateSet())
+    {
+        apply(*(drawable.getStateSet()));
+    }
 }
 
 void StateToCompile::apply(osg::StateSet& stateset)

src/osgUtil/Statistics.cpp

@@ -251,11 +251,6 @@ void StatsVisitor::apply(osg::Geode& node)
     ++_numInstancedGeode;
     _geodeSet.insert(&node);
 
-    for(unsigned int i=0; i<node.getNumDrawables();++i)
-    {
-        apply(*node.getDrawable(i));
-    }
-
     traverse(node);
 }