//C++ header - Open Scene Graph - Copyright (C) 1998-2002 Robert Osfield
//Distributed under the terms of the GNU Library General Public License (LGPL)
//as published by the Free Software Foundation.

#ifndef OSG_COLLECTOCCLUDERSVISITOR
#define OSG_COLLECTOCCLUDERSVISITOR 1

#include <osg/NodeVisitor>
#include <osg/CullStack>

#include <set>

namespace osg {

class SG_EXPORT CollectOccludersVisitor : public osg::NodeVisitor, public osg::CullStack
{
    public:


        typedef std::set<ShadowVolumeOccluder> ShadowVolumeOccluderSet;

        CollectOccludersVisitor();
        virtual ~CollectOccludersVisitor();

        virtual CollectOccludersVisitor* cloneType() const { return new CollectOccludersVisitor(); }

        virtual void reset();

        virtual void apply(osg::Node&);
        virtual void apply(osg::Transform& node);
        virtual void apply(osg::Projection& node);

        virtual void apply(osg::Switch& node);
        virtual void apply(osg::LOD& node);
        virtual void apply(osg::OccluderNode& node);


        void setMinimumShadowOccluderVolume(float vol) { _minimumShadowOccluderVolume = vol; }
        float getMinimumShadowOccluderVolume() const { return _minimumShadowOccluderVolume; }

        void setCreateDrawablesOnOccludeNodes(bool flag) { _createDrawables=flag; }
        bool getCreateDrawablesOnOccludeNodes() const { return _createDrawables; }

        void setCollectedOcculderList(const ShadowVolumeOccluderSet& svol) { _occluderSet = svol; }
        ShadowVolumeOccluderSet& getCollectedOccluderSet() { return _occluderSet; }
        const ShadowVolumeOccluderSet& getCollectedOccluderSet() const { return _occluderSet; }

        /** remove occluded occluders for the collected occluders list.*/
        void removeOccludedOccluders();


    protected:

        /** prevent unwanted copy construction.*/
        CollectOccludersVisitor(const CollectOccludersVisitor&):osg::NodeVisitor(),osg::CullStack() {}

        /** prevent unwanted copy operator.*/
        CollectOccludersVisitor& operator = (const CollectOccludersVisitor&) { return *this; }
        
        inline void handle_cull_callbacks_and_traverse(osg::Node& node)
        {
            /*osg::NodeCallback* callback = node.getCullCallback();
            if (callback) (*callback)(&node,this);
            else*/ if (node.getNumChildrenWithOccluderNodes()>0) traverse(node);
        }

        inline void handle_cull_callbacks_and_accept(osg::Node& node,osg::Node* acceptNode)
        {
            /*osg::NodeCallback* callback = node.getCullCallback();
            if (callback) (*callback)(&node,this);
            else*/ if (node.getNumChildrenWithOccluderNodes()>0) acceptNode->accept(*this);
        }

        float                       _minimumShadowOccluderVolume;
        bool                        _createDrawables;
        ShadowVolumeOccluderSet     _occluderSet;

};

}

#endif