//C++ header - Open Scene Graph - Copyright (C) 1998-2001 Robert Osfield
//Distributed under the terms of the GNU Library General Public License (LGPL)
//as published by the Free Software Foundation.

#ifndef OSG_CullingSet
#define OSG_CullingSet 1

#include <osg/Polytope>
#include <osg/ShadowOccluderVolume>
#include <osg/Referenced>

namespace osg {

/** A CullingSet class which contains a frustum and a list of occluder. */
class SG_EXPORT CullingSet : public Referenced
{

    public:
    
    
        CullingSet();
        CullingSet(const CullingSet& cs,const osg::Matrix& matrix):
            _mask(cs._mask),
            _clippingVolume(cs._clippingVolume),
            _occluderList(cs._occluderList),
            _pixelSizeOffset(cs._pixelSizeOffset),
            _pixelSizeVector(cs._pixelSizeVector)
        {
            _clippingVolume.transformProvidingInverse(matrix);
            for(OccluderList::iterator itr=_occluderList.begin();
                itr!=_occluderList.end();
                ++itr)
            {
                itr->transformProvidingInverse(matrix);
            }
        }
        
        ~CullingSet();
    
        typedef std::vector<ShadowOccluderVolume>   OccluderList;

        typedef unsigned int Mask;

        enum MaskValues
        {
            VIEW_FRUSTUM_CULLING        = 0x1,
            SMALL_FEATURE_CULLING       = 0x2,
            SHADOW_OCCLUSION_CULLING    = 0x4,
            ALL_CULLING                 = 0xffffffff
        };
        
        void setCullingMask(Mask mask) { _mask = mask; }

        void setFrustum(Polytope& cv) { _clippingVolume = cv; }

        Polytope& getFrustum() { return _clippingVolume; }
        
        void addOccluder(ShadowOccluderVolume& cv) { _occluderList.push_back(cv); }

        inline bool isCulled(const BoundingBox& bb)
        {
            if (_mask&VIEW_FRUSTUM_CULLING)
            {
                // is it outside the view frustum...
                if (!_clippingVolume.contains(bb)) return true;
            }
            
            if (_mask&SMALL_FEATURE_CULLING)
            {
            }

            if (_mask&SHADOW_OCCLUSION_CULLING)
            {
                // is it in one of the shadow occluder volumes.
                if (!_occluderList.empty())
                {
                    for(OccluderList::iterator itr=_occluderList.begin();
                        itr!=_occluderList.end();
                        ++itr)
                    {
                        if (itr->contains(bb)) return true;
                    }
                }
            }
                        
            return false;
        }
        
        inline bool isCulled(const BoundingSphere& bs)
        {
            if (_mask&VIEW_FRUSTUM_CULLING)
            {
                // is it outside the view frustum...
                if (!_clippingVolume.contains(bs)) return true;
            }
            
            if (_mask&SMALL_FEATURE_CULLING)
            {
                if ((bs.center()*_pixelSizeVector+_pixelSizeOffset)>bs.radius()) return true;
            }

            if (_mask&SHADOW_OCCLUSION_CULLING)
            {
                // is it in one of the shadow occluder volumes.
                if (!_occluderList.empty())
                {
                    for(OccluderList::iterator itr=_occluderList.begin();
                        itr!=_occluderList.end();
                        ++itr)
                    {
                        if (itr->contains(bs)) return true;
                    }
                }
            }
            
            return false;
        }
        
        inline void pushCurrentMask()
        {
            _clippingVolume.pushCurrentMask();
            
            if (!_occluderList.empty())
            {
                for(OccluderList::iterator itr=_occluderList.begin();
                    itr!=_occluderList.end();
                    ++itr)
                {
                    itr->pushCurrentMask();
                }
            }
        }
        
        inline void popCurrentMask()
        {
            _clippingVolume.popCurrentMask();

            if (!_occluderList.empty())
            {
                for(OccluderList::iterator itr=_occluderList.begin();
                    itr!=_occluderList.end();
                    ++itr)
                {
                    itr->popCurrentMask();
                }
            }
        }
        
        
    protected:
    
        Mask _mask;

        Polytope  _clippingVolume;
        
        OccluderList    _occluderList;
        
        float           _pixelSizeOffset;
        Vec3            _pixelSizeVector;

};

}	// end of namespace

#endif