OpenSceneGraph/include/osg/CullingSet

//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 Matrix& matrix, const Vec4& pixelSizeVector):
            _mask(cs._mask),
            _frustum(cs._frustum),
            _occluderList(cs._occluderList),
            _pixelSizeVector(pixelSizeVector),
            _smallFeatureCullingPixelSize(cs._smallFeatureCullingPixelSize)
        {
            _frustum.transformProvidingInverse(matrix);
            for(OccluderList::iterator itr=_occluderList.begin();
                itr!=_occluderList.end();
                ++itr)
            {
                itr->transformProvidingInverse(matrix);
            }
        }
        
        ~CullingSet();
    
        typedef std::vector<ShadowVolumeOccluder>   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) { _frustum = cv; }

        Polytope& getFrustum() { return _frustum; }
        const Polytope& getFrustum() const { return _frustum; }
        
        void addOccluder(ShadowVolumeOccluder& cv) { _occluderList.push_back(cv); }


        void setPixelSizeVector(const Vec4& v) { _pixelSizeVector = v; }

        Vec4& getPixelSizeVector() { return _pixelSizeVector; }
        const Vec4& getPixelSizeVector() const { return _pixelSizeVector; }

        void setSmallFeatureCullingPixelSize(float value) { _smallFeatureCullingPixelSize=value; }
        
        float& getSmallFeatureCullingPixelSize() { return _smallFeatureCullingPixelSize; }

        float getSmallFeatureCullingPixelSize() const { return _smallFeatureCullingPixelSize; }
    
    
        /** Compute the pixel of an object at position v, with specified radius.*/
        float pixelSize(const Vec3& v,float radius) const { return radius/(v*_pixelSizeVector); }

        /** Compute the pixel of an bounding sphere.*/
        float pixelSize(const BoundingSphere& bs) const { return bs.radius()/(bs.center()*_pixelSizeVector); }

        inline void disableOccluder(NodePath& nodePath)
        {
            for(OccluderList::iterator itr=_occluderList.begin();
                itr!=_occluderList.end();
                ++itr)
            {
                if (itr->getNodePath()==nodePath)
                {
                    // we have trapped for the case an occlude potentially occluding itself,
                    // to prevent this we disable the results mask so that no subsequnt 
                    // when the next pushCurrentMask calls happens this occluder is switched off.
                    itr->disableResultMasks();
                }
            }
        }


        inline bool isCulled(const BoundingBox& bb)
        {
            if (_mask&VIEW_FRUSTUM_CULLING)
            {
                // is it outside the view frustum...
                if (!_frustum.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 (!_frustum.contains(bs)) return true;
            }
            
            if (_mask&SMALL_FEATURE_CULLING)
            {
                if (((bs.center()*_pixelSizeVector)*_smallFeatureCullingPixelSize)>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()
        {
            _frustum.pushCurrentMask();
            
            if (!_occluderList.empty())
            {
                for(OccluderList::iterator itr=_occluderList.begin();
                    itr!=_occluderList.end();
                    ++itr)
                {
                    itr->pushCurrentMask();
                }
            }
        }
        
        inline void popCurrentMask()
        {
            _frustum.popCurrentMask();

            if (!_occluderList.empty())
            {
                for(OccluderList::iterator itr=_occluderList.begin();
                    itr!=_occluderList.end();
                    ++itr)
                {
                    itr->popCurrentMask();
                }
            }
        }
        
        
    protected:
    
        Mask            _mask;
        Polytope        _frustum;
        OccluderList    _occluderList;        
        Vec4            _pixelSizeVector;
        float           _smallFeatureCullingPixelSize;

};

}	// end of namespace

#endif