//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 OSGUTIL_CULLVIEWSTATE
#define OSGUTIL_CULLVIEWSTATE 1

#include <osg/BoundingSphere>
#include <osg/BoundingBox>
#include <osg/Matrix>
#include <osg/ClippingVolume>

#include <osgUtil/Export>

namespace osgUtil {

/** Container class for encapsulating the viewing state in local
    coordinates, during the cull traversal.
*/
class OSGUTIL_EXPORT CullViewState : public osg::Referenced
{
    public:

        CullViewState();

        osg::ref_ptr<osg::Matrix> _matrix;
        osg::ref_ptr<osg::Matrix> _inverse;
        osg::Vec3    _eyePoint;
        osg::Vec3    _centerPoint;
        osg::Vec3    _lookVector;
        osg::Vec3    _upVector;
	unsigned int _bbCornerFar;
	unsigned int _bbCornerNear;
        float        _ratio2;

        osg::ClippingVolume _clippingVolume;


        enum 
        {
            NO_CULLING                  = 0x00,
            FRUSTUM_LEFT_CULLING        = 0x01,
            FRUSTUM_RIGHT_CULLING       = 0x02,
            FRUSTUM_BOTTOM_CULLING      = 0x04,
            FRUSTUM_TOP_CULLING         = 0x08,
            FRUSTUM_NEAR_CULLING        = 0x10,
            FRUSTUM_FAR_CULLING         = 0x20,
            VIEW_FRUSTUM_CULLING        = 0x3F,
            SMALL_FEATURE_CULLING       = 0x40,
            ENALBE_ALL_CULLING          = 0x7F
        };
        
        typedef unsigned int CullingMode;

        inline bool isCulled(const osg::BoundingSphere& sp,CullingMode& mode) const
        {
            if (!sp.isValid()) return true;

            if (!_clippingVolume.contains(sp,mode)) return true;

            if (mode&SMALL_FEATURE_CULLING)
            {
                osg::Vec3 delta(sp._center-_eyePoint);
                if (sp.radius2()<delta.length2()*_ratio2)
                {
                    return true;
                }
            }
            return false;
        }
        
        inline bool isCulled(const osg::BoundingBox& bb,CullingMode mode) const
        {
            if (!bb.isValid()) return true;

            return !_clippingVolume.contains(bb,mode);
        }

    protected:

        ~CullViewState();

};


};

#endif