/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield 
 *
 * This library is open source and may be redistributed and/or modified under  
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 * OpenSceneGraph Public License for more details.
 *
 * ViewDependentShadow codes Copyright (C) 2008 Wojciech Lewandowski
 * Thanks to to my company http://www.ai.com.pl for allowing me free this work.
*/


#ifndef OSGSHADOW_TRAPEZOIDALSHADOWMAP
#define OSGSHADOW_TRAPEZOIDALSHADOWMAP 1

#include <osgShadow/MinimalCullBoundsShadowMap>
#include <osgShadow/MinimalDrawBoundsShadowMap>
#include <osgShadow/ProjectionShadowMap>

namespace osgShadow {

// Class implements
// "Anti-aliasing and Continuity with Trapezoidal Shadow Maps"
// Tobias Martin (tobiasmartin@t-online.de) and Tiow-Seng Tan (tants@comp.nus.edu.sg)
// School of Computing, National University of Singapore
// http://www.comp.nus.edu.sg/~tants/tsm.html

struct TrapezoidalMapping;

class OSGSHADOW_EXPORT TrapezoidalShadowMapAlgorithm 
{
    public:
        TrapezoidalShadowMapAlgorithm();
        ~TrapezoidalShadowMapAlgorithm();

        void operator() (
            const osgShadow::ConvexPolyhedron* hullShadowedView,
            const osg::Camera* cameraMain, 
            osg::Camera* cameraShadow ) const;

    protected:
        TrapezoidalMapping * tm;
};

// Optimized for draw traversal shadow bounds 
class OSGSHADOW_EXPORT TrapezoidalShadowMapDB: public ProjectionShadowMap< MinimalDrawBoundsShadowMap, TrapezoidalShadowMapAlgorithm >
{
    public:
        /** Convenient typedef used in definition of ViewData struct and methods */
        typedef ProjectionShadowMap< MinimalDrawBoundsShadowMap, TrapezoidalShadowMapAlgorithm > BaseClass;

        /** Classic OSG constructor */
        TrapezoidalShadowMapDB()
        {
        }

        /** Classic OSG cloning constructor */
        TrapezoidalShadowMapDB(
            const TrapezoidalShadowMapDB& copy, 
            const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY) : BaseClass(copy,copyop)
        {
        }

        /** Declaration of standard OSG object methods */
        META_Object( osgShadow, TrapezoidalShadowMapDB );
};

// Optimized for cull traversal shadow bounds 
class OSGSHADOW_EXPORT TrapezoidalShadowMapCB: public ProjectionShadowMap< MinimalCullBoundsShadowMap, TrapezoidalShadowMapAlgorithm >
{
    public:
        /** Convenient typedef used in definition of ViewData struct and methods */
        typedef ProjectionShadowMap< MinimalCullBoundsShadowMap, TrapezoidalShadowMapAlgorithm > BaseClass;

        /** Classic OSG constructor */                
        TrapezoidalShadowMapCB()
        {
        }

        /** Classic OSG cloning constructor */
        TrapezoidalShadowMapCB(
            const TrapezoidalShadowMapCB& copy, 
            const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY) : BaseClass(copy,copyop)
        {
        }

        /** Declaration of standard OSG object methods */
        META_Object( osgShadow, TrapezoidalShadowMapCB );
};

// Optimized for view frustum bounds 
class OSGSHADOW_EXPORT TrapezoidalShadowMapVB: public ProjectionShadowMap< MinimalShadowMap, TrapezoidalShadowMapAlgorithm >
{
    public:
        /** Convenient typedef used in definition of ViewData struct and methods */
        typedef ProjectionShadowMap< MinimalShadowMap, TrapezoidalShadowMapAlgorithm > BaseClass;

        /** Classic OSG constructor */
        TrapezoidalShadowMapVB()
        {
        }

        /** Classic OSG cloning constructor */
        TrapezoidalShadowMapVB(
            const TrapezoidalShadowMapVB& copy, 
            const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY) : BaseClass(copy,copyop)
        {
        }

        /** Declaration of standard OSG object methods */
        META_Object( osgShadow, TrapezoidalShadowMapVB );
};

typedef TrapezoidalShadowMapDB TrapezoidalShadowMap;

} // namespace osgShadow

#endif