/* -*-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.
*/

#ifndef OSGSHADOW_SHADOWEMAP
#define OSGSHADOW_SHADOWEMAP 1

#include <osg/Camera>
#include <osg/Material>

#include <osgShadow/ShadowTechnique>

namespace osgShadow {

/** ShadowedTexture provides an implementation of shadow textures.*/
class OSGSHADOW_EXPORT ShadowMap : public ShadowTechnique
{
    public :
        ShadowMap();

        ShadowMap(const ShadowMap& es, const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);
            
        META_Object(osgShadow, ShadowMap);
        
        /** Set the texture unit that the shadow texture will be applied on.*/
        void setTextureUnit(unsigned int unit);

        /** Get the texture unit that the shadow texture will be applied on.*/
        unsigned int getTextureUnit() const { return _textureUnit; }

        /** Set the values for the ambient bias the shader will use.*/
        void setAmbientBias(const osg::Vec2& ambientBias );

        /** Get the values that are used for the ambient bias in the shader.*/
        const osg::Vec2& getAmbientBias() const { return _ambientBias; }
     
        /** initialize the ShadowedScene and local cached data structures.*/
        virtual void init();
        
        /** run the update traversal of the ShadowedScene and update any loca chached data structures.*/
        virtual void update(osg::NodeVisitor& nv);
        
        /** run the cull traversal of the ShadowedScene and set up the rendering for this ShadowTechnique.*/
        virtual void cull(osgUtil::CullVisitor& cv);
        
        /** Clean scene graph from any shadow technique specific nodes, state and drawables.*/
        virtual void cleanSceneGraph();
        

    protected :

        virtual ~ShadowMap() {}

        osg::ref_ptr<osg::Camera>       _camera;
        osg::ref_ptr<osg::TexGen>       _texgen;
        osg::ref_ptr<osg::Texture2D>    _texture;
        osg::ref_ptr<osg::StateSet>     _stateset;
        unsigned int                    _textureUnit;
        osg::Vec2                       _ambientBias;
        
};

}

#endif