/* -*-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 OSG_ArrayDispatchers
#define OSG_ArrayDispatchers 1

#include <osg/ref_ptr>
#include <osg/Array>
#include <osg/Matrixd>

namespace osg {

// forward declare
class State;
class GLBeginEndAdapter;
class AttributeDispatchMap;

struct AttributeDispatch : public osg::Referenced
{
    virtual void assign(const GLvoid*, const IndexArray*) {}
    virtual void operator() (unsigned int) {};
};

/** Helper class for managing the dispatch to OpenGL of various attribute arrays such as stored in osg::Geometry.*/
class OSG_EXPORT ArrayDispatchers : public osg::Referenced
{
    public:

        ArrayDispatchers(osg::State& state);
        ~ArrayDispatchers();

        void assignTexCoordDispatchers(unsigned int unit);
        void assignVertexAttribDispatchers(unsigned int unit);

        AttributeDispatch* vertexDispatcher(Array* array, IndexArray* indices);
        AttributeDispatch* normalDispatcher(Array* array, IndexArray* indices);
        AttributeDispatch* colorDispatcher(Array* array, IndexArray* indices);
        AttributeDispatch* secondaryColorDispatcher(Array* array, IndexArray* indices);
        AttributeDispatch* fogCoordDispatcher(Array* array, IndexArray* indices);
        AttributeDispatch* texCoordDispatcher(unsigned int unit, Array* array, IndexArray* indices);
        AttributeDispatch* vertexAttribDispatcher(unsigned int unit, Array* array, IndexArray* indices);

        void reset();

        void setUseGLBeginEndAdapter(bool flag) { _useGLBeginEndAdapter = flag; }
        bool getUseGLBeginEndAdapter() const { return _useGLBeginEndAdapter; }

        void activate(unsigned int binding, AttributeDispatch* at);

        void activateVertexArray(unsigned int binding, osg::Array* array, osg::IndexArray* indices) { activate(binding, vertexDispatcher(array, indices)); }
        void activateColorArray(unsigned int binding, osg::Array* array, osg::IndexArray* indices) { activate(binding, colorDispatcher(array, indices)); }
        void activateNormalArray(unsigned int binding, osg::Array* array, osg::IndexArray* indices) { activate(binding, normalDispatcher(array, indices)); }
        void activateSecondaryColorArray(unsigned int binding, osg::Array* array, osg::IndexArray* indices) { activate(binding, secondaryColorDispatcher(array, indices)); }
        void activateFogCoordArray(unsigned int binding, osg::Array* array, osg::IndexArray* indices) { activate(binding, fogCoordDispatcher(array, indices)); }
        void activateTexCoordArray(unsigned int binding, unsigned int unit, osg::Array* array, osg::IndexArray* indices) { activate(binding, texCoordDispatcher(unit, array, indices)); }
        void activateVertexAttribArray(unsigned int binding, unsigned int unit, osg::Array* array, osg::IndexArray* indices) { activate(binding, vertexAttribDispatcher(unit, array, indices)); }

        void dispatch(unsigned int binding);
        void dispatch(unsigned int binding, unsigned int index);

        void Begin(GLenum mode);
        void End();

    protected:

        State*                _state;
        GLBeginEndAdapter*    _glBeginEndAdapter;

        AttributeDispatchMap* _vertexDispatchers;
        AttributeDispatchMap* _normalDispatchers;
        AttributeDispatchMap* _colorDispatchers;
        AttributeDispatchMap* _secondaryColorDispatchers;
        AttributeDispatchMap* _fogCoordDispatchers;

        typedef std::vector<AttributeDispatchMap*> AttributeDispatchMapList;
        AttributeDispatchMapList _texCoordDispatchers;
        AttributeDispatchMapList _vertexAttribDispatchers;

        typedef std::vector<AttributeDispatch*> AttributeDispatchList;

        struct BindingGroup
        {
            unsigned int          _index;
            AttributeDispatchList _attributeDispatchList;
        };

        typedef std::vector<BindingGroup> BindingGroupList;
        BindingGroupList    _bindingGroupList;

        bool                _useGLBeginEndAdapter;
};


}

#endif