/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2004 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_SHADERATTRIBUTE
#define OSG_SHADERATTRIBUTE 1

#include <osg/StateAttribute>
#include <osg/Shader>
#include <osg/Uniform>

namespace osg {

class OSG_EXPORT ShaderAttribute : public StateAttribute
{
    public :

        ShaderAttribute();

        /** Copy constructor using CopyOp to manage deep vs shallow copy. */
        ShaderAttribute(const ShaderAttribute& sa,const CopyOp& copyop=CopyOp::SHALLOW_COPY);

        META_Object(osg, ShaderAttribute);

        /** return -1 if *this < *rhs, 0 if *this==*rhs, 1 if *this>*rhs. */
        virtual int compare(const StateAttribute& sa) const;


        void setType(Type type);
        virtual Type getType() const { return _type; }

        unsigned int addShader(Shader* shader);
        void removeShader(unsigned int i);
        unsigned int getNumShaders() const { return _shaders.size(); }
        Shader* getShader(unsigned int i) { return _shaders[i].get(); }
        Shader* getShader(unsigned int i) const { return _shaders[i].get(); }


        unsigned int addUniform(Uniform* uniform);
        void removeUniform(unsigned int i);
        unsigned int getNumUniforms() const { return _uniforms.size(); }
        Uniform* getUniform(unsigned int i) { return _uniforms[i].get(); }
        const Uniform* getUniform(unsigned int i) const { return _uniforms[i].get(); }


        virtual bool getModeUsage(StateAttribute::ModeUsage& usage) const;

        virtual void apply(State& state) const;

        virtual void compose(ShaderComposer& composer) const;

        virtual void compileGLObjects(State& state) const;

        virtual void resizeGLObjectBuffers(unsigned int maxSize);

        virtual void releaseGLObjects(State* state=0) const;

    protected :

        virtual ~ShaderAttribute();

        typedef std::vector< osg::ref_ptr<osg::Shader> > Shaders;
        typedef std::vector< osg::ref_ptr<osg::Uniform> > Uniforms;

        Type _type;
        Shaders _shaders;
        Uniforms _uniforms;

};

}

#endif