/*
 -----------------------------------------------------------------------------
 This source file is part of OGRE
 (Object-oriented Graphics Rendering Engine)
 For the latest info, see http://www.ogre3d.org/
 
 Copyright (c) 2000-2014 Torus Knot Software Ltd
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:
 
 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.
 
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 -----------------------------------------------------------------------------
 */
#ifndef __GLSLESProgramPipelineManager_H__
#define __GLSLESProgramPipelineManager_H__

#include "OgreGLES2Prerequisites.h"
#include "OgreSingleton.h"
#include "OgreGLSLESProgramPipeline.h"
#include "OgreGLSLESProgramManagerCommon.h"

namespace Ogre
{
    /** Ogre assumes that there are separate vertex and fragment
     programs to deal with but GLSL ES has one program pipeline object
     that represents the active vertex and fragment program objects
     during a rendering state.  GLSL vertex and fragment program
     objects are compiled separately and then attached to a program
     object and then the program pipeline object is linked. Since
     Ogre can only handle one vertex program stage and one fragment
     program stage being active in a pass, the GLSL ES Program
     Pipeline Manager does the same.  The GLSL ES Program Pipeline
     Manager acts as a state machine and activates a pipeline
     object based on the active vertex and fragment program.
     Previously created pipeline objects are stored along with a
     unique key in a hash map for quick retrieval the next time the
     pipeline object is required.
     */
    class _OgreGLES2Export GLSLESProgramPipelineManager : public GLSLESProgramManagerCommon, public Singleton<GLSLESProgramPipelineManager>
    {
    private:

        typedef map<uint64, GLSLESProgramPipeline*>::type ProgramPipelineMap;
        typedef ProgramPipelineMap::iterator ProgramPipelineIterator;

        /// Container holding previously created program pipeline objects 
        ProgramPipelineMap mProgramPipelines;

        /// Active objects defining the active rendering gpu state
        GLSLESProgramPipeline* mActiveProgramPipeline;

    public:

        GLSLESProgramPipelineManager(void);
        ~GLSLESProgramPipelineManager(void);

        /** Get the program pipeline that combines the current program
            objects. If the program pipeline object was not already
            created a new one is created.
         */
        GLSLESProgramPipeline* getActiveProgramPipeline(void);

        /** Set the active vertex and fragment link programs for the next rendering state.
         The active program pipeline object will be cleared.
         Normally called from the GLSLESShader::bindProgram and
         unbindProgram methods.
         */
        void setActiveVertexShader(GLSLESShader* vertexShader);
        void setActiveFragmentShader(GLSLESShader* fragmentShader);

        static GLSLESProgramPipelineManager& getSingleton(void);
        static GLSLESProgramPipelineManager* getSingletonPtr(void);
    };
}

#endif
