/*
-----------------------------------------------------------------------------
This source file is part of OGRE
    (Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org/

Copyright © 2000-2002 The OGRE Team
Also see acknowledgements in Readme.html

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.

This program 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 GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA, or go to
http://www.gnu.org/copyleft/lesser.txt.
-----------------------------------------------------------------------------
*/
#ifndef __QUAKE3SHADERMANAGER_H__
#define __QUAKE3SHADERMANAGER_H__

#include "OgreBspPrerequisites.h"
#include "OgreSingleton.h"
#include "OgreResourceManager.h"
#include "OgreQuake3Shader.h"
#include "OgreBlendMode.h"

namespace Ogre {


    /** Class for managing Quake3 custom shaders.
        Quake3 uses .shader files to define custom shaders, or Materials in Ogre-speak.
        When a surface texture is mentioned in a level file, it includes no file extension
        meaning that it can either be a standard texture image (+lightmap) if there is only a .jpg or .tga
        file, or it may refer to a custom shader if a shader with that name is included in one of the .shader
        files in the scripts/ folder. Because there are multiple shaders per file you have to parse all the
        .shader files available to know if there is a custom shader available. This class is designed to parse
        all the .shader files available and save their settings for future use. </p>
        I choose not to set up Material instances for shaders found since they may or may not be used by a level,
        so it would be very wasteful to set up Materials since they load texture images for each layer (apart from the
        lightmap). Once the usage of a shader is confirmed, a full Material instance can be set up from it.</p>
        Because this is a subclass of ResourceManager, any files mentioned will be searched for in any path or
        archive added to the resource paths/archives. See ResourceManager for details.
    */
    class Quake3ShaderManager : public ResourceManager, public Singleton<Quake3ShaderManager>
    {
    protected:
        void parseNewShaderPass(DataChunk& chunk, Quake3Shader* pShader);
        void parseShaderAttrib( const String& line, Quake3Shader* pShader);
        void parseShaderPassAttrib( const String& line, Quake3Shader* pShader, Quake3Shader::Pass* pPass);
        SceneBlendFactor convertBlendFunc( const String& q3func);

    public:
        Quake3ShaderManager();
        virtual ~Quake3ShaderManager();

        /** Parses a shader file passed as a chunk. */
        void parseShaderFile(DataChunk& chunk);
        /** Parses all shader files in resource folders & archives. */
        void parseAllSources(const String& extension = ".shader");

        /** Create implementation required by ResourceManager. */
        virtual Resource* create( const String& name);

        /** Override standard Singleton retrieval.
        @remarks
        Why do we do this? Well, it's because the Singleton
        implementation is in a .h file, which means it gets compiled
        into anybody who includes it. This is needed for the
        Singleton template to work, but we actually only want it
        compiled into the implementation of the class based on the
        Singleton, not all of them. If we don't change this, we get
        link errors when trying to use the Singleton-based class from
        an outside dll.
        @par
        This method just delegates to the template version anyway,
        but the implementation stays in this single compilation unit,
        preventing link errors.
        */
        static Quake3ShaderManager& getSingleton(void);
        /** Override standard Singleton retrieval.
        @remarks
        Why do we do this? Well, it's because the Singleton
        implementation is in a .h file, which means it gets compiled
        into anybody who includes it. This is needed for the
        Singleton template to work, but we actually only want it
        compiled into the implementation of the class based on the
        Singleton, not all of them. If we don't change this, we get
        link errors when trying to use the Singleton-based class from
        an outside dll.
        @par
        This method just delegates to the template version anyway,
        but the implementation stays in this single compilation unit,
        preventing link errors.
        */
        static Quake3ShaderManager* getSingletonPtr(void);


    };

}

#endif
