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

Copyright (c) 2000-2011 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 _ShaderProgramWriterGLSL_
#define _ShaderProgramWriterGLSL_

#include "OgreShaderProgramWriterManager.h"

namespace Ogre {
namespace RTShader {

/** \addtogroup Core
*  @{
*/
/** \addtogroup RTShader
*  @{
*/

/** GLSL target language writer implementation.
@see ProgramWriter.
*/
class _OgreRTSSExport GLSLProgramWriter : public ProgramWriter
{
	// Interface.
public:

	/** Class constructor. 
	@param language The target shader language.
	*/
	GLSLProgramWriter	();

	/** Class destructor */
	virtual ~GLSLProgramWriter	();


	/** 
	@see ProgramWriter::writeSourceCode.
	*/
	virtual void			writeSourceCode			(std::ostream& os, Program* program);

	/** 
	@see ProgramWriter::getTargetLanguage.
	*/
	virtual const String&  getTargetLanguage			() const { return TargetLanguage; }

	static String TargetLanguage;


	// Protected methods.
protected:

	/** Initialize string maps. */
	void				initializeStringMaps		();

	/** Write a local parameter. */
	void				writeLocalParameter			(std::ostream& os, ParameterPtr parameter);

	/** Write forward declarations. This is needed so that we can attach library shader at a later step. */
	void				writeForwardDeclarations	(std::ostream& os, Program* program);

	/** Write the input params of the function */
	void				writeInputParameters		(std::ostream& os, Function* function, GpuProgramType gpuType);
	
	/** Write the output params of the function */
	void				writeOutParameters			(std::ostream& os, Function* function, GpuProgramType gpuType);

protected:
	typedef		std::map<GpuConstantType, const char*>		GpuConstTypeToStringMap;
	typedef		std::map<Parameter::Semantic, const char*>	ParamSemanticToStringMap;
	typedef		std::map<Parameter::Content, const char*>	ParamContentToStringMap;
	typedef		std::map<String, String>					StringMap;

	// Attributes.
protected:
	GpuConstTypeToStringMap		mGpuConstTypeMap;				// Map between GPU constant type to string value.
	ParamSemanticToStringMap	mParamSemanticMap;				// Map between parameter semantic to string value.

	StringMap					mInputToGLStatesMap;			// Map parameter name to a new parameter name (sometime renaming is required to match names between vertex and fragment shader)
	ParamContentToStringMap		mContentToPerVertexAttributes;	// Map parameter content to vertex attributes 
	int							mGLSLVersion;					// Holds the current glsl version
	StringVector				mFragInputParams;				// Holds the fragment input params 
};

/** GLSL program writer factory implementation.
@see ProgramWriterFactory
*/
class _OgreRTSSExport ShaderProgramWriterGLSLFactory : public ProgramWriterFactory
{
public:
	ShaderProgramWriterGLSLFactory()
	{
		mLanguage = "glsl";
	}
	virtual ~ShaderProgramWriterGLSLFactory() {}

	/** 
	@see ProgramWriterFactory::getTargetLanguage
	*/
	virtual const String& getTargetLanguage(void) const
	{
		return mLanguage;
	}

	/** 
	@see ProgramWriterFactory::create
	*/
	virtual ProgramWriter* create(void)
	{
		return OGRE_NEW GLSLProgramWriter();
	}

private:
	String mLanguage;

};

/** @} */
/** @} */

}
}

#endif
