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

Copyright (c) 2000-2009 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.
-----------------------------------------------------------------------------
*/

#include "OgreShaderHLSLProgramWriter.h"
#include "OgreStringConverter.h"
#include "OgreGpuProgramManager.h"

namespace Ogre {
namespace RTShader {

String HLSLProgramWriter::TargetLanguage = "hlsl";

//-----------------------------------------------------------------------
HLSLProgramWriter::HLSLProgramWriter()
{
	initializeStringMaps();
}

//-----------------------------------------------------------------------
HLSLProgramWriter::~HLSLProgramWriter()
{

}

//-----------------------------------------------------------------------
void HLSLProgramWriter::initializeStringMaps()
{
	mGpuConstTypeMap[GCT_FLOAT1] = "float";
	mGpuConstTypeMap[GCT_FLOAT2] = "float2";
	mGpuConstTypeMap[GCT_FLOAT3] = "float3";
	mGpuConstTypeMap[GCT_FLOAT4] = "float4";
	mGpuConstTypeMap[GCT_SAMPLER1D] = "sampler1D";
	mGpuConstTypeMap[GCT_SAMPLER2D] = "sampler2D";
	mGpuConstTypeMap[GCT_SAMPLER3D] = "sampler3D";
	mGpuConstTypeMap[GCT_SAMPLERCUBE] = "samplerCUBE";
	mGpuConstTypeMap[GCT_MATRIX_2X2] = "float2x2";
	mGpuConstTypeMap[GCT_MATRIX_2X3] = "float2x3";
	mGpuConstTypeMap[GCT_MATRIX_2X4] = "float2x4";
	mGpuConstTypeMap[GCT_MATRIX_3X2] = "float3x2";
	mGpuConstTypeMap[GCT_MATRIX_3X3] = "float3x3";
	mGpuConstTypeMap[GCT_MATRIX_3X4] = "float3x4";
	mGpuConstTypeMap[GCT_MATRIX_4X2] = "float4x2";
	mGpuConstTypeMap[GCT_MATRIX_4X3] = "float4x3";
	mGpuConstTypeMap[GCT_MATRIX_4X4] = "float4x4";
	mGpuConstTypeMap[GCT_INT1] = "int";
	mGpuConstTypeMap[GCT_INT2] = "int2";
	mGpuConstTypeMap[GCT_INT3] = "int3";
	mGpuConstTypeMap[GCT_INT4] = "int4";


	mParamSemanticMap[Parameter::SPS_POSITION] = "POSITION";
	mParamSemanticMap[Parameter::SPS_BLEND_WEIGHTS] = "BLENDWEIGHT";
	mParamSemanticMap[Parameter::SPS_BLEND_INDICES] = "BLENDINDICES";
	mParamSemanticMap[Parameter::SPS_NORMAL] = "NORMAL";
	mParamSemanticMap[Parameter::SPS_COLOR] = "COLOR";
	mParamSemanticMap[Parameter::SPS_TEXTURE_COORDINATES] = "TEXCOORD";
	mParamSemanticMap[Parameter::SPS_BINORMAL] = "BINORMAL";
	mParamSemanticMap[Parameter::SPS_TANGENT] = "TANGENT";
	mParamSemanticMap[Parameter::SPS_UNKNOWN] = "";
}

//-----------------------------------------------------------------------
void HLSLProgramWriter::writeSourceCode(std::ostream& os, Program* program)
{
	const ShaderFunctionList& functionList = program->getFunctions();
	ShaderFunctionConstIterator itFunction;

	const UniformParameterList& parameterList = program->getParameters();
	UniformParameterConstIterator itUniformParam = parameterList.begin();

	// Generate source code header.
	writeProgramTitle(os, program);
	os << std::endl;

	// Generate dependencies.
	writeProgramDependencies(os, program);
	os << std::endl;

	// Generate global variable code.
	writeUniformParametersTitle(os, program);
	os << std::endl;

	for (itUniformParam=parameterList.begin();  itUniformParam != parameterList.end(); ++itUniformParam)
	{
		writeUniformParameter(os, *itUniformParam);			
		os << ";" << std::endl;				
	}
	os << std::endl;

	// Write program function(s).
	for (itFunction=functionList.begin(); itFunction != functionList.end(); ++itFunction)
	{
		Function* curFunction = *itFunction;
		bool needToTranslateHlsl4Color = false;
		ParameterPtr colorParameter;

		writeFunctionTitle(os, curFunction);

		writeFunctionDeclaration(os, curFunction, needToTranslateHlsl4Color, colorParameter);

		os << "{" << std::endl;

		// Write local parameters.
		const ShaderParameterList& localParams = curFunction->getLocalParameters();
		ShaderParameterConstIterator itParam = localParams.begin();

		for (;  itParam != localParams.end(); ++itParam)
		{
			os << "\t";
			writeLocalParameter(os, *itParam);			
			os << ";" << std::endl;						
		}

		//  translate hlsl 4 color parameter if needed
		if(needToTranslateHlsl4Color)
		{
			os << "\t";
			writeLocalParameter(os, colorParameter);			
			os << ";" << std::endl;						
			os << std::endl <<"\tFFP_Assign(iHlsl4Color_0, " << colorParameter->getName() << ");" << std::endl;
		}

		// Sort and write function atoms.
		curFunction->sortAtomInstances();

		const FunctionAtomInstanceList& atomInstances = curFunction->getAtomInstances();
		FunctionAtomInstanceConstIterator itAtom;

		for (itAtom=atomInstances.begin(); itAtom != atomInstances.end(); ++itAtom)
		{			
			writeAtomInstance(os, *itAtom);
		}


		os << "}" << std::endl;
	}

	os << std::endl;
}


//-----------------------------------------------------------------------
void HLSLProgramWriter::writeProgramDependencies(std::ostream& os, Program* program)
{
	os << "//-----------------------------------------------------------------------------" << std::endl;
	os << "//                         PROGRAM DEPENDENCIES" << std::endl;
	os << "//-----------------------------------------------------------------------------" << std::endl;


	for (unsigned int i=0; i < program->getDependencyCount(); ++i)
	{
		const String& curDependency = program->getDependency(i);

		os << "#include " << '\"' << curDependency << "." << getTargetLanguage() << '\"' << std::endl;
	}
}

//-----------------------------------------------------------------------
void HLSLProgramWriter::writeUniformParameter(std::ostream& os, UniformParameterPtr parameter)
{
	os << mGpuConstTypeMap[parameter->getType()];
	os << "\t";	
	os << parameter->getName();	
	if (parameter->isArray() == true)
	{
		os << "[" << parameter->getSize() << "]";	
	}
	if (parameter->isSampler())
	{
		os << " : register(s" << parameter->getIndex() << ")";		
	}

}

//-----------------------------------------------------------------------
void HLSLProgramWriter::writeFunctionParameter(std::ostream& os, ParameterPtr parameter)
{

	os << mGpuConstTypeMap[parameter->getType()];
	
	os << "\t";	
	os << parameter->getName();	
	if (parameter->isArray() == true)
	{
		os << "[" << parameter->getSize() << "]";	
	}

	if (parameter->getSemantic() != Parameter::SPS_UNKNOWN)
	{
		os << " : ";
		
		os << mParamSemanticMap[parameter->getSemantic()];

		if (parameter->getSemantic() != Parameter::SPS_POSITION && 
			parameter->getSemantic() != Parameter::SPS_NORMAL &&
			parameter->getSemantic() != Parameter::SPS_BLEND_INDICES &&
			parameter->getSemantic() != Parameter::SPS_BLEND_WEIGHTS &&
			(!(parameter->getSemantic() == Parameter::SPS_COLOR && parameter->getIndex() == 0)) &&
			parameter->getIndex() >= 0)
		{			
			os << StringConverter::toString(parameter->getIndex()).c_str();
		}
	}
}

//-----------------------------------------------------------------------
void HLSLProgramWriter::writeLocalParameter(std::ostream& os, ParameterPtr parameter)
{
	os << mGpuConstTypeMap[parameter->getType()];
	os << "\t";	
	os << parameter->getName();		
	if (parameter->isArray() == true)
	{
		os << "[" << parameter->getSize() << "]";	
	}
}

//-----------------------------------------------------------------------
void HLSLProgramWriter::writeFunctionDeclaration(std::ostream& os, Function* function, bool & needToTranslateHlsl4Color, ParameterPtr & colorParameter)
{
	const ShaderParameterList& inParams  = function->getInputParameters();
	const ShaderParameterList& outParams = function->getOutputParameters();


	os << "void";
	os << " ";

	os << function->getName();
	os << std::endl << "\t(" << std::endl;

	ShaderParameterConstIterator it;
	size_t paramsCount = inParams.size() + outParams.size();
	size_t curParamIndex = 0;

	// for shader model 4 - we need to get the color as unsigned int
	bool isVs4 = GpuProgramManager::getSingleton().isSyntaxSupported("vs_4_0");

	// Write input parameters.
	for (it=inParams.begin(); it != inParams.end(); ++it)
	{					
		os << "\t in ";

		if (isVs4 &&
			function->getFunctionType() == Function::FFT_VS_MAIN &&
			(*it)->getSemantic() == Parameter::SPS_COLOR 
			)
		{
			os << "unsigned int iHlsl4Color_0 : COLOR";
			needToTranslateHlsl4Color = true;
			colorParameter = *it;
		}
		else
		{
			writeFunctionParameter(os, *it);
		}
		

		if (curParamIndex + 1 != paramsCount)		
			os << ", " << std::endl;

		curParamIndex++;
	}

	// Write output parameters.
	for (it=outParams.begin(); it != outParams.end(); ++it)
	{
		os << "\t out ";
		if (isVs4 && function->getFunctionType() == Function::FFT_PS_MAIN)
		{
			os << mGpuConstTypeMap[(*it)->getType()] << " " << (*it)->getName() << " : SV_Target" << std::endl;
		}
		else
		{
			writeFunctionParameter(os, *it);
		}

		if (curParamIndex + 1 != paramsCount)				
			os << ", " << std::endl;

		curParamIndex++;
	}	
	
	os << std::endl << "\t)" << std::endl;
}

//-----------------------------------------------------------------------
void HLSLProgramWriter::writeAtomInstance(std::ostream& os, FunctionAtom* atom)
{
	os << std::endl << "\t";
	atom->writeSourceCode(os, getTargetLanguage());
	os << std::endl;
}

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