//********************************** Banshee Engine (www.banshee3d.com) **************************************************//
//**************** Copyright (c) 2016 Marko Pintera (marko.pintera@gmail.com). All rights reserved. **********************//
#pragma once

#include "BsD3D11Prerequisites.h"
#include "RenderAPI/BsVertexDeclaration.h"

namespace bs { namespace ct
{
	/** @addtogroup D3D11
	 *  @{
	 */

	/**	Handles parsing of GPU program microcode and extracting constant and input parameter data. */
	class D3D11HLSLParamParser
	{
	public:
		/**
		 * Parses the provided microcode and outputs constant parameter descriptions, and optionally for vertex GPU programs
		 * a set of input parameters.
		 *
		 * @param[in]	microcode	Compiled GPU program microcode to parse.
		 * @param[in]	type		Type of the GPU program.
		 * @param[out]	desc		Output object that will contain parameter descriptions.
		 * @param[out]	inputParams	Output object that will contain a set of program input parameters. Can be null if not 
		 *							required. Only relevant for vertex programs.
		 */
		void parse(ID3DBlob* microcode, GpuProgramType type, GpuParamDesc& desc, List<VertexElement>* inputParams);

	private:
		/** Types of HLSL parameters. */
		enum class ParamType
		{
			ConstantBuffer,
			Texture,
			Sampler,
			UAV,
			Count // Keep at end
		};

		/**
		 * Parses the provided constant buffer retrieving information about all of its members and storing them in the
		 * provided GPU params description object.
		 */
		void parseBuffer(ID3D11ShaderReflectionConstantBuffer* bufferReflection, GpuParamDesc& desc);

		/**	Parses the resource description structure and stores it in the provided GPU params description object. */
		void parseResource(D3D11_SHADER_INPUT_BIND_DESC& resourceDesc, GpuProgramType type, GpuParamDesc& desc);

		/**
		 * Parses a variable with the specified type and variable description. Adds the variable in the provided GPU params
		 * description object and assigns it to the provided param block.
		 */
		void parseVariable(D3D11_SHADER_TYPE_DESC& varTypeDesc, D3D11_SHADER_VARIABLE_DESC& varDesc, GpuParamDesc& desc,
			GpuParamBlockDesc& paramBlock);

		/** Maps a parameter in a specific shader stage, of a specific type to a unique set index. */
		static UINT32 mapParameterToSet(GpuProgramType progType, ParamType paramType);
	};

	/** @} */
}}