// Copyright (C) 2002-2009 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h

#ifndef __I_GPU_PROGRAMMING_SERVICES_H_INCLUDED__
#define __I_GPU_PROGRAMMING_SERVICES_H_INCLUDED__

#include "IReferenceCounted.h"
#include "SMaterial.h"

namespace irr
{

namespace io
{
	class IReadFile;
} // end namespace io

namespace video
{

class IVideoDriver;
class IShaderConstantSetCallBack;

//! Compile target enumeration for the addHighLevelShaderMaterial() method.
enum E_VERTEX_SHADER_TYPE
{
	EVST_VS_1_1 = 0,
	EVST_VS_2_0,
	EVST_VS_2_a,
	EVST_VS_3_0,

	//! This is not a type, but a value indicating how much types there are.
	EVST_COUNT
};

//! Names for all vertex shader types, each entry corresponds to a E_VERTEX_SHADER_TYPE entry.
const c8* const VERTEX_SHADER_TYPE_NAMES[] = {
	"vs_1_1",
	"vs_2_0",
	"vs_2_a",
	"vs_3_0",
	0 };

//! Compile target enumeration for the addHighLevelShaderMaterial() method.
enum E_PIXEL_SHADER_TYPE
{
	EPST_PS_1_1 = 0,
	EPST_PS_1_2,
	EPST_PS_1_3,
	EPST_PS_1_4,
	EPST_PS_2_0,
	EPST_PS_2_a,
	EPST_PS_2_b,
	EPST_PS_3_0,

	//! This is not a type, but a value indicating how much types there are.
	EPST_COUNT
};

//! Names for all pixel shader types, each entry corresponds to a E_PIXEL_SHADER_TYPE entry.
const c8* const PIXEL_SHADER_TYPE_NAMES[] = {
	"ps_1_1",
	"ps_1_2",
	"ps_1_3",
	"ps_1_4",
	"ps_2_0",
	"ps_2_a",
	"ps_2_b",
	"ps_3_0",
	0 };

//! Interface making it possible to create and use programs running on the GPU.
class IGPUProgrammingServices
{
public:

	//! Destructor
	virtual ~IGPUProgrammingServices() {}

	//! Adds a new high-level shading material renderer to the VideoDriver.
	/** Currently only HLSL/D3D9 and GLSL/OpenGL are supported.
	\param vertexShaderProgram: String containing the source of the vertex
	shader program. This can be 0 if no vertex program shall be used.
	\param vertexShaderEntryPointName: Name of the entry function of the
	vertexShaderProgram
	\param vsCompileTarget: Vertex shader version where the high level
	shader shall be compiled to.
	\param pixelShaderProgram: String containing the source of the pixel
	shader program. This can be 0 if no pixel shader shall be used.
	\param pixelShaderEntryPointName: Entry name of the function of the
	pixelShaderEntryPointName
	\param psCompileTarget: Pixel shader version where the high level
	shader shall be compiled to.
	\param callback: Pointer to an implementation of
	IShaderConstantSetCallBack in which you can set the needed vertex and
	pixel shader program constants. Set this to 0 if you don't need this.
	\param baseMaterial: Base material which renderstates will be used to
	shade the material.
	\param userData: a user data int. This int can be set to any value and
	will be set as parameter in the callback method when calling
	OnSetConstants(). In this way it is easily possible to use the same
	callback method for multiple materials and distinguish between them
	during the call.
	\return Returns the number of the material type which can be set in
	SMaterial::MaterialType to use the renderer. -1 is returned if an
	error occured, e.g. if a vertex or pixel shader program could not be
	compiled or a compile target is not reachable. The error strings are
	then printed to the error log and can be catched with a custom event
	receiver. */
	virtual s32 addHighLevelShaderMaterial(
		const c8* vertexShaderProgram,
		const c8* vertexShaderEntryPointName = "main",
		E_VERTEX_SHADER_TYPE vsCompileTarget = EVST_VS_1_1,
		const c8* pixelShaderProgram = 0,
		const c8* pixelShaderEntryPointName = "main",
		E_PIXEL_SHADER_TYPE psCompileTarget = EPST_PS_1_1,
		IShaderConstantSetCallBack* callback = 0,
		E_MATERIAL_TYPE baseMaterial = video::EMT_SOLID,
		s32 userData = 0 ) = 0;

	//! Like IGPUProgrammingServices::addShaderMaterial(), but loads from files.
	/** \param vertexShaderProgram: Text file containing the source of the
	 * vertex shader program.
	Set to 0 if no shader shall be created.
	\param vertexShaderEntryPointName: Name of the entry function of the
	vertexShaderProgram
	\param vsCompileTarget: Vertex shader version where the high level
	shader shall be compiled to.
	\param pixelShaderProgram: Text file containing the source of the pixel
	shader program. Set to 0 if no shader shall be created.
	\param vertexShaderEntryPointName: Name of the entry function of the
	vertexShaderProgram
	\param vsCompileTarget: Vertex shader version where the high level
	shader shall be compiled to.
	\param pixelShaderProgram: String containing the source of the pixel
	shader program. This can be 0 if no pixel shader shall be used.
	\param pixelShaderEntryPointName: Entry name of the function of the
	pixelShaderEntryPointName
	\param psCompileTarget: Pixel shader version where the high level
	shader shall be compiled to.
	\param callback: Pointer to an implementation of
	IShaderConstantSetCallBack in which you can set the needed vertex and
	pixel shader program constants. Set this to 0 if you don't need this.
	\param baseMaterial: Base material which renderstates will be used to
	shade the material.
	\param userData: a user data int. This int can be set to any value and
	will be set as parameter in the callback method when calling
	OnSetConstants(). In this way it is easily possible to use the same
	callback method for multiple materials and distinguish between them
	during the call.
	\return Returns the number of the material type which can be set in
	SMaterial::MaterialType to use the renderer. -1 is returned if an
	error occured, e.g. if a vertex or pixel shader program could not be
	compiled or a compile target is not reachable. The error strings are
	then printed to the error log and can be catched with a custom event
	receiver. */
	virtual s32 addHighLevelShaderMaterialFromFiles(
		const core::string<c16>& vertexShaderProgramFileName,
		const c8* vertexShaderEntryPointName = "main",
		E_VERTEX_SHADER_TYPE vsCompileTarget = EVST_VS_1_1,
		const core::string<c16>& pixelShaderProgramFileName = "",
		const c8* pixelShaderEntryPointName = "main",
		E_PIXEL_SHADER_TYPE psCompileTarget = EPST_PS_1_1,
		IShaderConstantSetCallBack* callback = 0,
		E_MATERIAL_TYPE baseMaterial = video::EMT_SOLID,
		s32 userData = 0) = 0;


	//! Like IGPUProgrammingServices::addShaderMaterial(), but loads from files.
	/** \param vertexShaderProgram: Text file handle containing the source
	 * of the vertex shader program.
	Set to 0 if no shader shall be created.
	\param vertexShaderEntryPointName: Name of the entry function of the
	vertexShaderProgram
	\param vsCompileTarget: Vertex shader version where the high level
	shader shall be compiled to.
	\param pixelShaderProgram: Text file containing the source of the pixel
	shader program. Set to
	\param pixelShaderProgram: Text file handle containing the source of
	the pixel shader program. Set to 0 if no shader shall be created.
	\param pixelShaderEntryPointName: Entry name of the function of the
	pixelShaderEntryPointName
	\param psCompileTarget: Pixel shader version where the high level
	shader shall be compiled to.
	\param callback: Pointer to an implementation of
	IShaderConstantSetCallBack in which you can set the needed vertex and
	pixel shader program constants. Set this to 0 if you don't need this.
	\param baseMaterial: Base material which renderstates will be used to
	shade the material.
	\param userData: a user data int. This int can be set to any value and
	will be set as parameter in the callback method when calling
	OnSetConstants(). In this way it is easily possible to use the same
	callback method for multiple materials and distinguish between them
	during the call.
	\return Returns the number of the material type which can be set in
	SMaterial::MaterialType to use the renderer. -1 is returned if an
	error occured, e.g. if a vertex or pixel shader program could not be
	compiled or a compile target is not reachable. The error strings are
	then printed to the error log and can be catched with a custom event
	receiver. */
	virtual s32 addHighLevelShaderMaterialFromFiles(
		io::IReadFile* vertexShaderProgram,
		const c8* vertexShaderEntryPointName = "main",
		E_VERTEX_SHADER_TYPE vsCompileTarget = EVST_VS_1_1,
		io::IReadFile* pixelShaderProgram = 0,
		const c8* pixelShaderEntryPointName = "main",
		E_PIXEL_SHADER_TYPE psCompileTarget = EPST_PS_1_1,
		IShaderConstantSetCallBack* callback = 0,
		E_MATERIAL_TYPE baseMaterial = video::EMT_SOLID,
		s32 userData = 0) = 0;

	//! Adds a new ASM shader material renderer to the VideoDriver
	/** Note that it is a good idea to call IVideoDriver::queryFeature() in
	advance to check if the IVideoDriver supports the vertex and/or pixel
	shader version your are using.

	The material is added to the VideoDriver like with
	IVideoDriver::addMaterialRenderer() and can be used like it had been
	added with that method.
	\param vertexShaderProgram: String containing the source of the vertex
	shader program. This can be 0 if no vertex program shall be used.

	For DX8 programs, the will always input registers look like this: v0:
	position, v1: normal, v2: color, v3: texture cooridnates, v4: texture
	coordinates 2 if available.

	For DX9 programs, you can manually set the registers using the dcl_
	statements.
	\param pixelShaderProgram: String containing the source of the pixel
	shader program. This can be 0 if you don't want to use a pixel shader.
	\param callback: Pointer to an implementation of
	IShaderConstantSetCallBack in which you can set the needed vertex and
	pixel shader program constants. Set this to 0 if you don't need this.
	\param baseMaterial: Base material which renderstates will be used to
	shade the material.
	\param userData: a user data int. This int can be set to any value and
	will be set as parameter in the callback method when calling
	OnSetConstants(). In this way it is easily possible to use the same
	callback method for multiple materials and distinguish between them
	during the call.
	\return Returns the number of the material type which can be set in
	SMaterial::MaterialType to use the renderer. -1 is returned if an
	error occured. -1 is returned for example if a vertex or pixel shader
	program could not be compiled, the error strings are then printed out
	into the error log, and can be catched with a custom event receiver. */
	virtual s32 addShaderMaterial(const c8* vertexShaderProgram = 0,
		const c8* pixelShaderProgram = 0,
		IShaderConstantSetCallBack* callback = 0,
		E_MATERIAL_TYPE baseMaterial = video::EMT_SOLID,
		s32 userData = 0) = 0;

	//! Like IGPUProgrammingServices::addShaderMaterial(), but loads from files.
	/** \param vertexShaderProgram: Text file containing the source of the
	vertex shader program. Set to 0 if no shader shall be created.
	\param pixelShaderProgram: Text file containing the source of the pixel
	shader program. Set to 0 if no shader shall be created.
	\param callback: Pointer to an IShaderConstantSetCallback object to
	which the OnSetConstants function is called.
	\param baseMaterial: baseMaterial
	\param userData: a user data int. This int can be set to any value and
	will be set as parameter in the callback method when calling
	OnSetConstants(). In this way it is easily possible to use the same
	callback method for multiple materials and distinguish between them
	during the call.
	\return Returns the number of the material type which can be set in
	SMaterial::MaterialType to use the renderer. -1 is returned if an
	error occured. -1 is returned for example if a vertex or pixel shader
	program could not be compiled, the error strings are then printed out
	into the error log, and can be catched with a custom event receiver. */
	virtual s32 addShaderMaterialFromFiles(io::IReadFile* vertexShaderProgram,
		io::IReadFile* pixelShaderProgram,
		IShaderConstantSetCallBack* callback = 0,
		E_MATERIAL_TYPE baseMaterial = video::EMT_SOLID,
		s32 userData = 0) = 0;

	//! Like IGPUProgrammingServices::addShaderMaterial(), but loads from files.
	/** \param vertexShaderProgramFileName: Text file name containing the
	source of the vertex shader program. Set to 0 if no shader shall be
	created.
	\param pixelShaderProgramFileName: Text file name containing the source
	of the pixel shader program. Set to 0 if no shader shall be created.
	\param callback: Pointer to an IShaderConstantSetCallback object on
	which the OnSetConstants function is called.
	\param baseMaterial: baseMaterial
	\param userData: a user data int. This int can be set to any value and
	will be set as parameter in the callback method when calling
	OnSetConstants(). In this way it is easily possible to use the same
	callback method for multiple materials and distinguish between them
	during the call.
	\return Returns the number of the material type which can be set in
	SMaterial::MaterialType to use the renderer. -1 is returned if an
	error occured. -1 is returned for example if a vertex or pixel shader
	program could not be compiled, the error strings are then printed out
	into the error log, and can be catched with a custom event receiver. */
	virtual s32 addShaderMaterialFromFiles(const core::string<c16>& vertexShaderProgramFileName,
		const core::string<c16>& pixelShaderProgramFileName,
		IShaderConstantSetCallBack* callback = 0,
		E_MATERIAL_TYPE baseMaterial = video::EMT_SOLID,
		s32 userData = 0) = 0;
};


} // end namespace video
} // end namespace irr

#endif