// Copyright (C) 2002-2006 Nikolaus Gebhardt
// This file is part of the LTE 3D Engine
// (C) 2006 - LTE Studios - by SiberianSTAR
// LTE 3D Engine is based on Irrlicht 1.0
// For conditions of distribution and use, see copyright notice in engine.h

#ifndef __S_MATERIAL_H_INCLUDED__
#define __S_MATERIAL_H_INCLUDED__

#include "SColor.h"
#include "ITexture.h"

namespace engine
{
namespace video
{
	//! Abstracted and easy to use fixed function/programmable pipeline material modes.
	enum E_MATERIAL_TYPE
	{
		//! Standard solid material. Only first texture is used, which is
		//! supposed to be the diffuse material.
		EMT_SOLID = 0,			

		//! Solid material with 2 texture layers. The second is blended onto the
		//! first using the alpha value of the vertex colors.
		//! This material is currently not implemented in OpenGL, but it
		//! works with DirectX.
		EMT_SOLID_2_LAYER,

		//! Material type with standard lightmap technique: 
		//! There should be 2 textures: The first texture layer is a diffuse map,
		//! the second is a light map. Vertex light is ignored.
		EMT_LIGHTMAP,

		//! Material type with lightmap technique like EMT_LIGHTMAP, but
		//! lightmap and diffuse texture are not modulated, but added instead.
		EMT_LIGHTMAP_ADD,

		//! Material type with standard lightmap technique: 
		//! There should be 2 textures: The first texture layer is a diffuse map,
		//! the second is a light map. Vertex light is ignored.
		//! The texture colors are effectively multiplyied by 2 for brightening.
		//! like known in DirectX as D3DTOP_MODULATE2X.
		EMT_LIGHTMAP_M2,

		//! Material type with standard lightmap technique: 
		//! There should be 2 textures: The first texture layer is a diffuse map,
		//! the second is a light map. Vertex light is ignored.
		//! The texture colors are effectively multiplyied by 4 for brightening.
		//! like known in DirectX as D3DTOP_MODULATE4X.
		EMT_LIGHTMAP_M4,

		//! Like EMT_LIGHTMAP, but also supports dynamic lighting.
		EMT_LIGHTMAP_LIGHTING,

		//! Like EMT_LIGHTMAP_M2, but also supports dynamic lighting.
		EMT_LIGHTMAP_LIGHTING_M2,

		//! Like EMT_LIGHTMAP_4, but also supports dynamic lighting.
		EMT_LIGHTMAP_LIGHTING_M4,

		//! Detail mapped material. The first texture is diffuse color map, the
		//! second is added to this and usually displayed with a bigger scale value
		//! so that it adds more detail. The detail map is added to the diffuse map using
		//! ADD_SIGNED, so that it is possible to add and substract color from the diffuse 
		//! map. For example a value of (127,127,127) will not change the appearance of 
		//! the diffuse map at all.
		//! Often used for terrain rendering. 
		EMT_DETAIL_MAP,

		//! Makes the material look like it was reflection the environment
		//! around it. To make this possible, a texture called 'sphere map'
		//! is used, which must be set as Texture1.
		EMT_SPHERE_MAP,

		//! A reflecting material with an 
		//! optional additional non reflecting texture layer. The reflection
		//! map should be set as Texture 1.
		EMT_REFLECTION_2_LAYER,

		//! A transparent material. Only the first texture is used.
		//! The new color is calculated by simply adding the source color and
		//! the dest color. This means if for example a billboard using a texture with 
		//! black background and a red circle on it is drawed with this material, the
		//! result is that only the red circle will be drawn a little bit transparent,
		//! and everything which was black is 100% transparent and not visible.
		//! This material type is useful for e.g. particle effects.
		EMT_TRANSPARENT_ADD_COLOR,

		//! Makes the material transparent based on the texture alpha channel.
		//! The final color is blended together from the destination color and the
		//! texture color, using the alpha channel value as blend factor.
		//! Only first texture is used. If you are using this material with small
		//! textures, it is a good idea to load the texture in 32 bit
		//! mode (video::IVideoDriver::setTextureCreationFlag()).
		//! Also, an alpha ref is used, which can be manipulated using SMaterial::MaterialTypeParam.
		//! If set to 0, the alpha ref gets its default value which is 0.5f and which means
		//! that pixels with an alpha value >127 will be written, others not.  In other, simple 
		//! words: this value controls how sharp the edges become when going from a 
		//! transparent to a solid spot on the texture.
		EMT_TRANSPARENT_ALPHA_CHANNEL,	

		//! Makes the material transparent based on the texture alpha channel.
		//! If the alpha channel value is greater than 127, a pixel is written to the
		//! target, otherwise not. This material does not use alpha blending
		//! and is a lot faster than EMT_TRANSPARENT_ALPHA_CHANNEL. It 
		//! is ideal for drawing stuff like leafes of plants, because the borders
		//! are not blurry but sharp.
		//! Only first texture is used. If you are using this material with small
		//! textures and 3d object, it is a good idea to load the texture in 32 bit
		//! mode (video::IVideoDriver::setTextureCreationFlag()).
		EMT_TRANSPARENT_ALPHA_CHANNEL_REF,	

		//! Makes the material transparent based on the vertex alpha value.
		EMT_TRANSPARENT_VERTEX_ALPHA,

		//! A transparent reflecting material with an 
		//! optional additional non reflecting texture layer. The reflection
		//! map should be set as Texture 1. The transparency depends on the
		//! alpha value in the vertex colors. A texture which will not reflect
		//! can be set als Texture 2.
		//! Please note that this material type is currently not 100% implemented
		//! in OpenGL. It works in Direct3D.
		EMT_TRANSPARENT_REFLECTION_2_LAYER,

		//! A solid normal map renderer. First texture is the color map, the 
		//! second should be the normal map. Note that you should use this material
		//! only when drawing geometry consisting of vertices of type S3DVertexTangents 
		//! (EVT_TANGENTS). You can convert any mesh into this format using
		//! IMeshManipulator::createMeshWithTangents() (See SpecialFX2 Tutorial).
		//! This shader runs on vertex shader 1.1 and pixel shader 1.1 capable hardware and 
		//! falls back on a fixed function lighted material if this hardware is not available.
		//! Only two lights are supported by this shader, if there are more, the nearest two
		//! are chosen. Currently, this shader is only implemented for the D3D8 and D3D9 renderers.
		EMT_NORMAL_MAP_SOLID,

		//! A transparent normal map renderer. First texture is the color map, the 
		//! second should be the normal map. Note that you should use this material
		//! only when drawing geometry consisting of vertices of type S3DVertexTangents 
		//! (EVT_TANGENTS). You can convert any mesh into this format using
		//! IMeshManipulator::createMeshWithTangents() (See SpecialFX2 Tutorial).
		//! This shader runs on vertex shader 1.1 and pixel shader 1.1 capable hardware and 
		//! falls back on a fixed function lighted material if this hardware is not available.
		//! Only two lights are supported by this shader, if there are more, the nearest two
		//! are chosen. Currently, this shader is only implemented for the D3D8 and D3D9 renderers.
		EMT_NORMAL_MAP_TRANSPARENT_ADD_COLOR,

		//! A transparent (based on the vertex alpha value) normal map renderer.
		//! First texture is the color map, the 
		//! second should be the normal map. Note that you should use this material
		//! only when drawing geometry consisting of vertices of type S3DVertexTangents 
		//! (EVT_TANGENTS). You can convert any mesh into this format using
		//! IMeshManipulator::createMeshWithTangents() (See SpecialFX2 Tutorial).
		//! This shader runs on vertex shader 1.1 and pixel shader 1.1 capable hardware and 
		//! falls back on a fixed function lighted material if this hardware is not available.
		//! Only two lights are supported by this shader, if there are more, the nearest two
		//! are chosen. Currently, this shader is only implemented for the D3D8 and D3D9 renderers.
		EMT_NORMAL_MAP_TRANSPARENT_VERTEX_ALPHA,

		//! Just like EMT_NORMAL_MAP_SOLID, but uses parallax mapping too, which 
		//! looks a lot more realistic. This only works when the hardware supports at 
		//! least vertex shader 1.1 and pixel shader 1.4. 
		//! First texture is the color map, the  second should be the normal map.
		//! The normal map texture should contain the height value in the 
		//! alpha component. The IVideoDriver::makeNormalMapTexture() method writes 
		//! this value automaticly when creating normal maps from a heightmap when using a 32 bit
		//! texture. 
		//! The height scale of the material (affecting the bumpiness) is being controlled 
		//! by the SMaterial::MaterialTypeParam member. 
		//! If set to zero, the default value (0.02f) will be applied. Otherwise
		//! the value set in SMaterial::MaterialTypeParam is taken. This value depends on with which
		//! scale the texture is mapped on the material. Too high or low values of MaterialTypeParam
		//! can result in strange artifacts. 
		EMT_PARALLAX_MAP_SOLID,

		//! A material just like EMT_PARALLAX_MAP_SOLID, but it is transparent, using
		//! EMT_TRANSPARENT_ADD_COLOR as base material.
		EMT_PARALLAX_MAP_TRANSPARENT_ADD_COLOR,

		//! A material just like EMT_PARALLAX_MAP_SOLID, but it is transparent, using
		//! EMT_TRANSPARENT_VERTEX_ALPHA as base material.
		EMT_PARALLAX_MAP_TRANSPARENT_VERTEX_ALPHA,

		//! This value is not used. It only forces this enumeration to compile in 32 bit. 
		EMT_FORCE_32BIT = 0x7fffffff	
	};

	//! Material flags
	enum E_MATERIAL_FLAG
	{
		//! Draw as wireframe or filled triangles? Default: false
		EMF_WIREFRAME = 0,

		//! Flat or Gouraud shading? Default: true
		EMF_GOURAUD_SHADING,

		//! Will this material be lighted? Default: true
		EMF_LIGHTING,

		//! Is the ZBuffer enabled? Default: true
		EMF_ZBUFFER,

		//! May be written to the zbuffer or is it readonly. Default: true
		//! This flag is ignored, if the material type is a transparent type.
		EMF_ZWRITE_ENABLE,

		//! Is backfaceculling enabled? Default: true
		EMF_BACK_FACE_CULLING,

		//! Is bilinear filtering enabled? Default: true
		EMF_BILINEAR_FILTER,

		//! Is trilinear filtering enabled? Default: false
		//! If the trilinear filter flag is enabled,
		//! the bilinear filtering flag is ignored.
		EMF_TRILINEAR_FILTER,

		//! Is anisotropic filtering? Default: false
		//! In engine you can use anisotropic texture filtering in conjunction with bilinear or trilinear 
		//! texture filtering to improve rendering results. Primitives will look less blurry with this
		//! flag switched on.
		EMF_ANISOTROPIC_FILTER,

		//! Is fog enabled? Default: false
		EMF_FOG_ENABLE,

		//! Normalizes normals.You can enable this if you need 
		//! to scale a dynamic lighted model. Usually, its normals will get scaled 
		//! too then and it will get darker. If you enable the EMF_NORMALIZE_NORMALS flag,
		//! the normals will be normalized again, and the model will look as bright as it should.
		EMF_NORMALIZE_NORMALS,

		//! This is not a flag, but a value indicating how much flags there are.
		EMF_MATERIAL_FLAG_COUNT 
	};

	const s32 MATERIAL_MAX_TEXTURES = 2;


	//! struct for holding a material
	struct SMaterial
	{
		//! default constructor, creates a solid material with standard colors
		SMaterial()
		: AmbientColor(255,255,255,255), DiffuseColor(255,255,255,255),
		EmissiveColor(0,0,0,0), SpecularColor(255,255,255,255), Texture1(0), Texture2(0),
			MaterialType(EMT_SOLID), Wireframe(false), Lighting(true),
			ZBuffer(true), ZWriteEnable(true), BackfaceCulling(true),
			GouraudShading(true), Shininess(0.0f), MaterialTypeParam(0.0f),
			BilinearFilter(true), TrilinearFilter(false), FogEnable(false),
			NormalizeNormals(false), AnisotropicFilter(false)
		{}

		//! Type of the material. Specifies how everything is blended together
		E_MATERIAL_TYPE MaterialType;	

		//! How much ambient light (a global light) is reflected by this material.
		/** The default is full white, meaning objects are completely globally illuminated.
		 Reduce this if you want to see diffuse or specular light effects. */
		SColor AmbientColor;		

		//! How much diffuse light coming from a light source is reflected by this material.
		/** The default is full white. */
		SColor DiffuseColor;		

		//! Light emitted by this material. Default is to emitt no light.
		SColor EmissiveColor;	

		//! How much specular light (highlights from a light) is reflected. 
		/** The default is to reflect white specular light.  See SMaterial::Shininess how to 
		enable specular lights. */
		SColor SpecularColor;	

		//! Value affecting the size of specular highlights. A value of 20 is common.
		/** If set to 0, no specular highlights are being used. Currently, specular highlights
		are only implemented in the D3D9 and D3D8 driver.
		To activate, simply set the shininess of a material to a value other than 0: 
		Using scene nodes: 
		\code
		sceneNode->getMaterial(0).Shininess = 20.0f;
		\endcode

		You can also change the color of the highlights using 
		\code
		sceneNode->getMaterial(0).SpecularColor.set(255,255,255,255);
		\endcode

		The specular color of the dynamic lights (SLight::SpecularColor) will influence
		the the highlight color too, but they are set to a useful value by default when 
		creating the light scene node. Here is a simple example on how
		to use specular highlights:
		\code
		// load and display mesh
		scene::IAnimatedMeshSceneNode* node = smgr->addAnimatedMeshSceneNode(
		smgr->getMesh("data/faerie.md2"));
		node->setMaterialTexture(0, driver->getTexture("data/Faerie2.pcx")); // set diffuse texture
		node->setMaterialFlag(video::EMF_LIGHTING, true); // enable dynamic lighting
		node->getMaterial(0).Shininess = 20.0f; // set size of specular highlights
		
		// add white light
		scene::ILightSceneNode* light = smgr->addLightSceneNode(0,
		    core::vector3df(5,5,5), video::SColorf(1.0f, 1.0f, 1.0f));
		\endcode */
		f32 Shininess;		

		//! Free parameter dependend on the material type. 
		/** Mostly ignored, used for example in EMT_PARALLAX_MAP_SOLID and 
		EMT_TRANSPARENT_ALPHA_CHANNEL. */
		f32 MaterialTypeParam;

		//! Texture layer union.
		union
		{
			struct
			{
				//! Primary texture layer.
				ITexture* Texture1;	

				//! Secondary texture layer
				ITexture* Texture2;	
			};

			//! Array of textures, the same as accessing through Texture1 and Texture2
			ITexture* Textures[MATERIAL_MAX_TEXTURES];
		};

		//! material flag union. 
		/** This enables the user to access the
		material flag using e.g: material.Wireframe = true or
		material.flag[EMF_WIREFRAME] = true; */
		union
		{
			struct
			{
				//! Draw as wireframe or filled triangles? Default: false
				bool Wireframe;

				//! Flat or Gouraud shading? Default: true
				bool GouraudShading;				

				//! Will this material be lighted? Default: true
				bool Lighting;						

				//! Is the ZBuffer enabled? Default: true
				bool ZBuffer;						

				//! May be written to the zbuffer or is it readonly.
				/** Default: true This flag is ignored, if the MaterialType 
				is a transparent type. */
				bool ZWriteEnable;					

				//! Is backfaceculling enabled? Default: true
				bool BackfaceCulling;				

				//! Is bilinear filtering enabled? Default: true
				bool BilinearFilter;	

				//! Is trilinear filtering enabled? Default: false
				/** If the trilinear filter flag is enabled,
				the bilinear filtering flag is ignored. */
				bool TrilinearFilter;

				//! Is anisotropic filtering enabled? Default: false
				/** In engine you can use anisotropic texture filtering in conjunction with bilinear or trilinear 
				texture filtering to improve rendering results. Primitives will look less blurry with this
				flag switched on. */
				bool AnisotropicFilter;

				//! Is fog enabled? Default: false
				bool FogEnable;

				//! Should normals be normalized? Default: false
				bool NormalizeNormals;
			};

			//! Array representing all flags.
			bool Flags[EMF_MATERIAL_FLAG_COUNT];
		};


		//! Compare operator
		inline bool operator!=(const SMaterial& b)
		{
			return MaterialType != b.MaterialType ||
				AmbientColor != b.AmbientColor ||
				DiffuseColor != b.DiffuseColor ||
				EmissiveColor != b.EmissiveColor ||
				SpecularColor != b.SpecularColor ||
				Shininess != b.Shininess ||
				MaterialTypeParam != b.MaterialTypeParam ||
				Wireframe != b.Wireframe ||
				GouraudShading != b.GouraudShading ||
				Lighting != b.Lighting ||
				ZBuffer != b.ZBuffer ||
				ZWriteEnable != b.ZWriteEnable ||
				BackfaceCulling != b.BackfaceCulling ||
				BilinearFilter != b.BilinearFilter ||
				TrilinearFilter != b.TrilinearFilter ||
				AnisotropicFilter != b.AnisotropicFilter ||
				FogEnable != b.FogEnable ||
				NormalizeNormals != NormalizeNormals;
		}	
	};

} // end namespace video
} // end namespace engine

#endif

