/*********************************************************************NVMH3****
*******************************************************************************
$Revision: #4 $

Copyright NVIDIA Corporation 2008
TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, THIS SOFTWARE IS PROVIDED
*AS IS* AND NVIDIA AND ITS SUPPLIERS DISCLAIM ALL WARRANTIES, EITHER EXPRESS
OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL NVIDIA OR ITS SUPPLIERS
BE LIABLE FOR ANY SPECIAL, INCIDENTAL, INDIRECT, OR CONSEQUENTIAL DAMAGES
WHATSOEVER (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS PROFITS,
BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR ANY OTHER PECUNIARY
LOSS) ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF
NVIDIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

% Shading via multitexture. Two textures are interpolated over the
% surface, and their product results in the final specular BDRF.
%     The initial textures supplied approximate a Cook-Torrance model
% using one set of possible parameters, but different textures can
% be used to emulate a wide variety of isotropic BRDF models. Try painting
% some of your own!

This texture lookup is driven by vertex-shaded factors, so DirectX8 is actually
capable of performing the math -- though it SCREAMS on newer hardware.

keywords: material brdf_texture
date: 070403



To learn more about shading, shaders, and to bounce ideas off other shader
    authors and users, visit the NVIDIA Shader Library Forums at:

    http://developer.nvidia.com/forums/

*******************************************************************************
******************************************************************************/

/*****************************************************************/
/*** HOST APPLICATION IDENTIFIERS ********************************/
/*** Potentially predefined by varying host environments *********/
/*****************************************************************/

// #define _XSI_		/* predefined when running in XSI */

#ifndef FXCOMPOSER_VERSION	/* for very old versions */
#define FXCOMPOSER_VERSION 180
#endif /* FXCOMPOSER_VERSION */

// #define FLIP_TEXTURE_Y	/* Different in OpenGL & DirectX */

/*****************************************************************/
/*** EFFECT-SPECIFIC CODE BEGINS HERE ****************************/
/*****************************************************************/

/******* Lighting Macros *******/
/** To use "Object-Space" lighting definitions, change these two macros: **/
#define LIGHT_COORDS "World"
// #define OBJECT_SPACE_LIGHTS /* Define if LIGHT_COORDS is "Object" */
/** Define the macro USE_SHARED_SHADOW to permit the import and use of "shared
		surface "shadow maps created by COLLADA-FX. **/
// #define USE_SHARED_SHADOW


float Script : STANDARDSGLOBAL <
    string UIWidget = "none";
    string ScriptClass = "object";
    string ScriptOrder = "standard";
    string ScriptOutput = "color";
//  string Script = "Technique=Technique?Simple:Textured;";
> = 0.8;

/**** UNTWEAKABLES: Hidden & Automatically-Tracked Parameters **********/

// transform object vertices to world-space:
float4x4 gWorldXf : World < string UIWidget="None"; >;
// transform object normals, tangents, & binormals to world-space:
float4x4 gWorldITXf : WorldInverseTranspose < string UIWidget="None"; >;
// transform object vertices to view space and project them in perspective:
float4x4 gWvpXf : WorldViewProjection < string UIWidget="None"; >;
// provide tranform from "view" or "eye" coords back to world-space:
float4x4 gViewIXf : ViewInverse < string UIWidget="None"; >;

/************* TWEAKABLES **************/

/// Point Lamp 0 ////////////
float3 gLamp0Pos : POSITION <
    string Object = "PointLight0";
    string UIName =  "Lamp 0 Position";
    string Space = (LIGHT_COORDS);
> = {-0.5f,2.0f,1.25f};
float3 gLamp0Color <
    string UIName =  "Lamp 0";
    string Object = "Pointlight0";
    string UIWidget = "Color";
> = {1.0f,1.0f,1.0f};


// Ambient Light
float3 gAmbiColor <
    string UIName =  "Ambient Light";
    string UIWidget = "Color";
> = {0.07f,0.07f,0.07f};

// surface color
float3 gSurfaceColor <
    string UIName =  "Surface";
    string UIWidget = "Color";
> = {0.5f, 0.2f, 0.1f};

//////////////////////////////
// Textures //////////////////
//////////////////////////////

texture hmapTex  <
    string ResourceName = "ctHalf.dds";
    string UIName =  "Map with dot-half-angle factors";
    string ResourceType = "2D";
>;

sampler2D hmapSampler = sampler_state {
    Texture = <hmapTex>;
    MinFilter = LinearMipMapLinear;
    MagFilter = Linear;
    WrapS = ClampToEdge;
    WrapT = ClampToEdge;
};

texture nmapTex  <
    string ResourceName = "ctNorm.dds";
    string UIName =  "Map with dot-normal factors";
    string ResourceType = "2D";
>;

sampler2D nmapSampler = sampler_state {
    Texture = <nmapTex>;
    MinFilter = LinearMipMapLinear;
    MagFilter = Linear;
    WrapS = ClampToEdge;
    WrapT = ClampToEdge;
};

texture gColorTexture  <
    string ResourceName = "default_color.dds";
    string UIName =  "Diffuse Texture";
    string ResourceType = "2D";
>;

sampler2D gColorSampler = sampler_state {
    Texture = <gColorTexture>;
    MinFilter = LinearMipMapLinear;
    MagFilter = Linear;
    WrapS = Repeat;
    WrapT = Repeat;
};

#ifdef USE_SHARED_SHADOW
#define MAX_SHADOW_BIAS 0.01
#define MIN_SHADOW_BIAS 0.00005
#include "include/shadowMap.cgh"
DECLARE_SHADOW_XFORMS("SpotLight0",gLampViewXf,gLampProjXf,gShadowViewProjXf)
DECLARE_SHADOW_BIAS
DECLARE_SHADOW_MAPS(ColorShadTarget,ColorShadSampler,DepthShadTarget,DepthShadSampler)

float ShadDens <
    string UIWidget = "slider";
    float UIMin = 0.0;
    float UIMax = 1.0;
    float UIStep = 0.01;
    string UIName =  "Shadow Density";
> = 0.7;
#endif /* USE_SHARED_SHADOW */


/* data from application vertex buffer */
struct appdata {
    float3 Position	: POSITION;
    float4 UV		: TEXCOORD0;
    float4 Normal	: NORMAL;
    float4 Tangent	: TANGENT0;
    float4 Binormal	: BINORMAL0;
};

/* data passed from vertex shader to pixel shader */
struct vertexOutput {
    float4 HPosition	: POSITION;
    float2 UV		: TEXCOORD0;
    // The following values are passed in "World" coordinates since
    //   it tends to be the most flexible and easy for handling
    //   reflections, sky lighting, and other "global" effects.
    float3 LightVec	: TEXCOORD1;
    float3 WorldNormal	: TEXCOORD2;
    float3 WorldTangent	: TEXCOORD3;
    float3 WorldBinormal : TEXCOORD4;
    float3 WorldView	: TEXCOORD5;
#ifdef USE_SHARED_SHADOW
    // This optional value expresses the current location in "light"
    //   coordinates for use with shadow mapping.
    float4 LProj	: LPROJ_COORD;
#endif /* USE_SHARED_SHADOW */
};

/*********** vertex shader ******/

/*********** Generic Vertex Shader ******/

vertexOutput std_VS(appdata IN,
	uniform float4x4 WorldITXf, // our four standard "untweakable" xforms
	uniform float4x4 WorldXf,
	uniform float4x4 ViewIXf,
	uniform float4x4 WvpXf,
#ifdef USE_SHARED_SHADOW
	uniform float4x4 ShadowViewProjXf,
	uniform float ShadBias,
#endif /* USE_SHARED_SHADOW */
	uniform float3 LampPos) {
    vertexOutput OUT = (vertexOutput)0;
    OUT.WorldNormal = mul(WorldITXf,IN.Normal).xyz;
    OUT.WorldTangent = mul(WorldITXf,IN.Tangent).xyz;
    OUT.WorldBinormal = mul(WorldITXf,IN.Binormal).xyz;
    float4 Po = float4(IN.Position.xyz,1); // homogeneous location
    float4 Pw = mul(WorldXf,Po);	// convert to "world" space
#ifdef OBJECT_SPACE_LIGHTS
    float4 Lo = float4(LampPos.xyz,1.0); // homogeneous coordinates
    float4 Lw = mul(WorldXf,Lo);	// convert to "world" space
    OUT.LightVec = (Lw.xyz - Pw.xyz);
#else /* !OBJECT_SPACE_LIGHTS -- standard world-space lights */
    OUT.LightVec = (LampPos - Pw.xyz);
#endif /* !OBJECT_SPACE_LIGHTS */
#ifdef FLIP_TEXTURE_Y
    OUT.UV = float2(IN.UV.x,(1.0-IN.UV.y));
#else /* !FLIP_TEXTURE_Y */
    OUT.UV = IN.UV.xy;
#endif /* !FLIP_TEXTURE_Y */
#ifdef USE_SHARED_SHADOW
    float4 Pl = mul(ShadowViewProjXf,Pw);  // "P" in light coords
    float4x4 BiasXf = make_bias_mat(ShadBias);
    OUT.LProj = mul(BiasXf,Pl);		// bias to make texcoord
#endif /* USE_SHARED_SHADOW */
    OUT.WorldView = normalize(float3(ViewIXf[0].w,ViewIXf[1].w,ViewIXf[2].w) - Pw.xyz);
    OUT.HPosition = mul(WvpXf,Po);
    return OUT;
}

/********* pixel shader ********/

float3 tex_brdf(vertexOutput IN,
    uniform float3 SurfaceColor,
    uniform float3 LampColor,
    uniform float3 AmbiColor
) {
    float3 Nn = normalize(IN.WorldNormal);
    float3 Vn = normalize(IN.WorldView);
    float3 Ln = normalize(IN.LightVec.xyz);
    float3 Hn = normalize(Vn + Ln);
    float2 huv = float2(0.5+dot(Ln,Hn)/2.0,
		(0.5+dot(Nn,Hn)/2.0));
    float2 nuv = float2(0.5+dot(Ln,Nn)/2.0,
		(0.5+dot(Nn,Vn)/2.0));
    float3 ht = tex2D(hmapSampler,huv).rgb;
    float3 nt = tex2D(nmapSampler,nuv).rgb;
    float3 nspec = ht * nt * LampColor;
    #ifdef USE_SHARED_SHADOW
    float shadowed = tex2Dproj(DepthShadSampler,IN.LProj).x;
	float faded = 1.0-(ShadDens*(1.0-shadowed));
	diffContrib *= faded;
	nspec *= shadowed;
#endif /* USE_SHARED_SHADOW */
    float3 diffContrib = (AmbiColor*gSurfaceColor);
    return (diffContrib + nspec);
}

float4 tb_PS(vertexOutput IN,
		uniform float3 SurfaceColor,
		uniform float3 LampColor,
		uniform float3 AmbiColor
) : COLOR {
    float3 result = tex_brdf(IN,SurfaceColor,LampColor,AmbiColor);
    return float4(result.rgb,1.0);
}

float4 tb_PS_t(vertexOutput IN,
		uniform float3 SurfaceColor,
		uniform sampler2D ColorSampler,
		uniform float3 LampColor,
		uniform float3 AmbiColor
) : COLOR {
    float3 result = tex_brdf(IN,SurfaceColor,LampColor,AmbiColor) *
		    tex2D(ColorSampler,IN.UV).rgb;
    return float4(result.rgb,1.0);
}

///////////////////////////////////////
/// TECHNIQUES ////////////////////////
///////////////////////////////////////

technique Simple <
	string Script = "Pass=p0;";
> {
    pass p0 <
	string Script = "Draw=geometry;";
    > {
        VertexProgram = compile vp40 std_VS(gWorldITXf,gWorldXf,
				gViewIXf,gWvpXf,
#ifdef USE_SHARED_SHADOW
				gShadowViewProjXf, ShadBias,
#endif /* USE_SHARED_SHADOW */
				gLamp0Pos);
		DepthTestEnable = true;
		DepthMask = true;
		CullFaceEnable = false;
		BlendEnable = false;
		DepthFunc = LEqual;
        FragmentProgram = compile fp40 tb_PS(gSurfaceColor,gLamp0Color,gAmbiColor);
    }
}

technique Textured <
	string Script = "Pass=p0;";
> {
    pass p0 <
	string Script = "Draw=geometry;";
    > {
        VertexProgram = compile vp40 std_VS(gWorldITXf,gWorldXf,
				gViewIXf,gWvpXf,
#ifdef USE_SHARED_SHADOW
				gShadowViewProjXf, ShadBias,
#endif /* USE_SHARED_SHADOW */
				gLamp0Pos);
		DepthTestEnable = true;
		DepthMask = true;
		CullFaceEnable = false;
		BlendEnable = false;
		DepthFunc = LEqual;
        FragmentProgram = compile fp40 tb_PS_t(gSurfaceColor,gColorSampler,gLamp0Color,gAmbiColor);
    }
}

/***************************** eof ***/