/*********************************************************************NVMH3****
$Revision$

Copyright NVIDIA Corporation 2007
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.


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/

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

// #define FLIP_TEXTURE_Y

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

//// UN-TWEAKABLES - AUTOMATICALLY-TRACKED TRANSFORMS ////////////////

float4x4 WorldITXf : WorldInverseTranspose < string UIWidget="None"; >;
float4x4 WvpXf : WorldViewProjection < string UIWidget="None"; >;
float4x4 WorldXf : World < string UIWidget="None"; >;
float4x4 ViewIXf : ViewInverse < string UIWidget="None"; >;

//// TWEAKABLE PARAMETERS ////////////////////

/// Point Lamp 0 ////////////
float3 Lamp0Pos : Position <
    string Object = "PointLight0";
    string UIName =  "Lamp 0 Position";
    string Space = "World";
> = {-0.5f,2.0f,1.25f};
float3 Lamp0Color : Specular <
    string UIName =  "Lamp 0";
    string Object = "Pointlight0";
    string UIWidget = "Color";
> = {1.0f,1.0f,1.0f};

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

float Ks <
    string UIWidget = "slider";
    float UIMin = 0.0;
    float UIMax = 1.0;
    float UIStep = 0.05;
    string UIName =  "Specular";
> = 0.4;

float Eccentricity <
    string UIWidget = "slider";
    float UIMin = 0.0;
    float UIMax = 1.0;
    float UIStep = 0.0001;
    string UIName =  "Highlight Eccentricity";
> = 0.3;
 

//////// COLOR & TEXTURE /////////////////////

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

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

//
// #define this macro to permit the import and use of shared shadow
//  maps created by COLLADA-FX. Make sure that the macro is defined
//  and the code recompile *before* executing "Convert to Collada-FX"!
//
// #define USE_SHARED_SHADOW

#ifdef USE_SHARED_SHADOW
#include "include/shadowMap.cgh"
DECLARE_SHADOW_XFORMS("SpotLight0",LampViewXf,LampProjXf,ShadowViewProjXf)
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 */


//////// CONNECTOR DATA STRUCTURES ///////////

/* 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 SHADING /////////////////////

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

vertexOutput std_VS(appdata IN) {
    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);
    float3 Pw = mul(WorldXf,Po).xyz;
    OUT.LightVec = (Lamp0Pos - Pw);
#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);
    OUT.HPosition = mul(WvpXf,Po);
    return OUT;
}

///////// PIXEL SHADING //////////////////////

// Utility function for blinn shading

void blinn_shading(vertexOutput IN,
		    float3 LightColor,
		    float3 Nn,
		    float3 Ln,
		    float3 Vn,
		    out float3 DiffuseContrib,
		    out float3 SpecularContrib)
{
    float3 Hn = normalize(Vn + Ln);
    float hdn = dot(Hn,Nn);
    float3 R = reflect(-Ln,Nn);
    float rdv = dot(R,Vn);
    rdv = max(rdv,0.001);
    float ldn=dot(Ln,Nn);
    ldn = max(ldn,0.0);
    float ndv = dot(Nn,Vn);
    float hdv = dot(Hn,Vn);
    float eSq = Eccentricity*Eccentricity;
    float distrib = eSq / (rdv * rdv * (eSq - 1.0) + 1.0);
    distrib = distrib * distrib;
    float Gb = 2.0 * hdn * ndv / hdv;
    float Gc = 2.0 * hdn * ldn / hdv;
    float Ga = min(1.0,min(Gb,Gc));
    float fresnelHack = 1.0 - pow(ndv,5.0);
    hdn = distrib * Ga * fresnelHack / ndv;
    DiffuseContrib = ldn * LightColor;
    SpecularContrib = hdn * Ks * LightColor;
}

float4 std_PS(vertexOutput IN) : COLOR {
    float3 diffContrib;
    float3 specContrib;
    float3 Ln = normalize(IN.LightVec);
    float3 Vn = normalize(IN.WorldView);
    float3 Nn = normalize(IN.WorldNormal);
	blinn_shading(IN,Lamp0Color,Nn,Ln,Vn,diffContrib,specContrib);
    float3 diffuseColor = tex2D(ColorSampler,IN.UV).rgb;
#ifdef USE_SHARED_SHADOW
    float shadowed = tex2Dproj(DepthShadSampler,IN.LProj).x;
	float faded = 1.0-(ShadDens*(1.0-shadowed));
	diffContrib *= faded;
	specContrib *= shadowed;
#endif /* USE_SHARED_SHADOW */
    float3 result = specContrib+(diffuseColor*(diffContrib+AmbiColor));
    // return as float4
    return float4(result,1);
}

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

technique Main <
	string Script = "Pass=p0;";
> {
    pass p0 <
	string Script = "Draw=geometry;";
    > {
        VertexProgram = compile vp40 std_VS();
		DepthTestEnable = true;
		DepthMask = true;
		CullFaceEnable = false;
		BlendEnable = false;
		DepthFunc = LEqual;
        FragmentProgram = compile fp40 std_PS();
    }
}

/////////////////////////////////////// eof //