source: OGRE/trunk/ogrenew/Samples/Media/DeferredShadingMedia/DeferredShading/post/hlsl/LightMaterial_ps.hlsl @ 692

/******************************************************************************
Copyright (c) W.J. van der Laan

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/** Deferred shading framework
        // W.J. :wumpus: van der Laan 2005 //
        
        Post shader: Light geometry material
*/
sampler Tex0: register(s0);
sampler Tex1: register(s1);

float4x4 worldView;

// Attributes of light
float4 lightDiffuseColor;
float4 lightSpecularColor;
float4 lightFalloff;

float4 main(float2 texCoord: TEXCOORD0, float3 projCoord: TEXCOORD1) : COLOR 
{
        float4 a0 = tex2D(Tex0, texCoord); // Attribute 0: Diffuse color+shininess
    float4 a1 = tex2D(Tex1, texCoord); // Attribute 1: Normal+depth

    // Attributes
    float3 colour = a0.rgb;
    float alpha = a0.a;         // Specularity
    float distance = a1.w;  // Distance from viewer (w)
    float3 normal = a1.xyz;

        // Calculate position of texel in view space
    float3 position = projCoord*distance;
        
        // Extract position in view space from worldView matrix
        float3 lightPos = float3(worldView[0][3],worldView[1][3],worldView[2][3]);
        
    // Calculate light direction and distance
    float3 lightVec = lightPos - position;
    float len_sq = dot(lightVec, lightVec);
    float len = sqrt(len_sq);
    float3 lightDir = lightVec/len;
    
    /// Calculate attenuation    
    float attenuation = dot(lightFalloff, float3(1, len, len_sq));
    
    /// Calculate diffuse colour
    float3 light_diffuse = max(0,dot(lightDir, normal)) * lightDiffuseColor;
    
    /// Calculate specular component
    float3 viewDir = -normalize(position);
    float3 h = normalize(viewDir + lightDir);
    float3 light_specular = pow(dot(normal, h),32) * lightSpecularColor;
    
    // Calcalate total lighting for this fragment
    float3 total_light_contrib;
    total_light_contrib = light_diffuse;
        // Uncomment next line if specular desired
        //total_light_contrib += alpha * light_specular;
        
    return float4(total_light_contrib*colour/attenuation, 0);
}
// Debugging only
    //return lightDiffuseColor;
    //return lightDiffuseColor/attenuation;
    //return float4(abs(position-position2),0);
    //return length(lightPos-position)/1000.0;
    //return float4(abs(lightPos-lightPos2),0);
    //return float4(lightPos-position,0);
    //return float4(-global.position/1000.0f,0);
    //return float4(global.position/1000.0,0);
    ///return float4(lightPos[0], lightPos[1], -lightPos[2], 0)/1000.0f;
    //return lightDiffuseColor*a0.xyzw/2;