/**
* Geforce 4 diffuse bumpmapping program
* This compiles under the fp20 profile.
* compile with "-profile fp20"
*/

struct inputVertex {
    float4 lightVec : COLOR0;
    float4 texCoord0 : TEXCOORD0;
    float4 texCoord1 : TEXCOORD1;
    float4 texCoord2 : TEXCOORD2;
    float4 texCoord3 : TEXCOORD3;        
};

float4 main(inputVertex I, uniform sampler2D colorMap, uniform sampler2D normalMap, uniform samplerCUBE filter, uniform sampler3D atten) : COLOR
{
	//normalize light vector (talyor series around 1)
    float3 lightVector = 2 * (I.lightVec.xyz - 0.5);	
	float3 normLight = 1-(lightVector-1)/2;

    // Get the normal from normal map lookup
    float4 normal = 2 * (tex2D(normalMap, I.texCoord1.xy) - 0.5);
    	
    // Lookup the colorMap texture
    float4 texColor = tex2D(colorMap, I.texCoord0.xy);

    // N dot L
    float4 dot_result = saturate(dot(normLight, normal.xyz).xxxx);

	//selfshadow term, ok we just do a mul with 8 but the compiler doesn't recognize that
	//so we teach it a bit of math :)
	float selfShadow = (lightVector.z*4)+(lightVector.z*4);

	//Lookup the attenuation factor
	float4 attenv = tex3D(atten, I.texCoord2.xyz);
	
	//Lookup the filter color
	float3 filterv = texCUBE(filter, I.texCoord3.xyz).xyz;

    // Modulate color with N dot L
    float4 res;
    res.xyz = dot_result.xyz * texColor.xyz * attenv.xyz * filterv.xyz * selfShadow * attenv.xyz * texColor.xyz;
    res.w = attenv.w * selfShadow;
    return res;
}