source: GTP/trunk/App/Demos/Illum/Illumination Networks Demo [OpenGL]/src/Interpol_FinalDisplay.cg @ 845

struct VertexOut
{
        float4 Position                         :POSITION;
        float2 TexCoord                         :TEXCOORD;
        float2 PolarCoord                       :TEXCOORD1;
        float ID                                        :TEXCOORD2;
        float PSize                                     :PSIZE;
};


VertexOut VertexProgram(
                  float4 Position   : POSITION,
          float ID : TEXCOORD0,
          float4 Color : COLOR0,          
          uniform float4 PSize : state.point.size,
          uniform float4x4 modelView : state.matrix.modelview,
          uniform float4x4 modelViewProj:state.matrix.mvp,
                uniform float3 EyePosition
          )
{
        VertexOut Out;
        Out.ID=ID*512;
         
   float4 pos_eye = mul(modelView, Position);
    float dist = length(pos_eye.xyz);
    Out.PSize =PSize.x*sqrt(1.0 / (1 + dist*dist));
                
        Out.Position = mul(modelViewProj, Position);
    
    float3 toLight=-1*pos_eye.xyz;
    //polar coord
    float3 dir0=normalize(toLight);
        
        float2 angles;
        angles.y=asin(dir0.y); // -pi/2 -- pi/2
                
        float2 d=normalize(dir0.xz);
        angles.x=acos(d.x)*sign(d.y); // -pi -- pi
        angles.x=angles.x/6.28+0.5; // 0 -- 1
        angles.y=angles.y/3.14+0.5; // 0 -- 1
        
        Out.PolarCoord=angles;
        
    return Out;
}

float4 FragmentProgram(VertexOut In,
                                        uniform sampler2D BbTexture,
                                        uniform sampler2D DirMap,                                               
                                        uniform samplerRECT IllumTexture ) : COLOR
{
        float4 Color=float4(0,0,0,0);
                        
        float nearestdir=tex2D(DirMap,In.PolarCoord).r;
        float nearestdir2=tex2D(DirMap,In.PolarCoord).g;
        float weight1=tex2D(DirMap,In.PolarCoord).b;
        float weight2=tex2D(DirMap,In.PolarCoord).a;
        
        
        Color.rgb=texRECT(IllumTexture,float2(In.ID,nearestdir*64))*weight1;
        Color.rgb+=texRECT(IllumTexture,float2(In.ID,nearestdir2*64))*weight2;
        
        Color.a=tex2D(BbTexture, In.TexCoord.xy).r*0.6;
    return  Color;
}