source: GTP/branches/IllumWPdeliver2008dec/IlluminationWP/demos/Standalone/Hierarchical Systems Demo [OpenGL]/src/IllumPrograms.cg @ 3255

struct VertexOut
{
        float4 VertexPosition           :POSITION;
        float2 TexCoord                         :TEXCOORD;
        float4 Color1                           :COLOR; 
};


/*
  Vertex program for displaying particle system with rectangle rendertexture 
*/
VertexOut VertexProgram( float4 Position :POSITION,
                                                float4 Texcoord: TEXCOORD,
                                                uniform float transparency,
                                                uniform float4x4 ModelViewProj  :state.matrix.mvp
                                                )                                                                       
{
        VertexOut Out;  
        
        Out.VertexPosition=mul(ModelViewProj, Position);
        Out.TexCoord=Texcoord.xy;       
        
        Out.Color1=float4(transparency,transparency,transparency,transparency);
        
        
        float z=(Out.VertexPosition.z/Out.VertexPosition.w+1)/2;
        
        float4 planes=float4(0.33,0.5,0.66,1);  
        if(z>planes.x)
        {
                Out.Color1.r=0;
        }
        if(z>planes.y)
        {
                Out.Color1.g=0;
        }
        if(z>planes.z)
        {
                Out.Color1.b=0;
        }
        
        return Out;     
}


/*
  Fragment program for displaying particle system with rectangle rendertexture
*/
void FragmentProgram(   VertexOut       In,
                                                uniform sampler2D Texture,
                                                uniform samplerRECT PhaseTexture,
                                                uniform float Albedo,
                                                uniform float Symmetry,
                                                out float4 Color:COLOR
                                                )
{
        
        float4 extintion=tex2D(Texture,In.TexCoord).r*In.Color1;        
        float scattered=Albedo*texRECT(PhaseTexture,float2(Symmetry,1)*256)/1.5;
        Color=1-extintion+extintion*scattered;  
        //Color=float4(0,0,0,0);        
}