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;
}