#include <phong_lighting.cg>
#include <fragment_entry.cg>

DECLARE_TEXTURE(diffuseTexture)

SurfaceMaterial computeSurfaceMaterial(const FragmentParameters params)
{
	half4 diffuseTextureColor = tex2D(diffuseTexture, params.texcoord0.xy);
	
	SurfaceMaterial mout;
	
    // calculate eye-space sphere normal from texture coordinates
    float3 N;
    N.xy = params.texcoord0.xy*float2(2.0, -2.0) + float2(-1.0, 1.0);
    float r2 = dot(N.xy, N.xy);
    if (r2 > 0.5) discard;   // kill pixels outside circle
    N.z = sqrt(1.0-r2);
	
	mout.diffuseColor       = params.color.xyz*diffuseTextureColor.rgb;

    mout.alpha = clamp(1.0 - r2,0.0,1.0);//saturate(1.0 - r2);
    //alpha *= diffuseTextureColor.a;	


	mout.emissiveColor      = 0;
	mout.specularColor      = half3(1,1,1); // TODO: make this a constant parameter set by the material.
	mout.specularPower      = 16;
	mout.tangentSpaceNormal = half3(0,0,1);
	return mout;
}