float4x4 mvp : ModelViewProjection;
float4x4 mv : ModelView;
float4x4 mvit : ModelViewIT;
float3 refFactor = float3(1.1,1.3,1.5);
float fresOffset = 0.1;
float fresScale = 0.3;
float fresPower = 0.2;

samplerCUBE skybox : SKYBOX;
string jointGeo = "cylinder.obj";

float4 vertex(uniform float4x4 modelViewProj,
              uniform float4x4 modelView,
              uniform float4x4 modelViewIT,
              float4 P : POSITION,
              float4 N : NORMAL,
	      float2 uvIn : TEXCOORD0,
		 in float4 Cin : COLOR0,

              out float3 CC : COLOR0,
			  out float2 uv : TEXCOORD0,
              out float3 Pcam : TEXCOORD1,
              out float3 Ncam : TEXCOORD2) : POSITION
{
    CC.xyz =  normalize(N.xyz);
    uv = uvIn;
    Pcam = mul(modelView, P).xyz;
    Ncam = mul(modelView, N).xyz;
    return mul(modelViewProj, P);
}

float3 toRGB(float hue)
{
	float r = max(min(hue*3-2, 1), 0) + max(min(1-hue*3, 1), 0);
	float g = max(min(hue*3-0, 1), 0) - max(min(hue*3-1, 1), 0);
	float b = max(min(hue*3-1, 1), 0) - max(min(hue*3-2, 1), 0);
	return float3(r,g,b);
}

float3 toRGB2(float hue)
{
	float b = max(min(hue*2, 1), 0) - max(min(hue*2-1, 1), 0);
	float g = 1-b;
	return float3(0,g,b);
}

float4 rainbow(	  float4 col : COLOR0,
                  float3 texcoord : TEXCOORD0,
                  float3 Pcam : TEXCOORD1, 
                  float3 Ncam : TEXCOORD2) : COLOR 
{
	float dist = sqrt(Pcam.x*Pcam.x + Pcam.y*Pcam.y + Pcam.z*Pcam.z);
	float angle = dot(-normalize(Pcam), normalize(Ncam));
	float factor = (cos(dist*70)+1)/2;  //see stronger 'interference' effect: (1-angle)*(cos(dist*10000)+1)/2;
	float3 c = toRGB(factor);
	return float4(c, 1);
}

technique red <string target = "both";>
{
	pass p0
	{
		VertexProgram = compile arbvp1 vertex(mvp, mv, mvit);
		FragmentProgram = compile arbfp1 rainbow();
	}
}