void
main (out float4 lClip : TEXCOORD0,
      out float4 pClip : POSITION,
      out float diffuse : TEXCOORD1,
      float4 pObj : POSITION,
      float3 nObj : NORMAL,
      uniform float4x4 mvp,
      uniform float4x4 mv,
      uniform float4x4 mvIT,
      uniform float4x4 observerEyeToLightClip,
      uniform float4 lightPosEye)
{
    pClip = mul(mvp, pObj);
    float3 nEye = mul(mvIT, float4(nObj, 0)).xyz;
    float4 pEye = mul(mv, pObj);
    lClip = mul(observerEyeToLightClip, pEye);
    diffuse = dot(normalize(nEye), normalize(lightPosEye.xyz - pEye.xyz));
}