internal static uint FixedAttributeIndex( VertexElementSemantic semantic, uint index )
{
// Some drivers (e.g. OS X on nvidia) incorrectly determine the attribute binding automatically
// and end up aliasing existing built-ins. So avoid! Fixed builtins are:
// a builtin custom attrib name
// ----------------------------------------------
// 0 gl_Vertex vertex
// 1 n/a blendWeights
// 2 gl_Normal normal
// 3 gl_Color colour
// 4 gl_SecondaryColor secondary_colour
// 5 gl_FogCoord fog_coord
// 7 n/a blendIndices
// 8 gl_MultiTexCoord0 uv0
// 9 gl_MultiTexCoord1 uv1
// 10 gl_MultiTexCoord2 uv2
// 11 gl_MultiTexCoord3 uv3
// 12 gl_MultiTexCoord4 uv4
// 13 gl_MultiTexCoord5 uv5
// 14 gl_MultiTexCoord6 uv6, tangent
// 15 gl_MultiTexCoord7 uv7, binormal
switch (semantic)
{
case VertexElementSemantic.Position:
return 0;
case VertexElementSemantic.BlendWeights:
return 1;
case VertexElementSemantic.Normal:
return 2;
case VertexElementSemantic.Diffuse:
return 3;
case VertexElementSemantic.Specular:
return 4;
case VertexElementSemantic.BlendIndices:
return 7;
case VertexElementSemantic.TexCoords:
return 8 + index;
case VertexElementSemantic.Tangent:
return 14;
case VertexElementSemantic.Binormal:
return 15;
default:
Debug.Assert(false, "Missing attribute!");
return 0;
}
}
