39 static std::string patch_basis_source;
40 if (patch_basis_source.empty()) {
42 patch_basis_source = OpenSubdiv::Osd::MTLPatchShaderSource::GetPatchBasisShaderSource();
44 patch_basis_source = OpenSubdiv::Osd::GLSLPatchShaderSource::GetPatchBasisShaderSource();
47 return patch_basis_source.c_str();