-const bool use_diffuse_map = false;
-const bool use_specular = false;
-const bool use_specular_map = false;
-const bool use_shininess_map = false;
-const bool use_emission = false;
-const bool use_emission_map = false;
-const bool use_reflectivity = false;
-const bool use_reflectivity_map = false;
-const bool use_sky = false;
-const bool use_fog = false;
+layout(constant_id=auto) const bool use_diffuse_map = false;
+layout(constant_id=auto) const bool use_specular = false;
+layout(constant_id=auto) const bool use_specular_map = false;
+layout(constant_id=auto) const bool use_shininess_map = false;
+layout(constant_id=auto) const bool use_emission = false;
+layout(constant_id=auto) const bool use_emission_map = false;
+layout(constant_id=auto) const bool use_reflectivity = false;
+layout(constant_id=auto) const bool use_reflectivity_map = false;
+layout(constant_id=auto) const bool use_sky = false;
+layout(constant_id=auto) const bool use_fog = false;