4 // require_extensions: GL_ARB_shader_subroutine
7 // ARB_explicit_uniform_location spec allows a layout qualifier for
8 // subroutines, test for compile error when this is not available.
11 #extension GL_ARB_shader_subroutine: require
13 subroutine void func_type();
15 /* A subroutine matching the above type */
16 layout(index = 2) subroutine (func_type) void f() {}