4 // require_extensions: GL_ARB_shader_subroutine
8 #extension GL_ARB_shader_subroutine: require
11 out vec4 piglit_fragcolor;
12 subroutine float func_type(vec4 color);
14 subroutine uniform func_type f;
16 subroutine(func_type) float R(vec4 p)
21 subroutine(func_type) float G(vec4 p)
28 piglit_fragcolor = vec4(f(u));