prog.attach_shader_owned(new VertexShader(create_source(resolved_vars, VERTEX)));
prog.attach_shader_owned(new FragmentShader(create_source(resolved_vars, FRAGMENT)));
prog.attach_shader_owned(new VertexShader(create_source(resolved_vars, VERTEX)));
prog.attach_shader_owned(new FragmentShader(create_source(resolved_vars, FRAGMENT)));