2 // uniform sampler2D PREFIX(tex);
4 vec4 FUNCNAME(vec2 tc) {
5 // OpenGL's origin is bottom-left, but most graphics software assumes
6 // a top-left origin. Thus, for inputs that come from the user,
7 // we flip the y coordinate.
10 vec4 pixel = tex2D(PREFIX(tex), tc);
12 // These two are #defined to 0 or 1 in flat_input.cpp.
16 #if FIXUP_RED_TO_GRAYSCALE
23 #undef FIXUP_RED_TO_GRAYSCALE