uniform sampler2D PREFIX(tex); vec4 FUNCNAME(vec2 tc) { // OpenGL's origin is bottom-left, but most graphics software assumes // a top-left origin. Thus, for inputs that come from the user, // we flip the y coordinate. tc.y = 1.0 - tc.y; vec4 pixel = tex2D(PREFIX(tex), tc); // These two are #defined to 0 or 1 in flat_input.cpp. #if FIXUP_SWAP_RB pixel.rb = pixel.br; #endif #if FIXUP_RED_TO_GRAYSCALE pixel.gb = pixel.rr; #endif return pixel; } #undef FIXUP_SWAP_RB #undef FIXUP_RED_TO_GRAYSCALE