uniform sampler2D PREFIX(dither_tex); uniform vec2 PREFIX(tc_scale); uniform float PREFIX(round_fac), PREFIX(inv_round_fac); vec4 FUNCNAME(vec2 tc) { // We also choose to dither alpha, just in case. // Maybe it should in theory have a separate dither, // but I doubt it matters much. vec4 result = INPUT(tc) + texture2D(PREFIX(dither_tex), tc * PREFIX(tc_scale)).xxxx; // NEED_EXPLICIT_ROUND will be #defined to 1 if the GPU has inaccurate // fp32 -> int8 framebuffer rounding, and 0 otherwise. #if NEED_EXPLICIT_ROUND result = round(result * vec4(PREFIX(round_fac))) * vec4(PREFIX(inv_round_fac)); #endif return result; }