Allow dual Y'CbCr/RGBA outputs.

[movit] / dither_effect.frag

diff --git a/dither_effect.frag b/dither_effect.frag
index b12ecd7cedfd267d8a9935a2372303c9f62e3be9..f271b633c24edea92c54ac38f626cad2d28872a6 100644 (file)
--- a/dither_effect.frag
+++ b/dither_effect.frag
@@ -3,14 +3,36 @@
 // uniform vec2 PREFIX(tc_scale);
 // uniform float PREFIX(round_fac), PREFIX(inv_round_fac);
 
+#if YCBCR_ALSO_OUTPUT_RGBA
+
+// There are two values to dither; otherwise, exactly the same as the algorithm below
+// (so comments are not duplicated).
+
+vec4[2] FUNCNAME(vec2 tc) {
+       vec4[2] result = INPUT(tc);
+       float d = tex2D(PREFIX(dither_tex), tc * PREFIX(tc_scale)).x;
+       result[0].rgb += vec3(d);
+       result[1].rgb += vec3(d);
+
+#if NEED_EXPLICIT_ROUND
+       result[0] = round(result[0] * vec4(PREFIX(round_fac))) * vec4(PREFIX(inv_round_fac));
+       result[1] = round(result[1] * vec4(PREFIX(round_fac))) * vec4(PREFIX(inv_round_fac));
+#endif
+
+       return result;
+}
+
+#else
+
 vec4 FUNCNAME(vec2 tc) {
        vec4 result = INPUT(tc);
+       float d = tex2D(PREFIX(dither_tex), tc * PREFIX(tc_scale)).x;
 
        // Don't dither alpha; the case of alpha=255 (1.0) is very important to us,
        // and if there's any inaccuracy earlier in the chain so that it becomes e.g.
        // 254.8, it's better to just get it rounded off than to dither and have it
        // possibly get down to 254. This is not the case for the color components.
-       result.rgb += tex2D(PREFIX(dither_tex), tc * PREFIX(tc_scale)).xxx;
+       result.rgb += vec3(d);
 
        // NEED_EXPLICIT_ROUND will be #defined to 1 if the GPU has inaccurate
        // fp32 -> int8 framebuffer rounding, and 0 otherwise.
@@ -20,3 +42,5 @@ vec4 FUNCNAME(vec2 tc) {
 
        return result;
 }
+
+#endif