X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=dither_effect.frag;h=f9c6ad13c443e1919c4506790159c9134106d8a7;hp=930bd94fe68d3587270e04de1cb7811e1e64ce6b;hb=85f9719bf3519b1f1942738d11601584f5d38725;hpb=f1a81dca72da9aa5103527b8c9494381204e70c5;ds=sidebyside

diff --git a/dither_effect.frag b/dither_effect.frag
index 930bd94..f9c6ad1 100644
--- a/dither_effect.frag
+++ b/dither_effect.frag
@@ -1,10 +1,18 @@
 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. We currently don't
-	// really handle alpha in any case.
-	return INPUT(tc) + texture2D(PREFIX(dither_tex), tc * PREFIX(tc_scale)).xxxx;
+	// 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;
 }