In OverlayEffect, add support for swapping the inputs.

[movit] / overlay_effect.frag

diff --git a/overlay_effect.frag b/overlay_effect.frag
index 9e5709d1dad6271535701316d4ff1b60c4533d99..d32cc062204c4492dbb552c6930908e2f8b805be 100644 (file)
--- a/overlay_effect.frag
+++ b/overlay_effect.frag
@@ -13,7 +13,15 @@
 // C_o without the division by alpha_o).
 
 vec4 FUNCNAME(vec2 tc) {
+// SWAP_INPUTS will be #defined to 1 if we want to swap the two inputs,
+#if SWAP_INPUTS
+       vec4 bottom = INPUT2(tc);
+       vec4 top = INPUT1(tc);
+#else
        vec4 bottom = INPUT1(tc);
        vec4 top = INPUT2(tc);
+#endif
        return top + (1.0 - top.a) * bottom;
 }
+
+#undef SWAP_INPUTS