X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=overlay_effect.h;fp=overlay_effect.h;h=64224afe572b9a7e738af3ab0a72fe8bb61a15ea;hp=121027a9f891aef043a735be1a7ff004097ee1e3;hb=b10c546f579c7ccb5939161e61a71cd18a3f9bbd;hpb=caa05550e868db406e4b54e69d60b5573f59cb60

diff --git a/overlay_effect.h b/overlay_effect.h
index 121027a..64224af 100644
--- a/overlay_effect.h
+++ b/overlay_effect.h
@@ -20,6 +20,11 @@ public:
 
 	virtual bool needs_srgb_primaries() const { return false; }
 	virtual unsigned num_inputs() const { return 2; }
+
+	// Actually, if either image has blank alpha, our output will have
+	// blank alpha, too. However, understanding that would require changes
+	// to EffectChain, so postpone that optimization for later.
+	virtual AlphaHandling alpha_handling() const { return INPUT_AND_OUTPUT_ALPHA_PREMULTIPLIED; }
 };
 
 #endif // !defined(_OVERLAY_EFFECT_H)