X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=overlay_effect.h;h=c11569f4eec6c34e0eea4e169ee51b6142fef637;hp=d26d9175110ca636890e5c03084a98a7e747560f;hb=6f1efa8348a90a393187c12d70fd10d81bbd2c99;hpb=5d4c0425579de66b3e2dd7d0095e890278f8efcf

diff --git a/overlay_effect.h b/overlay_effect.h
index d26d917..c11569f 100644
--- a/overlay_effect.h
+++ b/overlay_effect.h
@@ -1,5 +1,5 @@
-#ifndef _OVERLAY_EFFECT_H
-#define _OVERLAY_EFFECT_H 1
+#ifndef _MOVIT_OVERLAY_EFFECT_H
+#define _MOVIT_OVERLAY_EFFECT_H 1
 
 // Put one image on top of another, using alpha where appropriate.
 // (If both images are the same aspect and the top image has alpha=1.0
@@ -10,8 +10,12 @@
 //
 // The first input is the bottom, and the second is the top.
 
+#include <string>
+
 #include "effect.h"
 
+namespace movit {
+
 class OverlayEffect : public Effect {
 public:
 	OverlayEffect();
@@ -20,11 +24,16 @@ public:
 
 	virtual bool needs_srgb_primaries() const { return false; }
 	virtual unsigned num_inputs() const { return 2; }
+	virtual bool one_to_one_sampling() const { return true; }
 
-	// Actually, if either image has blank alpha, our output will have
-	// blank alpha, too. However, understanding that would require changes
+	// Actually, if _either_ image has blank alpha, our output will have
+	// blank alpha, too (this only tells the framework that having _both_
+	// images with blank alpha would result in blank alpha).
+	// However, understanding that would require changes
 	// to EffectChain, so postpone that optimization for later.
-	virtual AlphaHandling alpha_handling() const { return INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA; }
+	virtual AlphaHandling alpha_handling() const { return INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK; }
 };
 
-#endif // !defined(_OVERLAY_EFFECT_H)
+}  // namespace movit
+
+#endif // !defined(_MOVIT_OVERLAY_EFFECT_H)