//
// The first input is the bottom, and the second is the top.
+#include <string>
+
#include "effect.h"
class OverlayEffect : public Effect {
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 (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_PREMULTIPLIED_ALPHA_KEEP_BLANK; }
};
#endif // !defined(_OVERLAY_EFFECT_H)