Add a inverse flag to LumaMixEffect.

[movit] / luma_mix_effect.h

diff --git a/luma_mix_effect.h b/luma_mix_effect.h
index 8bd3c506bc8bbc0c1e206cdf215af666a02037b2..ce890dfb557e887e6059d4178738fc5d1acad17c 100644 (file)
--- a/luma_mix_effect.h
+++ b/luma_mix_effect.h
@@ -2,8 +2,10 @@
 #define _MOVIT_LUMA_MIX_EFFECT_H 1
 
 // Fade between two images based on a third monochrome one; lighter pixels
-// will be faded before darker pixels. This allows a wide range of different
-// video wipes implemented using a single effect.
+// will be faded before darker pixels (unless the inverse flag is set,
+// in which case darker pixels will be faded before lighter pixels).
+// This allows a wide range of different video wipes implemented using
+// a single effect.
 //
 // Note that despite the name, the third input's _red_ channel is what's used
 // for transitions; there is no luma calculation done. If you need that,
@@ -28,6 +30,7 @@ public:
 
 private:
        float transition_width, progress;
+       int inverse;  // 0 or 1.
 };
 
 }  // namespace movit