Add a function to let non-input effects override texture bounce.

[movit] / effect.h

diff --git a/effect.h b/effect.h
index 6154dacaec1cf0e55cb7d3e734a3ed3c790cc16b..ebbb6726104051caaba9b4e58df21279682dc1f3 100644 (file)
--- a/effect.h
+++ b/effect.h
@@ -217,6 +217,20 @@ public:
        //     and allow dependent effects to change that sampler state.
        virtual bool is_single_texture() const { return false; }
 
+       // If set, this effect should never be bounced to an output, even if a
+       // dependent effect demands texture bounce.
+       //
+       // Note that setting this can invoke undefined behavior, up to and including crashing,
+       // so you should only use it if you have deep understanding of your entire chain
+       // and Movit's processing of it. The most likely use case is if you have an input
+       // that's cheap to compute but not a single texture (e.g. YCbCrInput), and want
+       // to run a ResampleEffect directly from it. Normally, this would require a bounce,
+       // but it's faster not to. (However, also note that in this case, effective texel
+       // subpixel precision will be too optimistic, since chroma is already subsampled.)
+       //
+       // Has no effect if is_single_texture() is set.
+       virtual bool override_disable_bounce() const { return false; }
+
        // If changes_output_size() is true, you must implement this to tell
        // the framework what output size you want. Also, you can set a
        // virtual width/height, which is the size the next effect (if any)