+ // Whether this effect wants to output to a different size than
+ // its input(s) (see inform_input_size(), below). If you set this to
+ // true, the output will be bounced to a texture (similarly to if the
+ // next effect set needs_texture_bounce()).
+ virtual bool changes_output_size() const { return false; }
+
+ // If changes_output_size() is true, you must implement this to tell
+ // the framework what output size you want.
+ //
+ // Note that it is explicitly allowed to change width and height
+ // from frame to frame; EffectChain will reallocate textures as needed.
+ virtual void get_output_size(unsigned *width, unsigned *height) const {
+ assert(false);
+ }
+
+ // Tells the effect the resolution of each of its input.
+ // This will be called every frame, and always before get_output_size(),
+ // so you can change your output size based on the input if so desired.
+ //
+ // Note that in some cases, an input might not have a single well-defined
+ // resolution (for instance if you fade between two inputs with
+ // different resolutions). In this case, you will get width=0 and height=0
+ // for that input. If you cannot handle that, you will need to set
+ // needs_texture_bounce() to true, which will force a render to a single
+ // given resolution before you get the input.
+ virtual void inform_input_size(unsigned input_num, unsigned width, unsigned height) {}
+