+ // 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. Also, you can set a
+ // virtual width/height, which is the size the next effect (if any)
+ // will _think_ your data is in. This is primarily useful if you are
+ // relying on getting OpenGL's bilinear resizing for free; otherwise,
+ // your virtual_width/virtual_height should be the same as width/height.
+ //
+ // 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,
+ unsigned *virtual_width, unsigned *virtual_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) {}
+
+ // How many inputs this effect will take (a fixed number).
+ // If you have only one input, it will be called INPUT() in GLSL;
+ // if you have several, they will be INPUT1(), INPUT2(), and so on.
+ virtual unsigned num_inputs() const { return 1; }
+
+ // Let the effect rewrite the effect chain as it sees fit.
+ // Most effects won't need to do this, but this is very useful
+ // if you have an effect that consists of multiple sub-effects
+ // (for instance, two passes). The effect is given to its own
+ // pointer, and it can add new ones (by using add_node()
+ // and connect_node()) as it sees fit. This is called at
+ // EffectChain::finalize() time, when the entire graph is known,
+ // in the order that the effects were originally added.
+ //
+ // Note that if the effect wants to take itself entirely out
+ // of the chain, it must set “disabled” to true and then disconnect
+ // itself from all other effects.
+ virtual void rewrite_graph(EffectChain *graph, Node *self) {}