#include <GL/gl.h>
+class EffectChain;
+
// Can alias on a float[2].
struct Point2D {
Point2D(float x, float y)
// the pixels, e.g. mirror, won't need to care, and can set this
// to false. If so, the input gamma will be undefined.
//
- // Also see the note on needs_many_samples(), below.
+ // Also see the note on needs_texture_bounce(), below.
virtual bool needs_linear_light() const { return true; }
// Whether this effect expects its input to be in the sRGB
// Again, most effects will want this.
virtual bool needs_srgb_primaries() const { return true; }
- // Whether this effect expects to be sampling many times from
- // its input. If this is true, the framework will not chain the
+ // Whether this effect expects its input to come directly from
+ // a texture. If this is true, the framework will not chain the
// input from other effects, but will store the results of the
// chain to a temporary (RGBA fp16) texture and let this effect
// sample directly from that.
//
- // Note that if you do _not_ set this, and do not sample on
- // whole pixels (ie. you request linear filtering), it is undefined
- // whether that filtering happen in linear gamma or not.
- // It _could_ be (for instance in the case where the input is sRGB
- // and your GPU applies gamma expansion before filtering), but you
- // have no such guarantee. For most uses, however, this will be fine.
- virtual bool needs_many_samples() const { return false; }
+ // There are two good reasons why you might want to set this:
+ //
+ // 1. You are sampling more than once from the input,
+ // in which case computing all the previous steps might
+ // be more expensive than going to a memory intermediate.
+ // 2. You rely on previous effects, possibly including gamma
+ // expansion, to happen pre-filtering instead of post-filtering.
+ // (This is only relevant if you actually need the filtering; if
+ // you sample on whole input pixels only, it makes no difference.)
+ //
+ // Note that in some cases, you might get post-filtered gamma expansion
+ // even when setting this option. More specifically, if you are the
+ // first effect in the chain, and the GPU is doing sRGB gamma
+ // expansion, it is undefined (from OpenGL's side) whether expansion
+ // happens pre- or post-filtering. For most uses, however,
+ // either will be fine.
+ virtual bool needs_texture_bounce() const { return false; }
// Whether this effect expects mipmaps or not. If you set this to
// true, you will be sampling with bilinear filtering; if not,
// needs mipmaps, you will also get them).
virtual bool needs_mipmaps() const { return false; }
+ // 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; }
+
// Requests that this effect adds itself to the given effect chain.
// For most effects, the default will be fine, but for effects that
// consist of multiple passes, it is often useful to replace this
// with something that adds completely different things to the chain.
- virtual void add_self_to_effect_chain(std::vector<Effect *> *chain) {
- chain->push_back(this);
- }
+ virtual void add_self_to_effect_chain(EffectChain *graph, const std::vector<Effect *> &inputs);
// Outputs one GLSL uniform declaration for each registered parameter
// (see below), with the right prefix prepended to each uniform name.