+ // Whether this effects expects its input (and output) to be in
+ // linear gamma, ie. without an applied gamma curve. Most effects
+ // will want this, although the ones that never actually look at
+ // 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_texture_bounce(), below.
+ virtual bool needs_linear_light() const { return true; }
+
+ // Whether this effect expects its input to be in the sRGB
+ // color space, ie. use the sRGB/Rec. 709 RGB primaries.
+ // (If not, it would typically come in as some slightly different
+ // set of RGB primaries; you would currently not get YCbCr
+ // or something similar).
+ //
+ // Again, most effects will want this, but you can set it to false
+ // if you process each channel independently, equally _and_
+ // in a linear fashion.
+ virtual bool needs_srgb_primaries() const { return true; }
+
+ // 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.
+ //
+ // 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,
+ // you could be sampling with simple linear filtering and no mipmaps
+ // (although there is no guarantee; if a different effect in the chain
+ // needs mipmaps, you will also get them).
+ virtual bool needs_mipmaps() const { return false; }