The views made it look like one cannot use Trade::ImageData etc. as
inputs, and the reason for using them was because there was a
load-bearing const in the view type that allowed slice() to work. The
slice() API is fixed now so this doesn't need to be silly anymore.
Because otherwise the users likely have to do something similar on their
end to perform a texture upload etc., which means they'll either take
the easy path and upload everything including the unused area, or they
introduce various bugs in the process, leading to random artifacts,
especially when it comes to padding.
Which is exactly what I think is causing random test failures in the Ui
library text rendering, because the glyph cache filling process in
plugins is calculating the rectangle too tight, without considering
padding. Gonna fix that now.
The overhead of maintaining two classes with only very slight
differences in the API and the internals being basically identical is
not worth it. Too much potential for inconsistencies and doc errors.
Additionally, when I attempted to use it for the reworked Text glyph
cache, I realized I'd need to wrap them both under a common interface,
allowing easy use for both 2D and 2D array textures. And then it's
easier to just have the Atlas class done that way directly instead of
papering over that in a downstream API.
Just the dumbest possible idea I had, and it compares surprisingly well
in both efficiency (~comparable to stb_rect_pack) and speed
(significantly faster than stb_rect_pack with tons of tiny images,
slower with larger ones -- would probably need to SIMD Math::max() and
such, haha). It's the very first implementation without any additional
improvements I have in mind, so it'll likely improve further.
Includes a benchmark with a bunch of "datasets" extracted from both
fonts and large glTF models. The stb_rect_pack file isn't commited as
it's not useful apart from this single benchmark, put it to
AtlasTestFiles/ and recompile.
Vladimír Vondruš