mp_uctx.c

There was a performance regression since then, probably located in these upstream commits:

* 720a5357 "rasterizer: always do at least one subidvision of beziers" - 15% FPS drop on sensors app
* 5b4d3d44 "ctx: the glyph API now takes glyph_ids and not unicode codepoints" - further 25% FPS drop on sensors app

Not terribly sure about the last commit because it doesn't work by itself (most glyphs don't render, this was fixed later in b5a9a81d), but it's most likely the group started by that one.

These commits happened to be 2-3 days after our last known good commit, and performance of the sensors app remained stable for months afterwards.

Because we're preparing for a release and pippin doesn't seem to have the time to address this right now, and I'd have no idea where to even begin, I'm doing the next best thing I know and reverting to the known good version.