I've just submitted a Merge Request to speed up the auto-hinter start-up. The previous code using HarfBuzz functions was far too slow to be acceptable – HarfBuzz (currently) doesn't exactly provide what we need, causing way to much overhead.
To speed things up it was necessary to (partially) parse, validate and access the GSUB table. I really tried to avoid that, but... Please have a look! The speed-up is really impressive, I think; the old code slowed down the start-up time by more than 300% (in comparison to a commit before introducing vertical accent positioning), while the new code only adds about 25%. https://gitlab.freedesktop.org/freetype/freetype/-/merge_requests/381 Ideally, I would like to get rid of the GSUB code since it doesn't fit conceptually into FreeType (and HarfBuzz does it anyway). Behdad, do you have ideas whether something similar to `af_map_lookup` could be added to HarfBuzz? This would be a long-term solution, since even if HarfBuzz gets fitting functionality I don't want to make FreeType depend on the newest HarfBuzz version... Werner