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

Reply via email to