There are more broken versions of Tahoma out there on various Windows releases,
so we need to add them to our blacklist to avoid broken rendering.
See https://bugzilla.mozilla.org/show_bug.cgi?id=1279925 for details.
In https://crbug.com/681813 another instance of Padauk was identified
triggering collapsed glyphs. Blacklist this version by patching
hb-ot-layout.cc to print out gdef, gsub, and gpos table length, then
adding those to the list of blacklisted versions.
Note, the function now returns "half of horizontal advance width"
if top accent attachment for glyph is not explicitly defined.
This is what the spec requires. Updated tests.
This is based on bug reports that have been filed against Firefox since it
updated to a version of harfbuzz that uses zeroing by GDEF rather than by
Unicode. I'm sure there are a bunch more font versions that should also be
included; these are just the ones I have on hand and have confirmed as having
bad GDEF data.
Given how the list here is growing, I think we should reconsider the approach,
and perhaps revert to zeroing by Unicode instead.
Fixes https://github.com/behdad/harfbuzz/issues/264
Fixes https://github.com/behdad/harfbuzz/pull/266
This speeds up shaping the Amiri font by over 15%.
This was primarily needed for my work on OpenType GX, since
we will be collecting only sublookups that are "active" for
current font instance; but it's a nice boost in general as
well.
We might, in the future, collect subtables in the lookup_accel.
That would also allow us to do a per-subtbale set-digest, which
should speed things up some more, specially for ContextChainFormat3
lookups... Amiri, for example, contains one lookup with 53
subtables!
Currently just announces lookup applications. Message-API *will* change.
hb-shape / hb-view are updated to print-out messages to stder if --debug
is specified.
Behdad Esfahbod
Ebrahim Byagowi
jfkthame
Dominik Röttsches
Frédéric Wang
Khaled Hosny