In Windows 7 on Chrome if the coverage table comes before any of the LigatureSet or Ligature subtables the font won't load. This changes the packing order to always place the Coverage table last. Virtual links are used to ensure the repacker maintains the desired ordering.
Coincidentally fontTools also does the same thing (a3f988fbf6/Lib/fontTools/ttLib/tables/otTables.py (L1137)) to reduce overflows during packing.
- Rename enum type and enum members.
- in_errors() now returns true for any error having been set. hb-subset now looks for offset overflow only errors to divert to repacker.
- Added INT_OVERFLOW and ARRAY_OVERFLOW enum values.
previously remove_redundant_sys () is missing in harfbuzz, after
redundant langsys removal, some features are removed as well in
prune_features() in fonttools. This change is trying to get the same
result between harfbuzz and fonttools.
optimize recurse_lookups in Context/ChainContext
glyph closure, only the glyphs that the parent lookup
can apply the recursion to can participate in recursing
the lookup.
Previous GSUB glyph closure is done by recursively visiting
all reachable lookup tables that apply to any glyphs in the
current/input glyph set, but actually only the glyphs that
the parent lookup can apply the recursion to can participate
in recursing the lookup. This is step 1 for glyph closure
optimization:
1. Add stack of currently active glyph set pointers into hb_closure_context_t
2. Update closure() method in simple GSUB tables to use
this stack in order not to change current glyph set at different stages
of recursion
3. Add function may_have_non_1to1() to GSUB tables
This matches fontTools behaviour. glyphset_gsub does not contain gids added from closing over composite glyphs in glyf, since these cannot particpate in GSUB/GPOS processing.
First time we do this in a way that if target object doesn't have the matching
function we basically "ignore". Risky but I feel like is the right decision
for this case.
I'm going to put back the template varargs and use those, which would make
the dispatcher be just that: "dispatcher", and wouldn't need to carry the
call context. That would be a refreshing change I think.
Added a variant of subset_offset_array which takes an extra arg passed to serialize_subset for this impl.
Added a new api test "test-subset-gpos" for this.
Garret Rieger
Behdad Esfahbod
Qunxin Liu
Ebrahim Byagowi
ariza