New API:
- hb_font_get_nominal_glyph_func_t
- hb_font_get_variation_glyph_func_t
- hb_font_funcs_set_nominal_glyph_func()
- hb_font_funcs_set_variation_glyph_func()
- hb_font_get_nominal_glyph()
- hb_font_get_variation_glyph()
Deprecated API:
- hb_font_get_glyph_func_t
- hb_font_funcs_set_glyph_func()
Clients that implement their own font-funcs are encouraged to replace
their get_glyph() implementation with a get_nominal_glyph() and
get_variation_glyph() pair. The variation version can assume that
variation_selector argument is not zero.
This is what Microsoft's implementation does. Marks that need advance
need to add it back using 'dist' or other feature in GPOS. Update tests to
match.
Before, we were just checking the use_category(). This detects as
halant a ligature that had the halant as first glyph (as seen in
NotoSansBalinese.) Change that to use the is_ligated() glyph prop
bit. The font is forming this ligature in ccmp, which is before
the rphf / pref tests. So we need to make sure the "ligated" bit
survives those tests. Since those only check the "substituted" bit,
we now only clear that bit for them and "ligated" survives.
Fixes https://github.com/behdad/harfbuzz/issues/180
Behdad Esfahbod
ThePhD