Finally: Fixes https://github.com/harfbuzz/harfbuzz/issues/1356
Test case:
$ ./hb-shape GeezaPro.ttc -u U+0628,U+064A,U+064E,U+0651,U+0629
[u0629.final.tehMarbuta=4+713|u064e_u0651.shaddaFatha=1@0,-200+0|u064a.medial.yeh=1+656|u0628.initial.beh=0+656]
The mark positioning (kern table CrossStream kerning) only works if deleted
glyph (as result of ligation) is still in stream and pushed through the
state machine.
This is like hb_script_t.
We had this exposed as unsigned int since 2.0.0 release in two APIs,
as well as hb_ot_layout_get_size_params() from earlier.
But since no one uses those (right?!), let's just fix this now.
* hb_ot_layout_feature_get_characters
* hb_ot_layout_feature_get_name_ids
However HarfBuzz currently doesn't expose an API for retrieving the actual
information associated with NameId from the `name` table and that should be
done separately.
Thanks to David Corbett who revamped our script and language processing
and implemented full BCP 47 support.
https://github.com/harfbuzz/harfbuzz/pull/730
New API:
+hb_ot_layout_table_select_script()
+hb_ot_layout_script_select_language()
+HB_OT_MAX_TAGS_PER_SCRIPT
+HB_OT_MAX_TAGS_PER_LANGUAGE
+hb_ot_tags_from_script_and_language()
+hb_ot_tags_to_script_and_language()
Deprecated API:
-hb_ot_layout_table_choose_script()
-hb_ot_layout_script_find_language()
-hb_ot_tags_from_script()
-hb_ot_tag_from_language()
The old hb-ot-tag.cc functions, `hb_ot_tags_from_script` and
`hb_ot_tag_from_language`, are now wrappers around a new function:
`hb_ot_tags`. It converts a script and a language to arrays of script
tags and language tags. This will make it easier to add new script tags
to scripts, like 'dev3'. It also allows for language fallback chains;
nothing produces more than one language yet though.
Where the old functions return the default tags 'DFLT' and 'dflt',
`hb_ot_tags` returns an empty array. The caller is responsible for
using the default tag in that case.
The new function also adds a new private use subtag syntax for script
overrides: "x-hbscabcd" requests a script tag of 'abcd'.
The old hb-ot-layout.cc functions,`hb_ot_layout_table_choose_script` and
`hb_ot_layout_script_find_language` are now wrappers around the new
functions `hb_ot_layout_table_select_script` and
`hb_ot_layout_script_select_language`. They are essentially the same as
the old ones plus a tag count parameter.
Closes#495.