walkero
/
harfbuzz
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Remove final pause from Arabic shaper 

Back in the old days, we used to apply 'calt' and 'cswh' in Arabic shaper,
with a pause in between.  Then we disabled the 'cswh' because Microsoft
disabled it, but forgot to remove the unnecessary pause.  Do that now.

This has the benefit that it fixes shaping with monbaiti from Windows 10.
In that version of that font, the lookups from 'calt' are duplicated in
'rclt', and Mongolian was changed to go through Universal Shaping Engine.
We still use the Arabic shaper for Mongolian.  With a pause after 'calt',
we were applying the duplicate lookups from 'calt' and 'rclt' twice.  It
happened to be the case that these lookups were NOT idempotent.  So we
were getting wrong shaping.  See thread "Windows 10 monbaiti.ttf upgrade
(5.01 -> 5.51) caused loss of diacritical marks when shaped with harfbuz"
on the mailing list.  This fixes that.
This commit is contained in:
Behdad Esfahbod 2015-12-07 21:38:47 +01:00
parent dee0fbf9e2
commit 98460779ba
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/hb-ot-shape-complex-arabic.cc
View File

@ -223,7 +223,6 @@ collect_features_arabic (hb_ot_shape_planner_t *plan)
map->add_gsub_pause (arabic_fallback_shape);
map->add_global_bool_feature (HB_TAG('c','a','l','t'));
map->add_gsub_pause (NULL);
/* The spec includes 'cswh'. Earlier versions of Windows
* used to enable this by default, but testing suggests
@ -233,6 +232,7 @@ collect_features_arabic (hb_ot_shape_planner_t *plan)
* Note that IranNastaliq uses this feature extensively
* to fixup broken glyph sequences. Oh well...
* Test case: U+0643,U+0640,U+0631. */
//map->add_gsub_pause (NULL);
//map->add_global_bool_feature (HB_TAG('c','s','w','h'));
map->add_global_bool_feature (HB_TAG('m','s','e','t'));
}