The decomposition is very obscure and unlikely to help
any fonts. Just remove it since Uniscribe probably doesn't
do this either.
Fixes https://github.com/behdad/harfbuzz/issues/382
New approach to fix this:
69f9fbc420
Previous approach was reverted as it was too broad. See context:
https://github.com/behdad/harfbuzz/issues/347#issuecomment-267838368
With U+05E9,U+05B8,U+05C1,U+05DC and Arial Unicode, we now (correctly) disable
GDEF and GPOS, so we get results very close to Uniscribe, but slightly different
since our fallback position logic is not exactly the same:
Before: [gid1166=3+991|gid1142=0+737|gid5798=0+1434]
After: [gid1166=3+991|gid1142=0@402,-26+0|gid5798=0+1434]
Uniscribe: [gid1166=3+991|gid1142=0@348,0+0|gid5798=0+1434]
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.
We regeressed Malayalam in 508cc3d3cf
This brings down the failures to 198 (from 750).
BENGALI: 353725 out of 354188 tests passed. 463 failed (0.130722%)
DEVANAGARI: 707307 out of 707394 tests passed. 87 failed (0.0122987%)
GUJARATI: 366349 out of 366457 tests passed. 108 failed (0.0294714%)
GURMUKHI: 60732 out of 60747 tests passed. 15 failed (0.0246926%)
KANNADA: 951190 out of 951913 tests passed. 723 failed (0.0759523%)
KHMER: 299070 out of 299124 tests passed. 54 failed (0.0180527%)
MALAYALAM: 1048136 out of 1048334 tests passed. 198 failed (0.0188871%)
ORIYA: 42320 out of 42329 tests passed. 9 failed (0.021262%)
SINHALA: 271662 out of 271847 tests passed. 185 failed (0.068053%)
TAMIL: 1091753 out of 1091754 tests passed. 1 failed (9.15957e-05%)
TELUGU: 970555 out of 970573 tests passed. 18 failed (0.00185457%)
MYANMAR: 1123865 out of 1123883 tests passed. 18 failed (0.00160159%)
Test stats remain unchanged, except for Malayalam, which we investigate:
BENGALI: 353725 out of 354188 tests passed. 463 failed (0.130722%)
DEVANAGARI: 707307 out of 707394 tests passed. 87 failed (0.0122987%)
GUJARATI: 366349 out of 366457 tests passed. 108 failed (0.0294714%)
GURMUKHI: 60732 out of 60747 tests passed. 15 failed (0.0246926%)
KANNADA: 951190 out of 951913 tests passed. 723 failed (0.0759523%)
KHMER: 299070 out of 299124 tests passed. 54 failed (0.0180527%)
MALAYALAM: 1047584 out of 1048334 tests passed. 750 failed (0.0715421%)
ORIYA: 42320 out of 42329 tests passed. 9 failed (0.021262%)
SINHALA: 271662 out of 271847 tests passed. 185 failed (0.068053%)
TAMIL: 1091753 out of 1091754 tests passed. 1 failed (9.15957e-05%)
TELUGU: 970555 out of 970573 tests passed. 18 failed (0.00185457%)
Myanmar, compared to Windows 10 mmrtext.ttf:
MYANMAR: 1123865 out of 1123883 tests passed. 18 failed (0.00160159%)
If pre-base reordering Ra is NOT formed (or formed and then
broken up), we should consider that Ra as base. This is
observable when there's a left matra or dotreph that positions
before base.
Now, it might be that we shouldn't do this if the Ra happend
to form a below form. We can't quite deduce that right now...
Micro test added. Also at:
https://code.google.com/a/google.com/p/noto-alpha/issues/detail?id=186#c29
Sometimes font designers form half/pref/etc consonant forms
unconditionally and then undo that conditionally. Try to
recover the OT_H classification in those cases.
No test number changes expected.
Normally if you want to, say, conditionally prevent a 'pref', you
would use blocking contextual matching. Some designers instead
form the 'pref' form, then undo it in context. To detect that
we now also remember glyphs that went through MultipleSubst.
In the only place that this is used, Uniscribe seems to only care
about the "last" transformation between Ligature and Multiple
substitions. Ie. if you ligate, expand, and ligate again, it
moves the pref, but if you ligate and expand it doesn't. That's
why we clear the MULTIPLIED bit when setting LIGATED.
Micro-test added. Test: U+0D2F,0D4D,0D30 with font from:
[1]
https://code.google.com/a/google.com/p/noto-alpha/issues/detail?id=186#c29
Behdad Esfahbod
ThePhD