Commit Graph

294 Commits

Author SHA1 Message Date
Behdad Esfahbod 2cc993e035 [dispatch] Minor 2018-12-12 10:07:38 -05:00
Behdad Esfahbod fb05908213 Revert ugly fixes
Now that we have 6daf45e0, revert cryptic hacks...

This reverts commit abd81ed4f5.
This reverts commit 9c6921c08c.
This reverts commit d39760cabf.
This reverts commit fedd8e6c17.

Fixes https://github.com/harfbuzz/harfbuzz/issues/1374
2018-11-30 20:56:15 -05:00
Behdad Esfahbod 9c6921c08c More...
hb-ot-layout-gsubgpos.hh:1707: error: ISO C++ says that these are ambiguous, even though the worst conversion for the first is better than the worst conversion for the second:
...
2018-11-30 15:16:57 -05:00
Behdad Esfahbod 5c4fead734 Convert "static const hb_tag_t" constants to enum 2018-11-29 15:05:47 -05:00
Behdad Esfahbod 574d888c8a [aat] Ignore GSUB table of Muthu Foundry if they have morx table
Fixes https://github.com/harfbuzz/harfbuzz/issues/1410
2018-11-25 16:51:22 -05:00
Ebrahim Byagowi 11aa0468ac [subset] minor, adjust spaces 2018-11-16 00:02:47 +03:30
Behdad Esfahbod e014405a21 Rename check_array(array, a, b) to check_range() 2018-11-12 14:23:31 -05:00
Behdad Esfahbod 1d66cdcf77 Better fix for MSVC 2008
Follow up on b4c6113032

Fixes https://github.com/harfbuzz/harfbuzz/issues/1374
2018-11-10 19:57:51 -05:00
Behdad Esfahbod 385f78b312 [aat] Remove deleted-glyhs after applying kerx/kern
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.
2018-11-07 17:20:47 -05:00
Behdad Esfahbod 6ee6cd93d8 [GPOS] Only mark unsafe-to-break if kerning happened
Fixes https://github.com/harfbuzz/harfbuzz/issues/1365
2018-11-07 15:40:55 -05:00
Behdad Esfahbod 501a364d9b [GPOS] Add TODO item 2018-11-07 15:02:16 -05:00
Behdad Esfahbod 33b006cc51 [ot-layout] Simplify some access 2018-11-05 23:19:04 -05:00
Behdad Esfahbod ca5e5a4979 Port Coverage::Iter off hb_auto_t<> 2018-10-29 22:30:21 -07:00
Behdad Esfahbod 39bd07aed5 Fix bunch of unused parameter warnings
Show up with gcc -O0.

There's a few more but those are functions that need to be filled in.

Maybe this is a lost battle...
2018-10-26 21:22:26 -07:00
Behdad Esfahbod 21ede867df Fix possible overflow in bsearch impls
From bungeman.

Fixes https://github.com/harfbuzz/harfbuzz/pull/1314
2018-10-25 13:19:58 -07:00
Bruce Mitchener 8d1e479d1d Use bool literals instead of 0/1. 2018-10-19 18:05:46 +02:00
Behdad Esfahbod 36f38ea703 [gpos] Protect mark attachment against out-of-bounds
Not sure how can happen, but does...
2018-10-16 16:24:03 -07:00
Behdad Esfahbod bf8469be9a Attach CursivePositioning backwards, not forward
This is how Uniscribe does it.  So, adjust.  This is only relevant
to fonts that apply cursive positioning from a contextual lookup.

Fixes https://github.com/harfbuzz/harfbuzz/issues/1181
2018-10-11 20:45:40 -04:00
Behdad Esfahbod 1622ba5943 [kerx] Implement Format4 'ankr'-based mark attachment
Tested with Kannada MN:

$ HB_OPTIONS=aat ./hb-shape Kannada\ MN.ttc -u 0CCD,0C95,0CD6
[kn_ka.vattu=0+230|kn_ai_length_mark=1@326,0+607]
2018-10-11 01:17:33 -04:00
Behdad Esfahbod dff2c45f1e Port rest from VAR to UnsizedArrayOf<> 2018-09-11 01:01:08 +02:00
Behdad Esfahbod 9507b05a7a Simplify sanitize->check_array()
Fix a bug in CBDT sanitize, and redundant check in avar.
2018-09-10 23:18:23 +02:00
Behdad Esfahbod 339d3603b9 [subset] Wire up subset() call down to subtables 2018-09-03 17:40:16 -07:00
Behdad Esfahbod 7b2ef551da Templatize Lookup::sanitize() 2018-09-03 17:16:09 -07:00
Behdad Esfahbod 9c3747c5e5 [subset] More 2018-09-03 16:53:03 -07:00
Behdad Esfahbod 6d618522d6 Templatize GSUBGPOS::sanitize() 2018-09-03 16:41:28 -07:00
Behdad Esfahbod 7c9cfa2b40 Add intersects() method to GSUB/GPOS lookups 2018-09-02 19:47:50 -07:00
Behdad Esfahbod 3a0b3a29cc Free up hb-ot-face.hh from includes
There might be a better way to do this, but I couldn't find...
2018-08-26 15:11:24 -07:00
Behdad Esfahbod 3999094682 [OT] Use relaxed ops for recursing into GSUB/GPOS lookups again 2018-08-26 09:12:25 -07:00
Behdad Esfahbod c44b0caf0d Fixup 2018-08-26 01:29:30 -07:00
Behdad Esfahbod b929100f87 [ot-face] Unify GSUB/GPOS accelerators in the table accelerator framework 2018-08-26 01:15:47 -07:00
Behdad Esfahbod 963413fc54 WIP 2018-08-26 00:47:55 -07:00
Behdad Esfahbod c77ae40852 Rename hb-*private.hh to hb-*.hh
Sorry for the noise, downstream custom builders.  Please adjust.
2018-08-25 22:36:36 -07:00
Behdad Esfahbod 1c6b369324 [ot] Rename hb_ot_layout_t to hb_ot_face_data_t 2018-08-23 11:30:21 -07:00
Behdad Esfahbod 0271c7ab3b [ot] Move GSUB/GPOS into tables_t 2018-08-03 16:45:57 -07:00
Behdad Esfahbod bddeb2b10c Minor renamings of internal inline functions 2018-07-10 14:13:21 +02:00
Behdad Esfahbod d3c0980ac2 Adjust MarkBasePos heuristic in presence of MultipleSubst
From the issue:
"In this font, the virama,ya first forms a ligature, then decomposes back to
virama,ya. This causes those two to be marked parts of a MultipleSubst
sequence. When attaching the matra, we look for the first of the MultipleSubst
sequence because that's where we attach to (because of eg #740). In this case,
the first glyph in the MultipleSubst sequence is a mark, so we skip it and
attach to the base char before it."

Font in question is Nirmala UI from Windows 10. Test sequence:

  U+0926,U+094D,U+092F,U+0941

Fixes https://github.com/harfbuzz/harfbuzz/issues/1020
2018-06-30 15:59:25 +04:30
Ebrahim Byagowi eaf649450a Resolve clang's conditional-uninitialize warnings 2018-04-23 11:38:45 -07:00
Ebrahim Byagowi a02c3ee70f Add or update tables specifications links 2018-04-12 13:44:32 +04:30
Behdad Esfahbod e347fb908b Minor 2018-02-26 01:08:50 -08:00
Behdad Esfahbod 1c50a88623 Readjust mark attachment heuristic a bit more
Previously adjusted logic could fail if nothing around was ligated,
and something moved.  This should take care of that.

CC https://github.com/harfbuzz/harfbuzz/issues/740
2018-02-18 15:58:09 -08:00
Behdad Esfahbod 978ace6fbb Improve _hb_popcount()
Support 128bit type.
2018-02-16 16:08:45 -08:00
Behdad Esfahbod 9b5af3ec7f [gpos] Adjust mark attachment heuristic
Hopefully it...
fixes https://github.com/harfbuzz/harfbuzz/issues/740
2018-02-10 21:50:44 -06:00
Behdad Esfahbod fd03449094 Rename hb_apply_context_t to hb_ot_apply_context_t 2018-01-19 16:40:13 -08:00
Behdad Esfahbod 188ee6e5ee Calculate anchor positions in float, then round
Hoping to reduce rounding error, to make tests happier...
No luck.
2018-01-10 05:13:47 +01:00
Behdad Esfahbod 7cdd6ab068 Round, instead of floor, when applying variations
Hoping this would fix remaining text-rendering-tests failures,
but so far no luck.
2018-01-10 04:44:33 +01:00
Behdad Esfahbod 6b19178ee3 Prefix int types with HB
Such a headache that Windows defines UINT8, ...; Just prefix it.
2018-01-10 03:07:30 +01:00
Behdad Esfahbod 71e6adf1e2 [collect_glyphs] handle ClassDef better 2017-12-16 11:07:37 -05:00
Behdad Esfahbod 87cc5a65cb [collect_glyphs] In PairPosFornat2 do not collect classDef1
The coverage already covered that.
2017-12-16 06:18:07 -08:00
Behdad Esfahbod 81f27df4d9 More work towards improving collect_glyphs() against bad input
The three "XXXXX"'s should be switched to false.  Doing that separately for ease
of bisecting...
2017-12-16 06:12:06 -08:00
Behdad Esfahbod 5d02572034 [set] Add add_sorted_array()
Not optimized to use sortedness yet.  Also start putting in place infra
to faster reject bad data.

A version of Chandas.ttf found on some Chrome bots has 660kb of GPOS,
mostly junk.  That is causing 48 million of set->add() calls in
collect_glyphs(), which is insane.

In the upcoming commits, I'll be speeding that up by optimizing
add_sorted_array(), while also reducing work by rejecting out-of-sort
arrays quickly and propagate the rejection.

Part of https://bugs.chromium.org/p/chromium/issues/detail?id=794896
2017-12-14 19:35:47 -08:00
Behdad Esfahbod 6f335ed1e5 Replace USHORT/SHORT/ULONG/etc with UINT16/INT16/UINT32/etc 2017-11-14 21:06:07 -08:00
Behdad Esfahbod 5d98de1f38 Tweak mark-base attachment
Apparently a base glyph can also become an attached component of a
ligature if the ligature-forming lookup used IgnoreBase.  This was
being confused with a non-first component of a MultipleSubst and
hence not matched for mark-attachment.  Tweak test to fix.

Fixes https://github.com/behdad/harfbuzz/issues/543
2017-10-03 13:49:40 +02:00
Behdad Esfahbod b65aa1cd47 [unsafe-to-break] Flag during mark attachment 2017-08-10 20:32:02 -07:00
Behdad Esfahbod 882ebdadd6 [unsafe-to-break] Flag during cursive positioning 2017-08-10 20:23:17 -07:00
Behdad Esfahbod 2d158ca376 [unsafe-to-break] Flag during kerning 2017-08-10 20:20:30 -07:00
Volker H. Simonis ad273881c5 Minor fixes to pacify Coverity code scan
Fixes https://github.com/behdad/harfbuzz/pull/377
2016-12-18 00:14:06 -06:00
Behdad Esfahbod 59055b5494 [GX] Implement Feature Variations
Not hooked up to shaper yet.
2016-12-16 19:06:26 -06:00
Behdad Esfahbod cf3de4d8f7 [GX] Rename VarStore to VariationStore 2016-12-16 19:06:26 -06:00
Behdad Esfahbod 1124d2ece5 [GX] Fix thinko 2016-12-16 19:06:26 -06:00
Behdad Esfahbod 151d93de8a [GX] Hook up GPOS to Variation Store stored in GDEF
Untested.
2016-12-16 19:06:26 -06:00
Behdad Esfahbod 49cb87850c [GX] Pass apply-context down to get_anchor()
Needed to access GDEF for varStore.
2016-12-16 19:06:26 -06:00
Behdad Esfahbod dc9f229799 [GX] Port variation stuff to Variation Store design
Not hooked up to GDEF yet.
2016-12-16 19:06:26 -06:00
Behdad Esfahbod ca28670316 [GX] Towards anisotropic interpolation
Also hookup to ValueRecord and Anchors.
2016-12-16 19:06:26 -06:00
Behdad Esfahbod ebd7431f82 Partially revert 86c68c7a2c
That commit moved the advance adjustment for mark positioning to
be applied immediately, instead of doing late before.  This breaks
if mark advances are zeroed late, like in Arabic.  Also, easier to
hit it in RTL scripts since a single mark with non-zero advance is
enough to hit the bug, whereas in LTR, at least two marks are needed.

This reopens https://github.com/behdad/harfbuzz/issues/211
The cursive+mark interaction is broken again.  To be fixed in a
different way.
2016-02-24 15:53:40 +09:00
Behdad Esfahbod 86c68c7a2c [GPOS] Fix interaction of mark attachments and cursive chaining
Fixes https://github.com/behdad/harfbuzz/issues/211

What happens in that bug is that a mark is attached to base first,
then a second mark is cursive-chained to the first mark.  This only
"works" because it's in the Indic shaper where mark advances are
not zeroed.

Before, we didn't allow cursive to run on marks at all.  Fix that.
We also where updating mark major offsets at the end of GPOS, such
that changes in advance of base will not change the mark attachment
position.  That was superior to the alternative (which is what Uniscribe
does BTW), but made it hard to apply cursive to the mark after it
was positioned.  We could track major-direction offset changes and
apply that to cursive in the post process, but that's a much trickier
thing to do than the fix here, which is to immediately apply the
major-direction advance-width offsets...  Ie.:

https://github.com/behdad/harfbuzz/issues/211#issuecomment-183194739

If this breaks any fonts, the font should be fixed to do mark attachment
after all the advances are set up first (kerning, etc).

Finally, this, still doesn't make us match Uniscribe, for I explained
in that bug.  Looks like Uniscribe applies minor-direction cursive
adjustment immediate as well.  We don't, and we like it our way, at
least for now.  Eg. the sequence in the test case does this:

- The first subscript attaches with mark-to-base, moving in x only,
- The second subscript attaches with cursive attachment to first subscript
  moving in x only,
- A final context rule moves the first subscript up by 104 units.

The way we do, the final shift-up, also shifts up the second subscript
mark because it's cursively-attached.  Uniscribe doesn't.  We get:

[ttaorya=0+1307|casubscriptorya=0@-242,104+-231|casubscriptnarroworya=0@20,104+507]

while Uniscribe gets:

[ttaorya=0+1307|casubscriptorya=0@-242,104+-211|casubscriptnarroworya=0+487]

note the different y-offset of the last glyph.  In our view, after cursive,
things move together, period.
2016-02-16 16:07:20 +07:00
Behdad Esfahbod 6ab920224c [GPOS] Minor
No effect.
2016-02-11 16:57:52 +07:00
Behdad Esfahbod cbc3a76c5a [GPOS] Merge fixing of offsets for cursive and mark attachments
Part of fixing https://github.com/behdad/harfbuzz/issues/211
2016-02-11 16:48:13 +07:00
Behdad Esfahbod 7d8d58ac81 [GPOS] Divide position_finish() into two phases, for advances and offsets
Right now the position_finish_advances() is empty.  To be used for
spacing attachments proposal later.
2016-02-11 16:34:28 +07:00
Behdad Esfahbod 8474231567 [ot] Minor shuffling code around 2016-02-11 16:27:41 +07:00
Behdad Esfahbod b0b11614e9 [GPOS] Add harmless recursion in fix_mark_attachment()
Will do nothing.  Just useful for merging two functions.
2016-02-11 15:28:55 +07:00
Behdad Esfahbod 686567baab [GPOS] Merge attach_chain() and cursive_chain()
Differentiate, using new attach_type().
2016-02-11 15:25:28 +07:00
Behdad Esfahbod 806ad8dc65 [GPOS] Minor shuffling 2016-02-11 14:53:11 +07:00
Behdad Esfahbod 0f6278d1fb [GPOS] Negate sign of attach_lookback(), and rename it to attach_chain()
No behavior change.  Preparing to unify how cursive and mark attachments
work.
2016-02-11 14:49:10 +07:00
Behdad Esfahbod fc38e6034c [layout] Collect coverage glyphs in PairPos
Apparently class=0 is used for ClassDef1.  See:
https://github.com/adobe-type-tools/afdko/issues/90
2015-12-23 14:50:53 +01:00
Behdad Esfahbod 550bd14d2b Actually commit changes for previous commit 2015-11-04 22:58:58 -08:00
Behdad Esfahbod ff31b3c1b8 Skip GPOS cursive / attachment adjustmnent if none happened
I'm starting to really like how free these new scratch_flags are.
2015-11-04 22:47:30 -08:00
Behdad Esfahbod f966649747 Fix another memory access issue discovered by libFuzzer
Fixes https://github.com/behdad/harfbuzz/issues/139#issuecomment-146984679
2015-10-13 00:30:50 -04:00
Behdad Esfahbod f396fbb000 Fix return value of sanitize when subformat is not readable
This is a fix on top of the previous issue fixed in
c917965b9e.

This was caught by "libFuzzer" testing.
2015-10-09 12:25:55 -04:00
Behdad Esfahbod b47159011c Define return_trace()
Not functional change (expected!).
2015-09-29 14:57:02 +01:00
Behdad Esfahbod c917965b9e Add missing returns
Fixes possible invalid read of two bytes.

Reported by Behzad Najjarpour Jabbari, Secunia Research.
2015-09-29 14:45:35 +01:00
Behdad Esfahbod 6578575cc8 [GPOS] Fix cursive connection with mix of RTL and non-RTL lookups
See thread "Issue with cursive attachment" started by Khaled.
Turned out fixing this wasn't as bad as I had assumed.  I like the
new code better; we now have a theoretical model of cursive
connections that is easier to reason about.
2015-08-25 20:29:36 +01:00
Behdad Esfahbod 58f2a73fb9 [GPOS] Rewrite cursive attachment slightly differently
In anticipation for upcoming fix for bug reported by
Khaled in thread "Issue with cursive attachment".
2015-08-25 18:58:24 +01:00
Behdad Esfahbod 2c8b3b2e53 [debug] Print lookup index in debug-apply output 2015-08-18 14:36:43 +01:00
Behdad Esfahbod fc3c59a1d7 Fix unused var warnings 2015-04-08 13:04:29 -07:00
Behdad Esfahbod bd047d3b7f [layout] Minor 2015-02-25 15:43:31 -08:00
Behdad Esfahbod 1a2322134a [layout] Don't check glyph props against lookup flags when recursing
Shouldn't be needed.  I have a hard time imagining this breaking any
legitimate use case.
2015-02-25 15:43:30 -08:00
Behdad Esfahbod 095a1257cc [layout] Port sanitize() to use dispatch()
Needed some rework of Extension table.  Hopefully I got it right, and
the new template usage doesn't break any compilers...
2015-02-25 15:43:30 -08:00
Behdad Esfahbod 40c58923cb [layout] Refactor Lookup::dispatch() 2015-02-25 15:43:30 -08:00
Behdad Esfahbod 70366f5d19 [layout] Refactor get_subtable() 2015-02-25 15:43:29 -08:00
Behdad Esfahbod f72f326aea Minor 2015-02-25 15:43:29 -08:00
Behdad Esfahbod 8e36ccfd4f [layout] Use dispatch() for add_coverage() 2015-02-25 15:43:29 -08:00
Behdad Esfahbod 50b8dc79da [layout] Add may_dispatch()
No functional change right now.
2015-02-25 15:43:29 -08:00
Behdad Esfahbod de2118ed7a Make sanitize() a const method
This makes a lot of code safer.  We only try modifying the object in one
place, after making sure it's safe to do so.  So, do a const_cast<> in
that one place...
2015-02-25 15:43:28 -08:00
Behdad Esfahbod 6759ed95a3 Minor 2015-02-25 15:43:28 -08:00
Behdad Esfahbod 6b599dac1f Remove unnecessary check in sanitize 2015-02-25 15:43:28 -08:00
Behdad Esfahbod 365576d246 [layout] Allocate iters in the context
Can be further optimized, but I think I didn't break anything.

Saves another 3% off Roboto shaping.
2015-02-25 15:43:28 -08:00
Behdad Esfahbod 514564f544 [layout] Move skippy_iter setup from constructor into init() 2015-02-25 15:43:27 -08:00
Behdad Esfahbod b051be542a [lookup] Add skippy_iter.reset()
Towards reducing the cost of initializing skippy_iter()
2015-02-25 15:43:27 -08:00
Behdad Esfahbod 696266981d [layout] Merge forward and backward iterators 2015-02-25 15:43:26 -08:00
Behdad Esfahbod 37d13acd8d [layout] Remove some unnecessary checks in skippy 2015-02-25 15:43:26 -08:00
Behdad Esfahbod baa14e1814 [lookup] Don't initialize skippy if coverage match fails
Currently:

  - Initializing skippy is very expensive,

  - Our lookup accelerator (using set-digests) can be very ineffecite,

As such, we end up many times initializing skippy but then failing
coverage check.  Reordering fixes that.

When, later, we fix our accelerator to have truly small false-positive
rate (for example by using the frozen-sets), then we might want to
reorder these checks such that we wouldn't calculate coverage number
if skippy is going to fail.

This shows a 5% speedup with Roboto already.
2015-02-25 15:43:26 -08:00
Behdad Esfahbod 7788993bc1 [layout] Use setter method to set c->lookup_props 2015-02-25 15:43:25 -08:00
Behdad Esfahbod 67dfa8c7c2 When matching second glyph of kerning pairs, use bsearch
Roboto has glyphs (like 'F') that have 200 kerning pairs.
Add a handcoded bsearch instead of previous linear search.

This doesn't show much speedup though, apparently we spend the
bulk of the time somewhere before here.
2015-01-19 17:00:31 -08:00
Behdad Esfahbod 093c520de5 [otlayout] Mark variables that are C arrays as opposed to OT::ArrayOf 2014-12-12 21:07:53 -08:00
Behdad Esfahbod 00f6a8e334 [ot] Print format in dispatch trace 2014-12-12 20:36:49 -08:00
Behdad Esfahbod 8f3eebf7ee Make sure gsubgpos buffer vars are available during fallback_position
Add buffer var allocation asserts to a few key places.
2014-08-02 19:07:49 -04:00
Behdad Esfahbod 7627100f42 Mark unsigned integer literals with the u suffix
Simplifies hb_in_range() calls as the type can be inferred.
The rest is obsessiveness, I admit.
2014-07-11 16:22:13 -04:00
Behdad Esfahbod 6faff8e413 Add static storage classifier to inline functions
Before we were just relying on the compiler inlining them and not
leaving a trace in our public API.  Try to fix.  Hopefully not
breaking anyone's build.
2014-04-28 14:30:44 -07:00
Konstantin Ritt 083225916a Micro optimizations 2014-01-28 11:14:12 -05:00
Behdad Esfahbod 333cc6e2d1 [otlayout] Remove unused is_inplace()
Patch from Jonathan Kew.
2013-10-30 17:30:11 +00:00
Behdad Esfahbod ac8cd51191 Refactor 2013-10-18 19:33:09 +02:00
Behdad Esfahbod 101303dbf7 [otlayout] More shuffling around 2013-10-18 11:21:15 +02:00
Behdad Esfahbod 3ddf892b53 [otlayout] Renaming 2013-10-18 11:21:15 +02:00
Behdad Esfahbod 6c48f20eea [otlayout] Add structs for JSTF table 2013-09-09 15:43:10 -04:00
Behdad Esfahbod 45f3d980c9 [OTLayout] Merge / templateize apply_string() 2013-05-04 16:04:04 -04:00
Behdad Esfahbod e015b8f218 [OTLayout] Minor 2013-05-04 16:04:04 -04:00
Behdad Esfahbod 780cd930a9 [OTLayout] Minor 2013-05-04 16:04:04 -04:00
Behdad Esfahbod 2e0c44f4be [OTLayout] Add is_inplace() method to GSUB 2013-05-04 16:04:04 -04:00
Behdad Esfahbod ed79dff517 Minor 2013-04-21 15:43:27 -04:00
Behdad Esfahbod 0dc3a4e034 Obssesive optimization
Not measurable by any means, but conceptually this is faster since
the mask matches more often than the digest.
2013-04-17 23:04:03 -04:00
Behdad Esfahbod ee5464d17f [OTLayout] Move code around 2013-03-09 01:59:30 -05:00
Behdad Esfahbod 9c5a9ee967 [OTLayout] Rename process() to dispatch() 2013-03-09 01:55:04 -05:00
Behdad Esfahbod 607feb7cff [OTLayout] Ignore default-ignorables when matching GSUB/GPOS
When matching lookups, be smart about default-ignorable characters.
In particular:

Do nothing specific about ZWNJ, but for the other default-ignorables:

If the lookup in question uses the ignorable character in a sequence,
then match it as we used to do.  However, if the sequence match will
fail because the default-ignorable blocked it, try skipping the
ignorable character and continue.

The most immediate thing it means is that if Lam-Alef forms a ligature,
then Lam-ZWJ-Alef will do to.  Finally!

One exception: when matching for GPOS, or for backtrack/lookahead of
GSUB, we ignore ZWNJ too.  That's the right thing to do.

It certainly is possible to build fonts that this feature will result
in undesirable glyphs, but it's hard to think of a real-world case
that that would happen.

This *does* break Indic shaping right now, since Indic Unicode has
specific rules for what ZWJ/ZWNJ mean, and skipping ZWJ is breaking
those rules.  That will be fixed in upcoming commits.
2013-02-14 12:57:50 -05:00
Behdad Esfahbod c074ebc466 [OTLayout] Minor refactoring 2013-02-13 11:22:42 -05:00
Behdad Esfahbod 407fc12466 [OTLayout] Remove bogus caching of glyph property 2013-02-13 11:13:06 -05:00
Behdad Esfahbod 568000274c Adjust mark advance-width zeroing logic for Myanmar
Before, we were zeroing advance width of attached marks for
non-Indic scripts, and not doing it for Indic.

We have now three different behaviors, which seem to better
reflect what Uniscribe is doing:

  - For Indic, no explicit zeroing happens whatsoever, which
    is the same as before,

  - For Myanmar, zero advance width of glyphs marked as marks
    *in GDEF*, and do that *before* applying GPOS.  This seems
    to be what the new Win8 Myanmar shaper does,

  - For everything else, zero advance width of glyphs that are
    from General_Category=Mn Unicode characters, and do so
    before applying GPOS.  This seems to be what Uniscribe does
    for Latin at least.

With these changes, positioning of all tests matches for Myanmar,
except for the glitch in Uniscribe not applying 'mark'.  See preivous
commit.
2013-02-12 09:44:57 -05:00
Behdad Esfahbod 54f7b4d9ec [OTLayout] Respect lookup-flags skipping over non-mark glyphs
Before, when matching ligatures, we never skipping over base / liga
glyphs even if that was what the LookupFlags asked for.

Fixed now.  We carefully reviewed all instances of this, and tested with
Amiri as well as some Indic scripts, and are confident that this should
NOT break anyone's fonts.  It's also how Uniscribe does it, from what
we can tell.
2013-02-11 13:27:17 -05:00
Behdad Esfahbod 9082efc4aa [OTLayout] s/mark_skipping/skipping/
In aticipation of upcoming changes.
2013-02-11 13:14:56 -05:00
Behdad Esfahbod e95e031b56 [GPOS] If an Anchor offset is NULL, return false
If in a MarkPos table, a base has no anchor for a particular mark class,
return NULL such that the subsequent subtables get a chance at it.

Test case:
hb-shape ./EBGaramond12-Regular.otf ἂ --features="ss20","smcp"
2013-01-08 16:17:06 -06:00
Behdad Esfahbod 8303593ba1 Minor
Use pointers instead of references, in preparation for upcoming change.
2012-12-04 17:08:41 -05:00
Behdad Esfahbod 1bcfa06d11 [OTLayout] Don't recurse in collect_glyphs() for GPOS 2012-12-04 16:58:09 -05:00
Behdad Esfahbod 3038ae6adb [OTLayout] Minor 2012-11-30 08:24:13 +02:00
Behdad Esfahbod 2dc1141d7d [OTLayout] Remove operator() from ClassDef 2012-11-24 19:16:34 -05:00
Behdad Esfahbod b67881b171 [OTLayout] Remove operator() from Coverage 2012-11-24 19:13:55 -05:00
Behdad Esfahbod cdd756b9f4 [OTLayout] Implement GPOS collect_glyphs() 2012-11-24 01:38:41 -05:00
Behdad Esfahbod 4c4e8f0e75 [OTLayout] Reuse apply context for recursion 2012-11-24 01:13:20 -05:00
Behdad Esfahbod 26514d51b6 [OTLayout] More collect_glyphs() 2012-11-23 18:13:48 -05:00
Behdad Esfahbod c6fb843f2a [OTLayout] Templatize process_recurse_func 2012-11-23 18:04:08 -05:00
Behdad Esfahbod f48ec0e834 [OTLayout] Add process() tracing 2012-11-23 17:23:41 -05:00
Behdad Esfahbod ed2e135944 [OTLayout] More Extension templatizing 2012-11-23 17:10:40 -05:00
Behdad Esfahbod 7dddd4e72b [OTLayout] More templatizing Extension 2012-11-23 17:04:55 -05:00
Behdad Esfahbod 653eeb2645 Make Extension a template 2012-11-23 16:57:36 -05:00
Behdad Esfahbod 08f1eede1b Minor 2012-11-23 16:51:43 -05:00
Behdad Esfahbod be218c688c Pass this object to trace macros 2012-11-23 15:32:14 -05:00
Behdad Esfahbod c779d82b2f Fix warnings 2012-11-23 14:09:21 -05:00
Behdad Esfahbod ec35a72a44 [OTLayout] Port apply() operator to process() template 2012-11-22 16:33:46 -05:00
Behdad Esfahbod 2005fa5340 [OTLayout] Port would_apply() and get_coverage() to process() templates 2012-11-22 16:33:46 -05:00
Behdad Esfahbod 7d52e6601f Whitespace 2012-11-16 18:49:54 -08:00
Behdad Esfahbod 5a08ecf920 Implement hb_ot_layout_get_glyph_class() 2012-11-16 13:34:29 -08:00
Behdad Esfahbod 1d3947a6bd Minor 2012-09-04 22:42:17 -04:00