src/hb-ot-layout-gpos-table.hh | 31 +++++----- test/shaping/fonts/sha1sum/706c5d7b625f207bc0d874c67237aad6f1e9cd6f.ttf |binary test/shaping/fonts/sha1sum/MANIFEST | 1 test/shaping/tests/cursive-positioning.tests | 1 4 files changed, 18 insertions(+), 15 deletions(-)
New commits: commit 86c68c7a2c971efe8e35b1f1bd99401dc8b688d2 Author: Behdad Esfahbod <beh...@behdad.org> Date: Tue Feb 16 16:07:20 2016 +0700 [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. diff --git a/src/hb-ot-layout-gpos-table.hh b/src/hb-ot-layout-gpos-table.hh index 22eb499..59dddcf 100644 --- a/src/hb-ot-layout-gpos-table.hh +++ b/src/hb-ot-layout-gpos-table.hh @@ -437,6 +437,22 @@ struct MarkArray : ArrayOf<MarkRecord> /* Array of MarkRecords--in Coverage orde o.attach_type() = ATTACH_TYPE_MARK; o.attach_chain() = (int) glyph_pos - (int) buffer->idx; buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT; + { + unsigned int i = buffer->idx; + unsigned int j = glyph_pos; + hb_glyph_position_t *pos = buffer->pos; + assert (j < i); + if (HB_DIRECTION_IS_FORWARD (c->direction)) + for (unsigned int k = j; k < i; k++) { + pos[i].x_offset -= pos[k].x_advance; + pos[i].y_offset -= pos[k].y_advance; + } + else + for (unsigned int k = j + 1; k < i + 1; k++) { + pos[i].x_offset += pos[k].x_advance; + pos[i].y_offset += pos[k].y_advance; + } + } buffer->idx++; return_trace (true); @@ -917,9 +933,6 @@ struct CursivePosFormat1 TRACE_APPLY (this); hb_buffer_t *buffer = c->buffer; - /* We don't handle mark glyphs here. */ - if (unlikely (_hb_glyph_info_is_mark (&buffer->cur()))) return_trace (false); - const EntryExitRecord &this_record = entryExitRecord[(this+coverage).get_coverage (buffer->cur().codepoint)]; if (!this_record.exitAnchor) return_trace (false); @@ -1580,18 +1593,6 @@ propagate_attachment_offsets (hb_glyph_position_t *pos, unsigned int i, hb_direc { pos[i].x_offset += pos[j].x_offset; pos[i].y_offset += pos[j].y_offset; - - assert (j < i); - if (HB_DIRECTION_IS_FORWARD (direction)) - for (unsigned int k = j; k < i; k++) { - pos[i].x_offset -= pos[k].x_advance; - pos[i].y_offset -= pos[k].y_advance; - } - else - for (unsigned int k = j + 1; k < i + 1; k++) { - pos[i].x_offset += pos[k].x_advance; - pos[i].y_offset += pos[k].y_advance; - } } } diff --git a/test/shaping/fonts/sha1sum/706c5d7b625f207bc0d874c67237aad6f1e9cd6f.ttf b/test/shaping/fonts/sha1sum/706c5d7b625f207bc0d874c67237aad6f1e9cd6f.ttf new file mode 100644 index 0000000..eb5c50c Binary files /dev/null and b/test/shaping/fonts/sha1sum/706c5d7b625f207bc0d874c67237aad6f1e9cd6f.ttf differ diff --git a/test/shaping/fonts/sha1sum/MANIFEST b/test/shaping/fonts/sha1sum/MANIFEST index a94bc51..5c8c9de 100644 --- a/test/shaping/fonts/sha1sum/MANIFEST +++ b/test/shaping/fonts/sha1sum/MANIFEST @@ -22,6 +22,7 @@ 5a5daf5eb5a4db77a2baa3ad9c7a6ed6e0655fa8.ttf 641bd9db850193064d17575053ae2bf8ec149ddc.ttf 6466d38c62e73a39202435a4f73bf5d6acbb73c0.ttf +706c5d7b625f207bc0d874c67237aad6f1e9cd6f.ttf 757ebd573617a24aa9dfbf0b885c54875c6fe06b.ttf 7a37dc4d5bf018456aea291cee06daf004c0221c.ttf 7e14e7883ed152baa158b80e207b66114c823a8b.ttf diff --git a/test/shaping/tests/cursive-positioning.tests b/test/shaping/tests/cursive-positioning.tests index b61d0c1..503554f 100644 --- a/test/shaping/tests/cursive-positioning.tests +++ b/test/shaping/tests/cursive-positioning.tests @@ -1,2 +1,3 @@ fonts/sha1sum/c4e48b0886ef460f532fb49f00047ec92c432ec0.ttf::U+0643,U+0645,U+0645,U+062B,U+0644:[gid8=4+738|gid5=3@441,1197+0|gid6=3@0,432+405|gid9=2@0,477+452|gid9=1@0,977+452|gid10=0@20,1577+207] fonts/sha1sum/298c9e1d955f10f6f72c6915c3c6ff9bf9695cec.ttf::U+0643,U+0645,U+0645,U+062B,U+0644:[gid8=4+738|gid5=3@441,1197+0|gid6=3@0,432+405|gid9=2@0,477+500|gid9=1@0,577+452|gid10=0@20,1177+207] +fonts/sha1sum/706c5d7b625f207bc0d874c67237aad6f1e9cd6f.ttf::U+0B1F,U+0B4D,U+0B1A,U+0B4D,U+0B1A:[ttaorya=0+1307|casubscriptorya=0@-242,104+-231|casubscriptnarroworya=0@20,104+507] _______________________________________________ HarfBuzz mailing list HarfBuzz@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/harfbuzz