Patch taken from ttfautohint, commit
071ae2c00e0d67f9d19418f4fade1c23d27dc185.
There were two bugs.
- We now use non-standard script tags like `khms' for special
purposes. However, HarfBuzz maps such tags to `DFLT', and
without this commit the associated lookups were incorrectly
assigned to the non-standard tags.
- Let's assume we have a Bengali font, and the font's `DFLT'
script tag handles the necessary lookups for Bengali, too.
Without this commit, the `DFLT' lookups were assigned to
ttfautohint's default script (usually `latn') before the
standard lookups for Bengali were handled.
We now have the following order while searching for covered
glyph indices.
special features of scripts (e.g. `sups' for Cyrillic)
Unicode mappings of scripts
remaining features of scripts (especially important for Indic
scripts)
default features of default script
* src/autofit/afshaper.c, src/autofit/afshaper.h
(af_shaper_get_coverage): Add boolean parameter to indicate default
script.
Update all callers.
* src/autofit/afglobal.c (af_face_globals_compute_style_coverage):
Fix search order for coverages.
Right now, it does nothing.
* src/autofit/afscript.h: Add another parameter to `SCRIPT',
specifying hinting direction.
* src/autofit/afglobal.c, scr/autofit/afglobal.h,
src/autofit/afpic.c, src/autofit/afranges.h, src/autofit/afshaper.c,
src/autofit/aftypes.h: Extend `SCRIPT' definitions.
This was removed while rewriting the HarfBuzz interface.
* src/autofit/afglobal.h (AF_FaceGlobalsRec): Add `hb_buf' field to
hold internal HarfBuzz buffer, needed for feature comparison.
* src/autofit/afglobal.c (af_face_globals_new,
af_face_globals_free): Initialize and destroy `hb_buf'.
* src/autofit/afshaper.c (af_shaper_get_cluster): Compare character
(cluster) with and without applied feature.
* src/autofit/aflatin.c (af_latin_metrics_init_blues): Fix tracing
message.
Scripts like Khmer have blue zones that can't be directly
represented by Unicode characters. Instead, it is necessary to let
HarfBuzz convert character clusters into proper glyph representation
forms, then deriving the blue zone information from the resulting
glyphs.
* src/autofit/hbshim.c, src/autofit/hbshim.h: Replaced by...
* src/autofit/afshaper.c, src/autofit/afshaper.h: ... these two new
files, providing a new API to access HarfBuzz.
The new API manages a HarfBuzz buffer with `af_shaper_buf_create'
and `af_shaper_buf_destroy'. The buffer receives a UTF8 encoded
string with function `af_shaper_get_cluster', and the resulting
glyph data (indices, advance widths, vertical offsets) can be
iteratively accessed with function `af_shaper_get_elem'.
* src/autofit/afcjk.c (af_cjk_metrics_init_widths,
af_cjk_metrics_init_blues, af_cjk_metrics_check_digits): Updated.
* src/autofit/aflatin.c (af_latin_metrics_init_widths,
af_latin_metrics_init_blues, af_latin_metrics_check_digits):
Updated.
* include/freetype/internal/fttrace.h: s/afharfbuzz/afshaper/.
* src/autofit/afglobal.c: s/hbshim.h/afshaper.h/.
(af_face_globals_compute_style_coverage): Updated.
* src/autofit/afglocal.h: s/hbshim.h/afshaper.h/.
* src/autofit/autofit.c: s/hbshim.c/afshaper.c/.
* src/autofit/Jamfile, src/autofit/rules.mk (AUTOF_DRV_SRC):
Updated.
Werner Lemberg