This mode uses fractional advance widths and doesn't scale glyphs
horizontally, only applying vertical scaling and hinting.
At the same time, the behaviour of the `light' auto-hinter gets
restored for backwards compatibility: Both vertical and horizontal
scaling is again based on rounded metrics values (this was changed
in a commit from 2017-03-30 as a side effect). To be more precise,
the behaviour is restored for TrueType fonts only; for other font
formats like Type 1, this is a new feature of the `light' hinting
mode.
* include/freetype/freetype.h (FT_LOAD_TARGET_SLIGHT): New macro.
(FT_RENDER_MODE_SLIGHT): New render mode.
* include/freetype/internal/ftobjs.h (FT_Size_InternalRec): Add
`autohint_mode' and `autohint_metrics' fields.
* src/autofit/afcjk.c (af_cjk_hints_init), src/autofit/aflatin.c
(af_latin_hints_init), src/autofit/aflatin2 (af_latin2_hints_init):
Updated.
* src/autofit/afloader.c (af_loader_embolden_glyph_in_slot): Use
`autohint_metrics'.
(af_loader_load_glyph): s/internal/slot_internal/.
Initialize `autohint_metrics' and `autohint_mode' depending on
current auto-hint mode.
Use `autohint_metrics'.
Updated.
* src/base/ftadvanc.c (LOAD_ADVANCE_FAST_CHECK): Updated.
* src/base/ftobjs.c (FT_Load_Glyph): Updated.
(FT_New_Size): Allocate `internal' object.
* src/pshinter/pshalgo.c (ps_hints_apply): Updated.
* src/smooth/ftsmooth.c (ft_smooth_render): Updated.
* src/autofit/afcjk.c, src/autofit/afindic.c: Include `afcjk.h'
earlier.
* src/sfnt/sfobjs.c (sfnt_init_face): Put `memory' variable into
TT_CONFIG_OPTION_GX_VAR_SUPPORT block.
(sfnt_done_face): Protect some code with
TT_CONFIG_OPTION_GX_VAR_SUPPORT.
* src/sfnt/ttsbit.c (tt_face_load_sbix_image): Remove compiler
warning.
* src/truetype/ttgload.c (TT_Load_Simple_Glyph): Put `tmp' variable
into TT_USE_BYTECODE_INTERPRETER block.
(tt_loader_init): Put `error' variable into
TT_USE_BYTECODE_INTERPRETER block.
This improves rendering of scripts like Bengali or Devanagari.
* src/autofit/afhints.c (af_axis_hints_new_edge): Add parameter to
pass top-to-bottom hinting flag. This makes the function sort edges
in descending vertical position.
* src/autofit/afhints.c: Updated.
* src/autofit/aflatin.c (af_latin_hints_compute_edges,
af_latin_hint_edges): Use `top_to_bottom_hinting' flag.
* src/autofit/afcjk.c (af_cjk_hints_compute_edges),
src/autofit/aflatin2.c (af_latin2_hints_compute_edges): Updated.
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.
This is more flexible; additionally, it would allow character
clusters.
* src/autofit/aftypes.h (SCRIPT, AF_DEFINE_SCRIPT_CLASS): Updated.
(AF_ScriptClassRec): Replace `standard_char[123]' with
`standard_charstring'.
* src/autofit/afscript.h: Replace last three character arguments
of the `SCRIPT' calls with a string parameter, holding the standard
characters (in UTF-8 encoding) separated with spaces.
* src/autofit/afglobal.c, src/autofit/afglobal.h,
src/autofit/afpic.c, src/autofit/afranges.c, src/autofit/hbshim.c
(SCRIPT): Updated.
* src/autofit/afcjk.c (af_cjk_metrics_init_widths),
src/autofit/aflatin.c (af_latin_metrics_init_widths): Updated.
We need the computed standard horizontal and vertical widths for the
emboldening calculation. This method provides a convenient way to
extract it from writing-system-specific metrics structures, which
all script definitions must implement.
* src/autofit/aftypes.h (AF_WritingSystem_GetStdWidthsFunc): New
function type.
(AF_WritingSystemClassRec): New member `style_metrics_getstdw'.
(AF_DEFINE_WRITING_SYSTEM_CLASS): Updated.
* src/autofit/afcjk.c (af_cjk_get_standard_width): New function.
(af_cjk_writing_system_class): Updated.
* src/autofit/afdummy.c (af_dummy_writing_system_class): Updated.
* src/autofit/afindic.c (af_cjk_get_standard_width): New function.
(af_indic_writing_system_class): Updated.
* src/autofit/aflatin.c (af_latin_get_standard_width): New function.
(af_indic_writing_system_class): Updated.
* src/autofit/aflatin.c (af_latin_get_standard_width): New function.
(af_indic_writing_system_class): Updated.
This code replaces the debugging hook from the previous commit with
a better, more generic solution.
* include/ftautoh.h: Document it.
* src/autofit/afmodule.h (AF_ModuleRec)
[AF_CONFIG_OPTION_USE_WARPER]: Add `warping' field.
* src/autofit/afmodule.c (_af_debug_disable_warper): Remove.
(af_property_set, af_property_get, af_autofitter_init)
[AF_CONFIG_OPTION_USE_WARPER]: Handle `warping' option.
* src/autofit/afhints.h (AF_HINTS_DO_WARP): Remove use of the no
longer existing `_af_debug_disable_warper'.
* src/autofit/afcjk.c (af_cjk_hints_init), src/autofit/aflatin.c
(af_latin_hints_init), src/autofit/aflatin2.c (af_latin2_hints_init)
[AF_CONFIG_OPTION_USE_WARPER]: Add `AF_SCALER_FLAG_NO_WARPER' to the
scaler flags if warping is off.
* src/autofit/aftypes.h: Updated.
* src/autofit/afmodule.c (_af_debug_disable_warper)
[FT_DEBUG_AUTOFIT]: New global variable.
* src/autofit/aftypes.h: Updated.
(AF_SCALER_FLAG_NO_WARPER): New macro (not actively used yet).
* src/autofit/afhints.h (AF_HINTS_DO_WARP): New macro.
* src/autofi/aflatin.c (af_latin_hints_apply)
[AF_CONFIG_OPTION_USE_WARPER]: Use `AF_HINTS_DO_WARP' to control use
of warper.
* src/autofit/afcjk.c (af_cjk_hints_init, af_cjk_hints_apply)
[AF_CONFIG_OPTION_USE_WARPER]: Synchronize with `aflatin.c'.
* src/autofit/aflatin2.c (af_latin2_hints_apply)
[AF_CONFIG_OPTION_USE_WARPER]: Synchronize with `aflatin.c'.
This harmonizes with other code in FreeType (and reduces the number
of necessary casts to avoid compiler warnings).
* src/autofit/afblue.hin: Make flag macros unsigned.
* src/autofit/afblue.h: Regenerated.
* src/autofit/afcjk.h: Replace flag enumeration with macros.
* src/autofit/afcjk.c: Updated.
* src/autofit/afhints.h (AF_Flags, AF_Edge_Flags): Replace with
macros.
* src/autofit/afhints.c: Updated.
* src/autofit/aflatin.h: Replace flag enumerations with macros.
* src/autofit/aflatin.c, src/autofit/aflatin2.c: Updated.
* src/autofit/aftypes.h (AF_ScalerFlags): Replace with macros.
The adaptation of the cjk auto-hinter module to blue stringsets in
2013-08-25 had three severe bugs. Mea culpa.
1. Contrary to the latin auto-hinter, characters for reference and
overshoot values of a blue zone are specified separately. Due to
the screwed-up change it didn't work at all.
2. A boolean comparison was erroneously replaced with a cast,
causing invalid results with the `^' operator later on. The
visual artifact caused by this problem is the topic of the bug
report.
3. Two flag values were inverted, causing incorrect assignment of
reference and overshoot values.
* src/autofit/afblue.dat: Fix CJK bluestrings, introducing a new
syntax to have both reference and overshoot characters in a single
string. This is error #1.
Add extensive comments.
* src/autofit/afblue.hin (AF_BLUE_PROPERTY_CJK_FILL): Removed, no
longer used.
(AF_BLUE_PROPERTY_CJK_TOP, AF_BLUE_PROPERTY_CJK_HORIZ): Fix values.
This is error #3.
* src/autofit/afblue.c, src/autofit/afblue.h: Regenerated.
* src/autofit/afcjk.c (af_cjk_metrics_init_blues): Correct error #1.
Use character `|' to separate characters for reference and overshoot
values.
Improve tracing messages, synchronizing them with the latin
auto-hinter.
(af_cjk_hints_compute_blue_edges): Fix value of `is_top_right_blue'.
This is error #2.
(af_cjk_align_linked_edge): Add tracing message.
* src/autofit/afcjk.h (AF_CJK_IS_FILLED_BLUE): Removed, no longer
used.
Problem reported by Karsten Lücke <karsten.luecke@kltf.de>.
The new algorithm takes care of the width of stems: If the distance
between two segments is larger than the largest stem width, the
demerits quickly increase for larger distances. This improves
hinting of slanted fonts (especially if the inner parts of serifs
have non-horizontal `shoulders'), avoiding false stem links.
* src/autofit/aflatin.c (af_latin_hints_link_segments): Use largest
stem width (if available) to compute better demerits for distances
between stems.
(af_latin_hints_detect_features): Pass stem width array and array
size.
(af_latin_metrics_init_widths): Updated to use original algorithm.
(af_latin_hints_apply): Updated to use new algorithm.
* src/autofit/aflatin.h: Updated.
* src/autofit/afcjk.c: Updated.
* src/autofit/afcjk.c (af_cjk_metrics_init_widths),
src/autofit/aflatin.c (af_latin_metrics_init_widths): Fix handling
of alternative standard characters.
This also fixes a compilation warning in non-debug mode.
This is useful for OpenType features like `c2sc' (caps to small
caps) that don't have lowercase letters by definition, or other
features that mainly operate on numerals.
* src/autofit/afscript.h: Add more standard characters.
* src/autofit/aftypes.h: Update use of `SCRIPT' macro.
(AF_ScriptClassRec): Add members to hold two more standard
characters.
(AF_DEFINE_SCRIPT_CLASS): Updated.
* src/autofit/afglobal.c, src/autofit/afglobal.h,
* src/autofit/afpic.c, src/autofit/afranges.h, src/autofit/hbshim.c:
Update use of `SCRIPT' macro.
* src/autofit/afcjk.c (af_cjk_metrics_init_widths),
src/autofit/aflatin.c (af_latin_metrics_init_widths): Scan two more
standard characters.
* src/autofit/hbshim.c (af_get_char_index): Return error value.
Add argument for y offset (to be used in a yet-to-come patch).
* src/autofit/hbshim.h, src/autofit/afcjk.c,
src/autofit/aflatin.c: Updated.
Yet-to-come changes will provide HarfBuzz functionality for the new
function.
* src/autofit/hbshim.c (af_get_char_index): New function.
* src/autofit/hbshim.h: Updated.
* 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.
* src/autofit/afblue.cin, src/autofit/afblue.c: Don't include
`afblue.h' but `aftypes.h'.
* src/autofit/afcjk.c: Don't include `aftypes.h' but `afglobal.h'.
* src/autofit/afcjk.c (AF_CJK_MAX_TEST_CHARACTERS): Removed.
(af_cjk_hani_blue_chars): Removed.
(AF_CJK_BLUE_TYPE_*): Removed.
(af_cjk_metrics_init_blues): Replace AF_CJK_MAX_TEST_CHARACTERS with
AF_BLUE_STRING_MAX_LEN.
Change loops to use offsets (in file `afblue.h') into the new arrays
`af_blue_stringsets' and `af_blue_strings' (in file `afblue.c').
Instead of three dimensions (as used in the old blue string array)
we now use properties to do the same, saving one loop nesting level.
* src/autofit/afcjk.h: Remove old enumeration values superseded by
the new data in `afblue.h'.
(AF_CJK_IS_TOP_BLUE, AF_CJK_IS_HORIZ_BLUE, AF_CJK_IS_FILLED_BLUE,
AF_CJK_IS_RIGHT_BLUE): New macros, to be used in
`af_cjk_metrics_init_blues'.
(AF_CJK_BLUE_IS_RIGHT): Remove this now redundant enum value.
(AF_CJK_BLUE_IS_TOP): Renamed to...
(AF_CJK_BLUE_TOP): This.
(AF_CJK_MAX_BLUES): Remove.
(AF_CJKAxisRec): Updated.
This patch adds a new top level to the auto-hinter's script class
hierarchy. It defines `writing systems' which can contain multiple
scripts.
For example, the `latin' writing system (in file `aflatin.c') is
able to support scripts like Latin, Cyrillic, Armenian, etc., which
can be handled similarly.
Scripts are now named using four-letter OpenType tags.
* src/autofit/aftypes.h (AF_ScriptClassRec): Move relevant members
to...
(AF_WritingSystemClassRec): This new structure. It holds pointers
to functions which can be shared among related scripts.
(AF_WritingSystem): New enumeration.
(AF_Script): Revised values using four-letter tags.
(AF_DEFINE_WRITING_SYSTEM_CLASS): New macro.
(AF_DEFINE_SCRIPT_CLASS): Updated.
* src/autofit/afglobal.c (af_writing_system_classes): New global,
constant array.
(af_script_classes): Updated.
(af_face_globals_free): Updated.
Remove assertion.
(af_face_globals_get_metrics): Updated.
* src/autofit/afglobal.h (AF_SCRIPT_FALLBACK)
[!AF_CONFIG_OPTION_CJK]: Handle this case.
* src/autofit/afloader.c (af_loader_load_g, af_loader_load_glyph):
Updated.
* src/autofit/afpic.c (autofit_module_class_pic_init): Updated;
initialize structures for both writing systems and scripts.
* src/autofit/afpic.h: Updated.
(AF_WRITING_SYSTEM_CLASSES_GET): New macro.
* src/autofit/afcjk.c (af_cjk_writing_system_class): New writing
system.
(af_cjk_uniranges): Renamed to...
(af_hani_uniranges): This.
(af_cjk_script_class): Reduced and renamed to...
(af_hani_script_class): This.
* src/autofit/afcjk.h: Updated.
* src/autofit/afdummy.c (af_dummy_writing_system_class): New writing
system.
(af_dummy_script_class): Reduced and renamed to...
(af_dflt_script_class): This.
* src/autofit/afdummy.h: Updated.
* src/autofit/afindic.c (af_indic_writing_system_class): New writing
system.
(af_indic_uniranges): Renamed to...
(af_deva_uniranges): This.
(af_indic_script_class): Reduced and renamed to...
(af_deva_script_class): This.
* src/autofit/afcjk.h: Updated.
* src/autofit/aflatin.c (af_latin_writing_system_class): New writing
system.
(af_latin_uniranges): Renamed to...
(af_latn_uniranges): This.
(af_latin_script_class): Reduced and renamed to...
(af_latn_script_class): This.
* src/autofit/aflatin.h: Updated.
* src/autofit/aflatin2.c (af_latin2_writing_system_class): New
writing system.
(af_latin2_uniranges): Renamed to...
(af_ltn2_uniranges): This.
Synchronize ranges with `latin'.
(af_latin2_script_class): Reduced and renamed to...
(af_ltn2_script_class): This.
* src/autofit/aflatin2.h: Updated.
