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/aflatin.c (af_latin_metrics_init_blues): Report blue
zone types.
(af_latin_metrics_scale_dim): Report scaling changes due to x height
alignment.
Report scaled stroke width and blue zone values.
This change introduces a new blue zone property
`AF_BLUE_PROPERTY_LATIN_LONG' to make the auto-hinter ignore short
top segments.
* src/autofit/afblue.dat: Fix Hebrew blue strings.
Use AF_BLUE_PROPERTY_LATIN_LONG for AF_BLUE_STRING_HEBREW_TOP.
* src/autofit/afblue.hin (AF_BLUE_PROPERTY_LATIN_LONG): New macro.
* src/autofit/afblue.c, src/autofit/afblue.h: Updated.
* src/autofit/aflatin.c (af_latin_metrics_init_blues): Handle
`AF_LATIN_IS_LONG_BLUE'.
* src/autofit/aflatin.h (AF_LATIN_IS_LONG_BLUE): New macro.
* src/autofit/aflatin.c (AF_LATIN_MAX_TEST_CHARACTERS): Removed.
(af_latin_blue_chars): Removed.
(af_latin_metrics_init_blues): Replace AF_LATIN_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').
Use `AF_LATIN_IS_SMALL_TOP_BLUE' macro.
* src/autofit/aflatin.h: Remove old enumeration values superseded by
the new data in `afblue.h'.
(AF_LATIN_IS_TOP_BLUE): Updated definition.
(AF_LATIN_IS_SMALL_TOP_BLUE): New macro.
(AF_LATIN_MAX_BLUES): Remove.
(AF_LatinAxisRec): 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.
The old code (essentially unchanged since the very beginning)
incorrectly handled this configuration
x -o- x
/ \
/ \
/ \
o o
as flat and this
o o
/ /
x| x|
| |
o---------------o
as round. (`o' and `x' are on and off points, respectively).
This is a major change which should improve the rendering results
enormously for many TrueType fonts, especially in the range approx.
20-40ppem, fixing the appearance of many overshoots.
* src/autofit/aflatin.c (af_latin_metrics_init_blues): Look at the
first and last points of the segment, not the points right before
and after.
* src/autofit/aflatin.c, src/autofit/aflatin2.c: Include
`afglobal.h'.
* src/autofit/afloader.c: Fix order of header files.
* src/autofit/afmodule.c: Include `afglobal.h' and `aferrors.h'.
This is an improved version of a similar fix contained in the
so-called `Infinality patch', taken from
http://www.infinality.net/fedora/linux/zips/freetype-infinality-2.4.10-20120616_01-x86_64.tar.bz2
which addresses various enhancements of the auto-hinter. Without
properties to control a module's metadata it wasn't possible to
adapt the patches because everything was originally controlled by
environment variables which I consider not suitable in general.
A patch to control `increase_x_height' follows.
* src/autofit/afglobal.h (AF_PROP_INCREASE_X_HEIGHT_MIN,
AF_PROP_INCREASE_X_HEIGHT_MAX): New macros.
(AF_FaceGlobalsRec): Add `increase_x_height' member.
* src/autofit/afglobal.c (af_face_globals_new): Initialize it.
* src/autofit/aflatin.c (af_latin_metrics_scale_dim),
* src/autofit/aflatin2.c (af_latin2_metrics_scale_dim): Implement
handling of `increase_x_height'.
The auto-hinter's latin module only handles latin ligatures in the
`Alphabetical Presentation Forms' block.
* src/autofit/aflatin.c (af_latin_uniranges): Fix it.
