The bug was caused by switching to the initial hintmap (the one in
effect when `moveto' executes) just before drawing the final element
in the charstring. This ensured that the path was closed (in both
Character Space and Device Space). But if the final element was a
curve and if the final hintmap was different enough from the initial
one, then the curve was visibly distorted.
The first part of the fix is to draw the final curve using the final
hintmap as specified by the charstring. This corrects the
distortion but does not ensure closing in Device Space. It may
require the rasterizer to automatically generate an extra closing
line. Depending on the hintmap differences, this line could be from
zero to a couple pixels in length.
The second part of the fix covers the case where the charstring
subpath is closed with an explicit line. We now modify that line's
end point to avoid the distortion.
Some glyphs in the bug report font (TexGyreHeros-Regular) that show
the change are:
25ppem S (98)
24ppem eight (52)
25.5ppem p (85)
Curves at the *end* of a subpath are no longer distorted. However,
some of these glyphs have bad hint substitutions in the middle of a
subpath, and these are not affected.
The patch has been tested with a set of 106 fonts that shipped with
Adobe Creative Suite 4, together with 756 Open Source CFF fonts from
Google Fonts. There are 1.5 million glyphs, of which some 20k are
changed with the fix. A sampling of a few hundred of these changes
have been examined more closely, and the changes look good (or at
least acceptable).
* src/cff/cf2hints.h (CF2_GlyphPathRec): New element `pathIsClosing'
to indicate that we synthesize a closepath line.
* src/cff/cf2hints.c (cf2_glyphpath_init): Updated.
(cf2_glyphpath_pushPrevElem): If closing, use first hint map (for
`lineto' operator) and adjust hint zone.
For synthesized closing lines, use end point in first hint zone.
(cf2_glyphpath_lineTo): Take care of synthesized closing lines. In
particular, shift the detection of zero-length lines from character
space to device space.
(cf2_glyphpath_closeOpenPath): Remove assertion.
Updated.
Suggested by Akira Tagoh, see
http://lists.gnu.org/archive/html/freetype/2013-09/msg00030.html
* src/bdf/bdfdrivr.c (BDF_Face_Init): Return Invalid_Argument error
when the font could be opened but non-zero face_index is given.
* src/pcf/pcfdrivr.c (PCF_Face_Init): Ditto.
* src/type42/t42objs.c (T42_Face_Init): Remove unrequired FT_UNUSED
macro for face_index because it is validated in later.
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.
We simply synthesize a SFNT from the WOFF, create a memory stream
for the new data, and load the SFNT as usual.
Does NOT add any API to access WOFF metadata or private blocks.
* include/freetype/internal/tttypes.h (WOFF_HeaderRec,
WOFF_TableRec): New structures.
* include/freetype/tttags.h (TTAG_wOFF): New macro.
* src/base/ftobjs.c (FT_Open_Face): Set `stream' after calling
`open_face'.
* src/sfnt/sfobjs.c [FT_CONFIG_OPTION_SYSTEM_ZLIB]: Include
`FT_GZIP_H'.
(WRITE_BYTE, WRITE_USHORT, WRITE_ULONG): New temporary macros for
writing to a stream.
(sfnt_stream_close, compare_offsets, woff_open_font): New functions.
(sfnt_open_font): Handle `TTAG_wOFF'.
(sfnt_init_face): Set `stream' after calling `sfnt_open_font'.
* src/truetype/ttobjs.c (tt_face_init): Set `stream' after calling
`sfnt->init_face'.
* src/base/ftobjs.c (open_face): Use a pointer to FT_Stream as an
argument so that a changed stream survives.
Update callers.
This is modeled after zlib's `uncompress' function. We need this
for WOFF support.
* include/freetype/ftgzip.h, src/gzip/ftgzip.c (FT_Gzip_Uncompress):
New function.
* src/gzip/rules.mk: Rewrite to better reflect dependencies.
* 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'.
If the font's `clazz->init_face' function wants to swap to new
stream, handling of whether original stream was external could
result to either memory leak or double free. Mark externality into
face flags before calling `init_face' such that the clazz can handle
external streams properly.
* src/base/ftobjs.c (FT_Open_Face): Move code to set
FT_FACE_FLAG_EXTERNAL_STREAM to...
(open_face): This function.
Previously, the loading of a glyph was traced at level 4, if at all.
With this change, all font loading routines emit a tracing message
at level 1, making it easier to select tracing output (for example
using F2_DEBUG="any:1 afhints:7 aflatin:7").
* src/bdf/bdfdrivr.c (BDF_Glyph_Load): Add tracing message.
* src/cff/cffdrivr.c (cff_glyph_load): Ditto.
* src/cff/cffgload.c (cff_decoder_prepare): Improve tracing
messages.
* src/cid/cidgload.c (cid_load_glyph): Use level 1 for tracing
message.
* src/pcf/pcfdrivr.c (PCF_Glyph_Load): Ditto.
* src/pfr/pfrobjs.c (pfr_slot_load): Add tracing message.
* src/truetype/ttgload.c (TT_Load_Glyph): Ditto.
* src/type1/t1gload.c (T1_Load_Glyph): Ditto.
* src/type42/t42objs.c (T42_GlyphSlot_Load): Ditto.
* src/winfonts/winfnt.c (FNT_Load_Glyph): Ditto.
* src/autofit/afglobal.c (af_face_globals_get_metrics): Use
`AF_SCRIPT_DFLT', not value 0.
Simplify code.
* src/autofit/afscript.h: Sort by script name.
* 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.
* 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.
The idea is to have a central file which gets processed by a Perl
script to create proper `.c' and `.h' files using templates. There
are two other reasons to do that:
. The data file should be easily readable. We use UTF-8 encoding
which then gets converted to single bytes.
. Since the number of supported scripts will increase soon, the
current usage of blue string arrays is a waste of space. Using
the Perl script it is possible to imitate jagged arrays,
defining enumeration constants as offsets into the arrays.
This commit only adds files without changing any functionality.
* src/autofit/afblue.dat: New data file.
* src/tools/afblue.pl: New Perl script for processing `afblue.dat'.
* src/autofit/afblue.cin, src/autofit/afblue.hin: New template files
for...
* src/autofit/afblue.c, src/autofit/afblue.c: New source files.
To avoid a dependency on Perl, we add them too.
* src/base/ftbbox.c (BBox_Conic_Check): Remove redundant checks for
extremum at the segment ends, which are already within the bbox.
Slightly modify calculations.
* src/cff/cffload.c (cff_index_get_pointers): Check for `cur_offset
!= 0'; this stronger test is mandated by the CFF specification.
Fix test for INDEX structures which have one or more empty entries
at the end.
* src/truetype/ttinterp.c (TT_MulFix14_long_long,
TT_DotFix14_long_long): `#pragma gcc diagnostic {push,pop}' has been
introduced with gcc version 4.6.
* builds/unix/ftconfig.h: Synchronize with
`include/freetype/config/ftconfig.h'.
* builds/vms/ftconfig.h: Ditto.
Make the differences to the master `ftconfig.h' file as small as
possible for easier maintainance.
Points which are very near to each other are now marked as such.
The `weak' flag is then computed by using the `in' vector of the
first and the `out' vector of the last point of a group of near
points.
For example, this fixes the rendering of glyph `Oslash' in
`Roboto-Thin.ttf'.
* src/autofit/afhints.h (AF_Flags): New value `AF_FLAGS_NEAR'.
* src/autofit/afhints.c (af_glyph_hints_reload): Introduce
the heuristic value `near_limit' to decide whether the current point
is near to the previous one, then set `AF_FLAG_NEAR' accordingly.
Store good `in' vector (of last non-near point) in
`last_good_in_{x,y}' and use it as an argument to
`ft_corner_is_flat' if necessary.
Dave Arnold