See the report by Yang Yinsen.
https://lists.gnu.org/archive/html/freetype-devel/2017-11/msg00000.html
* src/truetype/ttobjs.c (trick_names): Add `DFGothic-EB',
`DFGyoSho-Lt', `DFHSGothic-W5', `DFHSMincho-W3' and `DFHSMincho-W7'.
(tt_check_trickyness_sfnt_ids): Add checksums for DFGothic-EB,
DFGyoSho-Lt, DFHSGothic-W5, DFHSMincho-W3 and DFHSMincho-W7. Also
add checksums for DLCLiShu and DLCHayBold which their family names
were already listed but their checksums were previously unknown.
This commit completely separates the interaction between named
instances and variation functions. In particular, resetting the
variation returns to the current named instance (if set) and not to
the base font.
As a side effect, variation functions no longer change the named
instance index.
* src/cff/cffobjs.c (cff_face_init): Use MM service's `set_instance'
function.
Also apply `MVAR' table to named instances.
* src/truetype/ttgxvar.c (TT_Get_MM_Var): Add cast.
(tt_set_mm_blend): No longer check whether requested variation
coincides with a named instance.
(TT_Set_Var_Design): Use current named instance for default
coordinates.
* src/truetype/ttobjs.c (tt_face_init): Use `TT_Set_Named_Instance'.
Without this change, clang's AddressSanitizer reports many runtime
errors due to misaligned addresses.
* src/truetype/ttgxvar.c (TT_Get_MM_Var): Use multiples of pointer
size for sub-array offsets into `mmvar'.
The first 32bit of standard TrueType variants is 0x00010000,
`OTTO', `ttcf', `true' or `typ1'. 2 marginal dfonts on legacy Mac
OS X, Keyboard.dfont and LastResort.dfont, have the sfnt resources
starting 0xA5 followed by `kbd' or `lst'. Considering the following
data could be parsed as conventional TrueType fonts, the header
checking is updated to allow these tags. It seems that recent Mac
OS X has already switched to normal TTF for these fonts.
See the discussion at
http://u88.n24.queensu.ca/exiftool/forum/index.php?topic=3931.0
* include/freetype/tttags.h (TTAG_0xA5kbd, TTAG_0xA5lst): New header
tags for Keyboard.dfont and LastResort.dfont.
* src/sfnt/sfobjs.c (sfnt_open_font): Accept the sfnt resource
starts with TTAG_0xA5kbd or TTAG_0xA5lst.
* src/truetype/ttobjs.c (tt_face_init): Accept the face with the
format tag is TTAG_0xA5kbd or TTAG_0xA5lst.
Requested by Behdad.
Modern bitmap-only SFNTs like `NotoColorEmoji.ttf' don't contain
entries in the bitmap strike(s) for empty glyphs. Instead, they
rely that a space glyph gets created from the font's metrics data.
This commit makes FreeType behave accordingly.
* include/freetype/fterrdef.h (FT_Err_Missing_Bitmap): New error
code.
* src/sfnt/ttsbit.c (tt_sbit_decoder_load_image): Change error codes
to make a distinction between a missing bitmap in a composite and a
simple missing bitmap.
* src/truetype/ttgload.c (TT_Load_Glyph): For a missing bitmap (in a
bitmap-only font), synthesize an empty bitmap glyph if metrics are
available.
The reserved `flags' field got a value in OpenType version 1.8.2;
unfortunately, the public `FT_Var_Axis' structure misses the
corresponding element. Since we can't add a new field, we add an
access function.
* src/base/ftmm.c (FT_Get_Var_Axis_Flags): New function.
* include/freetype/ftmm.h (FT_VAR_AXIS_FLAG_HIDDEN): New macro.
Updated.
* src/truetype/ttgxvar.c (TT_Get_MM_Var): Increase allocated memory
of `mmvar' to hold axis flags.
Fill the axis flags array.
* docs/CHANGES: Updated.
Phantom points are now saved outside v40 backwards compatibility
mode. This fixes the jumping glyphs when switching between v35 and
v40 monochrome mode.
* src/truetype/ttgload.c (TT_Hint_Glyph): Fix inversed bool logic.
This fixes weird behavior of instructions that resulted in rendering
differences between v35 and v40 in monochrome mode, e.g., in
`timesbi.ttf'.
* src/truetype/ttinterp.c (Ins_GETINFO)
[TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL]: Check
`subpixel_hinting_lean'.
* src/sfnt/sfobjs.c (sfnt_load_face): The units per EM value has now
(tighter) limits.
* src/truetype/ttgload.c (load_truetype_glyph): The new OpenType
version explicitly allows all negative values for the number of
contours if we have a composite glyph (this is for better backwards
compatibility I guess), but it still recommends value -1.
Reported by Nikolaus Waxweiler <madigens@gmail.com>.
* src/truetype/ttgxvar.c (TT_Set_Var_Design): Correctly handle the
case where we have less input coordinates than axes.
Problem reported by Marek Kašík <mkasik@redhat.com>.
The problematic font that exceeds the old limit is Padauk-Bold,
version 3.002, containing bytecode generated by a buggy version of
ttfautohint.
* src/truetype/ttgxvar.c (tt_set_mm_blend): Compute all design
coordinates if we have to create the `blends->coord' array.
(TT_Get_MM_Blend, TT_Get_Var_Design): Select default instance
coordinates if no instance is selected yet.
Problem reported by Hin-Tak Leung <htl10@users.sourceforge.net>.
* src/truetype/ttgload.c (TT_Load_Glyph)
[TT_CONFIG_OPTION_EMBEDDED_BITMAPS]: Handle error if font is not
scalable.
When points are not touched by gvar interpolation deltas, FreeType
gave a slightly different result than Apple's CoreText.
The OpenType working group will update the specification to document
the following behaviour: If the two points with deltas to the `left'
and `right' of the untouched point have the same coordinate, then
the inferred delta for the untouched point should be zero.
* src/truetype/ttgxvar.c (tt_delta_interpolate): Implement new
behaviour.
