When the font size or variations settings on underlying FT_Face change,
one can call hb_ft_font_changed() and continue using hb_font created using
hb_ft_font_create().
Fixes https://github.com/behdad/harfbuzz/issues/559
New API:
hb_ft_font_changed()
This one:
map->mask = (1 << (next_bit + bits_needed)) - (1 << next_bit);
before the fix, the shift was done as an int, causing overflow
if it ever got to 1 << 31. Sprinkle 'u's around.
Fixes https://bugs.chromium.org/p/chromium/issues/detail?id=634805
Prior to this change the function `FT_Error FT_Done_Face(FT_Face *)` was
called through a pointer with the signature `void (void *)` resulting in
undefined behaviour.
New API:
- hb_font_get_nominal_glyph_func_t
- hb_font_get_variation_glyph_func_t
- hb_font_funcs_set_nominal_glyph_func()
- hb_font_funcs_set_variation_glyph_func()
- hb_font_get_nominal_glyph()
- hb_font_get_variation_glyph()
Deprecated API:
- hb_font_get_glyph_func_t
- hb_font_funcs_set_glyph_func()
Clients that implement their own font-funcs are encouraged to replace
their get_glyph() implementation with a get_nominal_glyph() and
get_variation_glyph() pair. The variation version can assume that
variation_selector argument is not zero.
The default FreeType load flags where changed from FT_LOAD_NO_HINTING
to FT_LOAD_DEFAULT in 2a9627c564.
This is crashing HarfBuzz-enabled FreeType as I suppose it causes
infinite recursion between HB and FT autohinter...
Revert the behavior change.
Fixes https://github.com/behdad/harfbuzz/issues/143
This changes the default load_flags of fonts created using
hb_ft_font_create() from NO_HINTING to DEFAULT. Hope that doesn't
break too much client code.
Code calling hb_ft_font_set_funcs() is unaffected.
For discussion see:
http://lists.freedesktop.org/archives/harfbuzz/2012-April/001905.html
Over time we have had added NO_HINTING all over the place in hb-ft. Finish it off.
Not setting ppem on hb-font disables get_contour_point() calls which is good anyway.
See comments in the commit.
When I originally wrote hb-ft, FreeType objects did not support reference
counting. As such, hb_ft_face_create() and hb_ft_font_create() had a
"destroy" callback and client was responsible for making sure FT_Face is
kept around as long as the hb-font/face are alive.
However, since this was not clearly documented, some clienets didn't
correctly did that. In particular, some clients assumed that it's safe
to destroy FT_Face and then hb_face_t. This, indeed, used to work, until
45fd9424c7, which make face destroy access
font tables.
Now, I fixed that issue in 395b35903e since
the access was not needed, but the problem remains that not all clients
handle this correctly. See:
https://bugs.freedesktop.org/show_bug.cgi?id=86300
Fortunately, FT_Reference_Face() was added to FreeType in 2010, and so we
can use it now. Originally I wanted to change hb_ft_face_create() and
hb_ft_font_create() to reference the face if destroy==NULL was passed in.
That would improve pretty much all clients, with little undesired effects.
Except that FreeType itself, when compiled with HarfBuzz support, calls
hb_ft_font_create() with destroy==NULL and saves the resulting hb-font on
the ft-face (why does it not free it immediately?). Making hb-face
reference ft-face causes a cycling reference there. At least, that's my
current understanding.
At any rate, a cleaner approach, even if it means all clients will need a
change, is to introduce brand new API. Which this commit does.
Some comments added to hb-ft.h, hoping to make future clients make better
choices.
Fixes https://bugs.freedesktop.org/show_bug.cgi?id=75299
Apparently they are not (advertised as?) safe on BSD systems.
We ignore the case of static libraries.
Whitelisted on glibc, Android, and MSVC / mingw.
https://bugs.freedesktop.org/show_bug.cgi?id=82246
Lohit-Punjabi has a upem of 769! We were losing one unit in our
code, and FreeType is losing another one... Test with U+0A06.
Has an advance of 854 in the font. We were producing 852.
Now we do 853, which is what FreeType is telling us.
This changes the semantics of get_glyph() callback and expect that
callbacks return false if the requested variant is not available, and
then we will call them back with variation_selector=0 and will retain
the glyph for the selector in the glyph stream.
Apparently most Mongolian fonts implement the Mongolian Variation
Selectors using GSUB, not cmap.
https://bugs.freedesktop.org/show_bug.cgi?id=65258
Note that this doesn't fix the Mongolian shaping yet, because the way
that's implemented is that the, say, 'init' feature ligates the letter
and the variation-selector. However, since currently the variation
selector doesn't have the 'init' mask on, it will not be matched...
That flag is redundant, deprecated, and ignored since April 2011.
From FreeType git log:
commit 8c82ec5b17d0cfc9b0876a2d848acc207a62a25a
Author: Behdad Esfahbod <behdad@behdad.org>
Date: Thu Apr 21 08:21:37 2011 +0200
Always ignore global advance.
This makes FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH redundant,
deprecated, and ignored. The new behavior is what every major user
of FreeType has been requesting. Global advance is broken in many
CJK fonts. Just ignoring it by default makes most sense.
* src/truetype/ttdriver.c (tt_get_advances),
src/truetype/ttgload.c (TT_Get_HMetrics, TT_Get_VMetrics,
tt_get_metrics, compute_glyph_metrics, TT_Load_Glyph),
src/truetype/ttgload.h: Implement it.
* docs/CHANGES: Updated.
Remove hb_ft_get_font_funcs() as it cannot be used by the user anyway.
Add hb_ft_font_set_funcs(). Which will make the font internally use
FreeType. That is, no need for the font to have created using the
hb-ft API. Just create using hb_face_create()/hb_font_create() and
then call this on the font (after having set font scale). This
internally creates an FT_Face and attached to the font.
We need to know whether the glyph exists, so we can fallback to
composing / decomposing. Assuming that glyph==0 means "doesn't exist"
wouldn't work for applications like Pango that want to use different
"doesn't exist" glyph codes for different characters. An explicit
return value fixes that.
hb_font_set_scale() now sets the value to be used to represent a unit
pixel. For example, if rendering a 10px font with a 26.6 representation,
you would set scale to (10 << 6). For 10px in 16.16 you would set it to
(10 << 16). This space should be the same space that the get_glyph_metrics
and get_kerning callbacks work in.
Behdad Esfahbod
Sascha Brawer
Birunthan Mohanathas
Simon Cozens
Chris Peterson