If shaping can't resolve some glyphs, queue the font locator
fallback resolution to another thread; meanwhile, a last resort
glyph is used.
That thread can trigger an invalidation once the fallback resolve
is complete, the window is invalidated and the last resort glyph
is replaced by the resolve glyph.
refs: https://github.com/wez/wezterm/issues/559
refs: https://github.com/wez/wezterm/issues/508
Keep track of the glyphs we've already advised about (until the
config is reloaded) so that we don't keep spamming the user.
refs: https://github.com/wez/wezterm/issues/559
* Check built-in fonts before asking the system for codepoint coverage
* If one of the earlier stages resolved some fonts, skip the remaining
stages and speculatively shape what we have. This avoids triggering
the system font lookup for fonts that are present in the font_dirs
or that are built-in, such as powerline symbols.
refs: https://github.com/wez/wezterm/issues/559
The dwrote crate offers functions that can extract the underlying
font file name(s) from the system, so let's use those to get
OnDisk font handles and save some memory.
refs: https://github.com/wez/wezterm/issues/559
In an earlier incarnation of both wezterm and freetype, FT_New_Face
would lead file descriptors into child processes because it didn't
set O_CLOEXEC. That led to the slightly pessimistic approach of
loading the font into memory for the lifetime of the wezterm process.
With the improved fallback handling on macos, this can result in
hundreds of MB of font data being loaded, in some cases multiple
times.
Since those days, freetype now sets O_CLOEXEC and wezterm has some
logic to close other random fds, so the descriptor leaking problem
is gone and we can now let freetype manage a file handle instead
of a memory-baked font.
This reduces the memory utilization by at least 1GB in the case
that a glyphs need to be resolved from the system fallback fonts.
refs: https://github.com/wez/wezterm/issues/559
terminus-bold.otb reports 0 height!
Detect and force that case to go through the bitmap strike loading
code path.
Improve the size selection heuristic for bitmap strikes: previously,
we would just pick the largest bitmap and allow it to be scaled down,
which was OK for emoji fonts that just had 128px square glyphs, but
is not ok for pre-rendered pixel strikes like terminus.
Note that IncreaseFontSize works in terms of percentages only,
so using a font like this may have "gaps" when ctrl-+ or - to change
the font size.
refs: https://github.com/wez/wezterm/issues/560
This is a bit unfortunate, but necessary, because the system fallback
list contains a handful of special fonts that apple doesn't ship on
disk in ttf/otf files.
One of those is `.AppleSymbolsFB` which would normally satisfy
the symbol lookup.
This commit hard codes the "Apple Symbols" font to use instead,
which is a disk based font. I don't know what the difference
is between it and `.AppleSymbolsFB`, but this is sufficient
to satisfy the glyph in question from the referenced issue.
refs: https://github.com/wez/wezterm/issues/506
Continuing along the same lines as the prior commit, the goal
of this commit is to remove the buffer transformation that was
part of uploading the texture to the GPU provided surface.
In order to do so:
* The sense of our local textures needs to change from bgra32 to rgba32.
bgra32 was a hangover from earlier versions of our window crate that
allowed direct-to-fb writes in software mode. We had to pick bgra32
for that for the broadest OS compatibility. I believe that that
constraint has been totally removed, although there is a chance that
this will flip the colors on macos.
* There was an additional linear-to-srgb conversion inlined in that
buffer transformation. I have no idea where that is needed because
the source data is carefully constructed as SRGB. I don't yet know
how to signal that, but for now I've moved that gamma correction
into the shader when we sample the texture.
With this change, timg playback now has vtparse as the hottest
region of code.
refs: #537
This commit expands on the prior commits to introduce the concept
of per-window configuration overrides.
Each TermWindow maintains json compatible object value holding
a map of config key -> config value overrides.
When the window notices that the config has changed, the config
file is loaded, the CLI overrides (if any) are applied, and then
finally the per-window overrides, before attempting to coerce
the resultant lua value into a Config object.
This mechanism has some important constraints:
* Only data can be assigned to the overrides. Closures or special
lua userdata object handles are not permitted. This is because
the lifetime of those objects is tied to the lua context in which
they were parsed, which doesn't really exist in the context of
the window.
* Only simple keys are supported for the per-window overrides.
That means that trying to override a very specific field of
a deeply structured value (eg: something like `font_rules[1].italic = false`
isn't able to be expressed in this scheme. Instead, you would
need to assign the entire `font_rules` key. I don't anticipate
this being a common desire at this time; if more advance manipulations
are required, then I have some thoughts on an event where arbitrary
lua modifications can be applied.
The implementation details are fairly straight-forward, but in testing
the two examplary use cases I noticed that some hangovers from
supporting overrides for a couple of font related options meant that the
window-specific config wasn't being honored. I've removed the code that
handled those overrides in favor of the newer more general CLI option
override support, and threaded the config through to the font code.
closes: #469closes: #329
for fonts located by core text, if they are singular TTF files rather
than TTC files, and the font doesn't exactly match the search critiera,
we could loop forever re-parsing the same file over and over again.
This commit restructures the logic to definitively check the number
of contained font entries and constrain the loop to that number.
In addition, it adjusts the name matching, as macos can return
names like "Cascadia Code Roman" when the underlying font is named
"Cascadia Code".
refs: https://github.com/wez/wezterm/issues/475
Connect the gui to the new shaping logic; this means that we
can now correctly render fg/bg color when the cursor moves
through the cells that comprise a ligature.
refs: https://github.com/wez/wezterm/issues/478
This function is intended to deal with certain kinds of ligatures
and certain combining sequences that don't have corresponding glyphs.
It isn't hooked up to the gui yet, but does have unit tests that
are probably mostly correct.
refs: https://github.com/wez/wezterm/issues/478
Refine the colorization logic to make it more of a blending operation.
Previously, we were relying on opengl to carry out blending between
layers on our behalf, but that wasn't perfect.
This commit is inspired by this post:
https://www.puredevsoftware.com/blog/2019/01/22/sub-pixel-gamma-correct-font-rendering/
and factors in the background color when computing the colorized
glyph.
This appears to reduce the dark fringes/edges that we were seeing
before, without noticeably changing the brightness of the result.
refs: #491
https://learnopengl.com/Advanced-Lighting/Gamma-Correction suggests
some good practices:
* Only enable SRGB output on the final draw call, so that all prior
stages can operate on linear values and avoid converting to/from
linear multiple times.
* The SRGBA textures automatically linearize when sampled, but:
* The RGB data must be SRGB (non-linear)
* The A channel is assumed to be linear!
This commit nudges us closer to that by:
* Converting the freetype coverage map from its linear value to
non-linear when rasterizing.
* Splitting the shader files into one per stage (background, lines,
glyphs) and only setting outputs_srgb for the glyph stage
refs: #491
In the earlier times wezterm supported different font rasterizers,
and the configuration was a bit vague and generic to accomodate
differences in how the rasterizers worked.
Since then, we've standardized on freetype.
One of the things that's been bothering me for a while is that
we have some fiddly logic to transform from the config to the freetype
flags.
This commit does away with the transformation and simply exposes
the two sets of freetype options.
The main thing that I expect people to play with is
`freetype_load_target` which can have one of the following values:
```
pub enum FreeTypeLoadTarget {
/// This corresponds to the default hinting algorithm, optimized
for standard gray-level rendering.
Normal,
/// A lighter hinting algorithm for non-monochrome modes. Many
generated glyphs are more fuzzy but better resemble its original
shape. A bit like rendering on Mac OS X. This target implies
FT_LOAD_FORCE_AUTOHINT.
Light,
/// Strong hinting algorithm that should only be used for
monochrome output. The result is probably unpleasant if the glyph
is rendered in non-monochrome modes.
Mono,
/// A variant of Normal optimized for horizontally decimated LCD displays.
HorizontalLcd,
/// A variant of Normal optimized for vertically decimated LCD displays.
VerticalLcd,
}
```
I expect most people will want to set this to one of `Normal`, `Light`
or `HorizontalLcd`. `HorizontalLcd` is what `font_antialias=Subpixel`
used to select.
refs: #491
If a font doesn't have any latin glyphs then we'd compute 0 as the
average width. Later, during rendering, we'd compute an `inf` scaling
factor and then subsequently fail to allocate texture space.
This commit takes the average width from a "random" selection of glyphs
(whatever the first few glyphs in the font may be) to avoid that
situation.
refs: https://github.com/wez/wezterm/issues/404
This defaults to None, taking the default from the freetype library.
You can select an integer value to tell the library to use an
alternative version.
Versions that are available in the build used by wezterm are 35, 38 and
40.
See https://freetype.org/freetype2/docs/subpixel-hinting.html for
more information.
Revise logging so that we use info level for things that we want
to always log, and adjust the logger config to always log info
level messages.
That means shifting some warning level logs down lower to debug level so
that they aren't noisy.
closes: https://github.com/wez/wezterm/issues/388
My original goal was to update to allsorts 0.5 but the API
changes are significant and not clearly described.
To make that transition easier, the prior commit moved the shaping
logic into our allsorts shaper module, leaving the name parsing
here in parser.rs.
This commit now replaces that logic with ttf_parser, which is
potentially faster (there's more emphasis on optimal code in that
crate than in allsorts) but definitely simpler.
It's not a slam-dunk transition: ttf_parser doesn't know how to
decode MacRoman encoded text, so there's a bit of logic borrowed
from allsorts here to handle that.
The root cause of this was that I'd added a fontformat=TrueType
constraint to the fontconfig pattern and since fontconfig has
fontformat=CFF for Hasklig, it wasn't the primary font candidate.
When I cut out redundant fontconfig checks in
ee1d84829a it meant that we'd never
"see" the hasklig result that turns up ~20 or so fonts into the
fallback list.
This commit removes the TrueType constraint so that the results
are ranked correctly again.
I've also switched the main font lookup path to using an alternative
font config API that returns only the best match as that more closely
aligns our intent in this function; originally, fallback was intended
to be handled in this code path, but these days it has its own separate
method.
closes: https://github.com/wez/wezterm/issues/383
refs: https://github.com/wez/wezterm/issues/379
font-config can return very long lists of fallback fonts like:
```
2020-12-16T16:23:13.306Z TRACE wezterm_font::locator::font_config > query font-config for Pattern(Operator Mono SSm Lig Medium,DejaVu Sans,PT Sans,PT Sans Caption,Bitstream Vera Sans,DejaVu Sans,Verdana,Arial,Albany AMT,Luxi Sans,Nimbus Sans L,Nimbus Sans,Nimbus Sans,Helvetica,Nimbus Sans,Lucida Sans Unicode,BPG Glaho International,Tahoma,Comfortaa,Montserrat,URW Gothic,Nimbus Sans,Nimbus Sans Narrow,Carlito,Droid Sans,Nachlieli,Lucida Sans Unicode,Yudit Unicode,Kerkis,ArmNet Helvetica,Artsounk,BPG UTF8 M,Waree,Loma,Garuda,Umpush,Saysettha Unicode,JG Lao Old Arial,GF Zemen Unicode,Pigiarniq,B Davat,B Compset,Kacst\-Qr,Urdu Nastaliq Unicode,Raghindi,Mukti Narrow,malayalam,Sampige,padmaa,Hapax Berbère,MS Gothic,UmePlus P Gothic,Microsoft YaHei,Microsoft JhengHei,WenQuanYi Zen Hei,WenQuanYi Bitmap Song,AR PL ShanHeiSun Uni,AR PL New Sung,MgOpen Modata,VL Gothic,IPAMonaGothic,IPAGothic,Sazanami Gothic,Kochi Gothic,AR PL KaitiM GB,AR PL KaitiM Big5,AR PL ShanHeiSun Uni,AR PL SungtiL GB,AR PL Mingti2L Big5,ＭＳ ゴシック,ZYSong18030,TSCu_Paranar,NanumGothic,UnDotum,Baekmuk Dotum,Baekmuk Gulim,KacstQura,Lohit Bengali,Lohit Gujarati,Lohit Hindi,Lohit Marathi,Lohit Maithili,Lohit Kashmiri,Lohit Konkani,Lohit Nepali,Lohit Sindhi,Lohit Punjabi,Lohit Tamil,Meera,Lohit Malayalam,Lohit Kannada,Lohit Telugu,Lohit Oriya,LKLUG,Mingzat,Padauk,Nuosu SIL,FreeSans,FreeSans,Arial Unicode MS,Arial Unicode,Code2000,Code2001,sans\-serif,Roya,Koodak,Terafik,sans\-serif,sans\-serif,sans\-serif,ITC Avant Garde Gothic,URW Gothic,sans\-serif,sans\-serif,Helvetica,Helvetica Narrow,Nimbus Sans Narrow,sans\-serif,sans\-serif,sans\-serif:slant=0:weight=80:spacing=100:fontformat=TrueType) took 1.344155ms
```
In the context of that particular call, we only care about whether the
first result matches what we're looking up. The fallbacks are processed
separately in a different method.
Therefore, we can skip additional processing and save a non-trivial
number of milliseconds overall parsing/re-parsing them to verify
whether they are the one we wanted to match.
refs: https://github.com/wez/wezterm/issues/379
