The introduction of the Emoji vs Text VS processing means that we might
in some cases not find a glyph with the requested presentation.
In that case, we'd rather show the emoji presentation glyph than none at
all, so we'll retry fallback processing with unspecified presentation.
refs: #997
The recent presentation logic needs to be tweaked to ensure that
we ignore presentation when we reach the fallback font, otherwise
we'll end up in a bad error stack and crash the program.
This commit annotates fonts with a boolean that indicates whether
we think it contains glyphs with emoji presentation, and then
passes the cluster.presentation field down to the shaper.
If the presentation doesn't match the current font in the fallback,
then it will be skipped until we exhaust its options.
`wezterm ls-fonts` also shows whether we think a font has emoji
presentation.
refs: #997
This commit hooks up DECRQM so that we can report that we implement
synchronized updates, and then refines the code that manages sending
data to the terminal model; the first cut at synchronized updates
was a bit simplistic, and now we make a point of "flushing" pending
actions when we start a sync point, and again as soon as we release
the sync point.
This smooths out the jaggies around the orca that I mentioned in
dcbbda7702
and while testing this, I realized that recent parser changes had
mangled processing bundled dec private mode sequences where multiple
modes were specified in the same overall escape sequence. I've
added the missing unit test case for this and made that work again.
refs: https://github.com/wez/wezterm/issues/955
refs: https://github.com/wez/wezterm/issues/882
opentype allows a font to have a weight in the range 0-1000.
MacOS has its own concept of symbolic weight names and opentype
values that is a slightly different scale of boldness to Windows
and Linux.
That means that Medium could be a different range of opentype
weight values depending on the system.
To further complicate things, the font designer can name their
variant with any name they like and assign it an arbitrary
opentype weight value.
For the Operator Mono font, it has Book variant with opentype
weight 325 and a Light variant with an opentype weight of 300.
wezterm was considering these both to have `FontWeight::Light` because
that's how those values were bucketed, which results in amibiguity in
resolve the font and frustration in not being able to access one of the
variants.
This commit changes the `FontWeight` type to now hold the unambiguous
opentype weight value, and to define some symbolic aliases for
some specified weights.
When serializing, if the weight matches a symbolic alias, then that
name will be used in the canonical name (eg: as listed via ls-fonts).
Otherwise, the numeric value will be used.
When parsing the font configuration, wezterm will allow both symbolic
and numeric values.
This allows all of the Operator Mono variants to be referenced
unambiguously, although some variants have to be specified via the
numeric weight:
```
wezterm.font("Operator Mono", {weight=275, stretch="Normal", italic=false}) -- /Users/wez/.fonts/OperatorMono-XLight.otf, FontDirs
wezterm.font("Operator Mono", {weight="Light", stretch="Normal", italic=false}) -- /Users/wez/.fonts/OperatorMono-Light.otf, FontDirs
wezterm.font("Operator Mono", {weight=325, stretch="Normal", italic=false}) -- /Users/wez/.fonts/OperatorMono-Book.otf, FontDirs
wezterm.font("Operator Mono", {weight="DemiLight", stretch="Normal", italic=false}) -- /Users/wez/.fonts/OperatorMono-Medium.otf, FontDirs
wezterm.font("Operator Mono", {weight="Regular", stretch="Normal", italic=false}) -- /Users/wez/.fonts/OperatorMono-Bold.otf, FontDirs
```
https://github.com/wez/wezterm/issues/849#issuecomment-873454483
Change the loader so that it has better matching weight and stretch
characteristics, and ask core text to return all possible candidates
so that we can then apply our CSS-style font matching rules.
Previously, the font descriptor we created would only match the
family name and return the normal/regular variant only.
refs: https://github.com/wez/wezterm/issues/873
This commit adds a slant to *scalable* (not bitmap!) fonts whose
originating font attributes requested italics but for for which
the resolved face is not italic.
refs: #815
This commit introduces the knowledge about whether a font is
scalable or was using bitmap strikes (eg: color emoji bitmaps).
Then that information is used to help figure out whether and
how to scale a glyph.
refs: https://github.com/wez/wezterm/issues/685
I *think* the heart of the issue is that the problematic fonts
don't define a `spacing` property, and we were being stric
about matching it.
This commit changes the behavior to strictly match the spacing
value when it is defined, but to allow an undefined spacing
value to match.
refs: https://github.com/wez/wezterm/issues/726
It now outputs something that you could conceivably put into
your config file, although the intent is to show the canonical
way to reference the individual fonts that were found, rather
than to specify a fully baked list to paste into a config.
eg:
```
; ./target/debug/wezterm ls-fonts
Primary font:
wezterm.font_with_fallback({
-- /home/wez/.fonts/OperatorMonoSSmLig-Medium.otf, FontDirs
{family="Operator Mono SSm Lig", weight="DemiLight"},
-- /home/wez/.fonts/OperatorMonoSSmLig-Medium.otf, FontConfig
{family="Operator Mono SSm Lig", weight="DemiLight"},
-- /home/wez/.fonts/MaterialDesignIconsDesktop.ttf, FontDirs
"Material Design Icons Desktop",
-- /home/wez/.fonts/terminus-bold.otb, FontDirs
{family="Terminus", weight="Bold"},
-- /home/wez/.fonts/JetBrainsMono-Regular.ttf, FontDirs
"JetBrains Mono",
-- /home/wez/.fonts/NotoColorEmoji.ttf, FontDirs
"Noto Color Emoji",
-- /home/wez/.fonts/MaterialDesignIconsDesktop.ttf, FontConfig
"Material Design Icons Desktop",
-- /usr/share/fonts/terminus-fonts/ter-u32n.otb, FontConfig
"Terminus",
-- /home/wez/.fonts/JetBrainsMono-Regular.ttf, FontConfig
"JetBrains Mono",
-- /home/wez/.fonts/NotoColorEmoji.ttf, FontConfig
"Noto Color Emoji",
-- <built-in>, BuiltIn
"Last Resort High-Efficiency",
})
```
In earlier times, in an effort to avoid bleeding resources into
child processes, the fontconfig wrapper grew some logic to keep
track of how many fontconfig objects we'd loaded so that we could
aggressively unload it when there were none.
Since that time we've evolved differently pessimistic logic that forces
random fds closed when we spawn children so the critical need for unloading
fontconfig is no longer present.
Importantly, with the over-eager unloading, each font query we make
effectively needs to initialize fontconfig from scratch, which is a
fixed minimum cost of ~5-6ms on my system, and I've seen some traces
with a number as high as 100ms (those systems need `fc-cache` to be
run).
Removing the unloading keeps fontconfig initialized so we only pay
the 5ms cost once, then subsequent queries are in the order of 100us.
It seems difficult/impossible to phrase precisely the constraints
that we want when making a font config query, so this changes our
queries to use relative broad family and postscriptname list operations
and then we parse and filter using our own CSS-inspired font matching
criteria.
refs: #689
we now compute the ratio of the cap height (the height of a capital
letter) vs. the em-square (which relates to our chosen point size) to
understand what proportion of the font point-size that a given font
occupies when rendered.
When rendering glyphs from secondary fonts we can use the cap height
ratios of both to scale the secondary font such that its effective
cap height matches that of the primary font.
In plainer-english: if you mix say bold, italic and regular text
style in the same line, and you have different font families for
those fonts, then they will now appear to be the same height where
previously they may have varied more noticeably.
For emoji and symbol fonts there may not be a cap-height metric
encoded in the font. We can however, improve our scaling: prior
to this commit we'd use the ratio of the cell metrics of the two
fonts to scale the icon/emoji glyph, but this could cause the glyph
to be slightly oversized as seen in https://github.com/wez/wezterm/issues/624
If we know the cap-height of the primary font then we can additionaly
apply that factor to scale the emoji to better fit the cell.
While looking at this, I noticed that the aspect ratio calculation
for when to apply to the allow_square_glyphs_to_overflow_width option
had width and height flipped :-(
See also: https://tonsky.me/blog/font-size/
refs: https://github.com/wez/wezterm/issues/624
Sort the available fonts list by family name (rather than full name),
then the styling attributes.
Display the font name in the preferred form for inclusion in the
wezterm config.
* Log which codepoints we're about to perform fallback resolution for
* Rank the fallback fonts by decreasing amount of coverage
* If a fallback covers the desired codepoints, remove those codepoints
from the set and reduce, so that we only add the minimal set of
fallback fonts for the set of codepoints
You can see what triggered fallback processing using:
```
; WEZTERM_LOG=wezterm_font=trace wezterm -n 2> /tmp/font.txt
; grep 'fallback font' /tmp/font.txt
2021-04-11T21:41:09.653Z TRACE wezterm_font > Looking for \u{d604}\u{c7ac}\u{be0c}\u{b79c}\u{ce58} in fallback fonts
2021-04-11T21:41:12.132Z TRACE wezterm_font > Looking for \u{f4e9} in fallback fonts
```
refs: https://github.com/wez/wezterm/issues/559#issuecomment-817260512
Now that all platforms know whether the system fallbacks
covered the requested glyph range, it is reasonable to
restore the configuration error window to advise the user
if they are missing fonts for the text they want to display.
refs: https://github.com/wez/wezterm/issues/671
Previously, we would add a list of ~100 or so fallback fonts to
the shaper's fallback list.
In pathological cases where a wide range of glyphs that have no
corresponding font are repeatedly emitted to the output, we'd
keep loading and unloading that large list of fallbacks in the
hope of finding a match.
Since that code was written, we're now able to compute the
codepoint coverage for ourselves, so teach the core text locator
how to reduce the the list of fallback fonts to just those that
contain the missing glyphs.
Furthermore, we restrict that list to just the normal/regular
weight/stretch/style fonts.
refs: https://github.com/wez/wezterm/issues/671
The intent is to reveal more context on what's happening in
https://github.com/wez/wezterm/issues/671
As a nice side benefit, this avoids the potential inability
to open paths that are not utf8 or representable as c-strings
on Windows.
And on top of that: this enables memory mapped file IO as well,
which wasn't enabled previously. This should help to reduce
extraneous copies of the font in memory, have fewer open files
and minimize the chances of racing with O_CLOEXEC.
