wez/wezterm
1
1
Fork 0
mirror of https://github.com/wez/wezterm.git synced 2024-10-27 08:09:45 +03:00
Code Issues Projects Releases Wiki Activity

macos: fonts: use alternative fallback approach

Browse Source 
The approach we were using previously was to ask macOS for the fallback
font list, but it didn't include the correct fonts for certain
codepoints.

Switch to using an alternative API that asks macOS which font to use for
a specific codepoint.

refs: #4099
This commit is contained in:
Wez Furlong 2023-08-05 18:09:03 -07:00
parent 33187d0e79
commit 085e8da478
No known key found for this signature in database
GPG Key ID: 7A7F66A31EC9B387
2 changed files with 43 additions and 98 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
docs/changelog.md
View File

@ -69,6 +69,7 @@ As features stabilize some brief notes about them will accumulate here.
* X11: fd leak on each call to
[wezterm.gui.enumerate_gpus](config/lua/wezterm.gui/enumerate_gpus.md). #3612
* Charselect and repl recency/history were not persisted across restarts. #4047 ?4019
* macOS: system font fallback didn't always find a workable fallback font. #4099 #849
#### Updated
* Bundled harfbuzz to 8.1.1

134
wezterm-font/src/locator/core_text.rs
View File

@ -2,21 +2,24 @@
use crate::locator::{FontDataSource, FontLocator, FontOrigin};
use crate::parser::ParsedFont;
use cocoa::base::id;
use config::{FontAttributes, FontStretch, FontStyle, FontWeight};
use config::FontAttributes;
use core_foundation::array::CFArray;
use core_foundation::base::TCFType;
use core_foundation::base::{CFRange, TCFType};
use core_foundation::dictionary::CFDictionary;
use core_foundation::string::CFString;
use core_foundation::string::{CFString, CFStringRef};
use core_text::font::*;
use core_text::font_descriptor::*;
use objc::*;
use rangeset::RangeSet;
use std::cmp::Ordering;
use std::collections::HashSet;
lazy_static::lazy_static! {
static ref FALLBACK: Vec<ParsedFont> = build_fallback_list();
#[link(name = "CoreText", kind = "framework")]
extern "C" {
fn CTFontCreateForString(
currentFont: CTFontRef,
string: CFStringRef,
range: CFRange,
) -> CTFontRef;
}
/// A FontLocator implemented using the system font loading
@ -116,18 +119,41 @@ impl FontLocator for CoreTextFontLocator {
&self,
codepoints: &[char],
) -> anyhow::Result<Vec<ParsedFont>> {
let mut matches = vec![];
let mut wanted = RangeSet::new();
let menlo =
new_from_name("Menlo", 0.0).map_err(|_| anyhow::anyhow!("failed to get Menlo font"))?;
for &c in codepoints {
wanted.add(c as u32);
let text = CFString::new(&c.to_string());
let font = unsafe {
CTFontCreateForString(
menlo.as_concrete_TypeRef(),
text.as_concrete_TypeRef(),
CFRange::init(0, 1),
)
};
if font.is_null() {
continue;
}
let mut matches = vec![];
for font in FALLBACK.iter() {
let font = unsafe { CTFont::wrap_under_create_rule(font) };
let candidates = handles_from_descriptor(&font.copy_descriptor());
for font in candidates {
if let Ok(cov) = font.coverage_intersection(&wanted) {
if !cov.is_empty() {
matches.push((cov.len(), font.clone()));
matches.push((cov.len(), font));
}
}
}
}
// Add the handles in order of descending coverage; the idea being
// that if a font has a large coverage then it is probably a better
// candidate and more likely to result in other glyphs matching
@ -140,6 +166,9 @@ impl FontLocator for CoreTextFontLocator {
primary
}
});
matches.dedup();
log::trace!("fallback candidates for {codepoints:?} is {matches:#?}");
Ok(matches.into_iter().map(|(_len, handle)| handle).collect())
}
@ -159,88 +188,3 @@ impl FontLocator for CoreTextFontLocator {
Ok(fonts)
}
}
fn build_fallback_list() -> Vec<ParsedFont> {
build_fallback_list_impl().unwrap_or_else(|err| {
log::error!("Error getting system fallback fonts: {:#}", err);
Vec::new()
})
}
fn build_fallback_list_impl() -> anyhow::Result<Vec<ParsedFont>> {
let menlo =
new_from_name("Menlo", 0.0).map_err(|_| anyhow::anyhow!("failed to get Menlo font"))?;
let user_defaults: id = unsafe { msg_send![class!(NSUserDefaults), standardUserDefaults] };
let apple_lang = "AppleLanguages"
.parse::<CFString>()
.map_err(|_| anyhow::anyhow!("failed to parse lang name en as CFString"))?;
let langs: CFArray<CFString> =
unsafe { msg_send![user_defaults, stringArrayForKey:apple_lang] };
let cascade = cascade_list_for_languages(&menlo, &langs);
let mut fonts = vec![];
// Explicitly include Menlo itself, as it appears to be the only
// font on macOS that contains U+2718.
// <https://github.com/wez/wezterm/issues/849>
fonts.append(&mut handles_from_descriptor(&menlo.copy_descriptor()));
for descriptor in &cascade {
fonts.append(&mut handles_from_descriptor(&descriptor));
}
// Some of the fallback fonts are special fonts that don't exist on
// disk, and that we can't open.
// In particular, `.AppleSymbolsFB` is one such font. Let's try
// a nearby approximation.
let symbols = FontAttributes {
family: "Apple Symbols".to_string(),
weight: FontWeight::REGULAR,
stretch: FontStretch::Normal,
style: FontStyle::Normal,
is_fallback: true,
is_synthetic: true,
harfbuzz_features: None,
freetype_load_target: None,
freetype_render_target: None,
freetype_load_flags: None,
scale: None,
assume_emoji_presentation: None,
};
if let Ok(descriptors) = descriptor_from_attr(&symbols) {
for descriptor in descriptors.iter() {
fonts.append(&mut handles_from_descriptor(&descriptor));
}
}
// Constrain to default weight/stretch/style
fonts.retain(|f| {
f.weight() == FontWeight::REGULAR
&& f.stretch() == FontStretch::Normal
&& f.style() == FontStyle::Normal
});
let mut seen = HashSet::new();
let fonts: Vec<ParsedFont> = fonts
.into_iter()
.filter_map(|f| {
if seen.contains(&f.handle) {
None
} else {
seen.insert(f.handle.clone());
Some(f)
}
})
.collect();
// Pre-compute coverage
let empty = RangeSet::new();
for font in &fonts {
if let Err(err) = font.coverage_intersection(&empty) {
log::error!("Error computing coverage for {:?}: {:#}", font, err);
}
}
Ok(fonts)
}