cosmic-text/src/font/system/std.rs

140 lines
4.3 KiB
Rust

// SPDX-License-Identifier: MIT OR Apache-2.0
use std::{
collections::HashMap,
sync::{Arc, Mutex},
};
use crate::{Attrs, AttrsOwned, Font, FontMatches};
#[ouroboros::self_referencing]
struct FontSystemInner {
locale: String,
db: fontdb::Database,
#[borrows(db)]
#[not_covariant]
font_cache: Mutex<HashMap<fontdb::ID, Option<Arc<Font<'this>>>>>,
#[borrows(locale, db)]
#[not_covariant]
font_matches_cache: Mutex<HashMap<AttrsOwned, Arc<FontMatches<'this>>>>,
}
/// Access system fonts
pub struct FontSystem(FontSystemInner);
impl FontSystem {
/// Create a new [`FontSystem`], that allows access to any installed system fonts
pub fn new() -> Self {
let locale = sys_locale::get_locale().unwrap_or_else(|| {
log::warn!("failed to get system locale, falling back to en-US");
String::from("en-US")
});
log::info!("Locale: {}", locale);
let mut db = fontdb::Database::new();
{
let now = std::time::Instant::now();
db.load_system_fonts();
//TODO: configurable default fonts
db.set_monospace_family("Fira Mono");
db.set_sans_serif_family("Fira Sans");
db.set_serif_family("DejaVu Serif");
log::info!(
"Parsed {} font faces in {}ms.",
db.len(),
now.elapsed().as_millis()
);
}
Self::new_with_locale_and_db(&locale, db)
}
/// Create a new [`FontSystem`], manually specifying the current locale and font database.
pub fn new_with_locale_and_db(locale: &str, mut db: fontdb::Database) -> Self {
{
let now = std::time::Instant::now();
//TODO only do this on demand!
for i in 0..db.faces().len() {
let id = db.faces()[i].id;
unsafe { db.make_shared_face_data(id); }
}
log::info!(
"Mapped {} font faces in {}ms.",
db.len(),
now.elapsed().as_millis()
);
}
Self(FontSystemInnerBuilder {
locale,
db,
font_cache_builder: |_| Mutex::new(HashMap::new()),
font_matches_cache_builder: |_, _| Mutex::new(HashMap::new())
}.build())
}
pub fn locale(&self) -> &str {
self.0.borrow_locale()
}
pub fn db(&self) -> &fontdb::Database {
self.0.borrow_db()
}
// Clippy false positive
#[allow(clippy::needless_lifetimes)]
pub fn get_font<'a>(&'a self, id: fontdb::ID) -> Option<Arc<Font<'a>>> {
self.0.with(|fields| {
get_font(&fields, id)
})
}
pub fn get_font_matches<'a>(&'a self, attrs: Attrs) -> Arc<FontMatches<'a>> {
self.0.with(|fields| {
let mut font_matches_cache = fields.font_matches_cache.lock().expect("failed to lock font matches cache");
//TODO: do not create AttrsOwned unless entry does not already exist
font_matches_cache.entry(AttrsOwned::new(attrs)).or_insert_with(|| {
let now = std::time::Instant::now();
let mut fonts = Vec::new();
for face in fields.db.faces() {
if !attrs.matches(face) {
continue;
}
if let Some(font) = get_font(&fields, face.id) {
fonts.push(font);
}
}
let font_matches = Arc::new(FontMatches {
locale: fields.locale,
default_family: fields.db.family_name(&attrs.family).to_string(),
fonts
});
let elapsed = now.elapsed();
log::debug!("font matches for {:?} in {:?}", attrs, elapsed);
font_matches
}).clone()
})
}
}
fn get_font<'b>(fields: &ouroboros_impl_font_system_inner::BorrowedFields<'_, 'b>, id: fontdb::ID) -> Option<Arc<Font<'b>>> {
fields.font_cache.lock().expect("failed to lock font cache").entry(id).or_insert_with(|| {
let face = fields.db.face(id)?;
match Font::new(face) {
Some(font) => Some(Arc::new(font)),
None => {
log::warn!("failed to load font '{}'", face.post_script_name);
None
}
}
}).clone()
}