1use crate::{
2 point, size, Bounds, DevicePixels, Font, FontFeatures, FontId, FontMetrics, FontRun, FontStyle,
3 FontWeight, GlyphId, LineLayout, Pixels, PlatformTextSystem, Point, RenderGlyphParams,
4 ShapedGlyph, SharedString, Size,
5};
6use anyhow::{anyhow, Context, Ok, Result};
7use collections::HashMap;
8use cosmic_text::{
9 Attrs, AttrsList, CacheKey, Family, Font as CosmicTextFont, FontSystem, ShapeBuffer, ShapeLine,
10 SwashCache,
11};
12
13use itertools::Itertools;
14use parking_lot::RwLock;
15use pathfinder_geometry::{
16 rect::{RectF, RectI},
17 vector::{Vector2F, Vector2I},
18};
19use smallvec::SmallVec;
20use std::{borrow::Cow, sync::Arc};
21
22pub(crate) struct CosmicTextSystem(RwLock<CosmicTextSystemState>);
23
24struct CosmicTextSystemState {
25 swash_cache: SwashCache,
26 font_system: FontSystem,
27 scratch: ShapeBuffer,
28 /// Contains all already loaded fonts, including all faces. Indexed by `FontId`.
29 loaded_fonts_store: Vec<Arc<CosmicTextFont>>,
30 /// Caches the `FontId`s associated with a specific family to avoid iterating the font database
31 /// for every font face in a family.
32 font_ids_by_family_cache: HashMap<SharedString, SmallVec<[FontId; 4]>>,
33 /// The name of each font associated with the given font id
34 postscript_names: HashMap<FontId, String>,
35}
36
37impl CosmicTextSystem {
38 pub(crate) fn new() -> Self {
39 let mut font_system = FontSystem::new();
40
41 // todo(linux) make font loading non-blocking
42 font_system.db_mut().load_system_fonts();
43
44 Self(RwLock::new(CosmicTextSystemState {
45 font_system,
46 swash_cache: SwashCache::new(),
47 scratch: ShapeBuffer::default(),
48 loaded_fonts_store: Vec::new(),
49 font_ids_by_family_cache: HashMap::default(),
50 postscript_names: HashMap::default(),
51 }))
52 }
53}
54
55impl Default for CosmicTextSystem {
56 fn default() -> Self {
57 Self::new()
58 }
59}
60
61impl PlatformTextSystem for CosmicTextSystem {
62 fn add_fonts(&self, fonts: Vec<Cow<'static, [u8]>>) -> Result<()> {
63 self.0.write().add_fonts(fonts)
64 }
65
66 fn all_font_names(&self) -> Vec<String> {
67 let mut result = self
68 .0
69 .read()
70 .font_system
71 .db()
72 .faces()
73 .filter_map(|face| face.families.first().map(|family| family.0.clone()))
74 .collect_vec();
75 result.sort();
76 result.dedup();
77 result
78 }
79
80 fn all_font_families(&self) -> Vec<String> {
81 self.0
82 .read()
83 .font_system
84 .db()
85 .faces()
86 // todo(linux) this will list the same font family multiple times
87 .filter_map(|face| face.families.first().map(|family| family.0.clone()))
88 .collect_vec()
89 }
90
91 fn font_id(&self, font: &Font) -> Result<FontId> {
92 // todo(linux): Do we need to use CosmicText's Font APIs? Can we consolidate this to use font_kit?
93 let mut state = self.0.write();
94
95 let candidates = if let Some(font_ids) = state.font_ids_by_family_cache.get(&font.family) {
96 font_ids.as_slice()
97 } else {
98 let font_ids = state.load_family(&font.family, &font.features)?;
99 state
100 .font_ids_by_family_cache
101 .insert(font.family.clone(), font_ids);
102 state.font_ids_by_family_cache[&font.family].as_ref()
103 };
104
105 // todo(linux) ideally we would make fontdb's `find_best_match` pub instead of using font-kit here
106 let candidate_properties = candidates
107 .iter()
108 .map(|font_id| {
109 let database_id = state.loaded_fonts_store[font_id.0].id();
110 let face_info = state.font_system.db().face(database_id).expect("");
111 face_info_into_properties(face_info)
112 })
113 .collect::<SmallVec<[_; 4]>>();
114
115 let ix =
116 font_kit::matching::find_best_match(&candidate_properties, &font_into_properties(font))
117 .context("requested font family contains no font matching the other parameters")?;
118
119 Ok(candidates[ix])
120 }
121
122 fn font_metrics(&self, font_id: FontId) -> FontMetrics {
123 let metrics = self.0.read().loaded_fonts_store[font_id.0]
124 .as_swash()
125 .metrics(&[]);
126
127 FontMetrics {
128 units_per_em: metrics.units_per_em as u32,
129 ascent: metrics.ascent,
130 descent: -metrics.descent, // todo(linux) confirm this is correct
131 line_gap: metrics.leading,
132 underline_position: metrics.underline_offset,
133 underline_thickness: metrics.stroke_size,
134 cap_height: metrics.cap_height,
135 x_height: metrics.x_height,
136 // todo(linux): Compute this correctly
137 bounding_box: Bounds {
138 origin: point(0.0, 0.0),
139 size: size(metrics.max_width, metrics.ascent + metrics.descent),
140 },
141 }
142 }
143
144 fn typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>> {
145 let lock = self.0.read();
146 let glyph_metrics = lock.loaded_fonts_store[font_id.0]
147 .as_swash()
148 .glyph_metrics(&[]);
149 let glyph_id = glyph_id.0 as u16;
150 // todo(linux): Compute this correctly
151 // see https://github.com/servo/font-kit/blob/master/src/loaders/freetype.rs#L614-L620
152 Ok(Bounds {
153 origin: point(0.0, 0.0),
154 size: size(
155 glyph_metrics.advance_width(glyph_id),
156 glyph_metrics.advance_height(glyph_id),
157 ),
158 })
159 }
160
161 fn advance(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Size<f32>> {
162 self.0.read().advance(font_id, glyph_id)
163 }
164
165 fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
166 self.0.read().glyph_for_char(font_id, ch)
167 }
168
169 fn glyph_raster_bounds(&self, params: &RenderGlyphParams) -> Result<Bounds<DevicePixels>> {
170 self.0.write().raster_bounds(params)
171 }
172
173 fn rasterize_glyph(
174 &self,
175 params: &RenderGlyphParams,
176 raster_bounds: Bounds<DevicePixels>,
177 ) -> Result<(Size<DevicePixels>, Vec<u8>)> {
178 self.0.write().rasterize_glyph(params, raster_bounds)
179 }
180
181 fn layout_line(&self, text: &str, font_size: Pixels, runs: &[FontRun]) -> LineLayout {
182 self.0.write().layout_line(text, font_size, runs)
183 }
184}
185
186impl CosmicTextSystemState {
187 #[profiling::function]
188 fn add_fonts(&mut self, fonts: Vec<Cow<'static, [u8]>>) -> Result<()> {
189 let db = self.font_system.db_mut();
190 for bytes in fonts {
191 match bytes {
192 Cow::Borrowed(embedded_font) => {
193 db.load_font_data(embedded_font.to_vec());
194 }
195 Cow::Owned(bytes) => {
196 db.load_font_data(bytes);
197 }
198 }
199 }
200 Ok(())
201 }
202
203 // todo(linux) handle `FontFeatures`
204 #[profiling::function]
205 fn load_family(
206 &mut self,
207 name: &str,
208 _features: &FontFeatures,
209 ) -> Result<SmallVec<[FontId; 4]>> {
210 // TODO: Determine the proper system UI font.
211 let name = if name == ".SystemUIFont" {
212 "Zed Plex Sans"
213 } else {
214 name
215 };
216
217 let mut font_ids = SmallVec::new();
218 let families = self
219 .font_system
220 .db()
221 .faces()
222 .filter(|face| face.families.iter().any(|family| *name == family.0))
223 .map(|face| (face.id, face.post_script_name.clone()))
224 .collect::<SmallVec<[_; 4]>>();
225
226 for (font_id, postscript_name) in families {
227 let font = self
228 .font_system
229 .get_font(font_id)
230 .ok_or_else(|| anyhow!("Could not load font"))?;
231
232 // HACK: To let the storybook run and render Windows caption icons. We should actually do better font fallback.
233 let allowed_bad_font_names = [
234 "SegoeFluentIcons", // NOTE: Segoe fluent icons postscript name is inconsistent
235 "Segoe Fluent Icons",
236 ];
237
238 if font.as_swash().charmap().map('m') == 0
239 && !allowed_bad_font_names.contains(&postscript_name.as_str())
240 {
241 self.font_system.db_mut().remove_face(font.id());
242 continue;
243 };
244
245 let font_id = FontId(self.loaded_fonts_store.len());
246 font_ids.push(font_id);
247 self.loaded_fonts_store.push(font);
248 self.postscript_names.insert(font_id, postscript_name);
249 }
250
251 Ok(font_ids)
252 }
253
254 fn advance(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Size<f32>> {
255 let width = self.loaded_fonts_store[font_id.0]
256 .as_swash()
257 .glyph_metrics(&[])
258 .advance_width(glyph_id.0 as u16);
259 let height = self.loaded_fonts_store[font_id.0]
260 .as_swash()
261 .glyph_metrics(&[])
262 .advance_height(glyph_id.0 as u16);
263 Ok(Size { width, height })
264 }
265
266 fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
267 let glyph_id = self.loaded_fonts_store[font_id.0]
268 .as_swash()
269 .charmap()
270 .map(ch);
271 if glyph_id == 0 {
272 None
273 } else {
274 Some(GlyphId(glyph_id.into()))
275 }
276 }
277
278 fn is_emoji(&self, font_id: FontId) -> bool {
279 // TODO: Include other common emoji fonts
280 self.postscript_names
281 .get(&font_id)
282 .map_or(false, |postscript_name| postscript_name == "NotoColorEmoji")
283 }
284
285 fn raster_bounds(&mut self, params: &RenderGlyphParams) -> Result<Bounds<DevicePixels>> {
286 let font = &self.loaded_fonts_store[params.font_id.0];
287 let font_system = &mut self.font_system;
288 let image = self
289 .swash_cache
290 .get_image(
291 font_system,
292 CacheKey::new(
293 font.id(),
294 params.glyph_id.0 as u16,
295 (params.font_size * params.scale_factor).into(),
296 (0.0, 0.0),
297 cosmic_text::CacheKeyFlags::empty(),
298 )
299 .0,
300 )
301 .clone()
302 .with_context(|| format!("no image for {params:?} in font {font:?}"))?;
303 Ok(Bounds {
304 origin: point(image.placement.left.into(), (-image.placement.top).into()),
305 size: size(image.placement.width.into(), image.placement.height.into()),
306 })
307 }
308
309 #[profiling::function]
310 fn rasterize_glyph(
311 &mut self,
312 params: &RenderGlyphParams,
313 glyph_bounds: Bounds<DevicePixels>,
314 ) -> Result<(Size<DevicePixels>, Vec<u8>)> {
315 if glyph_bounds.size.width.0 == 0 || glyph_bounds.size.height.0 == 0 {
316 Err(anyhow!("glyph bounds are empty"))
317 } else {
318 // todo(linux) handle subpixel variants
319 let bitmap_size = glyph_bounds.size;
320 let font = &self.loaded_fonts_store[params.font_id.0];
321 let font_system = &mut self.font_system;
322 let mut image = self
323 .swash_cache
324 .get_image(
325 font_system,
326 CacheKey::new(
327 font.id(),
328 params.glyph_id.0 as u16,
329 (params.font_size * params.scale_factor).into(),
330 (0.0, 0.0),
331 cosmic_text::CacheKeyFlags::empty(),
332 )
333 .0,
334 )
335 .clone()
336 .with_context(|| format!("no image for {params:?} in font {font:?}"))?;
337
338 if params.is_emoji {
339 // Convert from RGBA to BGRA.
340 for pixel in image.data.chunks_exact_mut(4) {
341 pixel.swap(0, 2);
342 }
343 }
344
345 Ok((bitmap_size, image.data))
346 }
347 }
348
349 fn font_id_for_cosmic_id(&mut self, id: cosmic_text::fontdb::ID) -> FontId {
350 if let Some(ix) = self
351 .loaded_fonts_store
352 .iter()
353 .position(|font| font.id() == id)
354 {
355 FontId(ix)
356 } else {
357 // This matches the behavior of the mac text system
358 let font = self.font_system.get_font(id).unwrap();
359 let face = self
360 .font_system
361 .db()
362 .faces()
363 .find(|info| info.id == id)
364 .unwrap();
365
366 let font_id = FontId(self.loaded_fonts_store.len());
367 self.loaded_fonts_store.push(font);
368 self.postscript_names
369 .insert(font_id, face.post_script_name.clone());
370
371 font_id
372 }
373 }
374
375 #[profiling::function]
376 fn layout_line(&mut self, text: &str, font_size: Pixels, font_runs: &[FontRun]) -> LineLayout {
377 let mut attrs_list = AttrsList::new(Attrs::new());
378 let mut offs = 0;
379 for run in font_runs {
380 let font = &self.loaded_fonts_store[run.font_id.0];
381 let font = self.font_system.db().face(font.id()).unwrap();
382 attrs_list.add_span(
383 offs..(offs + run.len),
384 Attrs::new()
385 .family(Family::Name(&font.families.first().unwrap().0))
386 .stretch(font.stretch)
387 .style(font.style)
388 .weight(font.weight),
389 );
390 offs += run.len;
391 }
392 let mut line = ShapeLine::new_in_buffer(
393 &mut self.scratch,
394 &mut self.font_system,
395 text,
396 &attrs_list,
397 cosmic_text::Shaping::Advanced,
398 4,
399 );
400
401 let mut layout = Vec::with_capacity(1);
402 line.layout_to_buffer(
403 &mut self.scratch,
404 font_size.0,
405 None, // We do our own wrapping
406 cosmic_text::Wrap::None,
407 None,
408 &mut layout,
409 None,
410 );
411
412 let mut runs = Vec::new();
413 let layout = layout.first().unwrap();
414 for glyph in &layout.glyphs {
415 let font_id = glyph.font_id;
416 let font_id = self.font_id_for_cosmic_id(font_id);
417 let is_emoji = self.is_emoji(font_id);
418 let mut glyphs = SmallVec::new();
419
420 // HACK: Prevent crash caused by variation selectors.
421 if glyph.glyph_id == 3 && is_emoji {
422 continue;
423 }
424
425 // todo(linux) this is definitely wrong, each glyph in glyphs from cosmic-text is a cluster with one glyph, ShapedRun takes a run of glyphs with the same font and direction
426 glyphs.push(ShapedGlyph {
427 id: GlyphId(glyph.glyph_id as u32),
428 position: point(glyph.x.into(), glyph.y.into()),
429 index: glyph.start,
430 is_emoji,
431 });
432
433 runs.push(crate::ShapedRun { font_id, glyphs });
434 }
435
436 LineLayout {
437 font_size,
438 width: layout.w.into(),
439 ascent: layout.max_ascent.into(),
440 descent: layout.max_descent.into(),
441 runs,
442 len: text.len(),
443 }
444 }
445}
446
447impl From<RectF> for Bounds<f32> {
448 fn from(rect: RectF) -> Self {
449 Bounds {
450 origin: point(rect.origin_x(), rect.origin_y()),
451 size: size(rect.width(), rect.height()),
452 }
453 }
454}
455
456impl From<RectI> for Bounds<DevicePixels> {
457 fn from(rect: RectI) -> Self {
458 Bounds {
459 origin: point(DevicePixels(rect.origin_x()), DevicePixels(rect.origin_y())),
460 size: size(DevicePixels(rect.width()), DevicePixels(rect.height())),
461 }
462 }
463}
464
465impl From<Vector2I> for Size<DevicePixels> {
466 fn from(value: Vector2I) -> Self {
467 size(value.x().into(), value.y().into())
468 }
469}
470
471impl From<RectI> for Bounds<i32> {
472 fn from(rect: RectI) -> Self {
473 Bounds {
474 origin: point(rect.origin_x(), rect.origin_y()),
475 size: size(rect.width(), rect.height()),
476 }
477 }
478}
479
480impl From<Point<u32>> for Vector2I {
481 fn from(size: Point<u32>) -> Self {
482 Vector2I::new(size.x as i32, size.y as i32)
483 }
484}
485
486impl From<Vector2F> for Size<f32> {
487 fn from(vec: Vector2F) -> Self {
488 size(vec.x(), vec.y())
489 }
490}
491
492impl From<FontWeight> for cosmic_text::Weight {
493 fn from(value: FontWeight) -> Self {
494 cosmic_text::Weight(value.0 as u16)
495 }
496}
497
498impl From<FontStyle> for cosmic_text::Style {
499 fn from(style: FontStyle) -> Self {
500 match style {
501 FontStyle::Normal => cosmic_text::Style::Normal,
502 FontStyle::Italic => cosmic_text::Style::Italic,
503 FontStyle::Oblique => cosmic_text::Style::Oblique,
504 }
505 }
506}
507
508fn font_into_properties(font: &crate::Font) -> font_kit::properties::Properties {
509 font_kit::properties::Properties {
510 style: match font.style {
511 crate::FontStyle::Normal => font_kit::properties::Style::Normal,
512 crate::FontStyle::Italic => font_kit::properties::Style::Italic,
513 crate::FontStyle::Oblique => font_kit::properties::Style::Oblique,
514 },
515 weight: font_kit::properties::Weight(font.weight.0),
516 stretch: Default::default(),
517 }
518}
519
520fn face_info_into_properties(
521 face_info: &cosmic_text::fontdb::FaceInfo,
522) -> font_kit::properties::Properties {
523 font_kit::properties::Properties {
524 style: match face_info.style {
525 cosmic_text::Style::Normal => font_kit::properties::Style::Normal,
526 cosmic_text::Style::Italic => font_kit::properties::Style::Italic,
527 cosmic_text::Style::Oblique => font_kit::properties::Style::Oblique,
528 },
529 // both libs use the same values for weight
530 weight: font_kit::properties::Weight(face_info.weight.0.into()),
531 stretch: match face_info.stretch {
532 cosmic_text::Stretch::Condensed => font_kit::properties::Stretch::CONDENSED,
533 cosmic_text::Stretch::Expanded => font_kit::properties::Stretch::EXPANDED,
534 cosmic_text::Stretch::ExtraCondensed => font_kit::properties::Stretch::EXTRA_CONDENSED,
535 cosmic_text::Stretch::ExtraExpanded => font_kit::properties::Stretch::EXTRA_EXPANDED,
536 cosmic_text::Stretch::Normal => font_kit::properties::Stretch::NORMAL,
537 cosmic_text::Stretch::SemiCondensed => font_kit::properties::Stretch::SEMI_CONDENSED,
538 cosmic_text::Stretch::SemiExpanded => font_kit::properties::Stretch::SEMI_EXPANDED,
539 cosmic_text::Stretch::UltraCondensed => font_kit::properties::Stretch::ULTRA_CONDENSED,
540 cosmic_text::Stretch::UltraExpanded => font_kit::properties::Stretch::ULTRA_EXPANDED,
541 },
542 }
543}