1mod font_fallbacks;
2mod font_features;
3mod line;
4mod line_layout;
5mod line_wrapper;
6
7pub use font_fallbacks::*;
8pub use font_features::*;
9pub use line::*;
10pub use line_layout::*;
11pub use line_wrapper::*;
12use schemars::JsonSchema;
13use serde::{Deserialize, Serialize};
14
15use crate::{
16 Bounds, DevicePixels, Hsla, Pixels, PlatformTextSystem, Point, Result, SharedString, Size,
17 StrikethroughStyle, TextRenderingMode, UnderlineStyle, px,
18};
19use anyhow::{Context as _, anyhow};
20use collections::FxHashMap;
21use core::fmt;
22use derive_more::{Add, Deref, FromStr, Sub};
23use itertools::Itertools;
24use parking_lot::{Mutex, RwLock, RwLockUpgradableReadGuard};
25use smallvec::{SmallVec, smallvec};
26use std::{
27 borrow::Cow,
28 cmp,
29 fmt::{Debug, Display, Formatter},
30 hash::{Hash, Hasher},
31 ops::{Deref, DerefMut, Range},
32 sync::Arc,
33};
34
35/// An opaque identifier for a specific font.
36#[derive(Hash, PartialEq, Eq, Clone, Copy, Debug)]
37#[repr(C)]
38pub struct FontId(pub usize);
39
40/// An opaque identifier for a specific font family.
41#[derive(Hash, PartialEq, Eq, Clone, Copy, Debug)]
42pub struct FontFamilyId(pub usize);
43
44/// Number of subpixel glyph variants along the X axis.
45pub const SUBPIXEL_VARIANTS_X: u8 = 4;
46
47/// Number of subpixel glyph variants along the Y axis.
48pub const SUBPIXEL_VARIANTS_Y: u8 = if cfg!(target_os = "windows") || cfg!(target_os = "linux") {
49 1
50} else {
51 SUBPIXEL_VARIANTS_X
52};
53
54/// The GPUI text rendering sub system.
55pub struct TextSystem {
56 platform_text_system: Arc<dyn PlatformTextSystem>,
57 font_ids_by_font: RwLock<FxHashMap<Font, Result<FontId>>>,
58 font_metrics: RwLock<FxHashMap<FontId, FontMetrics>>,
59 raster_bounds: RwLock<FxHashMap<RenderGlyphParams, Bounds<DevicePixels>>>,
60 wrapper_pool: Mutex<FxHashMap<FontIdWithSize, Vec<LineWrapper>>>,
61 font_runs_pool: Mutex<Vec<Vec<FontRun>>>,
62 fallback_font_stack: SmallVec<[Font; 2]>,
63}
64
65impl TextSystem {
66 pub(crate) fn new(platform_text_system: Arc<dyn PlatformTextSystem>) -> Self {
67 TextSystem {
68 platform_text_system,
69 font_metrics: RwLock::default(),
70 raster_bounds: RwLock::default(),
71 font_ids_by_font: RwLock::default(),
72 wrapper_pool: Mutex::default(),
73 font_runs_pool: Mutex::default(),
74 fallback_font_stack: smallvec![
75 // TODO: Remove this when Linux have implemented setting fallbacks.
76 font(".ZedMono"),
77 font(".ZedSans"),
78 font("Helvetica"),
79 font("Segoe UI"), // Windows
80 font("Ubuntu"), // Gnome (Ubuntu)
81 font("Adwaita Sans"), // Gnome 47
82 font("Cantarell"), // Gnome
83 font("Noto Sans"), // KDE
84 font("DejaVu Sans"),
85 font("Arial"), // macOS, Windows
86 ],
87 }
88 }
89
90 /// Get a list of all available font names from the operating system.
91 pub fn all_font_names(&self) -> Vec<String> {
92 let mut names = self.platform_text_system.all_font_names();
93 names.extend(
94 self.fallback_font_stack
95 .iter()
96 .map(|font| font.family.to_string()),
97 );
98 names.push(".SystemUIFont".to_string());
99 names.sort();
100 names.dedup();
101 names
102 }
103
104 /// Add a font's data to the text system.
105 pub fn add_fonts(&self, fonts: Vec<Cow<'static, [u8]>>) -> Result<()> {
106 self.platform_text_system.add_fonts(fonts)
107 }
108
109 /// Get the FontId for the configure font family and style.
110 fn font_id(&self, font: &Font) -> Result<FontId> {
111 fn clone_font_id_result(font_id: &Result<FontId>) -> Result<FontId> {
112 match font_id {
113 Ok(font_id) => Ok(*font_id),
114 Err(err) => Err(anyhow!("{err}")),
115 }
116 }
117
118 let font_id = self
119 .font_ids_by_font
120 .read()
121 .get(font)
122 .map(clone_font_id_result);
123 if let Some(font_id) = font_id {
124 font_id
125 } else {
126 let font_id = self.platform_text_system.font_id(font);
127 self.font_ids_by_font
128 .write()
129 .insert(font.clone(), clone_font_id_result(&font_id));
130 font_id
131 }
132 }
133
134 /// Get the Font for the Font Id.
135 pub fn get_font_for_id(&self, id: FontId) -> Option<Font> {
136 let lock = self.font_ids_by_font.read();
137 lock.iter()
138 .filter_map(|(font, result)| match result {
139 Ok(font_id) if *font_id == id => Some(font.clone()),
140 _ => None,
141 })
142 .next()
143 }
144
145 /// Resolves the specified font, falling back to the default font stack if
146 /// the font fails to load.
147 ///
148 /// # Panics
149 ///
150 /// Panics if the font and none of the fallbacks can be resolved.
151 pub fn resolve_font(&self, font: &Font) -> FontId {
152 if let Ok(font_id) = self.font_id(font) {
153 return font_id;
154 }
155 for fallback in &self.fallback_font_stack {
156 if let Ok(font_id) = self.font_id(fallback) {
157 return font_id;
158 }
159 }
160
161 panic!(
162 "failed to resolve font '{}' or any of the fallbacks: {}",
163 font.family,
164 self.fallback_font_stack
165 .iter()
166 .map(|fallback| &fallback.family)
167 .join(", ")
168 );
169 }
170
171 /// Get the bounding box for the given font and font size.
172 /// A font's bounding box is the smallest rectangle that could enclose all glyphs
173 /// in the font. superimposed over one another.
174 pub fn bounding_box(&self, font_id: FontId, font_size: Pixels) -> Bounds<Pixels> {
175 self.read_metrics(font_id, |metrics| metrics.bounding_box(font_size))
176 }
177
178 /// Get the typographic bounds for the given character, in the given font and size.
179 pub fn typographic_bounds(
180 &self,
181 font_id: FontId,
182 font_size: Pixels,
183 character: char,
184 ) -> Result<Bounds<Pixels>> {
185 let glyph_id = self
186 .platform_text_system
187 .glyph_for_char(font_id, character)
188 .with_context(|| format!("glyph not found for character '{character}'"))?;
189 let bounds = self
190 .platform_text_system
191 .typographic_bounds(font_id, glyph_id)?;
192 Ok(self.read_metrics(font_id, |metrics| {
193 (bounds / metrics.units_per_em as f32 * font_size.0).map(px)
194 }))
195 }
196
197 /// Get the advance width for the given character, in the given font and size.
198 pub fn advance(&self, font_id: FontId, font_size: Pixels, ch: char) -> Result<Size<Pixels>> {
199 let glyph_id = self
200 .platform_text_system
201 .glyph_for_char(font_id, ch)
202 .with_context(|| format!("glyph not found for character '{ch}'"))?;
203 let result = self.platform_text_system.advance(font_id, glyph_id)?
204 / self.units_per_em(font_id) as f32;
205
206 Ok(result * font_size)
207 }
208
209 // Consider removing this?
210 /// Returns the shaped layout width of for the given character, in the given font and size.
211 pub fn layout_width(&self, font_id: FontId, font_size: Pixels, ch: char) -> Pixels {
212 let mut buffer = [0; 4];
213 let buffer = ch.encode_utf8(&mut buffer);
214 self.platform_text_system
215 .layout_line(
216 buffer,
217 font_size,
218 &[FontRun {
219 len: buffer.len(),
220 font_id,
221 }],
222 )
223 .width
224 }
225
226 /// Returns the width of an `em`.
227 ///
228 /// Uses the width of the `m` character in the given font and size.
229 pub fn em_width(&self, font_id: FontId, font_size: Pixels) -> Result<Pixels> {
230 Ok(self.typographic_bounds(font_id, font_size, 'm')?.size.width)
231 }
232
233 /// Returns the advance width of an `em`.
234 ///
235 /// Uses the advance width of the `m` character in the given font and size.
236 pub fn em_advance(&self, font_id: FontId, font_size: Pixels) -> Result<Pixels> {
237 Ok(self.advance(font_id, font_size, 'm')?.width)
238 }
239
240 // Consider removing this?
241 /// Returns the shaped layout width of an `em`.
242 pub fn em_layout_width(&self, font_id: FontId, font_size: Pixels) -> Pixels {
243 self.layout_width(font_id, font_size, 'm')
244 }
245
246 /// Returns the width of an `ch`.
247 ///
248 /// Uses the width of the `0` character in the given font and size.
249 pub fn ch_width(&self, font_id: FontId, font_size: Pixels) -> Result<Pixels> {
250 Ok(self.typographic_bounds(font_id, font_size, '0')?.size.width)
251 }
252
253 /// Returns the advance width of an `ch`.
254 ///
255 /// Uses the advance width of the `0` character in the given font and size.
256 pub fn ch_advance(&self, font_id: FontId, font_size: Pixels) -> Result<Pixels> {
257 Ok(self.advance(font_id, font_size, '0')?.width)
258 }
259
260 /// Get the number of font size units per 'em square',
261 /// Per MDN: "an abstract square whose height is the intended distance between
262 /// lines of type in the same type size"
263 pub fn units_per_em(&self, font_id: FontId) -> u32 {
264 self.read_metrics(font_id, |metrics| metrics.units_per_em)
265 }
266
267 /// Get the height of a capital letter in the given font and size.
268 pub fn cap_height(&self, font_id: FontId, font_size: Pixels) -> Pixels {
269 self.read_metrics(font_id, |metrics| metrics.cap_height(font_size))
270 }
271
272 /// Get the height of the x character in the given font and size.
273 pub fn x_height(&self, font_id: FontId, font_size: Pixels) -> Pixels {
274 self.read_metrics(font_id, |metrics| metrics.x_height(font_size))
275 }
276
277 /// Get the recommended distance from the baseline for the given font
278 pub fn ascent(&self, font_id: FontId, font_size: Pixels) -> Pixels {
279 self.read_metrics(font_id, |metrics| metrics.ascent(font_size))
280 }
281
282 /// Get the recommended distance below the baseline for the given font,
283 /// in single spaced text.
284 pub fn descent(&self, font_id: FontId, font_size: Pixels) -> Pixels {
285 self.read_metrics(font_id, |metrics| metrics.descent(font_size))
286 }
287
288 /// Get the recommended baseline offset for the given font and line height.
289 pub fn baseline_offset(
290 &self,
291 font_id: FontId,
292 font_size: Pixels,
293 line_height: Pixels,
294 ) -> Pixels {
295 let ascent = self.ascent(font_id, font_size);
296 let descent = self.descent(font_id, font_size);
297 let padding_top = (line_height - ascent - descent) / 2.;
298 padding_top + ascent
299 }
300
301 fn read_metrics<T>(&self, font_id: FontId, read: impl FnOnce(&FontMetrics) -> T) -> T {
302 let lock = self.font_metrics.upgradable_read();
303
304 if let Some(metrics) = lock.get(&font_id) {
305 read(metrics)
306 } else {
307 let mut lock = RwLockUpgradableReadGuard::upgrade(lock);
308 let metrics = lock
309 .entry(font_id)
310 .or_insert_with(|| self.platform_text_system.font_metrics(font_id));
311 read(metrics)
312 }
313 }
314
315 /// Returns a handle to a line wrapper, for the given font and font size.
316 pub fn line_wrapper(self: &Arc<Self>, font: Font, font_size: Pixels) -> LineWrapperHandle {
317 let lock = &mut self.wrapper_pool.lock();
318 let font_id = self.resolve_font(&font);
319 let wrappers = lock
320 .entry(FontIdWithSize { font_id, font_size })
321 .or_default();
322 let wrapper = wrappers
323 .pop()
324 .unwrap_or_else(|| LineWrapper::new(font_id, font_size, self.clone()));
325
326 LineWrapperHandle {
327 wrapper: Some(wrapper),
328 text_system: self.clone(),
329 }
330 }
331
332 /// Get the rasterized size and location of a specific, rendered glyph.
333 pub(crate) fn raster_bounds(&self, params: &RenderGlyphParams) -> Result<Bounds<DevicePixels>> {
334 let raster_bounds = self.raster_bounds.upgradable_read();
335 if let Some(bounds) = raster_bounds.get(params) {
336 Ok(*bounds)
337 } else {
338 let mut raster_bounds = RwLockUpgradableReadGuard::upgrade(raster_bounds);
339 let bounds = self.platform_text_system.glyph_raster_bounds(params)?;
340 raster_bounds.insert(params.clone(), bounds);
341 Ok(bounds)
342 }
343 }
344
345 pub(crate) fn rasterize_glyph(
346 &self,
347 params: &RenderGlyphParams,
348 ) -> Result<(Size<DevicePixels>, Vec<u8>)> {
349 let raster_bounds = self.raster_bounds(params)?;
350 self.platform_text_system
351 .rasterize_glyph(params, raster_bounds)
352 }
353
354 /// Returns the text rendering mode recommended by the platform for the given font and size.
355 /// The return value will never be [`TextRenderingMode::PlatformDefault`].
356 pub(crate) fn recommended_rendering_mode(
357 &self,
358 font_id: FontId,
359 font_size: Pixels,
360 ) -> TextRenderingMode {
361 self.platform_text_system
362 .recommended_rendering_mode(font_id, font_size)
363 }
364}
365
366/// The GPUI text layout subsystem.
367#[derive(Deref)]
368pub struct WindowTextSystem {
369 line_layout_cache: LineLayoutCache,
370 #[deref]
371 text_system: Arc<TextSystem>,
372}
373
374impl WindowTextSystem {
375 pub(crate) fn new(text_system: Arc<TextSystem>) -> Self {
376 Self {
377 line_layout_cache: LineLayoutCache::new(text_system.platform_text_system.clone()),
378 text_system,
379 }
380 }
381
382 pub(crate) fn layout_index(&self) -> LineLayoutIndex {
383 self.line_layout_cache.layout_index()
384 }
385
386 pub(crate) fn reuse_layouts(&self, index: Range<LineLayoutIndex>) {
387 self.line_layout_cache.reuse_layouts(index)
388 }
389
390 pub(crate) fn truncate_layouts(&self, index: LineLayoutIndex) {
391 self.line_layout_cache.truncate_layouts(index)
392 }
393
394 /// Shape the given line, at the given font_size, for painting to the screen.
395 /// Subsets of the line can be styled independently with the `runs` parameter.
396 ///
397 /// Note that this method can only shape a single line of text. It will panic
398 /// if the text contains newlines. If you need to shape multiple lines of text,
399 /// use [`Self::shape_text`] instead.
400 pub fn shape_line(
401 &self,
402 text: SharedString,
403 font_size: Pixels,
404 runs: &[TextRun],
405 force_width: Option<Pixels>,
406 ) -> ShapedLine {
407 debug_assert!(
408 text.find('\n').is_none(),
409 "text argument should not contain newlines"
410 );
411
412 let mut decoration_runs = SmallVec::<[DecorationRun; 32]>::new();
413 for run in runs {
414 if let Some(last_run) = decoration_runs.last_mut()
415 && last_run.color == run.color
416 && last_run.underline == run.underline
417 && last_run.strikethrough == run.strikethrough
418 && last_run.background_color == run.background_color
419 {
420 last_run.len += run.len as u32;
421 continue;
422 }
423 decoration_runs.push(DecorationRun {
424 len: run.len as u32,
425 color: run.color,
426 background_color: run.background_color,
427 underline: run.underline,
428 strikethrough: run.strikethrough,
429 });
430 }
431
432 let layout = self.layout_line(&text, font_size, runs, force_width);
433
434 ShapedLine {
435 layout,
436 text,
437 decoration_runs,
438 }
439 }
440
441 /// Shape a multi line string of text, at the given font_size, for painting to the screen.
442 /// Subsets of the text can be styled independently with the `runs` parameter.
443 /// If `wrap_width` is provided, the line breaks will be adjusted to fit within the given width.
444 pub fn shape_text(
445 &self,
446 text: SharedString,
447 font_size: Pixels,
448 runs: &[TextRun],
449 wrap_width: Option<Pixels>,
450 line_clamp: Option<usize>,
451 ) -> Result<SmallVec<[WrappedLine; 1]>> {
452 let mut runs = runs.iter().filter(|run| run.len > 0).cloned().peekable();
453 let mut font_runs = self.font_runs_pool.lock().pop().unwrap_or_default();
454
455 let mut lines = SmallVec::new();
456 let mut max_wrap_lines = line_clamp;
457 let mut wrapped_lines = 0;
458
459 let mut process_line = |line_text: SharedString, line_start, line_end| {
460 font_runs.clear();
461
462 let mut decoration_runs = <Vec<DecorationRun>>::with_capacity(32);
463 let mut run_start = line_start;
464 while run_start < line_end {
465 let Some(run) = runs.peek_mut() else {
466 log::warn!("`TextRun`s do not cover the entire to be shaped text");
467 break;
468 };
469
470 let run_len_within_line = cmp::min(line_end - run_start, run.len);
471
472 let decoration_changed = if let Some(last_run) = decoration_runs.last_mut()
473 && last_run.color == run.color
474 && last_run.underline == run.underline
475 && last_run.strikethrough == run.strikethrough
476 && last_run.background_color == run.background_color
477 {
478 last_run.len += run_len_within_line as u32;
479 false
480 } else {
481 decoration_runs.push(DecorationRun {
482 len: run_len_within_line as u32,
483 color: run.color,
484 background_color: run.background_color,
485 underline: run.underline,
486 strikethrough: run.strikethrough,
487 });
488 true
489 };
490
491 let font_id = self.resolve_font(&run.font);
492 if let Some(font_run) = font_runs.last_mut()
493 && font_id == font_run.font_id
494 && !decoration_changed
495 {
496 font_run.len += run_len_within_line;
497 } else {
498 font_runs.push(FontRun {
499 len: run_len_within_line,
500 font_id,
501 });
502 }
503
504 // Preserve the remainder of the run for the next line
505 run.len -= run_len_within_line;
506 if run.len == 0 {
507 runs.next();
508 }
509 run_start += run_len_within_line;
510 }
511
512 let layout = self.line_layout_cache.layout_wrapped_line(
513 &line_text,
514 font_size,
515 &font_runs,
516 wrap_width,
517 max_wrap_lines.map(|max| max.saturating_sub(wrapped_lines)),
518 );
519 wrapped_lines += layout.wrap_boundaries.len();
520
521 lines.push(WrappedLine {
522 layout,
523 decoration_runs,
524 text: line_text,
525 });
526
527 // Skip `\n` character.
528 if let Some(run) = runs.peek_mut() {
529 run.len -= 1;
530 if run.len == 0 {
531 runs.next();
532 }
533 }
534 };
535
536 let mut split_lines = text.split('\n');
537
538 // Special case single lines to prevent allocating a sharedstring
539 if let Some(first_line) = split_lines.next()
540 && let Some(second_line) = split_lines.next()
541 {
542 let mut line_start = 0;
543 process_line(
544 SharedString::new(first_line),
545 line_start,
546 line_start + first_line.len(),
547 );
548 line_start += first_line.len() + '\n'.len_utf8();
549 process_line(
550 SharedString::new(second_line),
551 line_start,
552 line_start + second_line.len(),
553 );
554 for line_text in split_lines {
555 line_start += line_text.len() + '\n'.len_utf8();
556 process_line(
557 SharedString::new(line_text),
558 line_start,
559 line_start + line_text.len(),
560 );
561 }
562 } else {
563 let end = text.len();
564 process_line(text, 0, end);
565 }
566
567 self.font_runs_pool.lock().push(font_runs);
568
569 Ok(lines)
570 }
571
572 pub(crate) fn finish_frame(&self) {
573 self.line_layout_cache.finish_frame()
574 }
575
576 /// Layout the given line of text, at the given font_size.
577 /// Subsets of the line can be styled independently with the `runs` parameter.
578 /// Generally, you should prefer to use [`Self::shape_line`] instead, which
579 /// can be painted directly.
580 pub fn layout_line(
581 &self,
582 text: &str,
583 font_size: Pixels,
584 runs: &[TextRun],
585 force_width: Option<Pixels>,
586 ) -> Arc<LineLayout> {
587 let mut last_run = None::<&TextRun>;
588 let mut font_runs = self.font_runs_pool.lock().pop().unwrap_or_default();
589 font_runs.clear();
590
591 for run in runs.iter() {
592 let decoration_changed = if let Some(last_run) = last_run
593 && last_run.color == run.color
594 && last_run.underline == run.underline
595 && last_run.strikethrough == run.strikethrough
596 // we do not consider differing background color relevant, as it does not affect glyphs
597 // && last_run.background_color == run.background_color
598 {
599 false
600 } else {
601 last_run = Some(run);
602 true
603 };
604
605 let font_id = self.resolve_font(&run.font);
606 if let Some(font_run) = font_runs.last_mut()
607 && font_id == font_run.font_id
608 && !decoration_changed
609 {
610 font_run.len += run.len;
611 } else {
612 font_runs.push(FontRun {
613 len: run.len,
614 font_id,
615 });
616 }
617 }
618
619 let layout = self.line_layout_cache.layout_line(
620 &SharedString::new(text),
621 font_size,
622 &font_runs,
623 force_width,
624 );
625
626 self.font_runs_pool.lock().push(font_runs);
627
628 layout
629 }
630}
631
632#[derive(Hash, Eq, PartialEq)]
633struct FontIdWithSize {
634 font_id: FontId,
635 font_size: Pixels,
636}
637
638/// A handle into the text system, which can be used to compute the wrapped layout of text
639pub struct LineWrapperHandle {
640 wrapper: Option<LineWrapper>,
641 text_system: Arc<TextSystem>,
642}
643
644impl Drop for LineWrapperHandle {
645 fn drop(&mut self) {
646 let mut state = self.text_system.wrapper_pool.lock();
647 let wrapper = self.wrapper.take().unwrap();
648 state
649 .get_mut(&FontIdWithSize {
650 font_id: wrapper.font_id,
651 font_size: wrapper.font_size,
652 })
653 .unwrap()
654 .push(wrapper);
655 }
656}
657
658impl Deref for LineWrapperHandle {
659 type Target = LineWrapper;
660
661 fn deref(&self) -> &Self::Target {
662 self.wrapper.as_ref().unwrap()
663 }
664}
665
666impl DerefMut for LineWrapperHandle {
667 fn deref_mut(&mut self) -> &mut Self::Target {
668 self.wrapper.as_mut().unwrap()
669 }
670}
671
672/// The degree of blackness or stroke thickness of a font. This value ranges from 100.0 to 900.0,
673/// with 400.0 as normal.
674#[derive(Clone, Copy, Debug, PartialEq, PartialOrd, Serialize, Deserialize, Add, Sub, FromStr)]
675#[serde(transparent)]
676pub struct FontWeight(pub f32);
677
678impl Display for FontWeight {
679 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
680 write!(f, "{}", self.0)
681 }
682}
683
684impl From<f32> for FontWeight {
685 fn from(weight: f32) -> Self {
686 FontWeight(weight)
687 }
688}
689
690impl Default for FontWeight {
691 #[inline]
692 fn default() -> FontWeight {
693 FontWeight::NORMAL
694 }
695}
696
697impl Hash for FontWeight {
698 fn hash<H: Hasher>(&self, state: &mut H) {
699 state.write_u32(u32::from_be_bytes(self.0.to_be_bytes()));
700 }
701}
702
703impl Eq for FontWeight {}
704
705impl FontWeight {
706 /// Thin weight (100), the thinnest value.
707 pub const THIN: FontWeight = FontWeight(100.0);
708 /// Extra light weight (200).
709 pub const EXTRA_LIGHT: FontWeight = FontWeight(200.0);
710 /// Light weight (300).
711 pub const LIGHT: FontWeight = FontWeight(300.0);
712 /// Normal (400).
713 pub const NORMAL: FontWeight = FontWeight(400.0);
714 /// Medium weight (500, higher than normal).
715 pub const MEDIUM: FontWeight = FontWeight(500.0);
716 /// Semibold weight (600).
717 pub const SEMIBOLD: FontWeight = FontWeight(600.0);
718 /// Bold weight (700).
719 pub const BOLD: FontWeight = FontWeight(700.0);
720 /// Extra-bold weight (800).
721 pub const EXTRA_BOLD: FontWeight = FontWeight(800.0);
722 /// Black weight (900), the thickest value.
723 pub const BLACK: FontWeight = FontWeight(900.0);
724
725 /// All of the font weights, in order from thinnest to thickest.
726 pub const ALL: [FontWeight; 9] = [
727 Self::THIN,
728 Self::EXTRA_LIGHT,
729 Self::LIGHT,
730 Self::NORMAL,
731 Self::MEDIUM,
732 Self::SEMIBOLD,
733 Self::BOLD,
734 Self::EXTRA_BOLD,
735 Self::BLACK,
736 ];
737}
738
739impl schemars::JsonSchema for FontWeight {
740 fn schema_name() -> std::borrow::Cow<'static, str> {
741 "FontWeight".into()
742 }
743
744 fn json_schema(_: &mut schemars::SchemaGenerator) -> schemars::Schema {
745 use schemars::json_schema;
746 json_schema!({
747 "type": "number",
748 "minimum": Self::THIN,
749 "maximum": Self::BLACK,
750 "default": Self::default(),
751 "description": "Font weight value between 100 (thin) and 900 (black)"
752 })
753 }
754}
755
756/// Allows italic or oblique faces to be selected.
757#[derive(Clone, Copy, Eq, PartialEq, Debug, Hash, Default, Serialize, Deserialize, JsonSchema)]
758pub enum FontStyle {
759 /// A face that is neither italic not obliqued.
760 #[default]
761 Normal,
762 /// A form that is generally cursive in nature.
763 Italic,
764 /// A typically-sloped version of the regular face.
765 Oblique,
766}
767
768impl Display for FontStyle {
769 fn fmt(&self, f: &mut Formatter) -> fmt::Result {
770 Debug::fmt(self, f)
771 }
772}
773
774/// A styled run of text, for use in [`crate::TextLayout`].
775#[derive(Clone, Debug, PartialEq, Eq, Default)]
776pub struct TextRun {
777 /// A number of utf8 bytes
778 pub len: usize,
779 /// The font to use for this run.
780 pub font: Font,
781 /// The color
782 pub color: Hsla,
783 /// The background color (if any)
784 pub background_color: Option<Hsla>,
785 /// The underline style (if any)
786 pub underline: Option<UnderlineStyle>,
787 /// The strikethrough style (if any)
788 pub strikethrough: Option<StrikethroughStyle>,
789}
790
791#[cfg(all(target_os = "macos", test))]
792impl TextRun {
793 fn with_len(&self, len: usize) -> Self {
794 let mut this = self.clone();
795 this.len = len;
796 this
797 }
798}
799
800/// An identifier for a specific glyph, as returned by [`WindowTextSystem::layout_line`].
801#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
802#[repr(C)]
803pub struct GlyphId(pub u32);
804
805#[derive(Clone, Debug, PartialEq)]
806#[expect(missing_docs)]
807pub struct RenderGlyphParams {
808 pub font_id: FontId,
809 pub glyph_id: GlyphId,
810 pub font_size: Pixels,
811 pub subpixel_variant: Point<u8>,
812 pub scale_factor: f32,
813 pub is_emoji: bool,
814 pub subpixel_rendering: bool,
815}
816
817impl Eq for RenderGlyphParams {}
818
819impl Hash for RenderGlyphParams {
820 fn hash<H: Hasher>(&self, state: &mut H) {
821 self.font_id.0.hash(state);
822 self.glyph_id.0.hash(state);
823 self.font_size.0.to_bits().hash(state);
824 self.subpixel_variant.hash(state);
825 self.scale_factor.to_bits().hash(state);
826 self.is_emoji.hash(state);
827 self.subpixel_rendering.hash(state);
828 }
829}
830
831/// The configuration details for identifying a specific font.
832#[derive(Clone, Debug, Eq, PartialEq, Hash)]
833pub struct Font {
834 /// The font family name.
835 ///
836 /// The special name ".SystemUIFont" is used to identify the system UI font, which varies based on platform.
837 pub family: SharedString,
838
839 /// The font features to use.
840 pub features: FontFeatures,
841
842 /// The fallbacks fonts to use.
843 pub fallbacks: Option<FontFallbacks>,
844
845 /// The font weight.
846 pub weight: FontWeight,
847
848 /// The font style.
849 pub style: FontStyle,
850}
851
852impl Default for Font {
853 fn default() -> Self {
854 font(".SystemUIFont")
855 }
856}
857
858/// Get a [`Font`] for a given name.
859pub fn font(family: impl Into<SharedString>) -> Font {
860 Font {
861 family: family.into(),
862 features: FontFeatures::default(),
863 weight: FontWeight::default(),
864 style: FontStyle::default(),
865 fallbacks: None,
866 }
867}
868
869impl Font {
870 /// Set this Font to be bold
871 pub fn bold(mut self) -> Self {
872 self.weight = FontWeight::BOLD;
873 self
874 }
875
876 /// Set this Font to be italic
877 pub fn italic(mut self) -> Self {
878 self.style = FontStyle::Italic;
879 self
880 }
881}
882
883/// A struct for storing font metrics.
884/// It is used to define the measurements of a typeface.
885#[derive(Clone, Copy, Debug)]
886pub struct FontMetrics {
887 /// The number of font units that make up the "em square",
888 /// a scalable grid for determining the size of a typeface.
889 pub units_per_em: u32,
890
891 /// The vertical distance from the baseline of the font to the top of the glyph covers.
892 pub ascent: f32,
893
894 /// The vertical distance from the baseline of the font to the bottom of the glyph covers.
895 pub descent: f32,
896
897 /// The recommended additional space to add between lines of type.
898 pub line_gap: f32,
899
900 /// The suggested position of the underline.
901 pub underline_position: f32,
902
903 /// The suggested thickness of the underline.
904 pub underline_thickness: f32,
905
906 /// The height of a capital letter measured from the baseline of the font.
907 pub cap_height: f32,
908
909 /// The height of a lowercase x.
910 pub x_height: f32,
911
912 /// The outer limits of the area that the font covers.
913 /// Corresponds to the xMin / xMax / yMin / yMax values in the OpenType `head` table
914 pub bounding_box: Bounds<f32>,
915}
916
917impl FontMetrics {
918 /// Returns the vertical distance from the baseline of the font to the top of the glyph covers in pixels.
919 pub fn ascent(&self, font_size: Pixels) -> Pixels {
920 Pixels((self.ascent / self.units_per_em as f32) * font_size.0)
921 }
922
923 /// Returns the vertical distance from the baseline of the font to the bottom of the glyph covers in pixels.
924 pub fn descent(&self, font_size: Pixels) -> Pixels {
925 Pixels((self.descent / self.units_per_em as f32) * font_size.0)
926 }
927
928 /// Returns the recommended additional space to add between lines of type in pixels.
929 pub fn line_gap(&self, font_size: Pixels) -> Pixels {
930 Pixels((self.line_gap / self.units_per_em as f32) * font_size.0)
931 }
932
933 /// Returns the suggested position of the underline in pixels.
934 pub fn underline_position(&self, font_size: Pixels) -> Pixels {
935 Pixels((self.underline_position / self.units_per_em as f32) * font_size.0)
936 }
937
938 /// Returns the suggested thickness of the underline in pixels.
939 pub fn underline_thickness(&self, font_size: Pixels) -> Pixels {
940 Pixels((self.underline_thickness / self.units_per_em as f32) * font_size.0)
941 }
942
943 /// Returns the height of a capital letter measured from the baseline of the font in pixels.
944 pub fn cap_height(&self, font_size: Pixels) -> Pixels {
945 Pixels((self.cap_height / self.units_per_em as f32) * font_size.0)
946 }
947
948 /// Returns the height of a lowercase x in pixels.
949 pub fn x_height(&self, font_size: Pixels) -> Pixels {
950 Pixels((self.x_height / self.units_per_em as f32) * font_size.0)
951 }
952
953 /// Returns the outer limits of the area that the font covers in pixels.
954 pub fn bounding_box(&self, font_size: Pixels) -> Bounds<Pixels> {
955 (self.bounding_box / self.units_per_em as f32 * font_size.0).map(px)
956 }
957}
958
959/// Maps well-known virtual font names to their concrete equivalents.
960#[allow(unused)]
961pub fn font_name_with_fallbacks<'a>(name: &'a str, system: &'a str) -> &'a str {
962 // Note: the "Zed Plex" fonts were deprecated as we are not allowed to use "Plex"
963 // in a derived font name. They are essentially indistinguishable from IBM Plex/Lilex,
964 // and so retained here for backward compatibility.
965 match name {
966 ".SystemUIFont" => system,
967 ".ZedSans" | "Zed Plex Sans" => "IBM Plex Sans",
968 ".ZedMono" | "Zed Plex Mono" => "Lilex",
969 _ => name,
970 }
971}
972
973/// Like [`font_name_with_fallbacks`] but accepts and returns [`SharedString`] references.
974#[allow(unused)]
975pub fn font_name_with_fallbacks_shared<'a>(
976 name: &'a SharedString,
977 system: &'a SharedString,
978) -> &'a SharedString {
979 // Note: the "Zed Plex" fonts were deprecated as we are not allowed to use "Plex"
980 // in a derived font name. They are essentially indistinguishable from IBM Plex/Lilex,
981 // and so retained here for backward compatibility.
982 match name.as_str() {
983 ".SystemUIFont" => system,
984 ".ZedSans" | "Zed Plex Sans" => const { &SharedString::new_static("IBM Plex Sans") },
985 ".ZedMono" | "Zed Plex Mono" => const { &SharedString::new_static("Lilex") },
986 _ => name,
987 }
988}