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