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