text_system.rs

  1use crate::{
  2    point, px, size, Bounds, Font, FontFeatures, FontId, FontMetrics, FontStyle, FontWeight, Glyph,
  3    GlyphId, LineLayout, Pixels, PlatformTextSystem, Point, RasterizationOptions, Result, Run,
  4    RunStyle, SharedString, Size,
  5};
  6use cocoa::appkit::{CGFloat, CGPoint};
  7use collections::HashMap;
  8use core_foundation::{
  9    array::CFIndex,
 10    attributed_string::{CFAttributedStringRef, CFMutableAttributedString},
 11    base::{CFRange, TCFType},
 12    string::CFString,
 13};
 14use core_graphics::{
 15    base::{kCGImageAlphaPremultipliedLast, CGGlyph},
 16    color_space::CGColorSpace,
 17    context::CGContext,
 18};
 19use core_text::{font::CTFont, line::CTLine, string_attributes::kCTFontAttributeName};
 20use font_kit::{
 21    font::Font as FontKitFont,
 22    handle::Handle,
 23    hinting::HintingOptions,
 24    metrics::Metrics,
 25    properties::{Style as FontkitStyle, Weight as FontkitWeight},
 26    source::SystemSource,
 27    sources::mem::MemSource,
 28};
 29use parking_lot::RwLock;
 30use pathfinder_geometry::{
 31    rect::{RectF, RectI},
 32    transform2d::Transform2F,
 33    vector::{Vector2F, Vector2I},
 34};
 35use smallvec::SmallVec;
 36use std::{cell::RefCell, char, cmp, convert::TryFrom, ffi::c_void, sync::Arc};
 37
 38use super::open_type;
 39
 40#[allow(non_upper_case_globals)]
 41const kCGImageAlphaOnly: u32 = 7;
 42
 43pub struct MacTextSystem(RwLock<MacTextSystemState>);
 44
 45struct MacTextSystemState {
 46    memory_source: MemSource,
 47    system_source: SystemSource,
 48    fonts: Vec<FontKitFont>,
 49    font_selections: HashMap<Font, FontId>,
 50    font_ids_by_postscript_name: HashMap<String, FontId>,
 51    font_ids_by_family_name: HashMap<SharedString, SmallVec<[FontId; 4]>>,
 52    postscript_names_by_font_id: HashMap<FontId, String>,
 53}
 54
 55impl MacTextSystem {
 56    pub fn new() -> Self {
 57        Self(RwLock::new(MacTextSystemState {
 58            memory_source: MemSource::empty(),
 59            system_source: SystemSource::new(),
 60            fonts: Vec::new(),
 61            font_selections: HashMap::default(),
 62            font_ids_by_postscript_name: HashMap::default(),
 63            font_ids_by_family_name: HashMap::default(),
 64            postscript_names_by_font_id: HashMap::default(),
 65        }))
 66    }
 67}
 68
 69impl Default for MacTextSystem {
 70    fn default() -> Self {
 71        Self::new()
 72    }
 73}
 74
 75impl PlatformTextSystem for MacTextSystem {
 76    fn add_fonts(&self, fonts: &[Arc<Vec<u8>>]) -> Result<()> {
 77        self.0.write().add_fonts(fonts)
 78    }
 79
 80    fn all_font_families(&self) -> Vec<String> {
 81        self.0
 82            .read()
 83            .system_source
 84            .all_families()
 85            .expect("core text should never return an error")
 86    }
 87
 88    fn font_id(&self, font: &Font) -> Result<FontId> {
 89        let lock = self.0.upgradable_read();
 90        if let Some(font_id) = lock.font_selections.get(font) {
 91            Ok(*font_id)
 92        } else {
 93            let mut lock = parking_lot::RwLockUpgradableReadGuard::upgrade(lock);
 94            let candidates = if let Some(font_ids) = lock.font_ids_by_family_name.get(&font.family)
 95            {
 96                font_ids.as_slice()
 97            } else {
 98                let font_ids = lock.load_family(&font.family, font.features)?;
 99                lock.font_ids_by_family_name
100                    .insert(font.family.clone(), font_ids);
101                lock.font_ids_by_family_name[&font.family].as_ref()
102            };
103
104            let candidate_properties = candidates
105                .iter()
106                .map(|font_id| lock.fonts[font_id.0].properties())
107                .collect::<SmallVec<[_; 4]>>();
108
109            let ix = font_kit::matching::find_best_match(
110                &candidate_properties,
111                &font_kit::properties::Properties {
112                    style: font.style.into(),
113                    weight: font.weight.into(),
114                    stretch: Default::default(),
115                },
116            )?;
117
118            Ok(candidates[ix])
119        }
120    }
121
122    fn font_metrics(&self, font_id: FontId) -> FontMetrics {
123        self.0.read().fonts[font_id.0].metrics().into()
124    }
125
126    fn typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>> {
127        Ok(self.0.read().fonts[font_id.0]
128            .typographic_bounds(glyph_id.into())?
129            .into())
130    }
131
132    fn advance(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Size<f32>> {
133        self.0.read().advance(font_id, glyph_id)
134    }
135
136    fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
137        self.0.read().glyph_for_char(font_id, ch)
138    }
139
140    fn rasterize_glyph(
141        &self,
142        font_id: FontId,
143        font_size: f32,
144        glyph_id: GlyphId,
145        subpixel_shift: Point<Pixels>,
146        scale_factor: f32,
147        options: RasterizationOptions,
148    ) -> Option<(Bounds<u32>, Vec<u8>)> {
149        self.0.read().rasterize_glyph(
150            font_id,
151            font_size,
152            glyph_id,
153            subpixel_shift,
154            scale_factor,
155            options,
156        )
157    }
158
159    fn layout_line(&self, text: &str, font_size: Pixels, runs: &[(usize, RunStyle)]) -> LineLayout {
160        self.0.write().layout_line(text, font_size, runs)
161    }
162
163    fn wrap_line(
164        &self,
165        text: &str,
166        font_id: FontId,
167        font_size: Pixels,
168        width: Pixels,
169    ) -> Vec<usize> {
170        self.0.read().wrap_line(text, font_id, font_size, width)
171    }
172}
173
174impl MacTextSystemState {
175    fn add_fonts(&mut self, fonts: &[Arc<Vec<u8>>]) -> Result<()> {
176        self.memory_source.add_fonts(
177            fonts
178                .iter()
179                .map(|bytes| Handle::from_memory(bytes.clone(), 0)),
180        )?;
181        Ok(())
182    }
183
184    fn load_family(
185        &mut self,
186        name: &SharedString,
187        features: FontFeatures,
188    ) -> Result<SmallVec<[FontId; 4]>> {
189        let mut font_ids = SmallVec::new();
190        let family = self
191            .memory_source
192            .select_family_by_name(name.as_ref())
193            .or_else(|_| self.system_source.select_family_by_name(name.as_ref()))?;
194        for font in family.fonts() {
195            let mut font = font.load()?;
196            open_type::apply_features(&mut font, features);
197            let font_id = FontId(self.fonts.len());
198            font_ids.push(font_id);
199            let postscript_name = font.postscript_name().unwrap();
200            self.font_ids_by_postscript_name
201                .insert(postscript_name.clone(), font_id);
202            self.postscript_names_by_font_id
203                .insert(font_id, postscript_name);
204            self.fonts.push(font);
205        }
206        Ok(font_ids)
207    }
208
209    fn advance(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Size<f32>> {
210        Ok(self.fonts[font_id.0].advance(glyph_id.into())?.into())
211    }
212
213    fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
214        self.fonts[font_id.0].glyph_for_char(ch).map(Into::into)
215    }
216
217    fn id_for_native_font(&mut self, requested_font: CTFont) -> FontId {
218        let postscript_name = requested_font.postscript_name();
219        if let Some(font_id) = self.font_ids_by_postscript_name.get(&postscript_name) {
220            *font_id
221        } else {
222            let font_id = FontId(self.fonts.len());
223            self.font_ids_by_postscript_name
224                .insert(postscript_name.clone(), font_id);
225            self.postscript_names_by_font_id
226                .insert(font_id, postscript_name);
227            self.fonts
228                .push(font_kit::font::Font::from_core_graphics_font(
229                    requested_font.copy_to_CGFont(),
230                ));
231            font_id
232        }
233    }
234
235    fn is_emoji(&self, font_id: FontId) -> bool {
236        self.postscript_names_by_font_id
237            .get(&font_id)
238            .map_or(false, |postscript_name| {
239                postscript_name == "AppleColorEmoji"
240            })
241    }
242
243    fn rasterize_glyph(
244        &self,
245        font_id: FontId,
246        font_size: f32,
247        glyph_id: GlyphId,
248        subpixel_shift: Point<Pixels>,
249        scale_factor: f32,
250        options: RasterizationOptions,
251    ) -> Option<(Bounds<u32>, Vec<u8>)> {
252        let font = &self.fonts[font_id.0];
253        let scale = Transform2F::from_scale(scale_factor);
254        let glyph_bounds = font
255            .raster_bounds(
256                glyph_id.into(),
257                font_size,
258                scale,
259                HintingOptions::None,
260                font_kit::canvas::RasterizationOptions::GrayscaleAa,
261            )
262            .ok()?;
263
264        if glyph_bounds.width() == 0 || glyph_bounds.height() == 0 {
265            None
266        } else {
267            // Make room for subpixel variants.
268            let subpixel_padding = subpixel_shift.map(|v| f32::from(v).ceil() as u32);
269            let cx_bounds = RectI::new(
270                glyph_bounds.origin(),
271                glyph_bounds.size() + Vector2I::from(subpixel_padding),
272            );
273
274            let mut bytes;
275            let cx;
276            match options {
277                RasterizationOptions::Alpha => {
278                    bytes = vec![0; cx_bounds.width() as usize * cx_bounds.height() as usize];
279                    cx = CGContext::create_bitmap_context(
280                        Some(bytes.as_mut_ptr() as *mut _),
281                        cx_bounds.width() as usize,
282                        cx_bounds.height() as usize,
283                        8,
284                        cx_bounds.width() as usize,
285                        &CGColorSpace::create_device_gray(),
286                        kCGImageAlphaOnly,
287                    );
288                }
289                RasterizationOptions::Bgra => {
290                    bytes = vec![0; cx_bounds.width() as usize * 4 * cx_bounds.height() as usize];
291                    cx = CGContext::create_bitmap_context(
292                        Some(bytes.as_mut_ptr() as *mut _),
293                        cx_bounds.width() as usize,
294                        cx_bounds.height() as usize,
295                        8,
296                        cx_bounds.width() as usize * 4,
297                        &CGColorSpace::create_device_rgb(),
298                        kCGImageAlphaPremultipliedLast,
299                    );
300                }
301            }
302
303            // Move the origin to bottom left and account for scaling, this
304            // makes drawing text consistent with the font-kit's raster_bounds.
305            cx.translate(
306                -glyph_bounds.origin_x() as CGFloat,
307                (glyph_bounds.origin_y() + glyph_bounds.height()) as CGFloat,
308            );
309            cx.scale(scale_factor as CGFloat, scale_factor as CGFloat);
310
311            cx.set_allows_font_subpixel_positioning(true);
312            cx.set_should_subpixel_position_fonts(true);
313            cx.set_allows_font_subpixel_quantization(false);
314            cx.set_should_subpixel_quantize_fonts(false);
315            font.native_font()
316                .clone_with_font_size(font_size as CGFloat)
317                .draw_glyphs(
318                    &[u32::from(glyph_id) as CGGlyph],
319                    &[CGPoint::new(
320                        (f32::from(subpixel_shift.x) / scale_factor) as CGFloat,
321                        (f32::from(subpixel_shift.y) / scale_factor) as CGFloat,
322                    )],
323                    cx,
324                );
325
326            if let RasterizationOptions::Bgra = options {
327                // Convert from RGBA with premultiplied alpha to BGRA with straight alpha.
328                for pixel in bytes.chunks_exact_mut(4) {
329                    pixel.swap(0, 2);
330                    let a = pixel[3] as f32 / 255.;
331                    pixel[0] = (pixel[0] as f32 / a) as u8;
332                    pixel[1] = (pixel[1] as f32 / a) as u8;
333                    pixel[2] = (pixel[2] as f32 / a) as u8;
334                }
335            }
336
337            Some((cx_bounds.into(), bytes))
338        }
339    }
340
341    fn layout_line(
342        &mut self,
343        text: &str,
344        font_size: Pixels,
345        runs: &[(usize, RunStyle)],
346    ) -> LineLayout {
347        // Construct the attributed string, converting UTF8 ranges to UTF16 ranges.
348        let mut string = CFMutableAttributedString::new();
349        {
350            string.replace_str(&CFString::new(text), CFRange::init(0, 0));
351            let utf16_line_len = string.char_len() as usize;
352
353            let last_run: RefCell<Option<(usize, Font)>> = Default::default();
354            let font_runs = runs
355                .iter()
356                .filter_map(|(len, style)| {
357                    let mut last_run = last_run.borrow_mut();
358                    if let Some((last_len, last_font)) = last_run.as_mut() {
359                        if style.font == *last_font {
360                            *last_len += *len;
361                            None
362                        } else {
363                            let result = (*last_len, last_font.clone());
364                            *last_len = *len;
365                            *last_font = style.font.clone();
366                            Some(result)
367                        }
368                    } else {
369                        *last_run = Some((*len, style.font.clone()));
370                        None
371                    }
372                })
373                .chain(std::iter::from_fn(|| last_run.borrow_mut().take()));
374
375            let mut ix_converter = StringIndexConverter::new(text);
376            for (run_len, font_descriptor) in font_runs {
377                let utf8_end = ix_converter.utf8_ix + run_len;
378                let utf16_start = ix_converter.utf16_ix;
379
380                if utf16_start >= utf16_line_len {
381                    break;
382                }
383
384                ix_converter.advance_to_utf8_ix(utf8_end);
385                let utf16_end = cmp::min(ix_converter.utf16_ix, utf16_line_len);
386
387                let cf_range =
388                    CFRange::init(utf16_start as isize, (utf16_end - utf16_start) as isize);
389
390                let font_id = self.font_selections[&font_descriptor];
391                let font: &FontKitFont = &self.fonts[font_id.0];
392                unsafe {
393                    string.set_attribute(
394                        cf_range,
395                        kCTFontAttributeName,
396                        &font.native_font().clone_with_font_size(font_size.into()),
397                    );
398                }
399
400                if utf16_end == utf16_line_len {
401                    break;
402                }
403            }
404        }
405
406        // Retrieve the glyphs from the shaped line, converting UTF16 offsets to UTF8 offsets.
407        let line = CTLine::new_with_attributed_string(string.as_concrete_TypeRef());
408
409        let mut runs = Vec::new();
410        for run in line.glyph_runs().into_iter() {
411            let attributes = run.attributes().unwrap();
412            let font = unsafe {
413                attributes
414                    .get(kCTFontAttributeName)
415                    .downcast::<CTFont>()
416                    .unwrap()
417            };
418            let font_id = self.id_for_native_font(font);
419
420            let mut ix_converter = StringIndexConverter::new(text);
421            let mut glyphs = Vec::new();
422            for ((glyph_id, position), glyph_utf16_ix) in run
423                .glyphs()
424                .iter()
425                .zip(run.positions().iter())
426                .zip(run.string_indices().iter())
427            {
428                let glyph_utf16_ix = usize::try_from(*glyph_utf16_ix).unwrap();
429                ix_converter.advance_to_utf16_ix(glyph_utf16_ix);
430                glyphs.push(Glyph {
431                    id: (*glyph_id).into(),
432                    position: point(position.x as f32, position.y as f32).map(px),
433                    index: ix_converter.utf8_ix,
434                    is_emoji: self.is_emoji(font_id),
435                });
436            }
437
438            runs.push(Run { font_id, glyphs })
439        }
440
441        let typographic_bounds = line.get_typographic_bounds();
442        LineLayout {
443            width: typographic_bounds.width.into(),
444            ascent: typographic_bounds.ascent.into(),
445            descent: typographic_bounds.descent.into(),
446            runs,
447            font_size,
448            len: text.len(),
449        }
450    }
451
452    fn wrap_line(
453        &self,
454        text: &str,
455        font_id: FontId,
456        font_size: Pixels,
457        width: Pixels,
458    ) -> Vec<usize> {
459        let mut string = CFMutableAttributedString::new();
460        string.replace_str(&CFString::new(text), CFRange::init(0, 0));
461        let cf_range = CFRange::init(0, text.encode_utf16().count() as isize);
462        let font = &self.fonts[font_id.0];
463        unsafe {
464            string.set_attribute(
465                cf_range,
466                kCTFontAttributeName,
467                &font.native_font().clone_with_font_size(font_size.into()),
468            );
469
470            let typesetter = CTTypesetterCreateWithAttributedString(string.as_concrete_TypeRef());
471            let mut ix_converter = StringIndexConverter::new(text);
472            let mut break_indices = Vec::new();
473            while ix_converter.utf8_ix < text.len() {
474                let utf16_len = CTTypesetterSuggestLineBreak(
475                    typesetter,
476                    ix_converter.utf16_ix as isize,
477                    width.into(),
478                ) as usize;
479                ix_converter.advance_to_utf16_ix(ix_converter.utf16_ix + utf16_len);
480                if ix_converter.utf8_ix >= text.len() {
481                    break;
482                }
483                break_indices.push(ix_converter.utf8_ix as usize);
484            }
485            break_indices
486        }
487    }
488}
489
490#[derive(Clone)]
491struct StringIndexConverter<'a> {
492    text: &'a str,
493    utf8_ix: usize,
494    utf16_ix: usize,
495}
496
497impl<'a> StringIndexConverter<'a> {
498    fn new(text: &'a str) -> Self {
499        Self {
500            text,
501            utf8_ix: 0,
502            utf16_ix: 0,
503        }
504    }
505
506    fn advance_to_utf8_ix(&mut self, utf8_target: usize) {
507        for (ix, c) in self.text[self.utf8_ix..].char_indices() {
508            if self.utf8_ix + ix >= utf8_target {
509                self.utf8_ix += ix;
510                return;
511            }
512            self.utf16_ix += c.len_utf16();
513        }
514        self.utf8_ix = self.text.len();
515    }
516
517    fn advance_to_utf16_ix(&mut self, utf16_target: usize) {
518        for (ix, c) in self.text[self.utf8_ix..].char_indices() {
519            if self.utf16_ix >= utf16_target {
520                self.utf8_ix += ix;
521                return;
522            }
523            self.utf16_ix += c.len_utf16();
524        }
525        self.utf8_ix = self.text.len();
526    }
527}
528
529#[repr(C)]
530pub struct __CFTypesetter(c_void);
531
532pub type CTTypesetterRef = *const __CFTypesetter;
533
534#[link(name = "CoreText", kind = "framework")]
535extern "C" {
536    fn CTTypesetterCreateWithAttributedString(string: CFAttributedStringRef) -> CTTypesetterRef;
537
538    fn CTTypesetterSuggestLineBreak(
539        typesetter: CTTypesetterRef,
540        start_index: CFIndex,
541        width: f64,
542    ) -> CFIndex;
543}
544
545impl From<Metrics> for FontMetrics {
546    fn from(metrics: Metrics) -> Self {
547        FontMetrics {
548            units_per_em: metrics.units_per_em,
549            ascent: metrics.ascent,
550            descent: metrics.descent,
551            line_gap: metrics.line_gap,
552            underline_position: metrics.underline_position,
553            underline_thickness: metrics.underline_thickness,
554            cap_height: metrics.cap_height,
555            x_height: metrics.x_height,
556            bounding_box: metrics.bounding_box.into(),
557        }
558    }
559}
560
561impl From<RectF> for Bounds<f32> {
562    fn from(rect: RectF) -> Self {
563        Bounds {
564            origin: point(rect.origin_x(), rect.origin_y()),
565            size: size(rect.width(), rect.height()),
566        }
567    }
568}
569
570impl From<RectI> for Bounds<u32> {
571    fn from(rect: RectI) -> Self {
572        Bounds {
573            origin: point(rect.origin_x() as u32, rect.origin_y() as u32),
574            size: size(rect.width() as u32, rect.height() as u32),
575        }
576    }
577}
578
579impl From<Point<u32>> for Vector2I {
580    fn from(size: Point<u32>) -> Self {
581        Vector2I::new(size.x as i32, size.y as i32)
582    }
583}
584
585impl From<Vector2F> for Size<f32> {
586    fn from(vec: Vector2F) -> Self {
587        size(vec.x(), vec.y())
588    }
589}
590
591impl From<FontWeight> for FontkitWeight {
592    fn from(value: FontWeight) -> Self {
593        FontkitWeight(value.0)
594    }
595}
596
597impl From<FontStyle> for FontkitStyle {
598    fn from(style: FontStyle) -> Self {
599        match style {
600            FontStyle::Normal => FontkitStyle::Normal,
601            FontStyle::Italic => FontkitStyle::Italic,
602            FontStyle::Oblique => FontkitStyle::Oblique,
603        }
604    }
605}
606
607// #[cfg(test)]
608// mod tests {
609//     use super::*;
610//     use crate::AppContext;
611//     use font_kit::properties::{Style, Weight};
612//     use platform::FontSystem as _;
613
614//     #[crate::test(self, retries = 5)]
615//     fn test_layout_str(_: &mut AppContext) {
616//         // This is failing intermittently on CI and we don't have time to figure it out
617//         let fonts = FontSystem::new();
618//         let menlo = fonts.load_family("Menlo", &Default::default()).unwrap();
619//         let menlo_regular = RunStyle {
620//             font_id: fonts.select_font(&menlo, &Properties::new()).unwrap(),
621//             color: Default::default(),
622//             underline: Default::default(),
623//         };
624//         let menlo_italic = RunStyle {
625//             font_id: fonts
626//                 .select_font(&menlo, Properties::new().style(Style::Italic))
627//                 .unwrap(),
628//             color: Default::default(),
629//             underline: Default::default(),
630//         };
631//         let menlo_bold = RunStyle {
632//             font_id: fonts
633//                 .select_font(&menlo, Properties::new().weight(Weight::BOLD))
634//                 .unwrap(),
635//             color: Default::default(),
636//             underline: Default::default(),
637//         };
638//         assert_ne!(menlo_regular, menlo_italic);
639//         assert_ne!(menlo_regular, menlo_bold);
640//         assert_ne!(menlo_italic, menlo_bold);
641
642//         let line = fonts.layout_line(
643//             "hello world",
644//             16.0,
645//             &[(2, menlo_bold), (4, menlo_italic), (5, menlo_regular)],
646//         );
647//         assert_eq!(line.runs.len(), 3);
648//         assert_eq!(line.runs[0].font_id, menlo_bold.font_id);
649//         assert_eq!(line.runs[0].glyphs.len(), 2);
650//         assert_eq!(line.runs[1].font_id, menlo_italic.font_id);
651//         assert_eq!(line.runs[1].glyphs.len(), 4);
652//         assert_eq!(line.runs[2].font_id, menlo_regular.font_id);
653//         assert_eq!(line.runs[2].glyphs.len(), 5);
654//     }
655
656//     #[test]
657//     fn test_glyph_offsets() -> crate::Result<()> {
658//         let fonts = FontSystem::new();
659//         let zapfino = fonts.load_family("Zapfino", &Default::default())?;
660//         let zapfino_regular = RunStyle {
661//             font_id: fonts.select_font(&zapfino, &Properties::new())?,
662//             color: Default::default(),
663//             underline: Default::default(),
664//         };
665//         let menlo = fonts.load_family("Menlo", &Default::default())?;
666//         let menlo_regular = RunStyle {
667//             font_id: fonts.select_font(&menlo, &Properties::new())?,
668//             color: Default::default(),
669//             underline: Default::default(),
670//         };
671
672//         let text = "This is, m𐍈re 𐍈r less, Zapfino!𐍈";
673//         let line = fonts.layout_line(
674//             text,
675//             16.0,
676//             &[
677//                 (9, zapfino_regular),
678//                 (13, menlo_regular),
679//                 (text.len() - 22, zapfino_regular),
680//             ],
681//         );
682//         assert_eq!(
683//             line.runs
684//                 .iter()
685//                 .flat_map(|r| r.glyphs.iter())
686//                 .map(|g| g.index)
687//                 .collect::<Vec<_>>(),
688//             vec![0, 2, 4, 5, 7, 8, 9, 10, 14, 15, 16, 17, 21, 22, 23, 24, 26, 27, 28, 29, 36, 37],
689//         );
690//         Ok(())
691//     }
692
693//     #[test]
694//     #[ignore]
695//     fn test_rasterize_glyph() {
696//         use std::{fs::File, io::BufWriter, path::Path};
697
698//         let fonts = FontSystem::new();
699//         let font_ids = fonts.load_family("Fira Code", &Default::default()).unwrap();
700//         let font_id = fonts.select_font(&font_ids, &Default::default()).unwrap();
701//         let glyph_id = fonts.glyph_for_char(font_id, 'G').unwrap();
702
703//         const VARIANTS: usize = 1;
704//         for i in 0..VARIANTS {
705//             let variant = i as f32 / VARIANTS as f32;
706//             let (bounds, bytes) = fonts
707//                 .rasterize_glyph(
708//                     font_id,
709//                     16.0,
710//                     glyph_id,
711//                     vec2f(variant, variant),
712//                     2.,
713//                     RasterizationOptions::Alpha,
714//                 )
715//                 .unwrap();
716
717//             let name = format!("/Users/as-cii/Desktop/twog-{}.png", i);
718//             let path = Path::new(&name);
719//             let file = File::create(path).unwrap();
720//             let w = &mut BufWriter::new(file);
721
722//             let mut encoder = png::Encoder::new(w, bounds.width() as u32, bounds.height() as u32);
723//             encoder.set_color(png::ColorType::Grayscale);
724//             encoder.set_depth(png::BitDepth::Eight);
725//             let mut writer = encoder.write_header().unwrap();
726//             writer.write_image_data(&bytes).unwrap();
727//         }
728//     }
729
730//     #[test]
731//     fn test_wrap_line() {
732//         let fonts = FontSystem::new();
733//         let font_ids = fonts.load_family("Helvetica", &Default::default()).unwrap();
734//         let font_id = fonts.select_font(&font_ids, &Default::default()).unwrap();
735
736//         let line = "one two three four five\n";
737//         let wrap_boundaries = fonts.wrap_line(line, font_id, 16., 64.0);
738//         assert_eq!(wrap_boundaries, &["one two ".len(), "one two three ".len()]);
739
740//         let line = "aaa Ξ±Ξ±Ξ± βœ‹βœ‹βœ‹ πŸŽ‰πŸŽ‰πŸŽ‰\n";
741//         let wrap_boundaries = fonts.wrap_line(line, font_id, 16., 64.0);
742//         assert_eq!(
743//             wrap_boundaries,
744//             &["aaa Ξ±Ξ±Ξ± ".len(), "aaa Ξ±Ξ±Ξ± βœ‹βœ‹βœ‹ ".len(),]
745//         );
746//     }
747
748//     #[test]
749//     fn test_layout_line_bom_char() {
750//         let fonts = FontSystem::new();
751//         let font_ids = fonts.load_family("Helvetica", &Default::default()).unwrap();
752//         let style = RunStyle {
753//             font_id: fonts.select_font(&font_ids, &Default::default()).unwrap(),
754//             color: Default::default(),
755//             underline: Default::default(),
756//         };
757
758//         let line = "\u{feff}";
759//         let layout = fonts.layout_line(line, 16., &[(line.len(), style)]);
760//         assert_eq!(layout.len, line.len());
761//         assert!(layout.runs.is_empty());
762
763//         let line = "a\u{feff}b";
764//         let layout = fonts.layout_line(line, 16., &[(line.len(), style)]);
765//         assert_eq!(layout.len, line.len());
766//         assert_eq!(layout.runs.len(), 1);
767//         assert_eq!(layout.runs[0].glyphs.len(), 2);
768//         assert_eq!(layout.runs[0].glyphs[0].id, 68); // a
769//                                                      // There's no glyph for \u{feff}
770//         assert_eq!(layout.runs[0].glyphs[1].id, 69); // b
771//     }
772// }