1use std::{borrow::Cow, mem::ManuallyDrop, sync::Arc};
2
3use ::util::ResultExt;
4use anyhow::Result;
5use collections::HashMap;
6use itertools::Itertools;
7use parking_lot::{RwLock, RwLockUpgradableReadGuard};
8use windows::{
9 Win32::{
10 Foundation::*,
11 Globalization::GetUserDefaultLocaleName,
12 Graphics::{DirectWrite::*, Dxgi::Common::*, Gdi::LOGFONTW, Imaging::*},
13 System::SystemServices::LOCALE_NAME_MAX_LENGTH,
14 UI::WindowsAndMessaging::*,
15 },
16 core::*,
17};
18use windows_numerics::Vector2;
19
20use crate::*;
21
22#[derive(Debug)]
23struct FontInfo {
24 font_family: String,
25 font_face: IDWriteFontFace3,
26 features: IDWriteTypography,
27 fallbacks: Option<IDWriteFontFallback>,
28 is_system_font: bool,
29}
30
31pub(crate) struct DirectWriteTextSystem(RwLock<DirectWriteState>);
32
33struct DirectWriteComponent {
34 locale: String,
35 factory: IDWriteFactory5,
36 bitmap_factory: AgileReference<IWICImagingFactory>,
37 in_memory_loader: IDWriteInMemoryFontFileLoader,
38 builder: IDWriteFontSetBuilder1,
39 text_renderer: Arc<TextRendererWrapper>,
40 render_context: GlyphRenderContext,
41}
42
43struct GlyphRenderContext {
44 params: IDWriteRenderingParams3,
45}
46
47struct DirectWriteState {
48 components: DirectWriteComponent,
49 system_ui_font_name: SharedString,
50 system_font_collection: IDWriteFontCollection1,
51 custom_font_collection: IDWriteFontCollection1,
52 fonts: Vec<FontInfo>,
53 font_selections: HashMap<Font, FontId>,
54 font_id_by_identifier: HashMap<FontIdentifier, FontId>,
55}
56
57#[derive(Debug, Clone, Hash, PartialEq, Eq)]
58struct FontIdentifier {
59 postscript_name: String,
60 weight: i32,
61 style: i32,
62}
63
64impl DirectWriteComponent {
65 pub fn new(bitmap_factory: &IWICImagingFactory) -> Result<Self> {
66 unsafe {
67 let factory: IDWriteFactory5 = DWriteCreateFactory(DWRITE_FACTORY_TYPE_SHARED)?;
68 let bitmap_factory = AgileReference::new(bitmap_factory)?;
69 // The `IDWriteInMemoryFontFileLoader` here is supported starting from
70 // Windows 10 Creators Update, which consequently requires the entire
71 // `DirectWriteTextSystem` to run on `win10 1703`+.
72 let in_memory_loader = factory.CreateInMemoryFontFileLoader()?;
73 factory.RegisterFontFileLoader(&in_memory_loader)?;
74 let builder = factory.CreateFontSetBuilder()?;
75 let mut locale_vec = vec![0u16; LOCALE_NAME_MAX_LENGTH as usize];
76 GetUserDefaultLocaleName(&mut locale_vec);
77 let locale = String::from_utf16_lossy(&locale_vec);
78 let text_renderer = Arc::new(TextRendererWrapper::new(&locale));
79 let render_context = GlyphRenderContext::new(&factory)?;
80
81 Ok(DirectWriteComponent {
82 locale,
83 factory,
84 bitmap_factory,
85 in_memory_loader,
86 builder,
87 text_renderer,
88 render_context,
89 })
90 }
91 }
92}
93
94impl GlyphRenderContext {
95 pub fn new(factory: &IDWriteFactory5) -> Result<Self> {
96 unsafe {
97 let default_params: IDWriteRenderingParams3 =
98 factory.CreateRenderingParams()?.cast()?;
99 let gamma = default_params.GetGamma();
100 let enhanced_contrast = default_params.GetEnhancedContrast();
101 let gray_contrast = default_params.GetGrayscaleEnhancedContrast();
102 let cleartype_level = default_params.GetClearTypeLevel();
103 let grid_fit_mode = default_params.GetGridFitMode();
104
105 let params = factory.CreateCustomRenderingParams(
106 gamma,
107 enhanced_contrast,
108 gray_contrast,
109 cleartype_level,
110 DWRITE_PIXEL_GEOMETRY_RGB,
111 DWRITE_RENDERING_MODE1_NATURAL_SYMMETRIC,
112 grid_fit_mode,
113 )?;
114
115 Ok(Self { params })
116 }
117 }
118}
119
120impl DirectWriteTextSystem {
121 pub(crate) fn new(bitmap_factory: &IWICImagingFactory) -> Result<Self> {
122 let components = DirectWriteComponent::new(bitmap_factory)?;
123 let system_font_collection = unsafe {
124 let mut result = std::mem::zeroed();
125 components
126 .factory
127 .GetSystemFontCollection(false, &mut result, true)?;
128 result.unwrap()
129 };
130 let custom_font_set = unsafe { components.builder.CreateFontSet()? };
131 let custom_font_collection = unsafe {
132 components
133 .factory
134 .CreateFontCollectionFromFontSet(&custom_font_set)?
135 };
136 let system_ui_font_name = get_system_ui_font_name();
137
138 Ok(Self(RwLock::new(DirectWriteState {
139 components,
140 system_ui_font_name,
141 system_font_collection,
142 custom_font_collection,
143 fonts: Vec::new(),
144 font_selections: HashMap::default(),
145 font_id_by_identifier: HashMap::default(),
146 })))
147 }
148}
149
150impl PlatformTextSystem for DirectWriteTextSystem {
151 fn add_fonts(&self, fonts: Vec<Cow<'static, [u8]>>) -> Result<()> {
152 self.0.write().add_fonts(fonts)
153 }
154
155 fn all_font_names(&self) -> Vec<String> {
156 self.0.read().all_font_names()
157 }
158
159 fn font_id(&self, font: &Font) -> Result<FontId> {
160 let lock = self.0.upgradable_read();
161 if let Some(font_id) = lock.font_selections.get(font) {
162 Ok(*font_id)
163 } else {
164 let mut lock = RwLockUpgradableReadGuard::upgrade(lock);
165 let font_id = lock.select_font(font);
166 lock.font_selections.insert(font.clone(), font_id);
167 Ok(font_id)
168 }
169 }
170
171 fn font_metrics(&self, font_id: FontId) -> FontMetrics {
172 self.0.read().font_metrics(font_id)
173 }
174
175 fn typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>> {
176 self.0.read().get_typographic_bounds(font_id, glyph_id)
177 }
178
179 fn advance(&self, font_id: FontId, glyph_id: GlyphId) -> anyhow::Result<Size<f32>> {
180 self.0.read().get_advance(font_id, glyph_id)
181 }
182
183 fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
184 self.0.read().glyph_for_char(font_id, ch)
185 }
186
187 fn glyph_raster_bounds(
188 &self,
189 params: &RenderGlyphParams,
190 ) -> anyhow::Result<Bounds<DevicePixels>> {
191 self.0.read().raster_bounds(params)
192 }
193
194 fn rasterize_glyph(
195 &self,
196 params: &RenderGlyphParams,
197 raster_bounds: Bounds<DevicePixels>,
198 ) -> anyhow::Result<(Size<DevicePixels>, Vec<u8>)> {
199 self.0.read().rasterize_glyph(params, raster_bounds)
200 }
201
202 fn layout_line(&self, text: &str, font_size: Pixels, runs: &[FontRun]) -> LineLayout {
203 self.0
204 .write()
205 .layout_line(text, font_size, runs)
206 .log_err()
207 .unwrap_or(LineLayout {
208 font_size,
209 ..Default::default()
210 })
211 }
212}
213
214impl DirectWriteState {
215 fn add_fonts(&mut self, fonts: Vec<Cow<'static, [u8]>>) -> Result<()> {
216 for font_data in fonts {
217 match font_data {
218 Cow::Borrowed(data) => unsafe {
219 let font_file = self
220 .components
221 .in_memory_loader
222 .CreateInMemoryFontFileReference(
223 &self.components.factory,
224 data.as_ptr() as _,
225 data.len() as _,
226 None,
227 )?;
228 self.components.builder.AddFontFile(&font_file)?;
229 },
230 Cow::Owned(data) => unsafe {
231 let font_file = self
232 .components
233 .in_memory_loader
234 .CreateInMemoryFontFileReference(
235 &self.components.factory,
236 data.as_ptr() as _,
237 data.len() as _,
238 None,
239 )?;
240 self.components.builder.AddFontFile(&font_file)?;
241 },
242 }
243 }
244 let set = unsafe { self.components.builder.CreateFontSet()? };
245 let collection = unsafe {
246 self.components
247 .factory
248 .CreateFontCollectionFromFontSet(&set)?
249 };
250 self.custom_font_collection = collection;
251
252 Ok(())
253 }
254
255 fn generate_font_fallbacks(
256 &self,
257 fallbacks: &FontFallbacks,
258 ) -> Result<Option<IDWriteFontFallback>> {
259 if fallbacks.fallback_list().is_empty() {
260 return Ok(None);
261 }
262 unsafe {
263 let builder = self.components.factory.CreateFontFallbackBuilder()?;
264 let font_set = &self.system_font_collection.GetFontSet()?;
265 for family_name in fallbacks.fallback_list() {
266 let Some(fonts) = font_set
267 .GetMatchingFonts(
268 &HSTRING::from(family_name),
269 DWRITE_FONT_WEIGHT_NORMAL,
270 DWRITE_FONT_STRETCH_NORMAL,
271 DWRITE_FONT_STYLE_NORMAL,
272 )
273 .log_err()
274 else {
275 continue;
276 };
277 if fonts.GetFontCount() == 0 {
278 log::error!("No matching font found for {}", family_name);
279 continue;
280 }
281 let font = fonts.GetFontFaceReference(0)?.CreateFontFace()?;
282 let mut count = 0;
283 font.GetUnicodeRanges(None, &mut count).ok();
284 if count == 0 {
285 continue;
286 }
287 let mut unicode_ranges = vec![DWRITE_UNICODE_RANGE::default(); count as usize];
288 let Some(_) = font
289 .GetUnicodeRanges(Some(&mut unicode_ranges), &mut count)
290 .log_err()
291 else {
292 continue;
293 };
294 let target_family_name = HSTRING::from(family_name);
295 builder.AddMapping(
296 &unicode_ranges,
297 &[target_family_name.as_ptr()],
298 None,
299 None,
300 None,
301 1.0,
302 )?;
303 }
304 let system_fallbacks = self.components.factory.GetSystemFontFallback()?;
305 builder.AddMappings(&system_fallbacks)?;
306 Ok(Some(builder.CreateFontFallback()?))
307 }
308 }
309
310 unsafe fn generate_font_features(
311 &self,
312 font_features: &FontFeatures,
313 ) -> Result<IDWriteTypography> {
314 let direct_write_features = unsafe { self.components.factory.CreateTypography()? };
315 apply_font_features(&direct_write_features, font_features)?;
316 Ok(direct_write_features)
317 }
318
319 unsafe fn get_font_id_from_font_collection(
320 &mut self,
321 family_name: &str,
322 font_weight: FontWeight,
323 font_style: FontStyle,
324 font_features: &FontFeatures,
325 font_fallbacks: Option<&FontFallbacks>,
326 is_system_font: bool,
327 ) -> Option<FontId> {
328 let collection = if is_system_font {
329 &self.system_font_collection
330 } else {
331 &self.custom_font_collection
332 };
333 let fontset = unsafe { collection.GetFontSet().log_err()? };
334 let font = unsafe {
335 fontset
336 .GetMatchingFonts(
337 &HSTRING::from(family_name),
338 font_weight.into(),
339 DWRITE_FONT_STRETCH_NORMAL,
340 font_style.into(),
341 )
342 .log_err()?
343 };
344 let total_number = unsafe { font.GetFontCount() };
345 for index in 0..total_number {
346 let Some(font_face_ref) = (unsafe { font.GetFontFaceReference(index).log_err() })
347 else {
348 continue;
349 };
350 let Some(font_face) = (unsafe { font_face_ref.CreateFontFace().log_err() }) else {
351 continue;
352 };
353 let Some(identifier) = get_font_identifier(&font_face, &self.components.locale) else {
354 continue;
355 };
356 let Some(direct_write_features) =
357 (unsafe { self.generate_font_features(font_features).log_err() })
358 else {
359 continue;
360 };
361 let fallbacks = font_fallbacks
362 .and_then(|fallbacks| self.generate_font_fallbacks(fallbacks).log_err().flatten());
363 let font_info = FontInfo {
364 font_family: family_name.to_owned(),
365 font_face,
366 features: direct_write_features,
367 fallbacks,
368 is_system_font,
369 };
370 let font_id = FontId(self.fonts.len());
371 self.fonts.push(font_info);
372 self.font_id_by_identifier.insert(identifier, font_id);
373 return Some(font_id);
374 }
375 None
376 }
377
378 unsafe fn update_system_font_collection(&mut self) {
379 let mut collection = unsafe { std::mem::zeroed() };
380 if unsafe {
381 self.components
382 .factory
383 .GetSystemFontCollection(false, &mut collection, true)
384 .log_err()
385 .is_some()
386 } {
387 self.system_font_collection = collection.unwrap();
388 }
389 }
390
391 fn select_font(&mut self, target_font: &Font) -> FontId {
392 unsafe {
393 if target_font.family == ".SystemUIFont" {
394 let family = self.system_ui_font_name.clone();
395 self.find_font_id(
396 family.as_ref(),
397 target_font.weight,
398 target_font.style,
399 &target_font.features,
400 target_font.fallbacks.as_ref(),
401 )
402 .unwrap()
403 } else {
404 self.find_font_id(
405 target_font.family.as_ref(),
406 target_font.weight,
407 target_font.style,
408 &target_font.features,
409 target_font.fallbacks.as_ref(),
410 )
411 .unwrap_or_else(|| {
412 #[cfg(any(test, feature = "test-support"))]
413 {
414 panic!("ERROR: {} font not found!", target_font.family);
415 }
416 #[cfg(not(any(test, feature = "test-support")))]
417 {
418 let family = self.system_ui_font_name.clone();
419 log::error!("{} not found, use {} instead.", target_font.family, family);
420 self.get_font_id_from_font_collection(
421 family.as_ref(),
422 target_font.weight,
423 target_font.style,
424 &target_font.features,
425 target_font.fallbacks.as_ref(),
426 true,
427 )
428 .unwrap()
429 }
430 })
431 }
432 }
433 }
434
435 unsafe fn find_font_id(
436 &mut self,
437 family_name: &str,
438 weight: FontWeight,
439 style: FontStyle,
440 features: &FontFeatures,
441 fallbacks: Option<&FontFallbacks>,
442 ) -> Option<FontId> {
443 // try to find target font in custom font collection first
444 unsafe {
445 self.get_font_id_from_font_collection(
446 family_name,
447 weight,
448 style,
449 features,
450 fallbacks,
451 false,
452 )
453 .or_else(|| {
454 self.get_font_id_from_font_collection(
455 family_name,
456 weight,
457 style,
458 features,
459 fallbacks,
460 true,
461 )
462 })
463 .or_else(|| {
464 self.update_system_font_collection();
465 self.get_font_id_from_font_collection(
466 family_name,
467 weight,
468 style,
469 features,
470 fallbacks,
471 true,
472 )
473 })
474 }
475 }
476
477 fn layout_line(
478 &mut self,
479 text: &str,
480 font_size: Pixels,
481 font_runs: &[FontRun],
482 ) -> Result<LineLayout> {
483 if font_runs.is_empty() {
484 return Ok(LineLayout {
485 font_size,
486 ..Default::default()
487 });
488 }
489 unsafe {
490 let text_renderer = self.components.text_renderer.clone();
491 let text_wide = text.encode_utf16().collect_vec();
492
493 let mut utf8_offset = 0usize;
494 let mut utf16_offset = 0u32;
495 let text_layout = {
496 let first_run = &font_runs[0];
497 let font_info = &self.fonts[first_run.font_id.0];
498 let collection = if font_info.is_system_font {
499 &self.system_font_collection
500 } else {
501 &self.custom_font_collection
502 };
503 let format: IDWriteTextFormat1 = self
504 .components
505 .factory
506 .CreateTextFormat(
507 &HSTRING::from(&font_info.font_family),
508 collection,
509 font_info.font_face.GetWeight(),
510 font_info.font_face.GetStyle(),
511 DWRITE_FONT_STRETCH_NORMAL,
512 font_size.0,
513 &HSTRING::from(&self.components.locale),
514 )?
515 .cast()?;
516 if let Some(ref fallbacks) = font_info.fallbacks {
517 format.SetFontFallback(fallbacks)?;
518 }
519
520 let layout = self.components.factory.CreateTextLayout(
521 &text_wide,
522 &format,
523 f32::INFINITY,
524 f32::INFINITY,
525 )?;
526 let current_text = &text[utf8_offset..(utf8_offset + first_run.len)];
527 utf8_offset += first_run.len;
528 let current_text_utf16_length = current_text.encode_utf16().count() as u32;
529 let text_range = DWRITE_TEXT_RANGE {
530 startPosition: utf16_offset,
531 length: current_text_utf16_length,
532 };
533 layout.SetTypography(&font_info.features, text_range)?;
534 utf16_offset += current_text_utf16_length;
535
536 layout
537 };
538
539 let mut first_run = true;
540 let mut ascent = Pixels::default();
541 let mut descent = Pixels::default();
542 for run in font_runs {
543 if first_run {
544 first_run = false;
545 let mut metrics = vec![DWRITE_LINE_METRICS::default(); 4];
546 let mut line_count = 0u32;
547 text_layout.GetLineMetrics(Some(&mut metrics), &mut line_count as _)?;
548 ascent = px(metrics[0].baseline);
549 descent = px(metrics[0].height - metrics[0].baseline);
550 continue;
551 }
552 let font_info = &self.fonts[run.font_id.0];
553 let current_text = &text[utf8_offset..(utf8_offset + run.len)];
554 utf8_offset += run.len;
555 let current_text_utf16_length = current_text.encode_utf16().count() as u32;
556
557 let collection = if font_info.is_system_font {
558 &self.system_font_collection
559 } else {
560 &self.custom_font_collection
561 };
562 let text_range = DWRITE_TEXT_RANGE {
563 startPosition: utf16_offset,
564 length: current_text_utf16_length,
565 };
566 utf16_offset += current_text_utf16_length;
567 text_layout.SetFontCollection(collection, text_range)?;
568 text_layout
569 .SetFontFamilyName(&HSTRING::from(&font_info.font_family), text_range)?;
570 text_layout.SetFontSize(font_size.0, text_range)?;
571 text_layout.SetFontStyle(font_info.font_face.GetStyle(), text_range)?;
572 text_layout.SetFontWeight(font_info.font_face.GetWeight(), text_range)?;
573 text_layout.SetTypography(&font_info.features, text_range)?;
574 }
575
576 let mut runs = Vec::new();
577 let renderer_context = RendererContext {
578 text_system: self,
579 index_converter: StringIndexConverter::new(text),
580 runs: &mut runs,
581 width: 0.0,
582 };
583 text_layout.Draw(
584 Some(&renderer_context as *const _ as _),
585 &text_renderer.0,
586 0.0,
587 0.0,
588 )?;
589 let width = px(renderer_context.width);
590
591 Ok(LineLayout {
592 font_size,
593 width,
594 ascent,
595 descent,
596 runs,
597 len: text.len(),
598 })
599 }
600 }
601
602 fn font_metrics(&self, font_id: FontId) -> FontMetrics {
603 unsafe {
604 let font_info = &self.fonts[font_id.0];
605 let mut metrics = std::mem::zeroed();
606 font_info.font_face.GetMetrics(&mut metrics);
607
608 FontMetrics {
609 units_per_em: metrics.Base.designUnitsPerEm as _,
610 ascent: metrics.Base.ascent as _,
611 descent: -(metrics.Base.descent as f32),
612 line_gap: metrics.Base.lineGap as _,
613 underline_position: metrics.Base.underlinePosition as _,
614 underline_thickness: metrics.Base.underlineThickness as _,
615 cap_height: metrics.Base.capHeight as _,
616 x_height: metrics.Base.xHeight as _,
617 bounding_box: Bounds {
618 origin: Point {
619 x: metrics.glyphBoxLeft as _,
620 y: metrics.glyphBoxBottom as _,
621 },
622 size: Size {
623 width: (metrics.glyphBoxRight - metrics.glyphBoxLeft) as _,
624 height: (metrics.glyphBoxTop - metrics.glyphBoxBottom) as _,
625 },
626 },
627 }
628 }
629 }
630
631 fn raster_bounds(&self, params: &RenderGlyphParams) -> Result<Bounds<DevicePixels>> {
632 let font = &self.fonts[params.font_id.0];
633 let glyph_id = [params.glyph_id.0 as u16];
634 let advance = [0.0f32];
635 let offset = [DWRITE_GLYPH_OFFSET::default()];
636 let glyph_run = DWRITE_GLYPH_RUN {
637 fontFace: unsafe { std::mem::transmute_copy(&font.font_face) },
638 fontEmSize: params.font_size.0,
639 glyphCount: 1,
640 glyphIndices: glyph_id.as_ptr(),
641 glyphAdvances: advance.as_ptr(),
642 glyphOffsets: offset.as_ptr(),
643 isSideways: BOOL(0),
644 bidiLevel: 0,
645 };
646
647 let rendering_mode = DWRITE_RENDERING_MODE1_NATURAL_SYMMETRIC;
648 let measuring_mode = DWRITE_MEASURING_MODE_NATURAL;
649 let baseline_origin_x = 0.0;
650 let baseline_origin_y = 0.0;
651
652 let glyph_analysis = unsafe {
653 self.components.factory.CreateGlyphRunAnalysis(
654 &glyph_run,
655 None,
656 rendering_mode,
657 measuring_mode,
658 DWRITE_GRID_FIT_MODE_DEFAULT,
659 DWRITE_TEXT_ANTIALIAS_MODE_CLEARTYPE,
660 baseline_origin_x,
661 baseline_origin_y,
662 )?
663 };
664
665 let texture_type = DWRITE_TEXTURE_CLEARTYPE_3x1;
666 let bounds = unsafe { glyph_analysis.GetAlphaTextureBounds(texture_type)? };
667
668 // todo(windows)
669 // This is a walkaround, deleted when figured out.
670 let y_offset;
671 let extra_height;
672 if params.is_emoji {
673 y_offset = 0;
674 extra_height = 0;
675 } else {
676 // make some room for scaler.
677 y_offset = -1;
678 extra_height = 2;
679 }
680
681 if bounds.right < bounds.left {
682 Ok(Bounds {
683 origin: point(0.into(), 0.into()),
684 size: size(0.into(), 0.into()),
685 })
686 } else {
687 Ok(Bounds {
688 origin: point(
689 ((bounds.left as f32 * params.scale_factor).ceil() as i32).into(),
690 ((bounds.top as f32 * params.scale_factor).ceil() as i32 + y_offset).into(),
691 ),
692 size: size(
693 (((bounds.right - bounds.left) as f32 * params.scale_factor).ceil() as i32)
694 .into(),
695 (((bounds.bottom - bounds.top) as f32 * params.scale_factor).ceil() as i32
696 + extra_height)
697 .into(),
698 ),
699 })
700 }
701 }
702
703 fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
704 let font_info = &self.fonts[font_id.0];
705 let codepoints = [ch as u32];
706 let mut glyph_indices = vec![0u16; 1];
707 unsafe {
708 font_info
709 .font_face
710 .GetGlyphIndices(codepoints.as_ptr(), 1, glyph_indices.as_mut_ptr())
711 .log_err()
712 }
713 .map(|_| GlyphId(glyph_indices[0] as u32))
714 }
715
716 fn rasterize_glyph(
717 &self,
718 params: &RenderGlyphParams,
719 glyph_bounds: Bounds<DevicePixels>,
720 ) -> Result<(Size<DevicePixels>, Vec<u8>)> {
721 if glyph_bounds.size.width.0 == 0 || glyph_bounds.size.height.0 == 0 {
722 anyhow::bail!("glyph bounds are empty");
723 }
724
725 let font_info = &self.fonts[params.font_id.0];
726 let glyph_id = [params.glyph_id.0 as u16];
727 let advance = [glyph_bounds.size.width.0 as f32];
728 let offset = [DWRITE_GLYPH_OFFSET {
729 advanceOffset: -glyph_bounds.origin.x.0 as f32 / params.scale_factor,
730 ascenderOffset: glyph_bounds.origin.y.0 as f32 / params.scale_factor,
731 }];
732 let glyph_run = DWRITE_GLYPH_RUN {
733 fontFace: ManuallyDrop::new(Some(font_info.font_face.cast()?)),
734 fontEmSize: params.font_size.0,
735 glyphCount: 1,
736 glyphIndices: glyph_id.as_ptr(),
737 glyphAdvances: advance.as_ptr(),
738 glyphOffsets: offset.as_ptr(),
739 isSideways: BOOL(0),
740 bidiLevel: 0,
741 };
742
743 // Add an extra pixel when the subpixel variant isn't zero to make room for anti-aliasing.
744 let mut bitmap_size = glyph_bounds.size;
745 if params.subpixel_variant.x > 0 {
746 bitmap_size.width += DevicePixels(1);
747 }
748 if params.subpixel_variant.y > 0 {
749 bitmap_size.height += DevicePixels(1);
750 }
751 let bitmap_size = bitmap_size;
752
753 let subpixel_shift = params
754 .subpixel_variant
755 .map(|v| v as f32 / SUBPIXEL_VARIANTS as f32);
756 let baseline_origin_x = subpixel_shift.x / params.scale_factor;
757 let baseline_origin_y = subpixel_shift.y / params.scale_factor;
758
759 let transform = DWRITE_MATRIX {
760 m11: params.scale_factor,
761 m12: 0.0,
762 m21: 0.0,
763 m22: params.scale_factor,
764 dx: 0.0,
765 dy: 0.0,
766 };
767
768 let rendering_mode = if params.is_emoji {
769 DWRITE_RENDERING_MODE1_NATURAL
770 } else {
771 DWRITE_RENDERING_MODE1_NATURAL_SYMMETRIC
772 };
773
774 let measuring_mode = DWRITE_MEASURING_MODE_NATURAL;
775
776 let glyph_analysis = unsafe {
777 self.components.factory.CreateGlyphRunAnalysis(
778 &glyph_run,
779 Some(&transform),
780 rendering_mode,
781 measuring_mode,
782 DWRITE_GRID_FIT_MODE_DEFAULT,
783 DWRITE_TEXT_ANTIALIAS_MODE_CLEARTYPE,
784 baseline_origin_x,
785 baseline_origin_y,
786 )?
787 };
788
789 let texture_type = DWRITE_TEXTURE_CLEARTYPE_3x1;
790 let texture_bounds = unsafe { glyph_analysis.GetAlphaTextureBounds(texture_type)? };
791 let texture_width = (texture_bounds.right - texture_bounds.left) as u32;
792 let texture_height = (texture_bounds.bottom - texture_bounds.top) as u32;
793
794 if texture_width == 0 || texture_height == 0 {
795 return Ok((
796 bitmap_size,
797 vec![
798 0u8;
799 bitmap_size.width.0 as usize
800 * bitmap_size.height.0 as usize
801 * if params.is_emoji { 4 } else { 1 }
802 ],
803 ));
804 }
805
806 let mut bitmap_data;
807 if params.is_emoji {
808 bitmap_data =
809 vec![0u8; bitmap_size.width.0 as usize * bitmap_size.height.0 as usize * 4];
810
811 let mut rgba_data = vec![0u8; (texture_width * texture_height * 4) as usize];
812 unsafe {
813 glyph_analysis.CreateAlphaTexture(texture_type, &texture_bounds, &mut rgba_data)?;
814 }
815
816 // Copy texture data into bitmap at correct position
817 let offset_x = texture_bounds.left.max(0) as usize;
818 let offset_y = texture_bounds.top.max(0) as usize;
819 for y in 0..texture_height as usize {
820 for x in 0..texture_width as usize {
821 let bitmap_x = offset_x + x;
822 let bitmap_y = offset_y + y;
823
824 if bitmap_x < bitmap_size.width.0 as usize
825 && bitmap_y < bitmap_size.height.0 as usize
826 {
827 let texture_idx = (y * texture_width as usize + x) * 4;
828 let bitmap_idx = (bitmap_y * bitmap_size.width.0 as usize + bitmap_x) * 4;
829
830 if texture_idx + 3 < rgba_data.len() && bitmap_idx + 3 < bitmap_data.len() {
831 bitmap_data[bitmap_idx..bitmap_idx + 4]
832 .copy_from_slice(&rgba_data[texture_idx..texture_idx + 4]);
833 }
834 }
835 }
836 }
837 } else {
838 bitmap_data = vec![0u8; bitmap_size.width.0 as usize * bitmap_size.height.0 as usize];
839
840 let mut alpha_data = vec![0u8; (texture_width * texture_height * 3) as usize];
841 unsafe {
842 glyph_analysis.CreateAlphaTexture(
843 texture_type,
844 &texture_bounds,
845 &mut alpha_data,
846 )?;
847 }
848
849 // Convert ClearType RGB data to grayscale and place in bitmap
850 let offset_x = texture_bounds.left.max(0) as usize;
851 let offset_y = texture_bounds.top.max(0) as usize;
852
853 for y in 0..texture_height as usize {
854 for x in 0..texture_width as usize {
855 let bitmap_x = offset_x + x;
856 let bitmap_y = offset_y + y;
857
858 if bitmap_x < bitmap_size.width.0 as usize
859 && bitmap_y < bitmap_size.height.0 as usize
860 {
861 let texture_idx = (y * texture_width as usize + x) * 3;
862 let bitmap_idx = bitmap_y * bitmap_size.width.0 as usize + bitmap_x;
863
864 if texture_idx + 2 < alpha_data.len() && bitmap_idx < bitmap_data.len() {
865 let avg = (alpha_data[texture_idx] as u32
866 + alpha_data[texture_idx + 1] as u32
867 + alpha_data[texture_idx + 2] as u32)
868 / 3;
869 bitmap_data[bitmap_idx] = avg as u8;
870 }
871 }
872 }
873 }
874 }
875
876 Ok((bitmap_size, bitmap_data))
877 }
878
879 fn get_typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>> {
880 unsafe {
881 let font = &self.fonts[font_id.0].font_face;
882 let glyph_indices = [glyph_id.0 as u16];
883 let mut metrics = [DWRITE_GLYPH_METRICS::default()];
884 font.GetDesignGlyphMetrics(glyph_indices.as_ptr(), 1, metrics.as_mut_ptr(), false)?;
885
886 let metrics = &metrics[0];
887 let advance_width = metrics.advanceWidth as i32;
888 let advance_height = metrics.advanceHeight as i32;
889 let left_side_bearing = metrics.leftSideBearing;
890 let right_side_bearing = metrics.rightSideBearing;
891 let top_side_bearing = metrics.topSideBearing;
892 let bottom_side_bearing = metrics.bottomSideBearing;
893 let vertical_origin_y = metrics.verticalOriginY;
894
895 let y_offset = vertical_origin_y + bottom_side_bearing - advance_height;
896 let width = advance_width - (left_side_bearing + right_side_bearing);
897 let height = advance_height - (top_side_bearing + bottom_side_bearing);
898
899 Ok(Bounds {
900 origin: Point {
901 x: left_side_bearing as f32,
902 y: y_offset as f32,
903 },
904 size: Size {
905 width: width as f32,
906 height: height as f32,
907 },
908 })
909 }
910 }
911
912 fn get_advance(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Size<f32>> {
913 unsafe {
914 let font = &self.fonts[font_id.0].font_face;
915 let glyph_indices = [glyph_id.0 as u16];
916 let mut metrics = [DWRITE_GLYPH_METRICS::default()];
917 font.GetDesignGlyphMetrics(glyph_indices.as_ptr(), 1, metrics.as_mut_ptr(), false)?;
918
919 let metrics = &metrics[0];
920
921 Ok(Size {
922 width: metrics.advanceWidth as f32,
923 height: 0.0,
924 })
925 }
926 }
927
928 fn all_font_names(&self) -> Vec<String> {
929 let mut result =
930 get_font_names_from_collection(&self.system_font_collection, &self.components.locale);
931 result.extend(get_font_names_from_collection(
932 &self.custom_font_collection,
933 &self.components.locale,
934 ));
935 result
936 }
937}
938
939impl Drop for DirectWriteState {
940 fn drop(&mut self) {
941 unsafe {
942 let _ = self
943 .components
944 .factory
945 .UnregisterFontFileLoader(&self.components.in_memory_loader);
946 }
947 }
948}
949
950struct TextRendererWrapper(pub IDWriteTextRenderer);
951
952impl TextRendererWrapper {
953 pub fn new(locale_str: &str) -> Self {
954 let inner = TextRenderer::new(locale_str);
955 TextRendererWrapper(inner.into())
956 }
957}
958
959#[implement(IDWriteTextRenderer)]
960struct TextRenderer {
961 locale: String,
962}
963
964impl TextRenderer {
965 pub fn new(locale_str: &str) -> Self {
966 TextRenderer {
967 locale: locale_str.to_owned(),
968 }
969 }
970}
971
972struct RendererContext<'t, 'a, 'b> {
973 text_system: &'t mut DirectWriteState,
974 index_converter: StringIndexConverter<'a>,
975 runs: &'b mut Vec<ShapedRun>,
976 width: f32,
977}
978
979#[derive(Debug)]
980struct ClusterAnalyzer<'t> {
981 utf16_idx: usize,
982 glyph_idx: usize,
983 glyph_count: usize,
984 cluster_map: &'t [u16],
985}
986
987impl<'t> ClusterAnalyzer<'t> {
988 pub fn new(cluster_map: &'t [u16], glyph_count: usize) -> Self {
989 ClusterAnalyzer {
990 utf16_idx: 0,
991 glyph_idx: 0,
992 glyph_count,
993 cluster_map,
994 }
995 }
996}
997
998impl Iterator for ClusterAnalyzer<'_> {
999 type Item = (usize, usize);
1000
1001 fn next(&mut self) -> Option<(usize, usize)> {
1002 if self.utf16_idx >= self.cluster_map.len() {
1003 return None; // No more clusters
1004 }
1005 let start_utf16_idx = self.utf16_idx;
1006 let current_glyph = self.cluster_map[start_utf16_idx] as usize;
1007
1008 // Find the end of current cluster (where glyph index changes)
1009 let mut end_utf16_idx = start_utf16_idx + 1;
1010 while end_utf16_idx < self.cluster_map.len()
1011 && self.cluster_map[end_utf16_idx] as usize == current_glyph
1012 {
1013 end_utf16_idx += 1;
1014 }
1015
1016 let utf16_len = end_utf16_idx - start_utf16_idx;
1017
1018 // Calculate glyph count for this cluster
1019 let next_glyph = if end_utf16_idx < self.cluster_map.len() {
1020 self.cluster_map[end_utf16_idx] as usize
1021 } else {
1022 self.glyph_count
1023 };
1024
1025 let glyph_count = next_glyph - current_glyph;
1026
1027 // Update state for next call
1028 self.utf16_idx = end_utf16_idx;
1029 self.glyph_idx = next_glyph;
1030
1031 Some((utf16_len, glyph_count))
1032 }
1033}
1034
1035#[allow(non_snake_case)]
1036impl IDWritePixelSnapping_Impl for TextRenderer_Impl {
1037 fn IsPixelSnappingDisabled(
1038 &self,
1039 _clientdrawingcontext: *const ::core::ffi::c_void,
1040 ) -> windows::core::Result<BOOL> {
1041 Ok(BOOL(0))
1042 }
1043
1044 fn GetCurrentTransform(
1045 &self,
1046 _clientdrawingcontext: *const ::core::ffi::c_void,
1047 transform: *mut DWRITE_MATRIX,
1048 ) -> windows::core::Result<()> {
1049 unsafe {
1050 *transform = DWRITE_MATRIX {
1051 m11: 1.0,
1052 m12: 0.0,
1053 m21: 0.0,
1054 m22: 1.0,
1055 dx: 0.0,
1056 dy: 0.0,
1057 };
1058 }
1059 Ok(())
1060 }
1061
1062 fn GetPixelsPerDip(
1063 &self,
1064 _clientdrawingcontext: *const ::core::ffi::c_void,
1065 ) -> windows::core::Result<f32> {
1066 Ok(1.0)
1067 }
1068}
1069
1070#[allow(non_snake_case)]
1071impl IDWriteTextRenderer_Impl for TextRenderer_Impl {
1072 fn DrawGlyphRun(
1073 &self,
1074 clientdrawingcontext: *const ::core::ffi::c_void,
1075 _baselineoriginx: f32,
1076 _baselineoriginy: f32,
1077 _measuringmode: DWRITE_MEASURING_MODE,
1078 glyphrun: *const DWRITE_GLYPH_RUN,
1079 glyphrundescription: *const DWRITE_GLYPH_RUN_DESCRIPTION,
1080 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1081 ) -> windows::core::Result<()> {
1082 let glyphrun = unsafe { &*glyphrun };
1083 let glyph_count = glyphrun.glyphCount as usize;
1084 if glyph_count == 0 || glyphrun.fontFace.is_none() {
1085 return Ok(());
1086 }
1087 let desc = unsafe { &*glyphrundescription };
1088 let context = unsafe {
1089 &mut *(clientdrawingcontext as *const RendererContext as *mut RendererContext)
1090 };
1091 let font_face = glyphrun.fontFace.as_ref().unwrap();
1092 // This `cast()` action here should never fail since we are running on Win10+, and
1093 // `IDWriteFontFace3` requires Win10
1094 let font_face = &font_face.cast::<IDWriteFontFace3>().unwrap();
1095 let Some((font_identifier, font_struct, color_font)) =
1096 get_font_identifier_and_font_struct(font_face, &self.locale)
1097 else {
1098 return Ok(());
1099 };
1100
1101 let font_id = if let Some(id) = context
1102 .text_system
1103 .font_id_by_identifier
1104 .get(&font_identifier)
1105 {
1106 *id
1107 } else {
1108 context.text_system.select_font(&font_struct)
1109 };
1110
1111 let glyph_ids = unsafe { std::slice::from_raw_parts(glyphrun.glyphIndices, glyph_count) };
1112 let glyph_advances =
1113 unsafe { std::slice::from_raw_parts(glyphrun.glyphAdvances, glyph_count) };
1114 let glyph_offsets =
1115 unsafe { std::slice::from_raw_parts(glyphrun.glyphOffsets, glyph_count) };
1116 let cluster_map =
1117 unsafe { std::slice::from_raw_parts(desc.clusterMap, desc.stringLength as usize) };
1118
1119 let mut cluster_analyzer = ClusterAnalyzer::new(cluster_map, glyph_count);
1120 let mut utf16_idx = desc.textPosition as usize;
1121 let mut glyph_idx = 0;
1122 let mut glyphs = Vec::with_capacity(glyph_count);
1123 for (cluster_utf16_len, cluster_glyph_count) in cluster_analyzer {
1124 context.index_converter.advance_to_utf16_ix(utf16_idx);
1125 utf16_idx += cluster_utf16_len;
1126 for (cluster_glyph_idx, glyph_id) in glyph_ids
1127 [glyph_idx..(glyph_idx + cluster_glyph_count)]
1128 .iter()
1129 .enumerate()
1130 {
1131 let id = GlyphId(*glyph_id as u32);
1132 let is_emoji = color_font
1133 && is_color_glyph(font_face, id, &context.text_system.components.factory);
1134 let this_glyph_idx = glyph_idx + cluster_glyph_idx;
1135 glyphs.push(ShapedGlyph {
1136 id,
1137 position: point(
1138 px(context.width + glyph_offsets[this_glyph_idx].advanceOffset),
1139 px(0.0),
1140 ),
1141 index: context.index_converter.utf8_ix,
1142 is_emoji,
1143 });
1144 context.width += glyph_advances[this_glyph_idx];
1145 }
1146 glyph_idx += cluster_glyph_count;
1147 }
1148 context.runs.push(ShapedRun { font_id, glyphs });
1149 Ok(())
1150 }
1151
1152 fn DrawUnderline(
1153 &self,
1154 _clientdrawingcontext: *const ::core::ffi::c_void,
1155 _baselineoriginx: f32,
1156 _baselineoriginy: f32,
1157 _underline: *const DWRITE_UNDERLINE,
1158 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1159 ) -> windows::core::Result<()> {
1160 Err(windows::core::Error::new(
1161 E_NOTIMPL,
1162 "DrawUnderline unimplemented",
1163 ))
1164 }
1165
1166 fn DrawStrikethrough(
1167 &self,
1168 _clientdrawingcontext: *const ::core::ffi::c_void,
1169 _baselineoriginx: f32,
1170 _baselineoriginy: f32,
1171 _strikethrough: *const DWRITE_STRIKETHROUGH,
1172 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1173 ) -> windows::core::Result<()> {
1174 Err(windows::core::Error::new(
1175 E_NOTIMPL,
1176 "DrawStrikethrough unimplemented",
1177 ))
1178 }
1179
1180 fn DrawInlineObject(
1181 &self,
1182 _clientdrawingcontext: *const ::core::ffi::c_void,
1183 _originx: f32,
1184 _originy: f32,
1185 _inlineobject: windows::core::Ref<IDWriteInlineObject>,
1186 _issideways: BOOL,
1187 _isrighttoleft: BOOL,
1188 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1189 ) -> windows::core::Result<()> {
1190 Err(windows::core::Error::new(
1191 E_NOTIMPL,
1192 "DrawInlineObject unimplemented",
1193 ))
1194 }
1195}
1196
1197struct StringIndexConverter<'a> {
1198 text: &'a str,
1199 utf8_ix: usize,
1200 utf16_ix: usize,
1201}
1202
1203impl<'a> StringIndexConverter<'a> {
1204 fn new(text: &'a str) -> Self {
1205 Self {
1206 text,
1207 utf8_ix: 0,
1208 utf16_ix: 0,
1209 }
1210 }
1211
1212 #[allow(dead_code)]
1213 fn advance_to_utf8_ix(&mut self, utf8_target: usize) {
1214 for (ix, c) in self.text[self.utf8_ix..].char_indices() {
1215 if self.utf8_ix + ix >= utf8_target {
1216 self.utf8_ix += ix;
1217 return;
1218 }
1219 self.utf16_ix += c.len_utf16();
1220 }
1221 self.utf8_ix = self.text.len();
1222 }
1223
1224 fn advance_to_utf16_ix(&mut self, utf16_target: usize) {
1225 for (ix, c) in self.text[self.utf8_ix..].char_indices() {
1226 if self.utf16_ix >= utf16_target {
1227 self.utf8_ix += ix;
1228 return;
1229 }
1230 self.utf16_ix += c.len_utf16();
1231 }
1232 self.utf8_ix = self.text.len();
1233 }
1234}
1235
1236impl Into<DWRITE_FONT_STYLE> for FontStyle {
1237 fn into(self) -> DWRITE_FONT_STYLE {
1238 match self {
1239 FontStyle::Normal => DWRITE_FONT_STYLE_NORMAL,
1240 FontStyle::Italic => DWRITE_FONT_STYLE_ITALIC,
1241 FontStyle::Oblique => DWRITE_FONT_STYLE_OBLIQUE,
1242 }
1243 }
1244}
1245
1246impl From<DWRITE_FONT_STYLE> for FontStyle {
1247 fn from(value: DWRITE_FONT_STYLE) -> Self {
1248 match value.0 {
1249 0 => FontStyle::Normal,
1250 1 => FontStyle::Italic,
1251 2 => FontStyle::Oblique,
1252 _ => unreachable!(),
1253 }
1254 }
1255}
1256
1257impl Into<DWRITE_FONT_WEIGHT> for FontWeight {
1258 fn into(self) -> DWRITE_FONT_WEIGHT {
1259 DWRITE_FONT_WEIGHT(self.0 as i32)
1260 }
1261}
1262
1263impl From<DWRITE_FONT_WEIGHT> for FontWeight {
1264 fn from(value: DWRITE_FONT_WEIGHT) -> Self {
1265 FontWeight(value.0 as f32)
1266 }
1267}
1268
1269fn get_font_names_from_collection(
1270 collection: &IDWriteFontCollection1,
1271 locale: &str,
1272) -> Vec<String> {
1273 unsafe {
1274 let mut result = Vec::new();
1275 let family_count = collection.GetFontFamilyCount();
1276 for index in 0..family_count {
1277 let Some(font_family) = collection.GetFontFamily(index).log_err() else {
1278 continue;
1279 };
1280 let Some(localized_family_name) = font_family.GetFamilyNames().log_err() else {
1281 continue;
1282 };
1283 let Some(family_name) = get_name(localized_family_name, locale).log_err() else {
1284 continue;
1285 };
1286 result.push(family_name);
1287 }
1288
1289 result
1290 }
1291}
1292
1293fn get_font_identifier_and_font_struct(
1294 font_face: &IDWriteFontFace3,
1295 locale: &str,
1296) -> Option<(FontIdentifier, Font, bool)> {
1297 let postscript_name = get_postscript_name(font_face, locale).log_err()?;
1298 let localized_family_name = unsafe { font_face.GetFamilyNames().log_err() }?;
1299 let family_name = get_name(localized_family_name, locale).log_err()?;
1300 let weight = unsafe { font_face.GetWeight() };
1301 let style = unsafe { font_face.GetStyle() };
1302 let identifier = FontIdentifier {
1303 postscript_name,
1304 weight: weight.0,
1305 style: style.0,
1306 };
1307 let font_struct = Font {
1308 family: family_name.into(),
1309 features: FontFeatures::default(),
1310 weight: weight.into(),
1311 style: style.into(),
1312 fallbacks: None,
1313 };
1314 let is_emoji = unsafe { font_face.IsColorFont().as_bool() };
1315 Some((identifier, font_struct, is_emoji))
1316}
1317
1318#[inline]
1319fn get_font_identifier(font_face: &IDWriteFontFace3, locale: &str) -> Option<FontIdentifier> {
1320 let weight = unsafe { font_face.GetWeight().0 };
1321 let style = unsafe { font_face.GetStyle().0 };
1322 get_postscript_name(font_face, locale)
1323 .log_err()
1324 .map(|postscript_name| FontIdentifier {
1325 postscript_name,
1326 weight,
1327 style,
1328 })
1329}
1330
1331#[inline]
1332fn get_postscript_name(font_face: &IDWriteFontFace3, locale: &str) -> Result<String> {
1333 let mut info = None;
1334 let mut exists = BOOL(0);
1335 unsafe {
1336 font_face.GetInformationalStrings(
1337 DWRITE_INFORMATIONAL_STRING_POSTSCRIPT_NAME,
1338 &mut info,
1339 &mut exists,
1340 )?
1341 };
1342 if !exists.as_bool() || info.is_none() {
1343 anyhow::bail!("No postscript name found for font face");
1344 }
1345
1346 get_name(info.unwrap(), locale)
1347}
1348
1349// https://learn.microsoft.com/en-us/windows/win32/api/dwrite/ne-dwrite-dwrite_font_feature_tag
1350fn apply_font_features(
1351 direct_write_features: &IDWriteTypography,
1352 features: &FontFeatures,
1353) -> Result<()> {
1354 let tag_values = features.tag_value_list();
1355 if tag_values.is_empty() {
1356 return Ok(());
1357 }
1358
1359 // All of these features are enabled by default by DirectWrite.
1360 // If you want to (and can) peek into the source of DirectWrite
1361 let mut feature_liga = make_direct_write_feature("liga", 1);
1362 let mut feature_clig = make_direct_write_feature("clig", 1);
1363 let mut feature_calt = make_direct_write_feature("calt", 1);
1364
1365 for (tag, value) in tag_values {
1366 if tag.as_str() == "liga" && *value == 0 {
1367 feature_liga.parameter = 0;
1368 continue;
1369 }
1370 if tag.as_str() == "clig" && *value == 0 {
1371 feature_clig.parameter = 0;
1372 continue;
1373 }
1374 if tag.as_str() == "calt" && *value == 0 {
1375 feature_calt.parameter = 0;
1376 continue;
1377 }
1378
1379 unsafe {
1380 direct_write_features.AddFontFeature(make_direct_write_feature(&tag, *value))?;
1381 }
1382 }
1383 unsafe {
1384 direct_write_features.AddFontFeature(feature_liga)?;
1385 direct_write_features.AddFontFeature(feature_clig)?;
1386 direct_write_features.AddFontFeature(feature_calt)?;
1387 }
1388
1389 Ok(())
1390}
1391
1392#[inline]
1393const fn make_direct_write_feature(feature_name: &str, parameter: u32) -> DWRITE_FONT_FEATURE {
1394 let tag = make_direct_write_tag(feature_name);
1395 DWRITE_FONT_FEATURE {
1396 nameTag: tag,
1397 parameter,
1398 }
1399}
1400
1401#[inline]
1402const fn make_open_type_tag(tag_name: &str) -> u32 {
1403 let bytes = tag_name.as_bytes();
1404 debug_assert!(bytes.len() == 4);
1405 u32::from_le_bytes([bytes[0], bytes[1], bytes[2], bytes[3]])
1406}
1407
1408#[inline]
1409const fn make_direct_write_tag(tag_name: &str) -> DWRITE_FONT_FEATURE_TAG {
1410 DWRITE_FONT_FEATURE_TAG(make_open_type_tag(tag_name))
1411}
1412
1413#[inline]
1414fn get_name(string: IDWriteLocalizedStrings, locale: &str) -> Result<String> {
1415 let mut locale_name_index = 0u32;
1416 let mut exists = BOOL(0);
1417 unsafe {
1418 string.FindLocaleName(
1419 &HSTRING::from(locale),
1420 &mut locale_name_index,
1421 &mut exists as _,
1422 )?
1423 };
1424 if !exists.as_bool() {
1425 unsafe {
1426 string.FindLocaleName(
1427 DEFAULT_LOCALE_NAME,
1428 &mut locale_name_index as _,
1429 &mut exists as _,
1430 )?
1431 };
1432 anyhow::ensure!(exists.as_bool(), "No localised string for {locale}");
1433 }
1434
1435 let name_length = unsafe { string.GetStringLength(locale_name_index) }? as usize;
1436 let mut name_vec = vec![0u16; name_length + 1];
1437 unsafe {
1438 string.GetString(locale_name_index, &mut name_vec)?;
1439 }
1440
1441 Ok(String::from_utf16_lossy(&name_vec[..name_length]))
1442}
1443
1444#[inline]
1445fn translate_color(color: &DWRITE_COLOR_F) -> [f32; 4] {
1446 [color.r, color.g, color.b, color.a]
1447}
1448
1449fn get_system_ui_font_name() -> SharedString {
1450 unsafe {
1451 let mut info: LOGFONTW = std::mem::zeroed();
1452 let font_family = if SystemParametersInfoW(
1453 SPI_GETICONTITLELOGFONT,
1454 std::mem::size_of::<LOGFONTW>() as u32,
1455 Some(&mut info as *mut _ as _),
1456 SYSTEM_PARAMETERS_INFO_UPDATE_FLAGS(0),
1457 )
1458 .log_err()
1459 .is_none()
1460 {
1461 // https://learn.microsoft.com/en-us/windows/win32/uxguide/vis-fonts
1462 // Segoe UI is the Windows font intended for user interface text strings.
1463 "Segoe UI".into()
1464 } else {
1465 let font_name = String::from_utf16_lossy(&info.lfFaceName);
1466 font_name.trim_matches(char::from(0)).to_owned().into()
1467 };
1468 log::info!("Use {} as UI font.", font_family);
1469 font_family
1470 }
1471}
1472
1473// One would think that with newer DirectWrite method: IDWriteFontFace4::GetGlyphImageFormats
1474// but that doesn't seem to work for some glyphs, say ❤
1475fn is_color_glyph(
1476 font_face: &IDWriteFontFace3,
1477 glyph_id: GlyphId,
1478 factory: &IDWriteFactory5,
1479) -> bool {
1480 let glyph_run = DWRITE_GLYPH_RUN {
1481 fontFace: unsafe { std::mem::transmute_copy(font_face) },
1482 fontEmSize: 14.0,
1483 glyphCount: 1,
1484 glyphIndices: &(glyph_id.0 as u16),
1485 glyphAdvances: &0.0,
1486 glyphOffsets: &DWRITE_GLYPH_OFFSET {
1487 advanceOffset: 0.0,
1488 ascenderOffset: 0.0,
1489 },
1490 isSideways: BOOL(0),
1491 bidiLevel: 0,
1492 };
1493 unsafe {
1494 factory.TranslateColorGlyphRun(
1495 Vector2::default(),
1496 &glyph_run as _,
1497 None,
1498 DWRITE_GLYPH_IMAGE_FORMATS_COLR
1499 | DWRITE_GLYPH_IMAGE_FORMATS_SVG
1500 | DWRITE_GLYPH_IMAGE_FORMATS_PNG
1501 | DWRITE_GLYPH_IMAGE_FORMATS_JPEG
1502 | DWRITE_GLYPH_IMAGE_FORMATS_PREMULTIPLIED_B8G8R8A8,
1503 DWRITE_MEASURING_MODE_NATURAL,
1504 None,
1505 0,
1506 )
1507 }
1508 .is_ok()
1509}
1510
1511const DEFAULT_LOCALE_NAME: PCWSTR = windows::core::w!("en-US");
1512
1513#[cfg(test)]
1514mod tests {
1515 use crate::platform::windows::direct_write::ClusterAnalyzer;
1516
1517 #[test]
1518 fn test_cluster_map() {
1519 let cluster_map = [0];
1520 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 1);
1521 let next = analyzer.next();
1522 assert_eq!(next, Some((1, 1)));
1523 let next = analyzer.next();
1524 assert_eq!(next, None);
1525
1526 let cluster_map = [0, 1, 2];
1527 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 3);
1528 let next = analyzer.next();
1529 assert_eq!(next, Some((1, 1)));
1530 let next = analyzer.next();
1531 assert_eq!(next, Some((1, 1)));
1532 let next = analyzer.next();
1533 assert_eq!(next, Some((1, 1)));
1534 let next = analyzer.next();
1535 assert_eq!(next, None);
1536 // 👨👩👧👦👩💻
1537 let cluster_map = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 4, 4, 4];
1538 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 5);
1539 let next = analyzer.next();
1540 assert_eq!(next, Some((11, 4)));
1541 let next = analyzer.next();
1542 assert_eq!(next, Some((5, 1)));
1543 let next = analyzer.next();
1544 assert_eq!(next, None);
1545 // 👩💻
1546 let cluster_map = [0, 0, 0, 0, 0];
1547 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 1);
1548 let next = analyzer.next();
1549 assert_eq!(next, Some((5, 1)));
1550 let next = analyzer.next();
1551 assert_eq!(next, None);
1552 }
1553}