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: ManuallyDrop::new(Some(font.font_face.cast()?)),
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 transform = DWRITE_MATRIX::default();
648 let rendering_mode = DWRITE_RENDERING_MODE1_NATURAL_SYMMETRIC;
649 let measuring_mode = DWRITE_MEASURING_MODE_NATURAL;
650 let baseline_origin_x = 0.0;
651 let baseline_origin_y = 0.0;
652
653 let glyph_analysis = unsafe {
654 self.components.factory.CreateGlyphRunAnalysis(
655 &glyph_run,
656 Some(&transform as *const _),
657 rendering_mode,
658 measuring_mode,
659 DWRITE_GRID_FIT_MODE_DEFAULT,
660 DWRITE_TEXT_ANTIALIAS_MODE_CLEARTYPE,
661 baseline_origin_x,
662 baseline_origin_y,
663 )?
664 };
665
666 let texture_type = DWRITE_TEXTURE_CLEARTYPE_3x1;
667 let bounds = unsafe { glyph_analysis.GetAlphaTextureBounds(texture_type)? };
668
669 // todo(windows)
670 // This is a walkaround, deleted when figured out.
671 let y_offset;
672 let extra_height;
673 if params.is_emoji {
674 y_offset = 0;
675 extra_height = 0;
676 } else {
677 // make some room for scaler.
678 y_offset = -1;
679 extra_height = 2;
680 }
681
682 if bounds.right < bounds.left {
683 Ok(Bounds {
684 origin: point(0.into(), 0.into()),
685 size: size(0.into(), 0.into()),
686 })
687 } else {
688 Ok(Bounds {
689 origin: point(
690 ((bounds.left as f32 * params.scale_factor).ceil() as i32).into(),
691 ((bounds.top as f32 * params.scale_factor).ceil() as i32 + y_offset).into(),
692 ),
693 size: size(
694 (((bounds.right - bounds.left) as f32 * params.scale_factor).ceil() as i32)
695 .into(),
696 (((bounds.bottom - bounds.top) as f32 * params.scale_factor).ceil() as i32
697 + extra_height)
698 .into(),
699 ),
700 })
701 }
702 }
703
704 fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
705 let font_info = &self.fonts[font_id.0];
706 let codepoints = [ch as u32];
707 let mut glyph_indices = vec![0u16; 1];
708 unsafe {
709 font_info
710 .font_face
711 .GetGlyphIndices(codepoints.as_ptr(), 1, glyph_indices.as_mut_ptr())
712 .log_err()
713 }
714 .map(|_| GlyphId(glyph_indices[0] as u32))
715 }
716
717 fn rasterize_glyph(
718 &self,
719 params: &RenderGlyphParams,
720 glyph_bounds: Bounds<DevicePixels>,
721 ) -> Result<(Size<DevicePixels>, Vec<u8>)> {
722 if glyph_bounds.size.width.0 == 0 || glyph_bounds.size.height.0 == 0 {
723 anyhow::bail!("glyph bounds are empty");
724 }
725
726 let font_info = &self.fonts[params.font_id.0];
727 let glyph_id = [params.glyph_id.0 as u16];
728 let advance = [glyph_bounds.size.width.0 as f32];
729 let offset = [DWRITE_GLYPH_OFFSET {
730 advanceOffset: -glyph_bounds.origin.x.0 as f32 / params.scale_factor,
731 ascenderOffset: glyph_bounds.origin.y.0 as f32 / params.scale_factor,
732 }];
733 let glyph_run = DWRITE_GLYPH_RUN {
734 fontFace: ManuallyDrop::new(Some(font_info.font_face.cast()?)),
735 fontEmSize: params.font_size.0,
736 glyphCount: 1,
737 glyphIndices: glyph_id.as_ptr(),
738 glyphAdvances: advance.as_ptr(),
739 glyphOffsets: offset.as_ptr(),
740 isSideways: BOOL(0),
741 bidiLevel: 0,
742 };
743
744 // Add an extra pixel when the subpixel variant isn't zero to make room for anti-aliasing.
745 let mut bitmap_size = glyph_bounds.size;
746 if params.subpixel_variant.x > 0 {
747 bitmap_size.width += DevicePixels(1);
748 }
749 if params.subpixel_variant.y > 0 {
750 bitmap_size.height += DevicePixels(1);
751 }
752 let bitmap_size = bitmap_size;
753
754 let subpixel_shift = params
755 .subpixel_variant
756 .map(|v| v as f32 / SUBPIXEL_VARIANTS as f32);
757 let baseline_origin_x = subpixel_shift.x / params.scale_factor;
758 let baseline_origin_y = subpixel_shift.y / params.scale_factor;
759
760 let transform = DWRITE_MATRIX {
761 m11: params.scale_factor,
762 m12: 0.0,
763 m21: 0.0,
764 m22: params.scale_factor,
765 dx: 0.0,
766 dy: 0.0,
767 };
768
769 let rendering_mode = if params.is_emoji {
770 DWRITE_RENDERING_MODE1_NATURAL
771 } else {
772 DWRITE_RENDERING_MODE1_NATURAL_SYMMETRIC
773 };
774
775 let measuring_mode = DWRITE_MEASURING_MODE_NATURAL;
776
777 let glyph_analysis = unsafe {
778 self.components.factory.CreateGlyphRunAnalysis(
779 &glyph_run,
780 Some(&transform),
781 rendering_mode,
782 measuring_mode,
783 DWRITE_GRID_FIT_MODE_DEFAULT,
784 DWRITE_TEXT_ANTIALIAS_MODE_CLEARTYPE,
785 baseline_origin_x,
786 baseline_origin_y,
787 )?
788 };
789
790 if params.is_emoji {
791 // For emoji, we need to handle color glyphs differently
792 // This is a simplified approach - in a full implementation you'd want to
793 // properly handle color glyph runs using TranslateColorGlyphRun
794 let texture_type = DWRITE_TEXTURE_CLEARTYPE_3x1;
795 let texture_bounds = unsafe { glyph_analysis.GetAlphaTextureBounds(texture_type)? };
796
797 let width = (texture_bounds.right - texture_bounds.left) as u32;
798 let height = (texture_bounds.bottom - texture_bounds.top) as u32;
799
800 if width == 0 || height == 0 {
801 return Ok((
802 bitmap_size,
803 vec![0u8; bitmap_size.width.0 as usize * bitmap_size.height.0 as usize * 4],
804 ));
805 }
806
807 let mut rgba_data = vec![0u8; (width * height * 4) as usize];
808
809 unsafe {
810 glyph_analysis.CreateAlphaTexture(texture_type, &texture_bounds, &mut rgba_data)?;
811 }
812
813 // Resize to match expected bitmap_size if needed
814 let expected_size = bitmap_size.width.0 as usize * bitmap_size.height.0 as usize * 4;
815 rgba_data.resize(expected_size, 0);
816
817 Ok((bitmap_size, rgba_data))
818 } else {
819 // For regular text, use grayscale or cleartype
820 let texture_type = DWRITE_TEXTURE_CLEARTYPE_3x1;
821 let texture_bounds = unsafe { glyph_analysis.GetAlphaTextureBounds(texture_type)? };
822
823 let width = (texture_bounds.right - texture_bounds.left) as u32;
824 let height = (texture_bounds.bottom - texture_bounds.top) as u32;
825
826 if width == 0 || height == 0 {
827 return Ok((
828 bitmap_size,
829 vec![0u8; bitmap_size.width.0 as usize * bitmap_size.height.0 as usize],
830 ));
831 }
832
833 let mut alpha_data = vec![0u8; (width * height) as usize];
834
835 unsafe {
836 glyph_analysis.CreateAlphaTexture(
837 texture_type,
838 &texture_bounds,
839 &mut alpha_data,
840 )?;
841 }
842
843 // For cleartype, we need to convert the 3x1 subpixel data to grayscale
844 // This is a simplified conversion - you might want to do proper subpixel rendering
845 let mut grayscale_data = Vec::new();
846 for chunk in alpha_data.chunks_exact(3) {
847 let avg = (chunk[0] as u32 + chunk[1] as u32 + chunk[2] as u32) / 3;
848 grayscale_data.push(avg as u8);
849 }
850
851 // Resize to match expected bitmap_size if needed
852 let expected_size = bitmap_size.width.0 as usize * bitmap_size.height.0 as usize;
853 grayscale_data.resize(expected_size, 0);
854
855 Ok((bitmap_size, grayscale_data))
856 }
857 }
858
859 fn get_typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>> {
860 unsafe {
861 let font = &self.fonts[font_id.0].font_face;
862 let glyph_indices = [glyph_id.0 as u16];
863 let mut metrics = [DWRITE_GLYPH_METRICS::default()];
864 font.GetDesignGlyphMetrics(glyph_indices.as_ptr(), 1, metrics.as_mut_ptr(), false)?;
865
866 let metrics = &metrics[0];
867 let advance_width = metrics.advanceWidth as i32;
868 let advance_height = metrics.advanceHeight as i32;
869 let left_side_bearing = metrics.leftSideBearing;
870 let right_side_bearing = metrics.rightSideBearing;
871 let top_side_bearing = metrics.topSideBearing;
872 let bottom_side_bearing = metrics.bottomSideBearing;
873 let vertical_origin_y = metrics.verticalOriginY;
874
875 let y_offset = vertical_origin_y + bottom_side_bearing - advance_height;
876 let width = advance_width - (left_side_bearing + right_side_bearing);
877 let height = advance_height - (top_side_bearing + bottom_side_bearing);
878
879 Ok(Bounds {
880 origin: Point {
881 x: left_side_bearing as f32,
882 y: y_offset as f32,
883 },
884 size: Size {
885 width: width as f32,
886 height: height as f32,
887 },
888 })
889 }
890 }
891
892 fn get_advance(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Size<f32>> {
893 unsafe {
894 let font = &self.fonts[font_id.0].font_face;
895 let glyph_indices = [glyph_id.0 as u16];
896 let mut metrics = [DWRITE_GLYPH_METRICS::default()];
897 font.GetDesignGlyphMetrics(glyph_indices.as_ptr(), 1, metrics.as_mut_ptr(), false)?;
898
899 let metrics = &metrics[0];
900
901 Ok(Size {
902 width: metrics.advanceWidth as f32,
903 height: 0.0,
904 })
905 }
906 }
907
908 fn all_font_names(&self) -> Vec<String> {
909 let mut result =
910 get_font_names_from_collection(&self.system_font_collection, &self.components.locale);
911 result.extend(get_font_names_from_collection(
912 &self.custom_font_collection,
913 &self.components.locale,
914 ));
915 result
916 }
917}
918
919impl Drop for DirectWriteState {
920 fn drop(&mut self) {
921 unsafe {
922 let _ = self
923 .components
924 .factory
925 .UnregisterFontFileLoader(&self.components.in_memory_loader);
926 }
927 }
928}
929
930struct TextRendererWrapper(pub IDWriteTextRenderer);
931
932impl TextRendererWrapper {
933 pub fn new(locale_str: &str) -> Self {
934 let inner = TextRenderer::new(locale_str);
935 TextRendererWrapper(inner.into())
936 }
937}
938
939#[implement(IDWriteTextRenderer)]
940struct TextRenderer {
941 locale: String,
942}
943
944impl TextRenderer {
945 pub fn new(locale_str: &str) -> Self {
946 TextRenderer {
947 locale: locale_str.to_owned(),
948 }
949 }
950}
951
952struct RendererContext<'t, 'a, 'b> {
953 text_system: &'t mut DirectWriteState,
954 index_converter: StringIndexConverter<'a>,
955 runs: &'b mut Vec<ShapedRun>,
956 width: f32,
957}
958
959#[derive(Debug)]
960struct ClusterAnalyzer<'t> {
961 utf16_idx: usize,
962 glyph_idx: usize,
963 glyph_count: usize,
964 cluster_map: &'t [u16],
965}
966
967impl<'t> ClusterAnalyzer<'t> {
968 pub fn new(cluster_map: &'t [u16], glyph_count: usize) -> Self {
969 ClusterAnalyzer {
970 utf16_idx: 0,
971 glyph_idx: 0,
972 glyph_count,
973 cluster_map,
974 }
975 }
976}
977
978impl Iterator for ClusterAnalyzer<'_> {
979 type Item = (usize, usize);
980
981 fn next(&mut self) -> Option<(usize, usize)> {
982 if self.utf16_idx >= self.cluster_map.len() {
983 return None; // No more clusters
984 }
985 let start_utf16_idx = self.utf16_idx;
986 let current_glyph = self.cluster_map[start_utf16_idx] as usize;
987
988 // Find the end of current cluster (where glyph index changes)
989 let mut end_utf16_idx = start_utf16_idx + 1;
990 while end_utf16_idx < self.cluster_map.len()
991 && self.cluster_map[end_utf16_idx] as usize == current_glyph
992 {
993 end_utf16_idx += 1;
994 }
995
996 let utf16_len = end_utf16_idx - start_utf16_idx;
997
998 // Calculate glyph count for this cluster
999 let next_glyph = if end_utf16_idx < self.cluster_map.len() {
1000 self.cluster_map[end_utf16_idx] as usize
1001 } else {
1002 self.glyph_count
1003 };
1004
1005 let glyph_count = next_glyph - current_glyph;
1006
1007 // Update state for next call
1008 self.utf16_idx = end_utf16_idx;
1009 self.glyph_idx = next_glyph;
1010
1011 Some((utf16_len, glyph_count))
1012 }
1013}
1014
1015#[allow(non_snake_case)]
1016impl IDWritePixelSnapping_Impl for TextRenderer_Impl {
1017 fn IsPixelSnappingDisabled(
1018 &self,
1019 _clientdrawingcontext: *const ::core::ffi::c_void,
1020 ) -> windows::core::Result<BOOL> {
1021 Ok(BOOL(0))
1022 }
1023
1024 fn GetCurrentTransform(
1025 &self,
1026 _clientdrawingcontext: *const ::core::ffi::c_void,
1027 transform: *mut DWRITE_MATRIX,
1028 ) -> windows::core::Result<()> {
1029 unsafe {
1030 *transform = DWRITE_MATRIX {
1031 m11: 1.0,
1032 m12: 0.0,
1033 m21: 0.0,
1034 m22: 1.0,
1035 dx: 0.0,
1036 dy: 0.0,
1037 };
1038 }
1039 Ok(())
1040 }
1041
1042 fn GetPixelsPerDip(
1043 &self,
1044 _clientdrawingcontext: *const ::core::ffi::c_void,
1045 ) -> windows::core::Result<f32> {
1046 Ok(1.0)
1047 }
1048}
1049
1050#[allow(non_snake_case)]
1051impl IDWriteTextRenderer_Impl for TextRenderer_Impl {
1052 fn DrawGlyphRun(
1053 &self,
1054 clientdrawingcontext: *const ::core::ffi::c_void,
1055 _baselineoriginx: f32,
1056 _baselineoriginy: f32,
1057 _measuringmode: DWRITE_MEASURING_MODE,
1058 glyphrun: *const DWRITE_GLYPH_RUN,
1059 glyphrundescription: *const DWRITE_GLYPH_RUN_DESCRIPTION,
1060 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1061 ) -> windows::core::Result<()> {
1062 let glyphrun = unsafe { &*glyphrun };
1063 let glyph_count = glyphrun.glyphCount as usize;
1064 if glyph_count == 0 || glyphrun.fontFace.is_none() {
1065 return Ok(());
1066 }
1067 let desc = unsafe { &*glyphrundescription };
1068 let context = unsafe {
1069 &mut *(clientdrawingcontext as *const RendererContext as *mut RendererContext)
1070 };
1071 let font_face = glyphrun.fontFace.as_ref().unwrap();
1072 // This `cast()` action here should never fail since we are running on Win10+, and
1073 // `IDWriteFontFace3` requires Win10
1074 let font_face = &font_face.cast::<IDWriteFontFace3>().unwrap();
1075 let Some((font_identifier, font_struct, color_font)) =
1076 get_font_identifier_and_font_struct(font_face, &self.locale)
1077 else {
1078 return Ok(());
1079 };
1080
1081 let font_id = if let Some(id) = context
1082 .text_system
1083 .font_id_by_identifier
1084 .get(&font_identifier)
1085 {
1086 *id
1087 } else {
1088 context.text_system.select_font(&font_struct)
1089 };
1090
1091 let glyph_ids = unsafe { std::slice::from_raw_parts(glyphrun.glyphIndices, glyph_count) };
1092 let glyph_advances =
1093 unsafe { std::slice::from_raw_parts(glyphrun.glyphAdvances, glyph_count) };
1094 let glyph_offsets =
1095 unsafe { std::slice::from_raw_parts(glyphrun.glyphOffsets, glyph_count) };
1096 let cluster_map =
1097 unsafe { std::slice::from_raw_parts(desc.clusterMap, desc.stringLength as usize) };
1098
1099 let mut cluster_analyzer = ClusterAnalyzer::new(cluster_map, glyph_count);
1100 let mut utf16_idx = desc.textPosition as usize;
1101 let mut glyph_idx = 0;
1102 let mut glyphs = Vec::with_capacity(glyph_count);
1103 for (cluster_utf16_len, cluster_glyph_count) in cluster_analyzer {
1104 context.index_converter.advance_to_utf16_ix(utf16_idx);
1105 utf16_idx += cluster_utf16_len;
1106 for (cluster_glyph_idx, glyph_id) in glyph_ids
1107 [glyph_idx..(glyph_idx + cluster_glyph_count)]
1108 .iter()
1109 .enumerate()
1110 {
1111 let id = GlyphId(*glyph_id as u32);
1112 let is_emoji = color_font
1113 && is_color_glyph(font_face, id, &context.text_system.components.factory);
1114 let this_glyph_idx = glyph_idx + cluster_glyph_idx;
1115 glyphs.push(ShapedGlyph {
1116 id,
1117 position: point(
1118 px(context.width + glyph_offsets[this_glyph_idx].advanceOffset),
1119 px(0.0),
1120 ),
1121 index: context.index_converter.utf8_ix,
1122 is_emoji,
1123 });
1124 context.width += glyph_advances[this_glyph_idx];
1125 }
1126 glyph_idx += cluster_glyph_count;
1127 }
1128 context.runs.push(ShapedRun { font_id, glyphs });
1129 Ok(())
1130 }
1131
1132 fn DrawUnderline(
1133 &self,
1134 _clientdrawingcontext: *const ::core::ffi::c_void,
1135 _baselineoriginx: f32,
1136 _baselineoriginy: f32,
1137 _underline: *const DWRITE_UNDERLINE,
1138 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1139 ) -> windows::core::Result<()> {
1140 Err(windows::core::Error::new(
1141 E_NOTIMPL,
1142 "DrawUnderline unimplemented",
1143 ))
1144 }
1145
1146 fn DrawStrikethrough(
1147 &self,
1148 _clientdrawingcontext: *const ::core::ffi::c_void,
1149 _baselineoriginx: f32,
1150 _baselineoriginy: f32,
1151 _strikethrough: *const DWRITE_STRIKETHROUGH,
1152 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1153 ) -> windows::core::Result<()> {
1154 Err(windows::core::Error::new(
1155 E_NOTIMPL,
1156 "DrawStrikethrough unimplemented",
1157 ))
1158 }
1159
1160 fn DrawInlineObject(
1161 &self,
1162 _clientdrawingcontext: *const ::core::ffi::c_void,
1163 _originx: f32,
1164 _originy: f32,
1165 _inlineobject: windows::core::Ref<IDWriteInlineObject>,
1166 _issideways: BOOL,
1167 _isrighttoleft: BOOL,
1168 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1169 ) -> windows::core::Result<()> {
1170 Err(windows::core::Error::new(
1171 E_NOTIMPL,
1172 "DrawInlineObject unimplemented",
1173 ))
1174 }
1175}
1176
1177struct StringIndexConverter<'a> {
1178 text: &'a str,
1179 utf8_ix: usize,
1180 utf16_ix: usize,
1181}
1182
1183impl<'a> StringIndexConverter<'a> {
1184 fn new(text: &'a str) -> Self {
1185 Self {
1186 text,
1187 utf8_ix: 0,
1188 utf16_ix: 0,
1189 }
1190 }
1191
1192 #[allow(dead_code)]
1193 fn advance_to_utf8_ix(&mut self, utf8_target: usize) {
1194 for (ix, c) in self.text[self.utf8_ix..].char_indices() {
1195 if self.utf8_ix + ix >= utf8_target {
1196 self.utf8_ix += ix;
1197 return;
1198 }
1199 self.utf16_ix += c.len_utf16();
1200 }
1201 self.utf8_ix = self.text.len();
1202 }
1203
1204 fn advance_to_utf16_ix(&mut self, utf16_target: usize) {
1205 for (ix, c) in self.text[self.utf8_ix..].char_indices() {
1206 if self.utf16_ix >= utf16_target {
1207 self.utf8_ix += ix;
1208 return;
1209 }
1210 self.utf16_ix += c.len_utf16();
1211 }
1212 self.utf8_ix = self.text.len();
1213 }
1214}
1215
1216impl Into<DWRITE_FONT_STYLE> for FontStyle {
1217 fn into(self) -> DWRITE_FONT_STYLE {
1218 match self {
1219 FontStyle::Normal => DWRITE_FONT_STYLE_NORMAL,
1220 FontStyle::Italic => DWRITE_FONT_STYLE_ITALIC,
1221 FontStyle::Oblique => DWRITE_FONT_STYLE_OBLIQUE,
1222 }
1223 }
1224}
1225
1226impl From<DWRITE_FONT_STYLE> for FontStyle {
1227 fn from(value: DWRITE_FONT_STYLE) -> Self {
1228 match value.0 {
1229 0 => FontStyle::Normal,
1230 1 => FontStyle::Italic,
1231 2 => FontStyle::Oblique,
1232 _ => unreachable!(),
1233 }
1234 }
1235}
1236
1237impl Into<DWRITE_FONT_WEIGHT> for FontWeight {
1238 fn into(self) -> DWRITE_FONT_WEIGHT {
1239 DWRITE_FONT_WEIGHT(self.0 as i32)
1240 }
1241}
1242
1243impl From<DWRITE_FONT_WEIGHT> for FontWeight {
1244 fn from(value: DWRITE_FONT_WEIGHT) -> Self {
1245 FontWeight(value.0 as f32)
1246 }
1247}
1248
1249fn get_font_names_from_collection(
1250 collection: &IDWriteFontCollection1,
1251 locale: &str,
1252) -> Vec<String> {
1253 unsafe {
1254 let mut result = Vec::new();
1255 let family_count = collection.GetFontFamilyCount();
1256 for index in 0..family_count {
1257 let Some(font_family) = collection.GetFontFamily(index).log_err() else {
1258 continue;
1259 };
1260 let Some(localized_family_name) = font_family.GetFamilyNames().log_err() else {
1261 continue;
1262 };
1263 let Some(family_name) = get_name(localized_family_name, locale).log_err() else {
1264 continue;
1265 };
1266 result.push(family_name);
1267 }
1268
1269 result
1270 }
1271}
1272
1273fn get_font_identifier_and_font_struct(
1274 font_face: &IDWriteFontFace3,
1275 locale: &str,
1276) -> Option<(FontIdentifier, Font, bool)> {
1277 let postscript_name = get_postscript_name(font_face, locale).log_err()?;
1278 let localized_family_name = unsafe { font_face.GetFamilyNames().log_err() }?;
1279 let family_name = get_name(localized_family_name, locale).log_err()?;
1280 let weight = unsafe { font_face.GetWeight() };
1281 let style = unsafe { font_face.GetStyle() };
1282 let identifier = FontIdentifier {
1283 postscript_name,
1284 weight: weight.0,
1285 style: style.0,
1286 };
1287 let font_struct = Font {
1288 family: family_name.into(),
1289 features: FontFeatures::default(),
1290 weight: weight.into(),
1291 style: style.into(),
1292 fallbacks: None,
1293 };
1294 let is_emoji = unsafe { font_face.IsColorFont().as_bool() };
1295 Some((identifier, font_struct, is_emoji))
1296}
1297
1298#[inline]
1299fn get_font_identifier(font_face: &IDWriteFontFace3, locale: &str) -> Option<FontIdentifier> {
1300 let weight = unsafe { font_face.GetWeight().0 };
1301 let style = unsafe { font_face.GetStyle().0 };
1302 get_postscript_name(font_face, locale)
1303 .log_err()
1304 .map(|postscript_name| FontIdentifier {
1305 postscript_name,
1306 weight,
1307 style,
1308 })
1309}
1310
1311#[inline]
1312fn get_postscript_name(font_face: &IDWriteFontFace3, locale: &str) -> Result<String> {
1313 let mut info = None;
1314 let mut exists = BOOL(0);
1315 unsafe {
1316 font_face.GetInformationalStrings(
1317 DWRITE_INFORMATIONAL_STRING_POSTSCRIPT_NAME,
1318 &mut info,
1319 &mut exists,
1320 )?
1321 };
1322 if !exists.as_bool() || info.is_none() {
1323 anyhow::bail!("No postscript name found for font face");
1324 }
1325
1326 get_name(info.unwrap(), locale)
1327}
1328
1329// https://learn.microsoft.com/en-us/windows/win32/api/dwrite/ne-dwrite-dwrite_font_feature_tag
1330fn apply_font_features(
1331 direct_write_features: &IDWriteTypography,
1332 features: &FontFeatures,
1333) -> Result<()> {
1334 let tag_values = features.tag_value_list();
1335 if tag_values.is_empty() {
1336 return Ok(());
1337 }
1338
1339 // All of these features are enabled by default by DirectWrite.
1340 // If you want to (and can) peek into the source of DirectWrite
1341 let mut feature_liga = make_direct_write_feature("liga", 1);
1342 let mut feature_clig = make_direct_write_feature("clig", 1);
1343 let mut feature_calt = make_direct_write_feature("calt", 1);
1344
1345 for (tag, value) in tag_values {
1346 if tag.as_str() == "liga" && *value == 0 {
1347 feature_liga.parameter = 0;
1348 continue;
1349 }
1350 if tag.as_str() == "clig" && *value == 0 {
1351 feature_clig.parameter = 0;
1352 continue;
1353 }
1354 if tag.as_str() == "calt" && *value == 0 {
1355 feature_calt.parameter = 0;
1356 continue;
1357 }
1358
1359 unsafe {
1360 direct_write_features.AddFontFeature(make_direct_write_feature(&tag, *value))?;
1361 }
1362 }
1363 unsafe {
1364 direct_write_features.AddFontFeature(feature_liga)?;
1365 direct_write_features.AddFontFeature(feature_clig)?;
1366 direct_write_features.AddFontFeature(feature_calt)?;
1367 }
1368
1369 Ok(())
1370}
1371
1372#[inline]
1373const fn make_direct_write_feature(feature_name: &str, parameter: u32) -> DWRITE_FONT_FEATURE {
1374 let tag = make_direct_write_tag(feature_name);
1375 DWRITE_FONT_FEATURE {
1376 nameTag: tag,
1377 parameter,
1378 }
1379}
1380
1381#[inline]
1382const fn make_open_type_tag(tag_name: &str) -> u32 {
1383 let bytes = tag_name.as_bytes();
1384 debug_assert!(bytes.len() == 4);
1385 u32::from_le_bytes([bytes[0], bytes[1], bytes[2], bytes[3]])
1386}
1387
1388#[inline]
1389const fn make_direct_write_tag(tag_name: &str) -> DWRITE_FONT_FEATURE_TAG {
1390 DWRITE_FONT_FEATURE_TAG(make_open_type_tag(tag_name))
1391}
1392
1393#[inline]
1394fn get_name(string: IDWriteLocalizedStrings, locale: &str) -> Result<String> {
1395 let mut locale_name_index = 0u32;
1396 let mut exists = BOOL(0);
1397 unsafe {
1398 string.FindLocaleName(
1399 &HSTRING::from(locale),
1400 &mut locale_name_index,
1401 &mut exists as _,
1402 )?
1403 };
1404 if !exists.as_bool() {
1405 unsafe {
1406 string.FindLocaleName(
1407 DEFAULT_LOCALE_NAME,
1408 &mut locale_name_index as _,
1409 &mut exists as _,
1410 )?
1411 };
1412 anyhow::ensure!(exists.as_bool(), "No localised string for {locale}");
1413 }
1414
1415 let name_length = unsafe { string.GetStringLength(locale_name_index) }? as usize;
1416 let mut name_vec = vec![0u16; name_length + 1];
1417 unsafe {
1418 string.GetString(locale_name_index, &mut name_vec)?;
1419 }
1420
1421 Ok(String::from_utf16_lossy(&name_vec[..name_length]))
1422}
1423
1424#[inline]
1425fn translate_color(color: &DWRITE_COLOR_F) -> [f32; 4] {
1426 [color.r, color.g, color.b, color.a]
1427}
1428
1429fn get_system_ui_font_name() -> SharedString {
1430 unsafe {
1431 let mut info: LOGFONTW = std::mem::zeroed();
1432 let font_family = if SystemParametersInfoW(
1433 SPI_GETICONTITLELOGFONT,
1434 std::mem::size_of::<LOGFONTW>() as u32,
1435 Some(&mut info as *mut _ as _),
1436 SYSTEM_PARAMETERS_INFO_UPDATE_FLAGS(0),
1437 )
1438 .log_err()
1439 .is_none()
1440 {
1441 // https://learn.microsoft.com/en-us/windows/win32/uxguide/vis-fonts
1442 // Segoe UI is the Windows font intended for user interface text strings.
1443 "Segoe UI".into()
1444 } else {
1445 let font_name = String::from_utf16_lossy(&info.lfFaceName);
1446 font_name.trim_matches(char::from(0)).to_owned().into()
1447 };
1448 log::info!("Use {} as UI font.", font_family);
1449 font_family
1450 }
1451}
1452
1453// One would think that with newer DirectWrite method: IDWriteFontFace4::GetGlyphImageFormats
1454// but that doesn't seem to work for some glyphs, say ❤
1455fn is_color_glyph(
1456 font_face: &IDWriteFontFace3,
1457 glyph_id: GlyphId,
1458 factory: &IDWriteFactory5,
1459) -> bool {
1460 let glyph_run = DWRITE_GLYPH_RUN {
1461 fontFace: unsafe { std::mem::transmute_copy(font_face) },
1462 fontEmSize: 14.0,
1463 glyphCount: 1,
1464 glyphIndices: &(glyph_id.0 as u16),
1465 glyphAdvances: &0.0,
1466 glyphOffsets: &DWRITE_GLYPH_OFFSET {
1467 advanceOffset: 0.0,
1468 ascenderOffset: 0.0,
1469 },
1470 isSideways: BOOL(0),
1471 bidiLevel: 0,
1472 };
1473 unsafe {
1474 factory.TranslateColorGlyphRun(
1475 Vector2::default(),
1476 &glyph_run as _,
1477 None,
1478 DWRITE_GLYPH_IMAGE_FORMATS_COLR
1479 | DWRITE_GLYPH_IMAGE_FORMATS_SVG
1480 | DWRITE_GLYPH_IMAGE_FORMATS_PNG
1481 | DWRITE_GLYPH_IMAGE_FORMATS_JPEG
1482 | DWRITE_GLYPH_IMAGE_FORMATS_PREMULTIPLIED_B8G8R8A8,
1483 DWRITE_MEASURING_MODE_NATURAL,
1484 None,
1485 0,
1486 )
1487 }
1488 .is_ok()
1489}
1490
1491const DEFAULT_LOCALE_NAME: PCWSTR = windows::core::w!("en-US");
1492
1493#[cfg(test)]
1494mod tests {
1495 use crate::platform::windows::direct_write::ClusterAnalyzer;
1496
1497 #[test]
1498 fn test_cluster_map() {
1499 let cluster_map = [0];
1500 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 1);
1501 let next = analyzer.next();
1502 assert_eq!(next, Some((1, 1)));
1503 let next = analyzer.next();
1504 assert_eq!(next, None);
1505
1506 let cluster_map = [0, 1, 2];
1507 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 3);
1508 let next = analyzer.next();
1509 assert_eq!(next, Some((1, 1)));
1510 let next = analyzer.next();
1511 assert_eq!(next, Some((1, 1)));
1512 let next = analyzer.next();
1513 assert_eq!(next, Some((1, 1)));
1514 let next = analyzer.next();
1515 assert_eq!(next, None);
1516 // 👨👩👧👦👩💻
1517 let cluster_map = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 4, 4, 4];
1518 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 5);
1519 let next = analyzer.next();
1520 assert_eq!(next, Some((11, 4)));
1521 let next = analyzer.next();
1522 assert_eq!(next, Some((5, 1)));
1523 let next = analyzer.next();
1524 assert_eq!(next, None);
1525 // 👩💻
1526 let cluster_map = [0, 0, 0, 0, 0];
1527 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 1);
1528 let next = analyzer.next();
1529 assert_eq!(next, Some((5, 1)));
1530 let next = analyzer.next();
1531 assert_eq!(next, None);
1532 }
1533}