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