1use std::{borrow::Cow, 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::{
13 Direct3D::D3D_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP,
14 Direct3D11::*,
15 DirectWrite::*,
16 Dxgi::Common::*,
17 Gdi::{IsRectEmpty, LOGFONTW},
18 Imaging::*,
19 },
20 System::SystemServices::LOCALE_NAME_MAX_LENGTH,
21 UI::WindowsAndMessaging::*,
22 },
23 core::*,
24};
25use windows_numerics::Vector2;
26
27use crate::*;
28
29#[derive(Debug)]
30struct FontInfo {
31 font_family: String,
32 font_face: IDWriteFontFace3,
33 features: IDWriteTypography,
34 fallbacks: Option<IDWriteFontFallback>,
35 is_system_font: bool,
36}
37
38pub(crate) struct DirectWriteTextSystem(RwLock<DirectWriteState>);
39
40struct DirectWriteComponent {
41 locale: String,
42 factory: IDWriteFactory5,
43 bitmap_factory: AgileReference<IWICImagingFactory>,
44 in_memory_loader: IDWriteInMemoryFontFileLoader,
45 builder: IDWriteFontSetBuilder1,
46 text_renderer: Arc<TextRendererWrapper>,
47
48 render_params: IDWriteRenderingParams3,
49 gpu_state: GPUState,
50}
51
52struct GPUState {
53 device: ID3D11Device,
54 device_context: ID3D11DeviceContext,
55 sampler: [Option<ID3D11SamplerState>; 1],
56 blend_state: ID3D11BlendState,
57 vertex_shader: ID3D11VertexShader,
58 pixel_shader: ID3D11PixelShader,
59}
60
61struct DirectWriteState {
62 components: DirectWriteComponent,
63 system_ui_font_name: SharedString,
64 system_font_collection: IDWriteFontCollection1,
65 custom_font_collection: IDWriteFontCollection1,
66 fonts: Vec<FontInfo>,
67 font_selections: HashMap<Font, FontId>,
68 font_id_by_identifier: HashMap<FontIdentifier, FontId>,
69}
70
71#[derive(Debug, Clone, Hash, PartialEq, Eq)]
72struct FontIdentifier {
73 postscript_name: String,
74 weight: i32,
75 style: i32,
76}
77
78impl DirectWriteComponent {
79 pub fn new(bitmap_factory: &IWICImagingFactory, gpu_context: &DirectXDevices) -> Result<Self> {
80 // todo: ideally this would not be a large unsafe block but smaller isolated ones for easier auditing
81 unsafe {
82 let factory: IDWriteFactory5 = DWriteCreateFactory(DWRITE_FACTORY_TYPE_SHARED)?;
83 let bitmap_factory = AgileReference::new(bitmap_factory)?;
84 // The `IDWriteInMemoryFontFileLoader` here is supported starting from
85 // Windows 10 Creators Update, which consequently requires the entire
86 // `DirectWriteTextSystem` to run on `win10 1703`+.
87 let in_memory_loader = factory.CreateInMemoryFontFileLoader()?;
88 factory.RegisterFontFileLoader(&in_memory_loader)?;
89 let builder = factory.CreateFontSetBuilder()?;
90 let mut locale_vec = vec![0u16; LOCALE_NAME_MAX_LENGTH as usize];
91 GetUserDefaultLocaleName(&mut locale_vec);
92 let locale = String::from_utf16_lossy(&locale_vec);
93 let text_renderer = Arc::new(TextRendererWrapper::new(&locale));
94
95 let render_params = {
96 let default_params: IDWriteRenderingParams3 =
97 factory.CreateRenderingParams()?.cast()?;
98 let gamma = default_params.GetGamma();
99 let enhanced_contrast = default_params.GetEnhancedContrast();
100 let gray_contrast = default_params.GetGrayscaleEnhancedContrast();
101 let cleartype_level = default_params.GetClearTypeLevel();
102 let grid_fit_mode = default_params.GetGridFitMode();
103
104 factory.CreateCustomRenderingParams(
105 gamma,
106 enhanced_contrast,
107 gray_contrast,
108 cleartype_level,
109 DWRITE_PIXEL_GEOMETRY_RGB,
110 DWRITE_RENDERING_MODE1_NATURAL_SYMMETRIC,
111 grid_fit_mode,
112 )?
113 };
114
115 let gpu_state = GPUState::new(gpu_context)?;
116
117 Ok(DirectWriteComponent {
118 locale,
119 factory,
120 bitmap_factory,
121 in_memory_loader,
122 builder,
123 text_renderer,
124 render_params,
125 gpu_state,
126 })
127 }
128 }
129}
130
131impl GPUState {
132 fn new(gpu_context: &DirectXDevices) -> Result<Self> {
133 let device = gpu_context.device.clone();
134 let device_context = gpu_context.device_context.clone();
135
136 let blend_state = {
137 let mut blend_state = None;
138 let desc = D3D11_BLEND_DESC {
139 AlphaToCoverageEnable: false.into(),
140 IndependentBlendEnable: false.into(),
141 RenderTarget: [
142 D3D11_RENDER_TARGET_BLEND_DESC {
143 BlendEnable: true.into(),
144 SrcBlend: D3D11_BLEND_SRC_ALPHA,
145 DestBlend: D3D11_BLEND_INV_SRC_ALPHA,
146 BlendOp: D3D11_BLEND_OP_ADD,
147 SrcBlendAlpha: D3D11_BLEND_SRC_ALPHA,
148 DestBlendAlpha: D3D11_BLEND_INV_SRC_ALPHA,
149 BlendOpAlpha: D3D11_BLEND_OP_ADD,
150 RenderTargetWriteMask: D3D11_COLOR_WRITE_ENABLE_ALL.0 as u8,
151 },
152 Default::default(),
153 Default::default(),
154 Default::default(),
155 Default::default(),
156 Default::default(),
157 Default::default(),
158 Default::default(),
159 ],
160 };
161 unsafe { device.CreateBlendState(&desc, Some(&mut blend_state)) }?;
162 blend_state.unwrap()
163 };
164
165 let sampler = {
166 let mut sampler = None;
167 let desc = D3D11_SAMPLER_DESC {
168 Filter: D3D11_FILTER_MIN_MAG_MIP_POINT,
169 AddressU: D3D11_TEXTURE_ADDRESS_BORDER,
170 AddressV: D3D11_TEXTURE_ADDRESS_BORDER,
171 AddressW: D3D11_TEXTURE_ADDRESS_BORDER,
172 MipLODBias: 0.0,
173 MaxAnisotropy: 1,
174 ComparisonFunc: D3D11_COMPARISON_ALWAYS,
175 BorderColor: [0.0, 0.0, 0.0, 0.0],
176 MinLOD: 0.0,
177 MaxLOD: 0.0,
178 };
179 unsafe { device.CreateSamplerState(&desc, Some(&mut sampler)) }?;
180 [sampler]
181 };
182
183 let vertex_shader = {
184 let source = shader_resources::RawShaderBytes::new(
185 shader_resources::ShaderModule::EmojiRasterization,
186 shader_resources::ShaderTarget::Vertex,
187 )?;
188 let mut shader = None;
189 unsafe { device.CreateVertexShader(source.as_bytes(), None, Some(&mut shader)) }?;
190 shader.unwrap()
191 };
192
193 let pixel_shader = {
194 let source = shader_resources::RawShaderBytes::new(
195 shader_resources::ShaderModule::EmojiRasterization,
196 shader_resources::ShaderTarget::Fragment,
197 )?;
198 let mut shader = None;
199 unsafe { device.CreatePixelShader(source.as_bytes(), None, Some(&mut shader)) }?;
200 shader.unwrap()
201 };
202
203 Ok(Self {
204 device,
205 device_context,
206 sampler,
207 blend_state,
208 vertex_shader,
209 pixel_shader,
210 })
211 }
212}
213
214impl DirectWriteTextSystem {
215 pub(crate) fn new(
216 gpu_context: &DirectXDevices,
217 bitmap_factory: &IWICImagingFactory,
218 ) -> Result<Self> {
219 let components = DirectWriteComponent::new(bitmap_factory, gpu_context)?;
220 let system_font_collection = unsafe {
221 let mut result = std::mem::zeroed();
222 components
223 .factory
224 .GetSystemFontCollection(false, &mut result, true)?;
225 result.unwrap()
226 };
227 let custom_font_set = unsafe { components.builder.CreateFontSet()? };
228 let custom_font_collection = unsafe {
229 components
230 .factory
231 .CreateFontCollectionFromFontSet(&custom_font_set)?
232 };
233 let system_ui_font_name = get_system_ui_font_name();
234
235 Ok(Self(RwLock::new(DirectWriteState {
236 components,
237 system_ui_font_name,
238 system_font_collection,
239 custom_font_collection,
240 fonts: Vec::new(),
241 font_selections: HashMap::default(),
242 font_id_by_identifier: HashMap::default(),
243 })))
244 }
245}
246
247impl PlatformTextSystem for DirectWriteTextSystem {
248 fn add_fonts(&self, fonts: Vec<Cow<'static, [u8]>>) -> Result<()> {
249 self.0.write().add_fonts(fonts)
250 }
251
252 fn all_font_names(&self) -> Vec<String> {
253 self.0.read().all_font_names()
254 }
255
256 fn font_id(&self, font: &Font) -> Result<FontId> {
257 let lock = self.0.upgradable_read();
258 if let Some(font_id) = lock.font_selections.get(font) {
259 Ok(*font_id)
260 } else {
261 let mut lock = RwLockUpgradableReadGuard::upgrade(lock);
262 let font_id = lock.select_font(font);
263 lock.font_selections.insert(font.clone(), font_id);
264 Ok(font_id)
265 }
266 }
267
268 fn font_metrics(&self, font_id: FontId) -> FontMetrics {
269 self.0.read().font_metrics(font_id)
270 }
271
272 fn typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>> {
273 self.0.read().get_typographic_bounds(font_id, glyph_id)
274 }
275
276 fn advance(&self, font_id: FontId, glyph_id: GlyphId) -> anyhow::Result<Size<f32>> {
277 self.0.read().get_advance(font_id, glyph_id)
278 }
279
280 fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
281 self.0.read().glyph_for_char(font_id, ch)
282 }
283
284 fn glyph_raster_bounds(
285 &self,
286 params: &RenderGlyphParams,
287 ) -> anyhow::Result<Bounds<DevicePixels>> {
288 self.0.read().raster_bounds(params)
289 }
290
291 fn rasterize_glyph(
292 &self,
293 params: &RenderGlyphParams,
294 raster_bounds: Bounds<DevicePixels>,
295 ) -> anyhow::Result<(Size<DevicePixels>, Vec<u8>)> {
296 self.0.read().rasterize_glyph(params, raster_bounds)
297 }
298
299 fn layout_line(&self, text: &str, font_size: Pixels, runs: &[FontRun]) -> LineLayout {
300 self.0
301 .write()
302 .layout_line(text, font_size, runs)
303 .log_err()
304 .unwrap_or(LineLayout {
305 font_size,
306 ..Default::default()
307 })
308 }
309}
310
311impl DirectWriteState {
312 fn add_fonts(&mut self, fonts: Vec<Cow<'static, [u8]>>) -> Result<()> {
313 for font_data in fonts {
314 match font_data {
315 Cow::Borrowed(data) => unsafe {
316 let font_file = self
317 .components
318 .in_memory_loader
319 .CreateInMemoryFontFileReference(
320 &self.components.factory,
321 data.as_ptr() as _,
322 data.len() as _,
323 None,
324 )?;
325 self.components.builder.AddFontFile(&font_file)?;
326 },
327 Cow::Owned(data) => unsafe {
328 let font_file = self
329 .components
330 .in_memory_loader
331 .CreateInMemoryFontFileReference(
332 &self.components.factory,
333 data.as_ptr() as _,
334 data.len() as _,
335 None,
336 )?;
337 self.components.builder.AddFontFile(&font_file)?;
338 },
339 }
340 }
341 let set = unsafe { self.components.builder.CreateFontSet()? };
342 let collection = unsafe {
343 self.components
344 .factory
345 .CreateFontCollectionFromFontSet(&set)?
346 };
347 self.custom_font_collection = collection;
348
349 Ok(())
350 }
351
352 fn generate_font_fallbacks(
353 &self,
354 fallbacks: &FontFallbacks,
355 ) -> Result<Option<IDWriteFontFallback>> {
356 if fallbacks.fallback_list().is_empty() {
357 return Ok(None);
358 }
359 unsafe {
360 let builder = self.components.factory.CreateFontFallbackBuilder()?;
361 let font_set = &self.system_font_collection.GetFontSet()?;
362 for family_name in fallbacks.fallback_list() {
363 let Some(fonts) = font_set
364 .GetMatchingFonts(
365 &HSTRING::from(family_name),
366 DWRITE_FONT_WEIGHT_NORMAL,
367 DWRITE_FONT_STRETCH_NORMAL,
368 DWRITE_FONT_STYLE_NORMAL,
369 )
370 .log_err()
371 else {
372 continue;
373 };
374 if fonts.GetFontCount() == 0 {
375 log::error!("No matching font found for {}", family_name);
376 continue;
377 }
378 let font = fonts.GetFontFaceReference(0)?.CreateFontFace()?;
379 let mut count = 0;
380 font.GetUnicodeRanges(None, &mut count).ok();
381 if count == 0 {
382 continue;
383 }
384 let mut unicode_ranges = vec![DWRITE_UNICODE_RANGE::default(); count as usize];
385 let Some(_) = font
386 .GetUnicodeRanges(Some(&mut unicode_ranges), &mut count)
387 .log_err()
388 else {
389 continue;
390 };
391 let target_family_name = HSTRING::from(family_name);
392 builder.AddMapping(
393 &unicode_ranges,
394 &[target_family_name.as_ptr()],
395 None,
396 None,
397 None,
398 1.0,
399 )?;
400 }
401 let system_fallbacks = self.components.factory.GetSystemFontFallback()?;
402 builder.AddMappings(&system_fallbacks)?;
403 Ok(Some(builder.CreateFontFallback()?))
404 }
405 }
406
407 unsafe fn generate_font_features(
408 &self,
409 font_features: &FontFeatures,
410 ) -> Result<IDWriteTypography> {
411 let direct_write_features = unsafe { self.components.factory.CreateTypography()? };
412 apply_font_features(&direct_write_features, font_features)?;
413 Ok(direct_write_features)
414 }
415
416 unsafe fn get_font_id_from_font_collection(
417 &mut self,
418 family_name: &str,
419 font_weight: FontWeight,
420 font_style: FontStyle,
421 font_features: &FontFeatures,
422 font_fallbacks: Option<&FontFallbacks>,
423 is_system_font: bool,
424 ) -> Option<FontId> {
425 let collection = if is_system_font {
426 &self.system_font_collection
427 } else {
428 &self.custom_font_collection
429 };
430 let fontset = unsafe { collection.GetFontSet().log_err()? };
431 let font = unsafe {
432 fontset
433 .GetMatchingFonts(
434 &HSTRING::from(family_name),
435 font_weight.into(),
436 DWRITE_FONT_STRETCH_NORMAL,
437 font_style.into(),
438 )
439 .log_err()?
440 };
441 let total_number = unsafe { font.GetFontCount() };
442 for index in 0..total_number {
443 let Some(font_face_ref) = (unsafe { font.GetFontFaceReference(index).log_err() })
444 else {
445 continue;
446 };
447 let Some(font_face) = (unsafe { font_face_ref.CreateFontFace().log_err() }) else {
448 continue;
449 };
450 let Some(identifier) = get_font_identifier(&font_face, &self.components.locale) else {
451 continue;
452 };
453 let Some(direct_write_features) =
454 (unsafe { self.generate_font_features(font_features).log_err() })
455 else {
456 continue;
457 };
458 let fallbacks = font_fallbacks
459 .and_then(|fallbacks| self.generate_font_fallbacks(fallbacks).log_err().flatten());
460 let font_info = FontInfo {
461 font_family: family_name.to_owned(),
462 font_face,
463 features: direct_write_features,
464 fallbacks,
465 is_system_font,
466 };
467 let font_id = FontId(self.fonts.len());
468 self.fonts.push(font_info);
469 self.font_id_by_identifier.insert(identifier, font_id);
470 return Some(font_id);
471 }
472 None
473 }
474
475 unsafe fn update_system_font_collection(&mut self) {
476 let mut collection = unsafe { std::mem::zeroed() };
477 if unsafe {
478 self.components
479 .factory
480 .GetSystemFontCollection(false, &mut collection, true)
481 .log_err()
482 .is_some()
483 } {
484 self.system_font_collection = collection.unwrap();
485 }
486 }
487
488 fn select_font(&mut self, target_font: &Font) -> FontId {
489 unsafe {
490 if target_font.family == ".SystemUIFont" {
491 let family = self.system_ui_font_name.clone();
492 self.find_font_id(
493 family.as_ref(),
494 target_font.weight,
495 target_font.style,
496 &target_font.features,
497 target_font.fallbacks.as_ref(),
498 )
499 .unwrap()
500 } else {
501 self.find_font_id(
502 target_font.family.as_ref(),
503 target_font.weight,
504 target_font.style,
505 &target_font.features,
506 target_font.fallbacks.as_ref(),
507 )
508 .unwrap_or_else(|| {
509 #[cfg(any(test, feature = "test-support"))]
510 {
511 panic!("ERROR: {} font not found!", target_font.family);
512 }
513 #[cfg(not(any(test, feature = "test-support")))]
514 {
515 let family = self.system_ui_font_name.clone();
516 log::error!("{} not found, use {} instead.", target_font.family, family);
517 self.get_font_id_from_font_collection(
518 family.as_ref(),
519 target_font.weight,
520 target_font.style,
521 &target_font.features,
522 target_font.fallbacks.as_ref(),
523 true,
524 )
525 .unwrap()
526 }
527 })
528 }
529 }
530 }
531
532 unsafe fn find_font_id(
533 &mut self,
534 family_name: &str,
535 weight: FontWeight,
536 style: FontStyle,
537 features: &FontFeatures,
538 fallbacks: Option<&FontFallbacks>,
539 ) -> Option<FontId> {
540 // try to find target font in custom font collection first
541 unsafe {
542 self.get_font_id_from_font_collection(
543 family_name,
544 weight,
545 style,
546 features,
547 fallbacks,
548 false,
549 )
550 .or_else(|| {
551 self.get_font_id_from_font_collection(
552 family_name,
553 weight,
554 style,
555 features,
556 fallbacks,
557 true,
558 )
559 })
560 .or_else(|| {
561 self.update_system_font_collection();
562 self.get_font_id_from_font_collection(
563 family_name,
564 weight,
565 style,
566 features,
567 fallbacks,
568 true,
569 )
570 })
571 }
572 }
573
574 fn layout_line(
575 &mut self,
576 text: &str,
577 font_size: Pixels,
578 font_runs: &[FontRun],
579 ) -> Result<LineLayout> {
580 if font_runs.is_empty() {
581 return Ok(LineLayout {
582 font_size,
583 ..Default::default()
584 });
585 }
586 unsafe {
587 let text_renderer = self.components.text_renderer.clone();
588 let text_wide = text.encode_utf16().collect_vec();
589
590 let mut utf8_offset = 0usize;
591 let mut utf16_offset = 0u32;
592 let text_layout = {
593 let first_run = &font_runs[0];
594 let font_info = &self.fonts[first_run.font_id.0];
595 let collection = if font_info.is_system_font {
596 &self.system_font_collection
597 } else {
598 &self.custom_font_collection
599 };
600 let format: IDWriteTextFormat1 = self
601 .components
602 .factory
603 .CreateTextFormat(
604 &HSTRING::from(&font_info.font_family),
605 collection,
606 font_info.font_face.GetWeight(),
607 font_info.font_face.GetStyle(),
608 DWRITE_FONT_STRETCH_NORMAL,
609 font_size.0,
610 &HSTRING::from(&self.components.locale),
611 )?
612 .cast()?;
613 if let Some(ref fallbacks) = font_info.fallbacks {
614 format.SetFontFallback(fallbacks)?;
615 }
616
617 let layout = self.components.factory.CreateTextLayout(
618 &text_wide,
619 &format,
620 f32::INFINITY,
621 f32::INFINITY,
622 )?;
623 let current_text = &text[utf8_offset..(utf8_offset + first_run.len)];
624 utf8_offset += first_run.len;
625 let current_text_utf16_length = current_text.encode_utf16().count() as u32;
626 let text_range = DWRITE_TEXT_RANGE {
627 startPosition: utf16_offset,
628 length: current_text_utf16_length,
629 };
630 layout.SetTypography(&font_info.features, text_range)?;
631 utf16_offset += current_text_utf16_length;
632
633 layout
634 };
635
636 let mut first_run = true;
637 let mut ascent = Pixels::default();
638 let mut descent = Pixels::default();
639 for run in font_runs {
640 if first_run {
641 first_run = false;
642 let mut metrics = vec![DWRITE_LINE_METRICS::default(); 4];
643 let mut line_count = 0u32;
644 text_layout.GetLineMetrics(Some(&mut metrics), &mut line_count as _)?;
645 ascent = px(metrics[0].baseline);
646 descent = px(metrics[0].height - metrics[0].baseline);
647 continue;
648 }
649 let font_info = &self.fonts[run.font_id.0];
650 let current_text = &text[utf8_offset..(utf8_offset + run.len)];
651 utf8_offset += run.len;
652 let current_text_utf16_length = current_text.encode_utf16().count() as u32;
653
654 let collection = if font_info.is_system_font {
655 &self.system_font_collection
656 } else {
657 &self.custom_font_collection
658 };
659 let text_range = DWRITE_TEXT_RANGE {
660 startPosition: utf16_offset,
661 length: current_text_utf16_length,
662 };
663 utf16_offset += current_text_utf16_length;
664 text_layout.SetFontCollection(collection, text_range)?;
665 text_layout
666 .SetFontFamilyName(&HSTRING::from(&font_info.font_family), text_range)?;
667 text_layout.SetFontSize(font_size.0, text_range)?;
668 text_layout.SetFontStyle(font_info.font_face.GetStyle(), text_range)?;
669 text_layout.SetFontWeight(font_info.font_face.GetWeight(), text_range)?;
670 text_layout.SetTypography(&font_info.features, text_range)?;
671 }
672
673 let mut runs = Vec::new();
674 let renderer_context = RendererContext {
675 text_system: self,
676 index_converter: StringIndexConverter::new(text),
677 runs: &mut runs,
678 width: 0.0,
679 };
680 text_layout.Draw(
681 Some(&renderer_context as *const _ as _),
682 &text_renderer.0,
683 0.0,
684 0.0,
685 )?;
686 let width = px(renderer_context.width);
687
688 Ok(LineLayout {
689 font_size,
690 width,
691 ascent,
692 descent,
693 runs,
694 len: text.len(),
695 })
696 }
697 }
698
699 fn font_metrics(&self, font_id: FontId) -> FontMetrics {
700 unsafe {
701 let font_info = &self.fonts[font_id.0];
702 let mut metrics = std::mem::zeroed();
703 font_info.font_face.GetMetrics(&mut metrics);
704
705 FontMetrics {
706 units_per_em: metrics.Base.designUnitsPerEm as _,
707 ascent: metrics.Base.ascent as _,
708 descent: -(metrics.Base.descent as f32),
709 line_gap: metrics.Base.lineGap as _,
710 underline_position: metrics.Base.underlinePosition as _,
711 underline_thickness: metrics.Base.underlineThickness as _,
712 cap_height: metrics.Base.capHeight as _,
713 x_height: metrics.Base.xHeight as _,
714 bounding_box: Bounds {
715 origin: Point {
716 x: metrics.glyphBoxLeft as _,
717 y: metrics.glyphBoxBottom as _,
718 },
719 size: Size {
720 width: (metrics.glyphBoxRight - metrics.glyphBoxLeft) as _,
721 height: (metrics.glyphBoxTop - metrics.glyphBoxBottom) as _,
722 },
723 },
724 }
725 }
726 }
727
728 fn create_glyph_run_analysis(
729 &self,
730 params: &RenderGlyphParams,
731 ) -> Result<IDWriteGlyphRunAnalysis> {
732 let font = &self.fonts[params.font_id.0];
733 let glyph_id = [params.glyph_id.0 as u16];
734 let advance = [0.0];
735 let offset = [DWRITE_GLYPH_OFFSET::default()];
736 let glyph_run = DWRITE_GLYPH_RUN {
737 fontFace: unsafe { std::mem::transmute_copy(&font.font_face) },
738 fontEmSize: params.font_size.0,
739 glyphCount: 1,
740 glyphIndices: glyph_id.as_ptr(),
741 glyphAdvances: advance.as_ptr(),
742 glyphOffsets: offset.as_ptr(),
743 isSideways: BOOL(0),
744 bidiLevel: 0,
745 };
746 let transform = DWRITE_MATRIX {
747 m11: params.scale_factor,
748 m12: 0.0,
749 m21: 0.0,
750 m22: params.scale_factor,
751 dx: 0.0,
752 dy: 0.0,
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 mut rendering_mode = DWRITE_RENDERING_MODE1::default();
761 let mut grid_fit_mode = DWRITE_GRID_FIT_MODE::default();
762 unsafe {
763 font.font_face.GetRecommendedRenderingMode(
764 params.font_size.0,
765 // The dpi here seems that it has the same effect with `Some(&transform)`
766 1.0,
767 1.0,
768 Some(&transform),
769 false,
770 DWRITE_OUTLINE_THRESHOLD_ANTIALIASED,
771 DWRITE_MEASURING_MODE_NATURAL,
772 &self.components.render_params,
773 &mut rendering_mode,
774 &mut grid_fit_mode,
775 )?;
776 }
777
778 let antialias_mode = if params.is_emoji {
779 DWRITE_TEXT_ANTIALIAS_MODE_CLEARTYPE
780 } else {
781 DWRITE_TEXT_ANTIALIAS_MODE_GRAYSCALE
782 };
783
784 let glyph_analysis = unsafe {
785 self.components.factory.CreateGlyphRunAnalysis(
786 &glyph_run,
787 Some(&transform),
788 rendering_mode,
789 DWRITE_MEASURING_MODE_NATURAL,
790 grid_fit_mode,
791 antialias_mode,
792 baseline_origin_x,
793 baseline_origin_y,
794 )
795 }?;
796 Ok(glyph_analysis)
797 }
798
799 fn raster_bounds(&self, params: &RenderGlyphParams) -> Result<Bounds<DevicePixels>> {
800 let glyph_analysis = self.create_glyph_run_analysis(params)?;
801
802 if params.is_emoji {
803 let bounds =
804 unsafe { glyph_analysis.GetAlphaTextureBounds(DWRITE_TEXTURE_CLEARTYPE_3x1)? };
805 // If it's empty, retry with grayscale AA.
806 if !unsafe { IsRectEmpty(&bounds) }.as_bool() {
807 return Ok(Bounds {
808 origin: point((bounds.left as i32).into(), (bounds.top as i32).into()),
809 size: size(
810 (bounds.right - bounds.left).into(),
811 (bounds.bottom - bounds.top).into(),
812 ),
813 });
814 }
815 }
816
817 let bounds = unsafe { glyph_analysis.GetAlphaTextureBounds(DWRITE_TEXTURE_ALIASED_1x1)? };
818
819 if bounds.right < bounds.left {
820 Ok(Bounds {
821 origin: point(0.into(), 0.into()),
822 size: size(0.into(), 0.into()),
823 })
824 } else {
825 Ok(Bounds {
826 origin: point((bounds.left as i32).into(), (bounds.top as i32).into()),
827 size: size(
828 (bounds.right - bounds.left).into(),
829 (bounds.bottom - bounds.top).into(),
830 ),
831 })
832 }
833 }
834
835 fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
836 let font_info = &self.fonts[font_id.0];
837 let codepoints = [ch as u32];
838 let mut glyph_indices = vec![0u16; 1];
839 unsafe {
840 font_info
841 .font_face
842 .GetGlyphIndices(codepoints.as_ptr(), 1, glyph_indices.as_mut_ptr())
843 .log_err()
844 }
845 .map(|_| GlyphId(glyph_indices[0] as u32))
846 }
847
848 fn rasterize_glyph(
849 &self,
850 params: &RenderGlyphParams,
851 glyph_bounds: Bounds<DevicePixels>,
852 ) -> Result<(Size<DevicePixels>, Vec<u8>)> {
853 if glyph_bounds.size.width.0 == 0 || glyph_bounds.size.height.0 == 0 {
854 anyhow::bail!("glyph bounds are empty");
855 }
856
857 let bitmap_size = glyph_bounds.size;
858
859 let glyph_analysis = self.create_glyph_run_analysis(params)?;
860
861 let mut bitmap_data: Vec<u8>;
862 if params.is_emoji {
863 if let Ok(color) = self.rasterize_color(¶ms, glyph_bounds) {
864 bitmap_data = color;
865 } else {
866 let monochrome = Self::rasterize_monochrome(&glyph_analysis, glyph_bounds)?;
867 bitmap_data = monochrome
868 .into_iter()
869 .flat_map(|pixel| [0, 0, 0, pixel])
870 .collect::<Vec<_>>();
871 }
872 } else {
873 bitmap_data = Self::rasterize_monochrome(&glyph_analysis, glyph_bounds)?;
874 }
875
876 Ok((bitmap_size, bitmap_data))
877 }
878
879 fn rasterize_monochrome(
880 glyph_analysis: &IDWriteGlyphRunAnalysis,
881 glyph_bounds: Bounds<DevicePixels>,
882 ) -> Result<Vec<u8>> {
883 let mut bitmap_data =
884 vec![0u8; glyph_bounds.size.width.0 as usize * glyph_bounds.size.height.0 as usize];
885
886 unsafe {
887 glyph_analysis.CreateAlphaTexture(
888 DWRITE_TEXTURE_ALIASED_1x1,
889 &RECT {
890 left: glyph_bounds.origin.x.0,
891 top: glyph_bounds.origin.y.0,
892 right: glyph_bounds.size.width.0 + glyph_bounds.origin.x.0,
893 bottom: glyph_bounds.size.height.0 + glyph_bounds.origin.y.0,
894 },
895 &mut bitmap_data,
896 )?;
897 }
898
899 Ok(bitmap_data)
900 }
901
902 fn rasterize_color(
903 &self,
904 params: &RenderGlyphParams,
905 glyph_bounds: Bounds<DevicePixels>,
906 ) -> Result<Vec<u8>> {
907 let bitmap_size = glyph_bounds.size;
908 let subpixel_shift = params
909 .subpixel_variant
910 .map(|v| v as f32 / SUBPIXEL_VARIANTS as f32);
911 let baseline_origin_x = subpixel_shift.x / params.scale_factor;
912 let baseline_origin_y = subpixel_shift.y / params.scale_factor;
913
914 let transform = DWRITE_MATRIX {
915 m11: params.scale_factor,
916 m12: 0.0,
917 m21: 0.0,
918 m22: params.scale_factor,
919 dx: 0.0,
920 dy: 0.0,
921 };
922
923 let font = &self.fonts[params.font_id.0];
924 let glyph_id = [params.glyph_id.0 as u16];
925 let advance = [glyph_bounds.size.width.0 as f32];
926 let offset = [DWRITE_GLYPH_OFFSET {
927 advanceOffset: -glyph_bounds.origin.x.0 as f32 / params.scale_factor,
928 ascenderOffset: glyph_bounds.origin.y.0 as f32 / params.scale_factor,
929 }];
930 let glyph_run = DWRITE_GLYPH_RUN {
931 fontFace: unsafe { std::mem::transmute_copy(&font.font_face) },
932 fontEmSize: params.font_size.0,
933 glyphCount: 1,
934 glyphIndices: glyph_id.as_ptr(),
935 glyphAdvances: advance.as_ptr(),
936 glyphOffsets: offset.as_ptr(),
937 isSideways: BOOL(0),
938 bidiLevel: 0,
939 };
940
941 // todo: support formats other than COLR
942 let color_enumerator = unsafe {
943 self.components.factory.TranslateColorGlyphRun(
944 Vector2::new(baseline_origin_x, baseline_origin_y),
945 &glyph_run,
946 None,
947 DWRITE_GLYPH_IMAGE_FORMATS_COLR,
948 DWRITE_MEASURING_MODE_NATURAL,
949 Some(&transform),
950 0,
951 )
952 }?;
953
954 let mut glyph_layers = Vec::new();
955 loop {
956 let color_run = unsafe { color_enumerator.GetCurrentRun() }?;
957 let color_run = unsafe { &*color_run };
958 let image_format = color_run.glyphImageFormat & !DWRITE_GLYPH_IMAGE_FORMATS_TRUETYPE;
959 if image_format == DWRITE_GLYPH_IMAGE_FORMATS_COLR {
960 let color_analysis = unsafe {
961 self.components.factory.CreateGlyphRunAnalysis(
962 &color_run.Base.glyphRun as *const _,
963 Some(&transform),
964 DWRITE_RENDERING_MODE1_NATURAL_SYMMETRIC,
965 DWRITE_MEASURING_MODE_NATURAL,
966 DWRITE_GRID_FIT_MODE_DEFAULT,
967 DWRITE_TEXT_ANTIALIAS_MODE_CLEARTYPE,
968 baseline_origin_x,
969 baseline_origin_y,
970 )
971 }?;
972
973 let color_bounds =
974 unsafe { color_analysis.GetAlphaTextureBounds(DWRITE_TEXTURE_CLEARTYPE_3x1) }?;
975
976 let color_size = size(
977 color_bounds.right - color_bounds.left,
978 color_bounds.bottom - color_bounds.top,
979 );
980 if color_size.width > 0 && color_size.height > 0 {
981 let mut alpha_data =
982 vec![0u8; (color_size.width * color_size.height * 3) as usize];
983 unsafe {
984 color_analysis.CreateAlphaTexture(
985 DWRITE_TEXTURE_CLEARTYPE_3x1,
986 &color_bounds,
987 &mut alpha_data,
988 )
989 }?;
990
991 let run_color = {
992 let run_color = color_run.Base.runColor;
993 Rgba {
994 r: run_color.r,
995 g: run_color.g,
996 b: run_color.b,
997 a: run_color.a,
998 }
999 };
1000 let bounds = bounds(point(color_bounds.left, color_bounds.top), color_size);
1001 let alpha_data = alpha_data
1002 .chunks_exact(3)
1003 .flat_map(|chunk| [chunk[0], chunk[1], chunk[2], 255])
1004 .collect::<Vec<_>>();
1005 glyph_layers.push(GlyphLayerTexture::new(
1006 &self.components.gpu_state,
1007 run_color,
1008 bounds,
1009 &alpha_data,
1010 )?);
1011 }
1012 }
1013
1014 let has_next = unsafe { color_enumerator.MoveNext() }
1015 .map(|e| e.as_bool())
1016 .unwrap_or(false);
1017 if !has_next {
1018 break;
1019 }
1020 }
1021
1022 let gpu_state = &self.components.gpu_state;
1023 let params_buffer = {
1024 let desc = D3D11_BUFFER_DESC {
1025 ByteWidth: std::mem::size_of::<GlyphLayerTextureParams>() as u32,
1026 Usage: D3D11_USAGE_DYNAMIC,
1027 BindFlags: D3D11_BIND_CONSTANT_BUFFER.0 as u32,
1028 CPUAccessFlags: D3D11_CPU_ACCESS_WRITE.0 as u32,
1029 MiscFlags: 0,
1030 StructureByteStride: 0,
1031 };
1032
1033 let mut buffer = None;
1034 unsafe {
1035 gpu_state
1036 .device
1037 .CreateBuffer(&desc, None, Some(&mut buffer))
1038 }?;
1039 [buffer]
1040 };
1041
1042 let render_target_texture = {
1043 let mut texture = None;
1044 let desc = D3D11_TEXTURE2D_DESC {
1045 Width: bitmap_size.width.0 as u32,
1046 Height: bitmap_size.height.0 as u32,
1047 MipLevels: 1,
1048 ArraySize: 1,
1049 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
1050 SampleDesc: DXGI_SAMPLE_DESC {
1051 Count: 1,
1052 Quality: 0,
1053 },
1054 Usage: D3D11_USAGE_DEFAULT,
1055 BindFlags: D3D11_BIND_RENDER_TARGET.0 as u32,
1056 CPUAccessFlags: 0,
1057 MiscFlags: 0,
1058 };
1059 unsafe {
1060 gpu_state
1061 .device
1062 .CreateTexture2D(&desc, None, Some(&mut texture))
1063 }?;
1064 texture.unwrap()
1065 };
1066
1067 let render_target_view = {
1068 let desc = D3D11_RENDER_TARGET_VIEW_DESC {
1069 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
1070 ViewDimension: D3D11_RTV_DIMENSION_TEXTURE2D,
1071 Anonymous: D3D11_RENDER_TARGET_VIEW_DESC_0 {
1072 Texture2D: D3D11_TEX2D_RTV { MipSlice: 0 },
1073 },
1074 };
1075 let mut rtv = None;
1076 unsafe {
1077 gpu_state.device.CreateRenderTargetView(
1078 &render_target_texture,
1079 Some(&desc),
1080 Some(&mut rtv),
1081 )
1082 }?;
1083 [rtv]
1084 };
1085
1086 let staging_texture = {
1087 let mut texture = None;
1088 let desc = D3D11_TEXTURE2D_DESC {
1089 Width: bitmap_size.width.0 as u32,
1090 Height: bitmap_size.height.0 as u32,
1091 MipLevels: 1,
1092 ArraySize: 1,
1093 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
1094 SampleDesc: DXGI_SAMPLE_DESC {
1095 Count: 1,
1096 Quality: 0,
1097 },
1098 Usage: D3D11_USAGE_STAGING,
1099 BindFlags: 0,
1100 CPUAccessFlags: D3D11_CPU_ACCESS_READ.0 as u32,
1101 MiscFlags: 0,
1102 };
1103 unsafe {
1104 gpu_state
1105 .device
1106 .CreateTexture2D(&desc, None, Some(&mut texture))
1107 }?;
1108 texture.unwrap()
1109 };
1110
1111 let device_context = &gpu_state.device_context;
1112 unsafe { device_context.IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP) };
1113 unsafe { device_context.VSSetShader(&gpu_state.vertex_shader, None) };
1114 unsafe { device_context.PSSetShader(&gpu_state.pixel_shader, None) };
1115 unsafe { device_context.VSSetConstantBuffers(0, Some(¶ms_buffer)) };
1116 unsafe { device_context.PSSetConstantBuffers(0, Some(¶ms_buffer)) };
1117 unsafe { device_context.OMSetRenderTargets(Some(&render_target_view), None) };
1118 unsafe { device_context.PSSetSamplers(0, Some(&gpu_state.sampler)) };
1119 unsafe { device_context.OMSetBlendState(&gpu_state.blend_state, None, 0xffffffff) };
1120
1121 for layer in glyph_layers {
1122 let params = GlyphLayerTextureParams {
1123 run_color: layer.run_color,
1124 bounds: layer.bounds,
1125 };
1126 unsafe {
1127 let mut dest = std::mem::zeroed();
1128 gpu_state.device_context.Map(
1129 params_buffer[0].as_ref().unwrap(),
1130 0,
1131 D3D11_MAP_WRITE_DISCARD,
1132 0,
1133 Some(&mut dest),
1134 )?;
1135 std::ptr::copy_nonoverlapping(¶ms as *const _, dest.pData as *mut _, 1);
1136 gpu_state
1137 .device_context
1138 .Unmap(params_buffer[0].as_ref().unwrap(), 0);
1139 };
1140
1141 let texture = [Some(layer.texture_view)];
1142 unsafe { device_context.PSSetShaderResources(0, Some(&texture)) };
1143
1144 let viewport = [D3D11_VIEWPORT {
1145 TopLeftX: layer.bounds.origin.x as f32,
1146 TopLeftY: layer.bounds.origin.y as f32,
1147 Width: layer.bounds.size.width as f32,
1148 Height: layer.bounds.size.height as f32,
1149 MinDepth: 0.0,
1150 MaxDepth: 1.0,
1151 }];
1152 unsafe { device_context.RSSetViewports(Some(&viewport)) };
1153
1154 unsafe { device_context.Draw(4, 0) };
1155 }
1156
1157 unsafe { device_context.CopyResource(&staging_texture, &render_target_texture) };
1158
1159 let mapped_data = {
1160 let mut mapped_data = D3D11_MAPPED_SUBRESOURCE::default();
1161 unsafe {
1162 device_context.Map(
1163 &staging_texture,
1164 0,
1165 D3D11_MAP_READ,
1166 0,
1167 Some(&mut mapped_data),
1168 )
1169 }?;
1170 mapped_data
1171 };
1172 let mut rasterized =
1173 vec![0u8; (bitmap_size.width.0 as u32 * bitmap_size.height.0 as u32 * 4) as usize];
1174
1175 for y in 0..bitmap_size.height.0 as usize {
1176 let width = bitmap_size.width.0 as usize;
1177 unsafe {
1178 std::ptr::copy_nonoverlapping::<u8>(
1179 (mapped_data.pData as *const u8).byte_add(mapped_data.RowPitch as usize * y),
1180 rasterized
1181 .as_mut_ptr()
1182 .byte_add(width * y * std::mem::size_of::<u32>()),
1183 width * std::mem::size_of::<u32>(),
1184 )
1185 };
1186 }
1187
1188 Ok(rasterized)
1189 }
1190
1191 fn get_typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>> {
1192 unsafe {
1193 let font = &self.fonts[font_id.0].font_face;
1194 let glyph_indices = [glyph_id.0 as u16];
1195 let mut metrics = [DWRITE_GLYPH_METRICS::default()];
1196 font.GetDesignGlyphMetrics(glyph_indices.as_ptr(), 1, metrics.as_mut_ptr(), false)?;
1197
1198 let metrics = &metrics[0];
1199 let advance_width = metrics.advanceWidth as i32;
1200 let advance_height = metrics.advanceHeight as i32;
1201 let left_side_bearing = metrics.leftSideBearing;
1202 let right_side_bearing = metrics.rightSideBearing;
1203 let top_side_bearing = metrics.topSideBearing;
1204 let bottom_side_bearing = metrics.bottomSideBearing;
1205 let vertical_origin_y = metrics.verticalOriginY;
1206
1207 let y_offset = vertical_origin_y + bottom_side_bearing - advance_height;
1208 let width = advance_width - (left_side_bearing + right_side_bearing);
1209 let height = advance_height - (top_side_bearing + bottom_side_bearing);
1210
1211 Ok(Bounds {
1212 origin: Point {
1213 x: left_side_bearing as f32,
1214 y: y_offset as f32,
1215 },
1216 size: Size {
1217 width: width as f32,
1218 height: height as f32,
1219 },
1220 })
1221 }
1222 }
1223
1224 fn get_advance(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Size<f32>> {
1225 unsafe {
1226 let font = &self.fonts[font_id.0].font_face;
1227 let glyph_indices = [glyph_id.0 as u16];
1228 let mut metrics = [DWRITE_GLYPH_METRICS::default()];
1229 font.GetDesignGlyphMetrics(glyph_indices.as_ptr(), 1, metrics.as_mut_ptr(), false)?;
1230
1231 let metrics = &metrics[0];
1232
1233 Ok(Size {
1234 width: metrics.advanceWidth as f32,
1235 height: 0.0,
1236 })
1237 }
1238 }
1239
1240 fn all_font_names(&self) -> Vec<String> {
1241 let mut result =
1242 get_font_names_from_collection(&self.system_font_collection, &self.components.locale);
1243 result.extend(get_font_names_from_collection(
1244 &self.custom_font_collection,
1245 &self.components.locale,
1246 ));
1247 result
1248 }
1249}
1250
1251impl Drop for DirectWriteState {
1252 fn drop(&mut self) {
1253 unsafe {
1254 let _ = self
1255 .components
1256 .factory
1257 .UnregisterFontFileLoader(&self.components.in_memory_loader);
1258 }
1259 }
1260}
1261
1262struct GlyphLayerTexture {
1263 run_color: Rgba,
1264 bounds: Bounds<i32>,
1265 texture: ID3D11Texture2D,
1266 texture_view: ID3D11ShaderResourceView,
1267}
1268
1269impl GlyphLayerTexture {
1270 pub fn new(
1271 gpu_state: &GPUState,
1272 run_color: Rgba,
1273 bounds: Bounds<i32>,
1274 alpha_data: &[u8],
1275 ) -> Result<Self> {
1276 let texture_size = bounds.size;
1277
1278 let desc = D3D11_TEXTURE2D_DESC {
1279 Width: texture_size.width as u32,
1280 Height: texture_size.height as u32,
1281 MipLevels: 1,
1282 ArraySize: 1,
1283 Format: DXGI_FORMAT_R8G8B8A8_UNORM,
1284 SampleDesc: DXGI_SAMPLE_DESC {
1285 Count: 1,
1286 Quality: 0,
1287 },
1288 Usage: D3D11_USAGE_DEFAULT,
1289 BindFlags: D3D11_BIND_SHADER_RESOURCE.0 as u32,
1290 CPUAccessFlags: D3D11_CPU_ACCESS_WRITE.0 as u32,
1291 MiscFlags: 0,
1292 };
1293
1294 let texture = {
1295 let mut texture: Option<ID3D11Texture2D> = None;
1296 unsafe {
1297 gpu_state
1298 .device
1299 .CreateTexture2D(&desc, None, Some(&mut texture))?
1300 };
1301 texture.unwrap()
1302 };
1303 let texture_view = {
1304 let mut view: Option<ID3D11ShaderResourceView> = None;
1305 unsafe {
1306 gpu_state
1307 .device
1308 .CreateShaderResourceView(&texture, None, Some(&mut view))?
1309 };
1310 view.unwrap()
1311 };
1312
1313 unsafe {
1314 gpu_state.device_context.UpdateSubresource(
1315 &texture,
1316 0,
1317 None,
1318 alpha_data.as_ptr() as _,
1319 (texture_size.width * 4) as u32,
1320 0,
1321 )
1322 };
1323
1324 Ok(GlyphLayerTexture {
1325 run_color,
1326 bounds,
1327 texture,
1328 texture_view,
1329 })
1330 }
1331}
1332
1333#[repr(C)]
1334struct GlyphLayerTextureParams {
1335 bounds: Bounds<i32>,
1336 run_color: Rgba,
1337}
1338
1339struct TextRendererWrapper(pub IDWriteTextRenderer);
1340
1341impl TextRendererWrapper {
1342 pub fn new(locale_str: &str) -> Self {
1343 let inner = TextRenderer::new(locale_str);
1344 TextRendererWrapper(inner.into())
1345 }
1346}
1347
1348#[implement(IDWriteTextRenderer)]
1349struct TextRenderer {
1350 locale: String,
1351}
1352
1353impl TextRenderer {
1354 pub fn new(locale_str: &str) -> Self {
1355 TextRenderer {
1356 locale: locale_str.to_owned(),
1357 }
1358 }
1359}
1360
1361struct RendererContext<'t, 'a, 'b> {
1362 text_system: &'t mut DirectWriteState,
1363 index_converter: StringIndexConverter<'a>,
1364 runs: &'b mut Vec<ShapedRun>,
1365 width: f32,
1366}
1367
1368#[derive(Debug)]
1369struct ClusterAnalyzer<'t> {
1370 utf16_idx: usize,
1371 glyph_idx: usize,
1372 glyph_count: usize,
1373 cluster_map: &'t [u16],
1374}
1375
1376impl<'t> ClusterAnalyzer<'t> {
1377 pub fn new(cluster_map: &'t [u16], glyph_count: usize) -> Self {
1378 ClusterAnalyzer {
1379 utf16_idx: 0,
1380 glyph_idx: 0,
1381 glyph_count,
1382 cluster_map,
1383 }
1384 }
1385}
1386
1387impl Iterator for ClusterAnalyzer<'_> {
1388 type Item = (usize, usize);
1389
1390 fn next(&mut self) -> Option<(usize, usize)> {
1391 if self.utf16_idx >= self.cluster_map.len() {
1392 return None; // No more clusters
1393 }
1394 let start_utf16_idx = self.utf16_idx;
1395 let current_glyph = self.cluster_map[start_utf16_idx] as usize;
1396
1397 // Find the end of current cluster (where glyph index changes)
1398 let mut end_utf16_idx = start_utf16_idx + 1;
1399 while end_utf16_idx < self.cluster_map.len()
1400 && self.cluster_map[end_utf16_idx] as usize == current_glyph
1401 {
1402 end_utf16_idx += 1;
1403 }
1404
1405 let utf16_len = end_utf16_idx - start_utf16_idx;
1406
1407 // Calculate glyph count for this cluster
1408 let next_glyph = if end_utf16_idx < self.cluster_map.len() {
1409 self.cluster_map[end_utf16_idx] as usize
1410 } else {
1411 self.glyph_count
1412 };
1413
1414 let glyph_count = next_glyph - current_glyph;
1415
1416 // Update state for next call
1417 self.utf16_idx = end_utf16_idx;
1418 self.glyph_idx = next_glyph;
1419
1420 Some((utf16_len, glyph_count))
1421 }
1422}
1423
1424#[allow(non_snake_case)]
1425impl IDWritePixelSnapping_Impl for TextRenderer_Impl {
1426 fn IsPixelSnappingDisabled(
1427 &self,
1428 _clientdrawingcontext: *const ::core::ffi::c_void,
1429 ) -> windows::core::Result<BOOL> {
1430 Ok(BOOL(0))
1431 }
1432
1433 fn GetCurrentTransform(
1434 &self,
1435 _clientdrawingcontext: *const ::core::ffi::c_void,
1436 transform: *mut DWRITE_MATRIX,
1437 ) -> windows::core::Result<()> {
1438 unsafe {
1439 *transform = DWRITE_MATRIX {
1440 m11: 1.0,
1441 m12: 0.0,
1442 m21: 0.0,
1443 m22: 1.0,
1444 dx: 0.0,
1445 dy: 0.0,
1446 };
1447 }
1448 Ok(())
1449 }
1450
1451 fn GetPixelsPerDip(
1452 &self,
1453 _clientdrawingcontext: *const ::core::ffi::c_void,
1454 ) -> windows::core::Result<f32> {
1455 Ok(1.0)
1456 }
1457}
1458
1459#[allow(non_snake_case)]
1460impl IDWriteTextRenderer_Impl for TextRenderer_Impl {
1461 fn DrawGlyphRun(
1462 &self,
1463 clientdrawingcontext: *const ::core::ffi::c_void,
1464 _baselineoriginx: f32,
1465 _baselineoriginy: f32,
1466 _measuringmode: DWRITE_MEASURING_MODE,
1467 glyphrun: *const DWRITE_GLYPH_RUN,
1468 glyphrundescription: *const DWRITE_GLYPH_RUN_DESCRIPTION,
1469 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1470 ) -> windows::core::Result<()> {
1471 let glyphrun = unsafe { &*glyphrun };
1472 let glyph_count = glyphrun.glyphCount as usize;
1473 if glyph_count == 0 || glyphrun.fontFace.is_none() {
1474 return Ok(());
1475 }
1476 let desc = unsafe { &*glyphrundescription };
1477 let context = unsafe {
1478 &mut *(clientdrawingcontext as *const RendererContext as *mut RendererContext)
1479 };
1480 let font_face = glyphrun.fontFace.as_ref().unwrap();
1481 // This `cast()` action here should never fail since we are running on Win10+, and
1482 // `IDWriteFontFace3` requires Win10
1483 let font_face = &font_face.cast::<IDWriteFontFace3>().unwrap();
1484 let Some((font_identifier, font_struct, color_font)) =
1485 get_font_identifier_and_font_struct(font_face, &self.locale)
1486 else {
1487 return Ok(());
1488 };
1489
1490 let font_id = if let Some(id) = context
1491 .text_system
1492 .font_id_by_identifier
1493 .get(&font_identifier)
1494 {
1495 *id
1496 } else {
1497 context.text_system.select_font(&font_struct)
1498 };
1499
1500 let glyph_ids = unsafe { std::slice::from_raw_parts(glyphrun.glyphIndices, glyph_count) };
1501 let glyph_advances =
1502 unsafe { std::slice::from_raw_parts(glyphrun.glyphAdvances, glyph_count) };
1503 let glyph_offsets =
1504 unsafe { std::slice::from_raw_parts(glyphrun.glyphOffsets, glyph_count) };
1505 let cluster_map =
1506 unsafe { std::slice::from_raw_parts(desc.clusterMap, desc.stringLength as usize) };
1507
1508 let mut cluster_analyzer = ClusterAnalyzer::new(cluster_map, glyph_count);
1509 let mut utf16_idx = desc.textPosition as usize;
1510 let mut glyph_idx = 0;
1511 let mut glyphs = Vec::with_capacity(glyph_count);
1512 for (cluster_utf16_len, cluster_glyph_count) in cluster_analyzer {
1513 context.index_converter.advance_to_utf16_ix(utf16_idx);
1514 utf16_idx += cluster_utf16_len;
1515 for (cluster_glyph_idx, glyph_id) in glyph_ids
1516 [glyph_idx..(glyph_idx + cluster_glyph_count)]
1517 .iter()
1518 .enumerate()
1519 {
1520 let id = GlyphId(*glyph_id as u32);
1521 let is_emoji = color_font
1522 && is_color_glyph(font_face, id, &context.text_system.components.factory);
1523 let this_glyph_idx = glyph_idx + cluster_glyph_idx;
1524 glyphs.push(ShapedGlyph {
1525 id,
1526 position: point(
1527 px(context.width + glyph_offsets[this_glyph_idx].advanceOffset),
1528 px(0.0),
1529 ),
1530 index: context.index_converter.utf8_ix,
1531 is_emoji,
1532 });
1533 context.width += glyph_advances[this_glyph_idx];
1534 }
1535 glyph_idx += cluster_glyph_count;
1536 }
1537 context.runs.push(ShapedRun { font_id, glyphs });
1538 Ok(())
1539 }
1540
1541 fn DrawUnderline(
1542 &self,
1543 _clientdrawingcontext: *const ::core::ffi::c_void,
1544 _baselineoriginx: f32,
1545 _baselineoriginy: f32,
1546 _underline: *const DWRITE_UNDERLINE,
1547 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1548 ) -> windows::core::Result<()> {
1549 Err(windows::core::Error::new(
1550 E_NOTIMPL,
1551 "DrawUnderline unimplemented",
1552 ))
1553 }
1554
1555 fn DrawStrikethrough(
1556 &self,
1557 _clientdrawingcontext: *const ::core::ffi::c_void,
1558 _baselineoriginx: f32,
1559 _baselineoriginy: f32,
1560 _strikethrough: *const DWRITE_STRIKETHROUGH,
1561 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1562 ) -> windows::core::Result<()> {
1563 Err(windows::core::Error::new(
1564 E_NOTIMPL,
1565 "DrawStrikethrough unimplemented",
1566 ))
1567 }
1568
1569 fn DrawInlineObject(
1570 &self,
1571 _clientdrawingcontext: *const ::core::ffi::c_void,
1572 _originx: f32,
1573 _originy: f32,
1574 _inlineobject: windows::core::Ref<IDWriteInlineObject>,
1575 _issideways: BOOL,
1576 _isrighttoleft: BOOL,
1577 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1578 ) -> windows::core::Result<()> {
1579 Err(windows::core::Error::new(
1580 E_NOTIMPL,
1581 "DrawInlineObject unimplemented",
1582 ))
1583 }
1584}
1585
1586struct StringIndexConverter<'a> {
1587 text: &'a str,
1588 utf8_ix: usize,
1589 utf16_ix: usize,
1590}
1591
1592impl<'a> StringIndexConverter<'a> {
1593 fn new(text: &'a str) -> Self {
1594 Self {
1595 text,
1596 utf8_ix: 0,
1597 utf16_ix: 0,
1598 }
1599 }
1600
1601 #[allow(dead_code)]
1602 fn advance_to_utf8_ix(&mut self, utf8_target: usize) {
1603 for (ix, c) in self.text[self.utf8_ix..].char_indices() {
1604 if self.utf8_ix + ix >= utf8_target {
1605 self.utf8_ix += ix;
1606 return;
1607 }
1608 self.utf16_ix += c.len_utf16();
1609 }
1610 self.utf8_ix = self.text.len();
1611 }
1612
1613 fn advance_to_utf16_ix(&mut self, utf16_target: usize) {
1614 for (ix, c) in self.text[self.utf8_ix..].char_indices() {
1615 if self.utf16_ix >= utf16_target {
1616 self.utf8_ix += ix;
1617 return;
1618 }
1619 self.utf16_ix += c.len_utf16();
1620 }
1621 self.utf8_ix = self.text.len();
1622 }
1623}
1624
1625impl Into<DWRITE_FONT_STYLE> for FontStyle {
1626 fn into(self) -> DWRITE_FONT_STYLE {
1627 match self {
1628 FontStyle::Normal => DWRITE_FONT_STYLE_NORMAL,
1629 FontStyle::Italic => DWRITE_FONT_STYLE_ITALIC,
1630 FontStyle::Oblique => DWRITE_FONT_STYLE_OBLIQUE,
1631 }
1632 }
1633}
1634
1635impl From<DWRITE_FONT_STYLE> for FontStyle {
1636 fn from(value: DWRITE_FONT_STYLE) -> Self {
1637 match value.0 {
1638 0 => FontStyle::Normal,
1639 1 => FontStyle::Italic,
1640 2 => FontStyle::Oblique,
1641 _ => unreachable!(),
1642 }
1643 }
1644}
1645
1646impl Into<DWRITE_FONT_WEIGHT> for FontWeight {
1647 fn into(self) -> DWRITE_FONT_WEIGHT {
1648 DWRITE_FONT_WEIGHT(self.0 as i32)
1649 }
1650}
1651
1652impl From<DWRITE_FONT_WEIGHT> for FontWeight {
1653 fn from(value: DWRITE_FONT_WEIGHT) -> Self {
1654 FontWeight(value.0 as f32)
1655 }
1656}
1657
1658fn get_font_names_from_collection(
1659 collection: &IDWriteFontCollection1,
1660 locale: &str,
1661) -> Vec<String> {
1662 unsafe {
1663 let mut result = Vec::new();
1664 let family_count = collection.GetFontFamilyCount();
1665 for index in 0..family_count {
1666 let Some(font_family) = collection.GetFontFamily(index).log_err() else {
1667 continue;
1668 };
1669 let Some(localized_family_name) = font_family.GetFamilyNames().log_err() else {
1670 continue;
1671 };
1672 let Some(family_name) = get_name(localized_family_name, locale).log_err() else {
1673 continue;
1674 };
1675 result.push(family_name);
1676 }
1677
1678 result
1679 }
1680}
1681
1682fn get_font_identifier_and_font_struct(
1683 font_face: &IDWriteFontFace3,
1684 locale: &str,
1685) -> Option<(FontIdentifier, Font, bool)> {
1686 let postscript_name = get_postscript_name(font_face, locale).log_err()?;
1687 let localized_family_name = unsafe { font_face.GetFamilyNames().log_err() }?;
1688 let family_name = get_name(localized_family_name, locale).log_err()?;
1689 let weight = unsafe { font_face.GetWeight() };
1690 let style = unsafe { font_face.GetStyle() };
1691 let identifier = FontIdentifier {
1692 postscript_name,
1693 weight: weight.0,
1694 style: style.0,
1695 };
1696 let font_struct = Font {
1697 family: family_name.into(),
1698 features: FontFeatures::default(),
1699 weight: weight.into(),
1700 style: style.into(),
1701 fallbacks: None,
1702 };
1703 let is_emoji = unsafe { font_face.IsColorFont().as_bool() };
1704 Some((identifier, font_struct, is_emoji))
1705}
1706
1707#[inline]
1708fn get_font_identifier(font_face: &IDWriteFontFace3, locale: &str) -> Option<FontIdentifier> {
1709 let weight = unsafe { font_face.GetWeight().0 };
1710 let style = unsafe { font_face.GetStyle().0 };
1711 get_postscript_name(font_face, locale)
1712 .log_err()
1713 .map(|postscript_name| FontIdentifier {
1714 postscript_name,
1715 weight,
1716 style,
1717 })
1718}
1719
1720#[inline]
1721fn get_postscript_name(font_face: &IDWriteFontFace3, locale: &str) -> Result<String> {
1722 let mut info = None;
1723 let mut exists = BOOL(0);
1724 unsafe {
1725 font_face.GetInformationalStrings(
1726 DWRITE_INFORMATIONAL_STRING_POSTSCRIPT_NAME,
1727 &mut info,
1728 &mut exists,
1729 )?
1730 };
1731 if !exists.as_bool() || info.is_none() {
1732 anyhow::bail!("No postscript name found for font face");
1733 }
1734
1735 get_name(info.unwrap(), locale)
1736}
1737
1738// https://learn.microsoft.com/en-us/windows/win32/api/dwrite/ne-dwrite-dwrite_font_feature_tag
1739fn apply_font_features(
1740 direct_write_features: &IDWriteTypography,
1741 features: &FontFeatures,
1742) -> Result<()> {
1743 let tag_values = features.tag_value_list();
1744 if tag_values.is_empty() {
1745 return Ok(());
1746 }
1747
1748 // All of these features are enabled by default by DirectWrite.
1749 // If you want to (and can) peek into the source of DirectWrite
1750 let mut feature_liga = make_direct_write_feature("liga", 1);
1751 let mut feature_clig = make_direct_write_feature("clig", 1);
1752 let mut feature_calt = make_direct_write_feature("calt", 1);
1753
1754 for (tag, value) in tag_values {
1755 if tag.as_str() == "liga" && *value == 0 {
1756 feature_liga.parameter = 0;
1757 continue;
1758 }
1759 if tag.as_str() == "clig" && *value == 0 {
1760 feature_clig.parameter = 0;
1761 continue;
1762 }
1763 if tag.as_str() == "calt" && *value == 0 {
1764 feature_calt.parameter = 0;
1765 continue;
1766 }
1767
1768 unsafe {
1769 direct_write_features.AddFontFeature(make_direct_write_feature(&tag, *value))?;
1770 }
1771 }
1772 unsafe {
1773 direct_write_features.AddFontFeature(feature_liga)?;
1774 direct_write_features.AddFontFeature(feature_clig)?;
1775 direct_write_features.AddFontFeature(feature_calt)?;
1776 }
1777
1778 Ok(())
1779}
1780
1781#[inline]
1782const fn make_direct_write_feature(feature_name: &str, parameter: u32) -> DWRITE_FONT_FEATURE {
1783 let tag = make_direct_write_tag(feature_name);
1784 DWRITE_FONT_FEATURE {
1785 nameTag: tag,
1786 parameter,
1787 }
1788}
1789
1790#[inline]
1791const fn make_open_type_tag(tag_name: &str) -> u32 {
1792 let bytes = tag_name.as_bytes();
1793 debug_assert!(bytes.len() == 4);
1794 u32::from_le_bytes([bytes[0], bytes[1], bytes[2], bytes[3]])
1795}
1796
1797#[inline]
1798const fn make_direct_write_tag(tag_name: &str) -> DWRITE_FONT_FEATURE_TAG {
1799 DWRITE_FONT_FEATURE_TAG(make_open_type_tag(tag_name))
1800}
1801
1802#[inline]
1803fn get_name(string: IDWriteLocalizedStrings, locale: &str) -> Result<String> {
1804 let mut locale_name_index = 0u32;
1805 let mut exists = BOOL(0);
1806 unsafe {
1807 string.FindLocaleName(
1808 &HSTRING::from(locale),
1809 &mut locale_name_index,
1810 &mut exists as _,
1811 )?
1812 };
1813 if !exists.as_bool() {
1814 unsafe {
1815 string.FindLocaleName(
1816 DEFAULT_LOCALE_NAME,
1817 &mut locale_name_index as _,
1818 &mut exists as _,
1819 )?
1820 };
1821 anyhow::ensure!(exists.as_bool(), "No localised string for {locale}");
1822 }
1823
1824 let name_length = unsafe { string.GetStringLength(locale_name_index) }? as usize;
1825 let mut name_vec = vec![0u16; name_length + 1];
1826 unsafe {
1827 string.GetString(locale_name_index, &mut name_vec)?;
1828 }
1829
1830 Ok(String::from_utf16_lossy(&name_vec[..name_length]))
1831}
1832
1833fn get_system_ui_font_name() -> SharedString {
1834 unsafe {
1835 let mut info: LOGFONTW = std::mem::zeroed();
1836 let font_family = if SystemParametersInfoW(
1837 SPI_GETICONTITLELOGFONT,
1838 std::mem::size_of::<LOGFONTW>() as u32,
1839 Some(&mut info as *mut _ as _),
1840 SYSTEM_PARAMETERS_INFO_UPDATE_FLAGS(0),
1841 )
1842 .log_err()
1843 .is_none()
1844 {
1845 // https://learn.microsoft.com/en-us/windows/win32/uxguide/vis-fonts
1846 // Segoe UI is the Windows font intended for user interface text strings.
1847 "Segoe UI".into()
1848 } else {
1849 let font_name = String::from_utf16_lossy(&info.lfFaceName);
1850 font_name.trim_matches(char::from(0)).to_owned().into()
1851 };
1852 log::info!("Use {} as UI font.", font_family);
1853 font_family
1854 }
1855}
1856
1857// One would think that with newer DirectWrite method: IDWriteFontFace4::GetGlyphImageFormats
1858// but that doesn't seem to work for some glyphs, say ❤
1859fn is_color_glyph(
1860 font_face: &IDWriteFontFace3,
1861 glyph_id: GlyphId,
1862 factory: &IDWriteFactory5,
1863) -> bool {
1864 let glyph_run = DWRITE_GLYPH_RUN {
1865 fontFace: unsafe { std::mem::transmute_copy(font_face) },
1866 fontEmSize: 14.0,
1867 glyphCount: 1,
1868 glyphIndices: &(glyph_id.0 as u16),
1869 glyphAdvances: &0.0,
1870 glyphOffsets: &DWRITE_GLYPH_OFFSET {
1871 advanceOffset: 0.0,
1872 ascenderOffset: 0.0,
1873 },
1874 isSideways: BOOL(0),
1875 bidiLevel: 0,
1876 };
1877 unsafe {
1878 factory.TranslateColorGlyphRun(
1879 Vector2::default(),
1880 &glyph_run as _,
1881 None,
1882 DWRITE_GLYPH_IMAGE_FORMATS_COLR
1883 | DWRITE_GLYPH_IMAGE_FORMATS_SVG
1884 | DWRITE_GLYPH_IMAGE_FORMATS_PNG
1885 | DWRITE_GLYPH_IMAGE_FORMATS_JPEG
1886 | DWRITE_GLYPH_IMAGE_FORMATS_PREMULTIPLIED_B8G8R8A8,
1887 DWRITE_MEASURING_MODE_NATURAL,
1888 None,
1889 0,
1890 )
1891 }
1892 .is_ok()
1893}
1894
1895const DEFAULT_LOCALE_NAME: PCWSTR = windows::core::w!("en-US");
1896
1897#[cfg(test)]
1898mod tests {
1899 use crate::platform::windows::direct_write::ClusterAnalyzer;
1900
1901 #[test]
1902 fn test_cluster_map() {
1903 let cluster_map = [0];
1904 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 1);
1905 let next = analyzer.next();
1906 assert_eq!(next, Some((1, 1)));
1907 let next = analyzer.next();
1908 assert_eq!(next, None);
1909
1910 let cluster_map = [0, 1, 2];
1911 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 3);
1912 let next = analyzer.next();
1913 assert_eq!(next, Some((1, 1)));
1914 let next = analyzer.next();
1915 assert_eq!(next, Some((1, 1)));
1916 let next = analyzer.next();
1917 assert_eq!(next, Some((1, 1)));
1918 let next = analyzer.next();
1919 assert_eq!(next, None);
1920 // 👨👩👧👦👩💻
1921 let cluster_map = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 4, 4, 4];
1922 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 5);
1923 let next = analyzer.next();
1924 assert_eq!(next, Some((11, 4)));
1925 let next = analyzer.next();
1926 assert_eq!(next, Some((5, 1)));
1927 let next = analyzer.next();
1928 assert_eq!(next, None);
1929 // 👩💻
1930 let cluster_map = [0, 0, 0, 0, 0];
1931 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 1);
1932 let next = analyzer.next();
1933 assert_eq!(next, Some((5, 1)));
1934 let next = analyzer.next();
1935 assert_eq!(next, None);
1936 }
1937}