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 let family = self.system_ui_font_name.clone();
502 self.find_font_id(
503 font_name_with_fallbacks(target_font.family.as_ref(), family.as_ref()),
504 target_font.weight,
505 target_font.style,
506 &target_font.features,
507 target_font.fallbacks.as_ref(),
508 )
509 .unwrap_or_else(|| {
510 #[cfg(any(test, feature = "test-support"))]
511 {
512 panic!("ERROR: {} font not found!", target_font.family);
513 }
514 #[cfg(not(any(test, feature = "test-support")))]
515 {
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 glyph_analysis = unsafe {
779 self.components.factory.CreateGlyphRunAnalysis(
780 &glyph_run,
781 Some(&transform),
782 rendering_mode,
783 DWRITE_MEASURING_MODE_NATURAL,
784 grid_fit_mode,
785 // We're using cleartype not grayscale for monochrome is because it provides better quality
786 DWRITE_TEXT_ANTIALIAS_MODE_CLEARTYPE,
787 baseline_origin_x,
788 baseline_origin_y,
789 )
790 }?;
791 Ok(glyph_analysis)
792 }
793
794 fn raster_bounds(&self, params: &RenderGlyphParams) -> Result<Bounds<DevicePixels>> {
795 let glyph_analysis = self.create_glyph_run_analysis(params)?;
796
797 let bounds = unsafe { glyph_analysis.GetAlphaTextureBounds(DWRITE_TEXTURE_CLEARTYPE_3x1)? };
798 // Some glyphs cannot be drawn with ClearType, such as bitmap fonts. In that case
799 // GetAlphaTextureBounds() supposedly returns an empty RECT, but I haven't tested that yet.
800 if !unsafe { IsRectEmpty(&bounds) }.as_bool() {
801 Ok(Bounds {
802 origin: point(bounds.left.into(), bounds.top.into()),
803 size: size(
804 (bounds.right - bounds.left).into(),
805 (bounds.bottom - bounds.top).into(),
806 ),
807 })
808 } else {
809 // If it's empty, retry with grayscale AA.
810 let bounds =
811 unsafe { glyph_analysis.GetAlphaTextureBounds(DWRITE_TEXTURE_ALIASED_1x1)? };
812
813 if bounds.right < bounds.left {
814 Ok(Bounds {
815 origin: point(0.into(), 0.into()),
816 size: size(0.into(), 0.into()),
817 })
818 } else {
819 Ok(Bounds {
820 origin: point(bounds.left.into(), bounds.top.into()),
821 size: size(
822 (bounds.right - bounds.left).into(),
823 (bounds.bottom - bounds.top).into(),
824 ),
825 })
826 }
827 }
828 }
829
830 fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
831 let font_info = &self.fonts[font_id.0];
832 let codepoints = [ch as u32];
833 let mut glyph_indices = vec![0u16; 1];
834 unsafe {
835 font_info
836 .font_face
837 .GetGlyphIndices(codepoints.as_ptr(), 1, glyph_indices.as_mut_ptr())
838 .log_err()
839 }
840 .map(|_| GlyphId(glyph_indices[0] as u32))
841 }
842
843 fn rasterize_glyph(
844 &self,
845 params: &RenderGlyphParams,
846 glyph_bounds: Bounds<DevicePixels>,
847 ) -> Result<(Size<DevicePixels>, Vec<u8>)> {
848 if glyph_bounds.size.width.0 == 0 || glyph_bounds.size.height.0 == 0 {
849 anyhow::bail!("glyph bounds are empty");
850 }
851
852 let bitmap_data = if params.is_emoji {
853 if let Ok(color) = self.rasterize_color(params, glyph_bounds) {
854 color
855 } else {
856 let monochrome = self.rasterize_monochrome(params, glyph_bounds)?;
857 monochrome
858 .into_iter()
859 .flat_map(|pixel| [0, 0, 0, pixel])
860 .collect::<Vec<_>>()
861 }
862 } else {
863 self.rasterize_monochrome(params, glyph_bounds)?
864 };
865
866 Ok((glyph_bounds.size, bitmap_data))
867 }
868
869 fn rasterize_monochrome(
870 &self,
871 params: &RenderGlyphParams,
872 glyph_bounds: Bounds<DevicePixels>,
873 ) -> Result<Vec<u8>> {
874 let mut bitmap_data =
875 vec![0u8; glyph_bounds.size.width.0 as usize * glyph_bounds.size.height.0 as usize * 3];
876
877 let glyph_analysis = self.create_glyph_run_analysis(params)?;
878 unsafe {
879 glyph_analysis.CreateAlphaTexture(
880 // We're using cleartype not grayscale for monochrome is because it provides better quality
881 DWRITE_TEXTURE_CLEARTYPE_3x1,
882 &RECT {
883 left: glyph_bounds.origin.x.0,
884 top: glyph_bounds.origin.y.0,
885 right: glyph_bounds.size.width.0 + glyph_bounds.origin.x.0,
886 bottom: glyph_bounds.size.height.0 + glyph_bounds.origin.y.0,
887 },
888 &mut bitmap_data,
889 )?;
890 }
891
892 let bitmap_factory = self.components.bitmap_factory.resolve()?;
893 let bitmap = unsafe {
894 bitmap_factory.CreateBitmapFromMemory(
895 glyph_bounds.size.width.0 as u32,
896 glyph_bounds.size.height.0 as u32,
897 &GUID_WICPixelFormat24bppRGB,
898 glyph_bounds.size.width.0 as u32 * 3,
899 &bitmap_data,
900 )
901 }?;
902
903 let grayscale_bitmap =
904 unsafe { WICConvertBitmapSource(&GUID_WICPixelFormat8bppGray, &bitmap) }?;
905
906 let mut bitmap_data =
907 vec![0u8; glyph_bounds.size.width.0 as usize * glyph_bounds.size.height.0 as usize];
908 unsafe {
909 grayscale_bitmap.CopyPixels(
910 std::ptr::null() as _,
911 glyph_bounds.size.width.0 as u32,
912 &mut bitmap_data,
913 )
914 }?;
915
916 Ok(bitmap_data)
917 }
918
919 fn rasterize_color(
920 &self,
921 params: &RenderGlyphParams,
922 glyph_bounds: Bounds<DevicePixels>,
923 ) -> Result<Vec<u8>> {
924 let bitmap_size = glyph_bounds.size;
925 let subpixel_shift = params
926 .subpixel_variant
927 .map(|v| v as f32 / SUBPIXEL_VARIANTS as f32);
928 let baseline_origin_x = subpixel_shift.x / params.scale_factor;
929 let baseline_origin_y = subpixel_shift.y / params.scale_factor;
930
931 let transform = DWRITE_MATRIX {
932 m11: params.scale_factor,
933 m12: 0.0,
934 m21: 0.0,
935 m22: params.scale_factor,
936 dx: 0.0,
937 dy: 0.0,
938 };
939
940 let font = &self.fonts[params.font_id.0];
941 let glyph_id = [params.glyph_id.0 as u16];
942 let advance = [glyph_bounds.size.width.0 as f32];
943 let offset = [DWRITE_GLYPH_OFFSET {
944 advanceOffset: -glyph_bounds.origin.x.0 as f32 / params.scale_factor,
945 ascenderOffset: glyph_bounds.origin.y.0 as f32 / params.scale_factor,
946 }];
947 let glyph_run = DWRITE_GLYPH_RUN {
948 fontFace: unsafe { std::mem::transmute_copy(&font.font_face) },
949 fontEmSize: params.font_size.0,
950 glyphCount: 1,
951 glyphIndices: glyph_id.as_ptr(),
952 glyphAdvances: advance.as_ptr(),
953 glyphOffsets: offset.as_ptr(),
954 isSideways: BOOL(0),
955 bidiLevel: 0,
956 };
957
958 // todo: support formats other than COLR
959 let color_enumerator = unsafe {
960 self.components.factory.TranslateColorGlyphRun(
961 Vector2::new(baseline_origin_x, baseline_origin_y),
962 &glyph_run,
963 None,
964 DWRITE_GLYPH_IMAGE_FORMATS_COLR,
965 DWRITE_MEASURING_MODE_NATURAL,
966 Some(&transform),
967 0,
968 )
969 }?;
970
971 let mut glyph_layers = Vec::new();
972 loop {
973 let color_run = unsafe { color_enumerator.GetCurrentRun() }?;
974 let color_run = unsafe { &*color_run };
975 let image_format = color_run.glyphImageFormat & !DWRITE_GLYPH_IMAGE_FORMATS_TRUETYPE;
976 if image_format == DWRITE_GLYPH_IMAGE_FORMATS_COLR {
977 let color_analysis = unsafe {
978 self.components.factory.CreateGlyphRunAnalysis(
979 &color_run.Base.glyphRun as *const _,
980 Some(&transform),
981 DWRITE_RENDERING_MODE1_NATURAL_SYMMETRIC,
982 DWRITE_MEASURING_MODE_NATURAL,
983 DWRITE_GRID_FIT_MODE_DEFAULT,
984 DWRITE_TEXT_ANTIALIAS_MODE_CLEARTYPE,
985 baseline_origin_x,
986 baseline_origin_y,
987 )
988 }?;
989
990 let color_bounds =
991 unsafe { color_analysis.GetAlphaTextureBounds(DWRITE_TEXTURE_CLEARTYPE_3x1) }?;
992
993 let color_size = size(
994 color_bounds.right - color_bounds.left,
995 color_bounds.bottom - color_bounds.top,
996 );
997 if color_size.width > 0 && color_size.height > 0 {
998 let mut alpha_data =
999 vec![0u8; (color_size.width * color_size.height * 3) as usize];
1000 unsafe {
1001 color_analysis.CreateAlphaTexture(
1002 DWRITE_TEXTURE_CLEARTYPE_3x1,
1003 &color_bounds,
1004 &mut alpha_data,
1005 )
1006 }?;
1007
1008 let run_color = {
1009 let run_color = color_run.Base.runColor;
1010 Rgba {
1011 r: run_color.r,
1012 g: run_color.g,
1013 b: run_color.b,
1014 a: run_color.a,
1015 }
1016 };
1017 let bounds = bounds(point(color_bounds.left, color_bounds.top), color_size);
1018 let alpha_data = alpha_data
1019 .chunks_exact(3)
1020 .flat_map(|chunk| [chunk[0], chunk[1], chunk[2], 255])
1021 .collect::<Vec<_>>();
1022 glyph_layers.push(GlyphLayerTexture::new(
1023 &self.components.gpu_state,
1024 run_color,
1025 bounds,
1026 &alpha_data,
1027 )?);
1028 }
1029 }
1030
1031 let has_next = unsafe { color_enumerator.MoveNext() }
1032 .map(|e| e.as_bool())
1033 .unwrap_or(false);
1034 if !has_next {
1035 break;
1036 }
1037 }
1038
1039 let gpu_state = &self.components.gpu_state;
1040 let params_buffer = {
1041 let desc = D3D11_BUFFER_DESC {
1042 ByteWidth: std::mem::size_of::<GlyphLayerTextureParams>() as u32,
1043 Usage: D3D11_USAGE_DYNAMIC,
1044 BindFlags: D3D11_BIND_CONSTANT_BUFFER.0 as u32,
1045 CPUAccessFlags: D3D11_CPU_ACCESS_WRITE.0 as u32,
1046 MiscFlags: 0,
1047 StructureByteStride: 0,
1048 };
1049
1050 let mut buffer = None;
1051 unsafe {
1052 gpu_state
1053 .device
1054 .CreateBuffer(&desc, None, Some(&mut buffer))
1055 }?;
1056 [buffer]
1057 };
1058
1059 let render_target_texture = {
1060 let mut texture = None;
1061 let desc = D3D11_TEXTURE2D_DESC {
1062 Width: bitmap_size.width.0 as u32,
1063 Height: bitmap_size.height.0 as u32,
1064 MipLevels: 1,
1065 ArraySize: 1,
1066 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
1067 SampleDesc: DXGI_SAMPLE_DESC {
1068 Count: 1,
1069 Quality: 0,
1070 },
1071 Usage: D3D11_USAGE_DEFAULT,
1072 BindFlags: D3D11_BIND_RENDER_TARGET.0 as u32,
1073 CPUAccessFlags: 0,
1074 MiscFlags: 0,
1075 };
1076 unsafe {
1077 gpu_state
1078 .device
1079 .CreateTexture2D(&desc, None, Some(&mut texture))
1080 }?;
1081 texture.unwrap()
1082 };
1083
1084 let render_target_view = {
1085 let desc = D3D11_RENDER_TARGET_VIEW_DESC {
1086 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
1087 ViewDimension: D3D11_RTV_DIMENSION_TEXTURE2D,
1088 Anonymous: D3D11_RENDER_TARGET_VIEW_DESC_0 {
1089 Texture2D: D3D11_TEX2D_RTV { MipSlice: 0 },
1090 },
1091 };
1092 let mut rtv = None;
1093 unsafe {
1094 gpu_state.device.CreateRenderTargetView(
1095 &render_target_texture,
1096 Some(&desc),
1097 Some(&mut rtv),
1098 )
1099 }?;
1100 [rtv]
1101 };
1102
1103 let staging_texture = {
1104 let mut texture = None;
1105 let desc = D3D11_TEXTURE2D_DESC {
1106 Width: bitmap_size.width.0 as u32,
1107 Height: bitmap_size.height.0 as u32,
1108 MipLevels: 1,
1109 ArraySize: 1,
1110 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
1111 SampleDesc: DXGI_SAMPLE_DESC {
1112 Count: 1,
1113 Quality: 0,
1114 },
1115 Usage: D3D11_USAGE_STAGING,
1116 BindFlags: 0,
1117 CPUAccessFlags: D3D11_CPU_ACCESS_READ.0 as u32,
1118 MiscFlags: 0,
1119 };
1120 unsafe {
1121 gpu_state
1122 .device
1123 .CreateTexture2D(&desc, None, Some(&mut texture))
1124 }?;
1125 texture.unwrap()
1126 };
1127
1128 let device_context = &gpu_state.device_context;
1129 unsafe { device_context.IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP) };
1130 unsafe { device_context.VSSetShader(&gpu_state.vertex_shader, None) };
1131 unsafe { device_context.PSSetShader(&gpu_state.pixel_shader, None) };
1132 unsafe { device_context.VSSetConstantBuffers(0, Some(¶ms_buffer)) };
1133 unsafe { device_context.PSSetConstantBuffers(0, Some(¶ms_buffer)) };
1134 unsafe { device_context.OMSetRenderTargets(Some(&render_target_view), None) };
1135 unsafe { device_context.PSSetSamplers(0, Some(&gpu_state.sampler)) };
1136 unsafe { device_context.OMSetBlendState(&gpu_state.blend_state, None, 0xffffffff) };
1137
1138 for layer in glyph_layers {
1139 let params = GlyphLayerTextureParams {
1140 run_color: layer.run_color,
1141 bounds: layer.bounds,
1142 };
1143 unsafe {
1144 let mut dest = std::mem::zeroed();
1145 gpu_state.device_context.Map(
1146 params_buffer[0].as_ref().unwrap(),
1147 0,
1148 D3D11_MAP_WRITE_DISCARD,
1149 0,
1150 Some(&mut dest),
1151 )?;
1152 std::ptr::copy_nonoverlapping(¶ms as *const _, dest.pData as *mut _, 1);
1153 gpu_state
1154 .device_context
1155 .Unmap(params_buffer[0].as_ref().unwrap(), 0);
1156 };
1157
1158 let texture = [Some(layer.texture_view)];
1159 unsafe { device_context.PSSetShaderResources(0, Some(&texture)) };
1160
1161 let viewport = [D3D11_VIEWPORT {
1162 TopLeftX: layer.bounds.origin.x as f32,
1163 TopLeftY: layer.bounds.origin.y as f32,
1164 Width: layer.bounds.size.width as f32,
1165 Height: layer.bounds.size.height as f32,
1166 MinDepth: 0.0,
1167 MaxDepth: 1.0,
1168 }];
1169 unsafe { device_context.RSSetViewports(Some(&viewport)) };
1170
1171 unsafe { device_context.Draw(4, 0) };
1172 }
1173
1174 unsafe { device_context.CopyResource(&staging_texture, &render_target_texture) };
1175
1176 let mapped_data = {
1177 let mut mapped_data = D3D11_MAPPED_SUBRESOURCE::default();
1178 unsafe {
1179 device_context.Map(
1180 &staging_texture,
1181 0,
1182 D3D11_MAP_READ,
1183 0,
1184 Some(&mut mapped_data),
1185 )
1186 }?;
1187 mapped_data
1188 };
1189 let mut rasterized =
1190 vec![0u8; (bitmap_size.width.0 as u32 * bitmap_size.height.0 as u32 * 4) as usize];
1191
1192 for y in 0..bitmap_size.height.0 as usize {
1193 let width = bitmap_size.width.0 as usize;
1194 unsafe {
1195 std::ptr::copy_nonoverlapping::<u8>(
1196 (mapped_data.pData as *const u8).byte_add(mapped_data.RowPitch as usize * y),
1197 rasterized
1198 .as_mut_ptr()
1199 .byte_add(width * y * std::mem::size_of::<u32>()),
1200 width * std::mem::size_of::<u32>(),
1201 )
1202 };
1203 }
1204
1205 Ok(rasterized)
1206 }
1207
1208 fn get_typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>> {
1209 unsafe {
1210 let font = &self.fonts[font_id.0].font_face;
1211 let glyph_indices = [glyph_id.0 as u16];
1212 let mut metrics = [DWRITE_GLYPH_METRICS::default()];
1213 font.GetDesignGlyphMetrics(glyph_indices.as_ptr(), 1, metrics.as_mut_ptr(), false)?;
1214
1215 let metrics = &metrics[0];
1216 let advance_width = metrics.advanceWidth as i32;
1217 let advance_height = metrics.advanceHeight as i32;
1218 let left_side_bearing = metrics.leftSideBearing;
1219 let right_side_bearing = metrics.rightSideBearing;
1220 let top_side_bearing = metrics.topSideBearing;
1221 let bottom_side_bearing = metrics.bottomSideBearing;
1222 let vertical_origin_y = metrics.verticalOriginY;
1223
1224 let y_offset = vertical_origin_y + bottom_side_bearing - advance_height;
1225 let width = advance_width - (left_side_bearing + right_side_bearing);
1226 let height = advance_height - (top_side_bearing + bottom_side_bearing);
1227
1228 Ok(Bounds {
1229 origin: Point {
1230 x: left_side_bearing as f32,
1231 y: y_offset as f32,
1232 },
1233 size: Size {
1234 width: width as f32,
1235 height: height as f32,
1236 },
1237 })
1238 }
1239 }
1240
1241 fn get_advance(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Size<f32>> {
1242 unsafe {
1243 let font = &self.fonts[font_id.0].font_face;
1244 let glyph_indices = [glyph_id.0 as u16];
1245 let mut metrics = [DWRITE_GLYPH_METRICS::default()];
1246 font.GetDesignGlyphMetrics(glyph_indices.as_ptr(), 1, metrics.as_mut_ptr(), false)?;
1247
1248 let metrics = &metrics[0];
1249
1250 Ok(Size {
1251 width: metrics.advanceWidth as f32,
1252 height: 0.0,
1253 })
1254 }
1255 }
1256
1257 fn all_font_names(&self) -> Vec<String> {
1258 let mut result =
1259 get_font_names_from_collection(&self.system_font_collection, &self.components.locale);
1260 result.extend(get_font_names_from_collection(
1261 &self.custom_font_collection,
1262 &self.components.locale,
1263 ));
1264 result
1265 }
1266}
1267
1268impl Drop for DirectWriteState {
1269 fn drop(&mut self) {
1270 unsafe {
1271 let _ = self
1272 .components
1273 .factory
1274 .UnregisterFontFileLoader(&self.components.in_memory_loader);
1275 }
1276 }
1277}
1278
1279struct GlyphLayerTexture {
1280 run_color: Rgba,
1281 bounds: Bounds<i32>,
1282 texture_view: ID3D11ShaderResourceView,
1283 // holding on to the texture to not RAII drop it
1284 _texture: ID3D11Texture2D,
1285}
1286
1287impl GlyphLayerTexture {
1288 pub fn new(
1289 gpu_state: &GPUState,
1290 run_color: Rgba,
1291 bounds: Bounds<i32>,
1292 alpha_data: &[u8],
1293 ) -> Result<Self> {
1294 let texture_size = bounds.size;
1295
1296 let desc = D3D11_TEXTURE2D_DESC {
1297 Width: texture_size.width as u32,
1298 Height: texture_size.height as u32,
1299 MipLevels: 1,
1300 ArraySize: 1,
1301 Format: DXGI_FORMAT_R8G8B8A8_UNORM,
1302 SampleDesc: DXGI_SAMPLE_DESC {
1303 Count: 1,
1304 Quality: 0,
1305 },
1306 Usage: D3D11_USAGE_DEFAULT,
1307 BindFlags: D3D11_BIND_SHADER_RESOURCE.0 as u32,
1308 CPUAccessFlags: D3D11_CPU_ACCESS_WRITE.0 as u32,
1309 MiscFlags: 0,
1310 };
1311
1312 let texture = {
1313 let mut texture: Option<ID3D11Texture2D> = None;
1314 unsafe {
1315 gpu_state
1316 .device
1317 .CreateTexture2D(&desc, None, Some(&mut texture))?
1318 };
1319 texture.unwrap()
1320 };
1321 let texture_view = {
1322 let mut view: Option<ID3D11ShaderResourceView> = None;
1323 unsafe {
1324 gpu_state
1325 .device
1326 .CreateShaderResourceView(&texture, None, Some(&mut view))?
1327 };
1328 view.unwrap()
1329 };
1330
1331 unsafe {
1332 gpu_state.device_context.UpdateSubresource(
1333 &texture,
1334 0,
1335 None,
1336 alpha_data.as_ptr() as _,
1337 (texture_size.width * 4) as u32,
1338 0,
1339 )
1340 };
1341
1342 Ok(GlyphLayerTexture {
1343 run_color,
1344 bounds,
1345 texture_view,
1346 _texture: texture,
1347 })
1348 }
1349}
1350
1351#[repr(C)]
1352struct GlyphLayerTextureParams {
1353 bounds: Bounds<i32>,
1354 run_color: Rgba,
1355}
1356
1357struct TextRendererWrapper(pub IDWriteTextRenderer);
1358
1359impl TextRendererWrapper {
1360 pub fn new(locale_str: &str) -> Self {
1361 let inner = TextRenderer::new(locale_str);
1362 TextRendererWrapper(inner.into())
1363 }
1364}
1365
1366#[implement(IDWriteTextRenderer)]
1367struct TextRenderer {
1368 locale: String,
1369}
1370
1371impl TextRenderer {
1372 pub fn new(locale_str: &str) -> Self {
1373 TextRenderer {
1374 locale: locale_str.to_owned(),
1375 }
1376 }
1377}
1378
1379struct RendererContext<'t, 'a, 'b> {
1380 text_system: &'t mut DirectWriteState,
1381 index_converter: StringIndexConverter<'a>,
1382 runs: &'b mut Vec<ShapedRun>,
1383 width: f32,
1384}
1385
1386#[derive(Debug)]
1387struct ClusterAnalyzer<'t> {
1388 utf16_idx: usize,
1389 glyph_idx: usize,
1390 glyph_count: usize,
1391 cluster_map: &'t [u16],
1392}
1393
1394impl<'t> ClusterAnalyzer<'t> {
1395 pub fn new(cluster_map: &'t [u16], glyph_count: usize) -> Self {
1396 ClusterAnalyzer {
1397 utf16_idx: 0,
1398 glyph_idx: 0,
1399 glyph_count,
1400 cluster_map,
1401 }
1402 }
1403}
1404
1405impl Iterator for ClusterAnalyzer<'_> {
1406 type Item = (usize, usize);
1407
1408 fn next(&mut self) -> Option<(usize, usize)> {
1409 if self.utf16_idx >= self.cluster_map.len() {
1410 return None; // No more clusters
1411 }
1412 let start_utf16_idx = self.utf16_idx;
1413 let current_glyph = self.cluster_map[start_utf16_idx] as usize;
1414
1415 // Find the end of current cluster (where glyph index changes)
1416 let mut end_utf16_idx = start_utf16_idx + 1;
1417 while end_utf16_idx < self.cluster_map.len()
1418 && self.cluster_map[end_utf16_idx] as usize == current_glyph
1419 {
1420 end_utf16_idx += 1;
1421 }
1422
1423 let utf16_len = end_utf16_idx - start_utf16_idx;
1424
1425 // Calculate glyph count for this cluster
1426 let next_glyph = if end_utf16_idx < self.cluster_map.len() {
1427 self.cluster_map[end_utf16_idx] as usize
1428 } else {
1429 self.glyph_count
1430 };
1431
1432 let glyph_count = next_glyph - current_glyph;
1433
1434 // Update state for next call
1435 self.utf16_idx = end_utf16_idx;
1436 self.glyph_idx = next_glyph;
1437
1438 Some((utf16_len, glyph_count))
1439 }
1440}
1441
1442#[allow(non_snake_case)]
1443impl IDWritePixelSnapping_Impl for TextRenderer_Impl {
1444 fn IsPixelSnappingDisabled(
1445 &self,
1446 _clientdrawingcontext: *const ::core::ffi::c_void,
1447 ) -> windows::core::Result<BOOL> {
1448 Ok(BOOL(0))
1449 }
1450
1451 fn GetCurrentTransform(
1452 &self,
1453 _clientdrawingcontext: *const ::core::ffi::c_void,
1454 transform: *mut DWRITE_MATRIX,
1455 ) -> windows::core::Result<()> {
1456 unsafe {
1457 *transform = DWRITE_MATRIX {
1458 m11: 1.0,
1459 m12: 0.0,
1460 m21: 0.0,
1461 m22: 1.0,
1462 dx: 0.0,
1463 dy: 0.0,
1464 };
1465 }
1466 Ok(())
1467 }
1468
1469 fn GetPixelsPerDip(
1470 &self,
1471 _clientdrawingcontext: *const ::core::ffi::c_void,
1472 ) -> windows::core::Result<f32> {
1473 Ok(1.0)
1474 }
1475}
1476
1477#[allow(non_snake_case)]
1478impl IDWriteTextRenderer_Impl for TextRenderer_Impl {
1479 fn DrawGlyphRun(
1480 &self,
1481 clientdrawingcontext: *const ::core::ffi::c_void,
1482 _baselineoriginx: f32,
1483 _baselineoriginy: f32,
1484 _measuringmode: DWRITE_MEASURING_MODE,
1485 glyphrun: *const DWRITE_GLYPH_RUN,
1486 glyphrundescription: *const DWRITE_GLYPH_RUN_DESCRIPTION,
1487 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1488 ) -> windows::core::Result<()> {
1489 let glyphrun = unsafe { &*glyphrun };
1490 let glyph_count = glyphrun.glyphCount as usize;
1491 if glyph_count == 0 || glyphrun.fontFace.is_none() {
1492 return Ok(());
1493 }
1494 let desc = unsafe { &*glyphrundescription };
1495 let context = unsafe {
1496 &mut *(clientdrawingcontext as *const RendererContext as *mut RendererContext)
1497 };
1498 let font_face = glyphrun.fontFace.as_ref().unwrap();
1499 // This `cast()` action here should never fail since we are running on Win10+, and
1500 // `IDWriteFontFace3` requires Win10
1501 let font_face = &font_face.cast::<IDWriteFontFace3>().unwrap();
1502 let Some((font_identifier, font_struct, color_font)) =
1503 get_font_identifier_and_font_struct(font_face, &self.locale)
1504 else {
1505 return Ok(());
1506 };
1507
1508 let font_id = if let Some(id) = context
1509 .text_system
1510 .font_id_by_identifier
1511 .get(&font_identifier)
1512 {
1513 *id
1514 } else {
1515 context.text_system.select_font(&font_struct)
1516 };
1517
1518 let glyph_ids = unsafe { std::slice::from_raw_parts(glyphrun.glyphIndices, glyph_count) };
1519 let glyph_advances =
1520 unsafe { std::slice::from_raw_parts(glyphrun.glyphAdvances, glyph_count) };
1521 let glyph_offsets =
1522 unsafe { std::slice::from_raw_parts(glyphrun.glyphOffsets, glyph_count) };
1523 let cluster_map =
1524 unsafe { std::slice::from_raw_parts(desc.clusterMap, desc.stringLength as usize) };
1525
1526 let mut cluster_analyzer = ClusterAnalyzer::new(cluster_map, glyph_count);
1527 let mut utf16_idx = desc.textPosition as usize;
1528 let mut glyph_idx = 0;
1529 let mut glyphs = Vec::with_capacity(glyph_count);
1530 for (cluster_utf16_len, cluster_glyph_count) in cluster_analyzer {
1531 context.index_converter.advance_to_utf16_ix(utf16_idx);
1532 utf16_idx += cluster_utf16_len;
1533 for (cluster_glyph_idx, glyph_id) in glyph_ids
1534 [glyph_idx..(glyph_idx + cluster_glyph_count)]
1535 .iter()
1536 .enumerate()
1537 {
1538 let id = GlyphId(*glyph_id as u32);
1539 let is_emoji = color_font
1540 && is_color_glyph(font_face, id, &context.text_system.components.factory);
1541 let this_glyph_idx = glyph_idx + cluster_glyph_idx;
1542 glyphs.push(ShapedGlyph {
1543 id,
1544 position: point(
1545 px(context.width + glyph_offsets[this_glyph_idx].advanceOffset),
1546 px(0.0),
1547 ),
1548 index: context.index_converter.utf8_ix,
1549 is_emoji,
1550 });
1551 context.width += glyph_advances[this_glyph_idx];
1552 }
1553 glyph_idx += cluster_glyph_count;
1554 }
1555 context.runs.push(ShapedRun { font_id, glyphs });
1556 Ok(())
1557 }
1558
1559 fn DrawUnderline(
1560 &self,
1561 _clientdrawingcontext: *const ::core::ffi::c_void,
1562 _baselineoriginx: f32,
1563 _baselineoriginy: f32,
1564 _underline: *const DWRITE_UNDERLINE,
1565 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1566 ) -> windows::core::Result<()> {
1567 Err(windows::core::Error::new(
1568 E_NOTIMPL,
1569 "DrawUnderline unimplemented",
1570 ))
1571 }
1572
1573 fn DrawStrikethrough(
1574 &self,
1575 _clientdrawingcontext: *const ::core::ffi::c_void,
1576 _baselineoriginx: f32,
1577 _baselineoriginy: f32,
1578 _strikethrough: *const DWRITE_STRIKETHROUGH,
1579 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1580 ) -> windows::core::Result<()> {
1581 Err(windows::core::Error::new(
1582 E_NOTIMPL,
1583 "DrawStrikethrough unimplemented",
1584 ))
1585 }
1586
1587 fn DrawInlineObject(
1588 &self,
1589 _clientdrawingcontext: *const ::core::ffi::c_void,
1590 _originx: f32,
1591 _originy: f32,
1592 _inlineobject: windows::core::Ref<IDWriteInlineObject>,
1593 _issideways: BOOL,
1594 _isrighttoleft: BOOL,
1595 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1596 ) -> windows::core::Result<()> {
1597 Err(windows::core::Error::new(
1598 E_NOTIMPL,
1599 "DrawInlineObject unimplemented",
1600 ))
1601 }
1602}
1603
1604struct StringIndexConverter<'a> {
1605 text: &'a str,
1606 utf8_ix: usize,
1607 utf16_ix: usize,
1608}
1609
1610impl<'a> StringIndexConverter<'a> {
1611 fn new(text: &'a str) -> Self {
1612 Self {
1613 text,
1614 utf8_ix: 0,
1615 utf16_ix: 0,
1616 }
1617 }
1618
1619 #[allow(dead_code)]
1620 fn advance_to_utf8_ix(&mut self, utf8_target: usize) {
1621 for (ix, c) in self.text[self.utf8_ix..].char_indices() {
1622 if self.utf8_ix + ix >= utf8_target {
1623 self.utf8_ix += ix;
1624 return;
1625 }
1626 self.utf16_ix += c.len_utf16();
1627 }
1628 self.utf8_ix = self.text.len();
1629 }
1630
1631 fn advance_to_utf16_ix(&mut self, utf16_target: usize) {
1632 for (ix, c) in self.text[self.utf8_ix..].char_indices() {
1633 if self.utf16_ix >= utf16_target {
1634 self.utf8_ix += ix;
1635 return;
1636 }
1637 self.utf16_ix += c.len_utf16();
1638 }
1639 self.utf8_ix = self.text.len();
1640 }
1641}
1642
1643impl Into<DWRITE_FONT_STYLE> for FontStyle {
1644 fn into(self) -> DWRITE_FONT_STYLE {
1645 match self {
1646 FontStyle::Normal => DWRITE_FONT_STYLE_NORMAL,
1647 FontStyle::Italic => DWRITE_FONT_STYLE_ITALIC,
1648 FontStyle::Oblique => DWRITE_FONT_STYLE_OBLIQUE,
1649 }
1650 }
1651}
1652
1653impl From<DWRITE_FONT_STYLE> for FontStyle {
1654 fn from(value: DWRITE_FONT_STYLE) -> Self {
1655 match value.0 {
1656 0 => FontStyle::Normal,
1657 1 => FontStyle::Italic,
1658 2 => FontStyle::Oblique,
1659 _ => unreachable!(),
1660 }
1661 }
1662}
1663
1664impl Into<DWRITE_FONT_WEIGHT> for FontWeight {
1665 fn into(self) -> DWRITE_FONT_WEIGHT {
1666 DWRITE_FONT_WEIGHT(self.0 as i32)
1667 }
1668}
1669
1670impl From<DWRITE_FONT_WEIGHT> for FontWeight {
1671 fn from(value: DWRITE_FONT_WEIGHT) -> Self {
1672 FontWeight(value.0 as f32)
1673 }
1674}
1675
1676fn get_font_names_from_collection(
1677 collection: &IDWriteFontCollection1,
1678 locale: &str,
1679) -> Vec<String> {
1680 unsafe {
1681 let mut result = Vec::new();
1682 let family_count = collection.GetFontFamilyCount();
1683 for index in 0..family_count {
1684 let Some(font_family) = collection.GetFontFamily(index).log_err() else {
1685 continue;
1686 };
1687 let Some(localized_family_name) = font_family.GetFamilyNames().log_err() else {
1688 continue;
1689 };
1690 let Some(family_name) = get_name(localized_family_name, locale).log_err() else {
1691 continue;
1692 };
1693 result.push(family_name);
1694 }
1695
1696 result
1697 }
1698}
1699
1700fn get_font_identifier_and_font_struct(
1701 font_face: &IDWriteFontFace3,
1702 locale: &str,
1703) -> Option<(FontIdentifier, Font, bool)> {
1704 let postscript_name = get_postscript_name(font_face, locale).log_err()?;
1705 let localized_family_name = unsafe { font_face.GetFamilyNames().log_err() }?;
1706 let family_name = get_name(localized_family_name, locale).log_err()?;
1707 let weight = unsafe { font_face.GetWeight() };
1708 let style = unsafe { font_face.GetStyle() };
1709 let identifier = FontIdentifier {
1710 postscript_name,
1711 weight: weight.0,
1712 style: style.0,
1713 };
1714 let font_struct = Font {
1715 family: family_name.into(),
1716 features: FontFeatures::default(),
1717 weight: weight.into(),
1718 style: style.into(),
1719 fallbacks: None,
1720 };
1721 let is_emoji = unsafe { font_face.IsColorFont().as_bool() };
1722 Some((identifier, font_struct, is_emoji))
1723}
1724
1725#[inline]
1726fn get_font_identifier(font_face: &IDWriteFontFace3, locale: &str) -> Option<FontIdentifier> {
1727 let weight = unsafe { font_face.GetWeight().0 };
1728 let style = unsafe { font_face.GetStyle().0 };
1729 get_postscript_name(font_face, locale)
1730 .log_err()
1731 .map(|postscript_name| FontIdentifier {
1732 postscript_name,
1733 weight,
1734 style,
1735 })
1736}
1737
1738#[inline]
1739fn get_postscript_name(font_face: &IDWriteFontFace3, locale: &str) -> Result<String> {
1740 let mut info = None;
1741 let mut exists = BOOL(0);
1742 unsafe {
1743 font_face.GetInformationalStrings(
1744 DWRITE_INFORMATIONAL_STRING_POSTSCRIPT_NAME,
1745 &mut info,
1746 &mut exists,
1747 )?
1748 };
1749 if !exists.as_bool() || info.is_none() {
1750 anyhow::bail!("No postscript name found for font face");
1751 }
1752
1753 get_name(info.unwrap(), locale)
1754}
1755
1756// https://learn.microsoft.com/en-us/windows/win32/api/dwrite/ne-dwrite-dwrite_font_feature_tag
1757fn apply_font_features(
1758 direct_write_features: &IDWriteTypography,
1759 features: &FontFeatures,
1760) -> Result<()> {
1761 let tag_values = features.tag_value_list();
1762 if tag_values.is_empty() {
1763 return Ok(());
1764 }
1765
1766 // All of these features are enabled by default by DirectWrite.
1767 // If you want to (and can) peek into the source of DirectWrite
1768 let mut feature_liga = make_direct_write_feature("liga", 1);
1769 let mut feature_clig = make_direct_write_feature("clig", 1);
1770 let mut feature_calt = make_direct_write_feature("calt", 1);
1771
1772 for (tag, value) in tag_values {
1773 if tag.as_str() == "liga" && *value == 0 {
1774 feature_liga.parameter = 0;
1775 continue;
1776 }
1777 if tag.as_str() == "clig" && *value == 0 {
1778 feature_clig.parameter = 0;
1779 continue;
1780 }
1781 if tag.as_str() == "calt" && *value == 0 {
1782 feature_calt.parameter = 0;
1783 continue;
1784 }
1785
1786 unsafe {
1787 direct_write_features.AddFontFeature(make_direct_write_feature(tag, *value))?;
1788 }
1789 }
1790 unsafe {
1791 direct_write_features.AddFontFeature(feature_liga)?;
1792 direct_write_features.AddFontFeature(feature_clig)?;
1793 direct_write_features.AddFontFeature(feature_calt)?;
1794 }
1795
1796 Ok(())
1797}
1798
1799#[inline]
1800const fn make_direct_write_feature(feature_name: &str, parameter: u32) -> DWRITE_FONT_FEATURE {
1801 let tag = make_direct_write_tag(feature_name);
1802 DWRITE_FONT_FEATURE {
1803 nameTag: tag,
1804 parameter,
1805 }
1806}
1807
1808#[inline]
1809const fn make_open_type_tag(tag_name: &str) -> u32 {
1810 let bytes = tag_name.as_bytes();
1811 debug_assert!(bytes.len() == 4);
1812 u32::from_le_bytes([bytes[0], bytes[1], bytes[2], bytes[3]])
1813}
1814
1815#[inline]
1816const fn make_direct_write_tag(tag_name: &str) -> DWRITE_FONT_FEATURE_TAG {
1817 DWRITE_FONT_FEATURE_TAG(make_open_type_tag(tag_name))
1818}
1819
1820#[inline]
1821fn get_name(string: IDWriteLocalizedStrings, locale: &str) -> Result<String> {
1822 let mut locale_name_index = 0u32;
1823 let mut exists = BOOL(0);
1824 unsafe {
1825 string.FindLocaleName(
1826 &HSTRING::from(locale),
1827 &mut locale_name_index,
1828 &mut exists as _,
1829 )?
1830 };
1831 if !exists.as_bool() {
1832 unsafe {
1833 string.FindLocaleName(
1834 DEFAULT_LOCALE_NAME,
1835 &mut locale_name_index as _,
1836 &mut exists as _,
1837 )?
1838 };
1839 anyhow::ensure!(exists.as_bool(), "No localised string for {locale}");
1840 }
1841
1842 let name_length = unsafe { string.GetStringLength(locale_name_index) }? as usize;
1843 let mut name_vec = vec![0u16; name_length + 1];
1844 unsafe {
1845 string.GetString(locale_name_index, &mut name_vec)?;
1846 }
1847
1848 Ok(String::from_utf16_lossy(&name_vec[..name_length]))
1849}
1850
1851fn get_system_ui_font_name() -> SharedString {
1852 unsafe {
1853 let mut info: LOGFONTW = std::mem::zeroed();
1854 let font_family = if SystemParametersInfoW(
1855 SPI_GETICONTITLELOGFONT,
1856 std::mem::size_of::<LOGFONTW>() as u32,
1857 Some(&mut info as *mut _ as _),
1858 SYSTEM_PARAMETERS_INFO_UPDATE_FLAGS(0),
1859 )
1860 .log_err()
1861 .is_none()
1862 {
1863 // https://learn.microsoft.com/en-us/windows/win32/uxguide/vis-fonts
1864 // Segoe UI is the Windows font intended for user interface text strings.
1865 "Segoe UI".into()
1866 } else {
1867 let font_name = String::from_utf16_lossy(&info.lfFaceName);
1868 font_name.trim_matches(char::from(0)).to_owned().into()
1869 };
1870 log::info!("Use {} as UI font.", font_family);
1871 font_family
1872 }
1873}
1874
1875// One would think that with newer DirectWrite method: IDWriteFontFace4::GetGlyphImageFormats
1876// but that doesn't seem to work for some glyphs, say ❤
1877fn is_color_glyph(
1878 font_face: &IDWriteFontFace3,
1879 glyph_id: GlyphId,
1880 factory: &IDWriteFactory5,
1881) -> bool {
1882 let glyph_run = DWRITE_GLYPH_RUN {
1883 fontFace: unsafe { std::mem::transmute_copy(font_face) },
1884 fontEmSize: 14.0,
1885 glyphCount: 1,
1886 glyphIndices: &(glyph_id.0 as u16),
1887 glyphAdvances: &0.0,
1888 glyphOffsets: &DWRITE_GLYPH_OFFSET {
1889 advanceOffset: 0.0,
1890 ascenderOffset: 0.0,
1891 },
1892 isSideways: BOOL(0),
1893 bidiLevel: 0,
1894 };
1895 unsafe {
1896 factory.TranslateColorGlyphRun(
1897 Vector2::default(),
1898 &glyph_run as _,
1899 None,
1900 DWRITE_GLYPH_IMAGE_FORMATS_COLR
1901 | DWRITE_GLYPH_IMAGE_FORMATS_SVG
1902 | DWRITE_GLYPH_IMAGE_FORMATS_PNG
1903 | DWRITE_GLYPH_IMAGE_FORMATS_JPEG
1904 | DWRITE_GLYPH_IMAGE_FORMATS_PREMULTIPLIED_B8G8R8A8,
1905 DWRITE_MEASURING_MODE_NATURAL,
1906 None,
1907 0,
1908 )
1909 }
1910 .is_ok()
1911}
1912
1913const DEFAULT_LOCALE_NAME: PCWSTR = windows::core::w!("en-US");
1914
1915#[cfg(test)]
1916mod tests {
1917 use crate::platform::windows::direct_write::ClusterAnalyzer;
1918
1919 #[test]
1920 fn test_cluster_map() {
1921 let cluster_map = [0];
1922 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 1);
1923 let next = analyzer.next();
1924 assert_eq!(next, Some((1, 1)));
1925 let next = analyzer.next();
1926 assert_eq!(next, None);
1927
1928 let cluster_map = [0, 1, 2];
1929 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 3);
1930 let next = analyzer.next();
1931 assert_eq!(next, Some((1, 1)));
1932 let next = analyzer.next();
1933 assert_eq!(next, Some((1, 1)));
1934 let next = analyzer.next();
1935 assert_eq!(next, Some((1, 1)));
1936 let next = analyzer.next();
1937 assert_eq!(next, None);
1938 // 👨👩👧👦👩💻
1939 let cluster_map = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 4, 4, 4];
1940 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 5);
1941 let next = analyzer.next();
1942 assert_eq!(next, Some((11, 4)));
1943 let next = analyzer.next();
1944 assert_eq!(next, Some((5, 1)));
1945 let next = analyzer.next();
1946 assert_eq!(next, None);
1947 // 👩💻
1948 let cluster_map = [0, 0, 0, 0, 0];
1949 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 1);
1950 let next = analyzer.next();
1951 assert_eq!(next, Some((5, 1)));
1952 let next = analyzer.next();
1953 assert_eq!(next, None);
1954 }
1955}