1use std::{borrow::Cow, sync::Arc};
2
3use ::util::ResultExt;
4use anyhow::{Context, 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, Direct3D11::*, DirectWrite::*,
14 Dxgi::Common::*, Gdi::LOGFONTW,
15 },
16 System::SystemServices::LOCALE_NAME_MAX_LENGTH,
17 UI::WindowsAndMessaging::*,
18 },
19 core::*,
20};
21use windows_numerics::Vector2;
22
23use crate::*;
24
25#[derive(Debug)]
26struct FontInfo {
27 font_family: String,
28 font_face: IDWriteFontFace3,
29 features: IDWriteTypography,
30 fallbacks: Option<IDWriteFontFallback>,
31 is_system_font: bool,
32}
33
34pub(crate) struct DirectWriteTextSystem(RwLock<DirectWriteState>);
35
36struct DirectWriteComponent {
37 locale: String,
38 factory: IDWriteFactory5,
39 in_memory_loader: IDWriteInMemoryFontFileLoader,
40 builder: IDWriteFontSetBuilder1,
41 text_renderer: Arc<TextRendererWrapper>,
42
43 gpu_state: GPUState,
44}
45
46struct GPUState {
47 device: ID3D11Device,
48 device_context: ID3D11DeviceContext,
49 sampler: [Option<ID3D11SamplerState>; 1],
50 blend_state: ID3D11BlendState,
51 vertex_shader: ID3D11VertexShader,
52 pixel_shader: ID3D11PixelShader,
53}
54
55struct DirectWriteState {
56 components: DirectWriteComponent,
57 system_ui_font_name: SharedString,
58 system_font_collection: IDWriteFontCollection1,
59 custom_font_collection: IDWriteFontCollection1,
60 fonts: Vec<FontInfo>,
61 font_selections: HashMap<Font, FontId>,
62 font_id_by_identifier: HashMap<FontIdentifier, FontId>,
63}
64
65#[derive(Debug, Clone, Hash, PartialEq, Eq)]
66struct FontIdentifier {
67 postscript_name: String,
68 weight: i32,
69 style: i32,
70}
71
72impl DirectWriteComponent {
73 pub fn new(directx_devices: &DirectXDevices) -> Result<Self> {
74 // todo: ideally this would not be a large unsafe block but smaller isolated ones for easier auditing
75 unsafe {
76 let factory: IDWriteFactory5 = DWriteCreateFactory(DWRITE_FACTORY_TYPE_SHARED)?;
77 // The `IDWriteInMemoryFontFileLoader` here is supported starting from
78 // Windows 10 Creators Update, which consequently requires the entire
79 // `DirectWriteTextSystem` to run on `win10 1703`+.
80 let in_memory_loader = factory.CreateInMemoryFontFileLoader()?;
81 factory.RegisterFontFileLoader(&in_memory_loader)?;
82 let builder = factory.CreateFontSetBuilder()?;
83 let mut locale_vec = vec![0u16; LOCALE_NAME_MAX_LENGTH as usize];
84 GetUserDefaultLocaleName(&mut locale_vec);
85 let locale = String::from_utf16_lossy(&locale_vec);
86 let text_renderer = Arc::new(TextRendererWrapper::new(&locale));
87
88 let gpu_state = GPUState::new(directx_devices)?;
89
90 Ok(DirectWriteComponent {
91 locale,
92 factory,
93 in_memory_loader,
94 builder,
95 text_renderer,
96 gpu_state,
97 })
98 }
99 }
100}
101
102impl GPUState {
103 fn new(directx_devices: &DirectXDevices) -> Result<Self> {
104 let device = directx_devices.device.clone();
105 let device_context = directx_devices.device_context.clone();
106
107 let blend_state = {
108 let mut blend_state = None;
109 let desc = D3D11_BLEND_DESC {
110 AlphaToCoverageEnable: false.into(),
111 IndependentBlendEnable: false.into(),
112 RenderTarget: [
113 D3D11_RENDER_TARGET_BLEND_DESC {
114 BlendEnable: true.into(),
115 SrcBlend: D3D11_BLEND_ONE,
116 DestBlend: D3D11_BLEND_INV_SRC_ALPHA,
117 BlendOp: D3D11_BLEND_OP_ADD,
118 SrcBlendAlpha: D3D11_BLEND_ONE,
119 DestBlendAlpha: D3D11_BLEND_INV_SRC_ALPHA,
120 BlendOpAlpha: D3D11_BLEND_OP_ADD,
121 RenderTargetWriteMask: D3D11_COLOR_WRITE_ENABLE_ALL.0 as u8,
122 },
123 Default::default(),
124 Default::default(),
125 Default::default(),
126 Default::default(),
127 Default::default(),
128 Default::default(),
129 Default::default(),
130 ],
131 };
132 unsafe { device.CreateBlendState(&desc, Some(&mut blend_state)) }?;
133 blend_state.unwrap()
134 };
135
136 let sampler = {
137 let mut sampler = None;
138 let desc = D3D11_SAMPLER_DESC {
139 Filter: D3D11_FILTER_MIN_MAG_MIP_POINT,
140 AddressU: D3D11_TEXTURE_ADDRESS_BORDER,
141 AddressV: D3D11_TEXTURE_ADDRESS_BORDER,
142 AddressW: D3D11_TEXTURE_ADDRESS_BORDER,
143 MipLODBias: 0.0,
144 MaxAnisotropy: 1,
145 ComparisonFunc: D3D11_COMPARISON_ALWAYS,
146 BorderColor: [0.0, 0.0, 0.0, 0.0],
147 MinLOD: 0.0,
148 MaxLOD: 0.0,
149 };
150 unsafe { device.CreateSamplerState(&desc, Some(&mut sampler)) }?;
151 [sampler]
152 };
153
154 let vertex_shader = {
155 let source = shader_resources::RawShaderBytes::new(
156 shader_resources::ShaderModule::EmojiRasterization,
157 shader_resources::ShaderTarget::Vertex,
158 )?;
159 let mut shader = None;
160 unsafe { device.CreateVertexShader(source.as_bytes(), None, Some(&mut shader)) }?;
161 shader.unwrap()
162 };
163
164 let pixel_shader = {
165 let source = shader_resources::RawShaderBytes::new(
166 shader_resources::ShaderModule::EmojiRasterization,
167 shader_resources::ShaderTarget::Fragment,
168 )?;
169 let mut shader = None;
170 unsafe { device.CreatePixelShader(source.as_bytes(), None, Some(&mut shader)) }?;
171 shader.unwrap()
172 };
173
174 Ok(Self {
175 device,
176 device_context,
177 sampler,
178 blend_state,
179 vertex_shader,
180 pixel_shader,
181 })
182 }
183}
184
185impl DirectWriteTextSystem {
186 pub(crate) fn new(directx_devices: &DirectXDevices) -> Result<Self> {
187 let components = DirectWriteComponent::new(directx_devices)?;
188 let system_font_collection = unsafe {
189 let mut result = std::mem::zeroed();
190 components
191 .factory
192 .GetSystemFontCollection(false, &mut result, true)?;
193 result.unwrap()
194 };
195 let custom_font_set = unsafe { components.builder.CreateFontSet()? };
196 let custom_font_collection = unsafe {
197 components
198 .factory
199 .CreateFontCollectionFromFontSet(&custom_font_set)?
200 };
201 let system_ui_font_name = get_system_ui_font_name();
202
203 Ok(Self(RwLock::new(DirectWriteState {
204 components,
205 system_ui_font_name,
206 system_font_collection,
207 custom_font_collection,
208 fonts: Vec::new(),
209 font_selections: HashMap::default(),
210 font_id_by_identifier: HashMap::default(),
211 })))
212 }
213
214 pub(crate) fn handle_gpu_lost(&self, directx_devices: &DirectXDevices) {
215 self.0.write().handle_gpu_lost(directx_devices);
216 }
217}
218
219impl PlatformTextSystem for DirectWriteTextSystem {
220 fn add_fonts(&self, fonts: Vec<Cow<'static, [u8]>>) -> Result<()> {
221 self.0.write().add_fonts(fonts)
222 }
223
224 fn all_font_names(&self) -> Vec<String> {
225 self.0.read().all_font_names()
226 }
227
228 fn font_id(&self, font: &Font) -> Result<FontId> {
229 let lock = self.0.upgradable_read();
230 if let Some(font_id) = lock.font_selections.get(font) {
231 Ok(*font_id)
232 } else {
233 let mut lock = RwLockUpgradableReadGuard::upgrade(lock);
234 let font_id = lock.select_font(font);
235 lock.font_selections.insert(font.clone(), font_id);
236 Ok(font_id)
237 }
238 }
239
240 fn font_metrics(&self, font_id: FontId) -> FontMetrics {
241 self.0.read().font_metrics(font_id)
242 }
243
244 fn typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>> {
245 self.0.read().get_typographic_bounds(font_id, glyph_id)
246 }
247
248 fn advance(&self, font_id: FontId, glyph_id: GlyphId) -> anyhow::Result<Size<f32>> {
249 self.0.read().get_advance(font_id, glyph_id)
250 }
251
252 fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
253 self.0.read().glyph_for_char(font_id, ch)
254 }
255
256 fn glyph_raster_bounds(
257 &self,
258 params: &RenderGlyphParams,
259 ) -> anyhow::Result<Bounds<DevicePixels>> {
260 self.0.read().raster_bounds(params)
261 }
262
263 fn rasterize_glyph(
264 &self,
265 params: &RenderGlyphParams,
266 raster_bounds: Bounds<DevicePixels>,
267 ) -> anyhow::Result<(Size<DevicePixels>, Vec<u8>)> {
268 self.0.read().rasterize_glyph(params, raster_bounds)
269 }
270
271 fn layout_line(&self, text: &str, font_size: Pixels, runs: &[FontRun]) -> LineLayout {
272 self.0
273 .write()
274 .layout_line(text, font_size, runs)
275 .log_err()
276 .unwrap_or(LineLayout {
277 font_size,
278 ..Default::default()
279 })
280 }
281}
282
283impl DirectWriteState {
284 fn add_fonts(&mut self, fonts: Vec<Cow<'static, [u8]>>) -> Result<()> {
285 for font_data in fonts {
286 match font_data {
287 Cow::Borrowed(data) => unsafe {
288 let font_file = self
289 .components
290 .in_memory_loader
291 .CreateInMemoryFontFileReference(
292 &self.components.factory,
293 data.as_ptr() as _,
294 data.len() as _,
295 None,
296 )?;
297 self.components.builder.AddFontFile(&font_file)?;
298 },
299 Cow::Owned(data) => unsafe {
300 let font_file = self
301 .components
302 .in_memory_loader
303 .CreateInMemoryFontFileReference(
304 &self.components.factory,
305 data.as_ptr() as _,
306 data.len() as _,
307 None,
308 )?;
309 self.components.builder.AddFontFile(&font_file)?;
310 },
311 }
312 }
313 let set = unsafe { self.components.builder.CreateFontSet()? };
314 let collection = unsafe {
315 self.components
316 .factory
317 .CreateFontCollectionFromFontSet(&set)?
318 };
319 self.custom_font_collection = collection;
320
321 Ok(())
322 }
323
324 fn generate_font_fallbacks(
325 &self,
326 fallbacks: &FontFallbacks,
327 ) -> Result<Option<IDWriteFontFallback>> {
328 if fallbacks.fallback_list().is_empty() {
329 return Ok(None);
330 }
331 unsafe {
332 let builder = self.components.factory.CreateFontFallbackBuilder()?;
333 let font_set = &self.system_font_collection.GetFontSet()?;
334 for family_name in fallbacks.fallback_list() {
335 let Some(fonts) = font_set
336 .GetMatchingFonts(
337 &HSTRING::from(family_name),
338 DWRITE_FONT_WEIGHT_NORMAL,
339 DWRITE_FONT_STRETCH_NORMAL,
340 DWRITE_FONT_STYLE_NORMAL,
341 )
342 .log_err()
343 else {
344 continue;
345 };
346 if fonts.GetFontCount() == 0 {
347 log::error!("No matching font found for {}", family_name);
348 continue;
349 }
350 let font = fonts.GetFontFaceReference(0)?.CreateFontFace()?;
351 let mut count = 0;
352 font.GetUnicodeRanges(None, &mut count).ok();
353 if count == 0 {
354 continue;
355 }
356 let mut unicode_ranges = vec![DWRITE_UNICODE_RANGE::default(); count as usize];
357 let Some(_) = font
358 .GetUnicodeRanges(Some(&mut unicode_ranges), &mut count)
359 .log_err()
360 else {
361 continue;
362 };
363 let target_family_name = HSTRING::from(family_name);
364 builder.AddMapping(
365 &unicode_ranges,
366 &[target_family_name.as_ptr()],
367 None,
368 None,
369 None,
370 1.0,
371 )?;
372 }
373 let system_fallbacks = self.components.factory.GetSystemFontFallback()?;
374 builder.AddMappings(&system_fallbacks)?;
375 Ok(Some(builder.CreateFontFallback()?))
376 }
377 }
378
379 unsafe fn generate_font_features(
380 &self,
381 font_features: &FontFeatures,
382 ) -> Result<IDWriteTypography> {
383 let direct_write_features = unsafe { self.components.factory.CreateTypography()? };
384 apply_font_features(&direct_write_features, font_features)?;
385 Ok(direct_write_features)
386 }
387
388 unsafe fn get_font_id_from_font_collection(
389 &mut self,
390 family_name: &str,
391 font_weight: FontWeight,
392 font_style: FontStyle,
393 font_features: &FontFeatures,
394 font_fallbacks: Option<&FontFallbacks>,
395 is_system_font: bool,
396 ) -> Option<FontId> {
397 let collection = if is_system_font {
398 &self.system_font_collection
399 } else {
400 &self.custom_font_collection
401 };
402 let fontset = unsafe { collection.GetFontSet().log_err()? };
403 let font = unsafe {
404 fontset
405 .GetMatchingFonts(
406 &HSTRING::from(family_name),
407 font_weight.into(),
408 DWRITE_FONT_STRETCH_NORMAL,
409 font_style.into(),
410 )
411 .log_err()?
412 };
413 let total_number = unsafe { font.GetFontCount() };
414 for index in 0..total_number {
415 let Some(font_face_ref) = (unsafe { font.GetFontFaceReference(index).log_err() })
416 else {
417 continue;
418 };
419 let Some(font_face) = (unsafe { font_face_ref.CreateFontFace().log_err() }) else {
420 continue;
421 };
422 let Some(identifier) = get_font_identifier(&font_face, &self.components.locale) else {
423 continue;
424 };
425 let Some(direct_write_features) =
426 (unsafe { self.generate_font_features(font_features).log_err() })
427 else {
428 continue;
429 };
430 let fallbacks = font_fallbacks
431 .and_then(|fallbacks| self.generate_font_fallbacks(fallbacks).log_err().flatten());
432 let font_info = FontInfo {
433 font_family: family_name.to_owned(),
434 font_face,
435 features: direct_write_features,
436 fallbacks,
437 is_system_font,
438 };
439 let font_id = FontId(self.fonts.len());
440 self.fonts.push(font_info);
441 self.font_id_by_identifier.insert(identifier, font_id);
442 return Some(font_id);
443 }
444 None
445 }
446
447 unsafe fn update_system_font_collection(&mut self) {
448 let mut collection = unsafe { std::mem::zeroed() };
449 if unsafe {
450 self.components
451 .factory
452 .GetSystemFontCollection(false, &mut collection, true)
453 .log_err()
454 .is_some()
455 } {
456 self.system_font_collection = collection.unwrap();
457 }
458 }
459
460 fn select_font(&mut self, target_font: &Font) -> FontId {
461 unsafe {
462 if target_font.family == ".SystemUIFont" {
463 let family = self.system_ui_font_name.clone();
464 self.find_font_id(
465 family.as_ref(),
466 target_font.weight,
467 target_font.style,
468 &target_font.features,
469 target_font.fallbacks.as_ref(),
470 )
471 .unwrap()
472 } else {
473 let family = self.system_ui_font_name.clone();
474 self.find_font_id(
475 font_name_with_fallbacks(target_font.family.as_ref(), family.as_ref()),
476 target_font.weight,
477 target_font.style,
478 &target_font.features,
479 target_font.fallbacks.as_ref(),
480 )
481 .unwrap_or_else(|| {
482 #[cfg(any(test, feature = "test-support"))]
483 {
484 panic!("ERROR: {} font not found!", target_font.family);
485 }
486 #[cfg(not(any(test, feature = "test-support")))]
487 {
488 log::error!("{} not found, use {} instead.", target_font.family, family);
489 self.get_font_id_from_font_collection(
490 family.as_ref(),
491 target_font.weight,
492 target_font.style,
493 &target_font.features,
494 target_font.fallbacks.as_ref(),
495 true,
496 )
497 .unwrap()
498 }
499 })
500 }
501 }
502 }
503
504 unsafe fn find_font_id(
505 &mut self,
506 family_name: &str,
507 weight: FontWeight,
508 style: FontStyle,
509 features: &FontFeatures,
510 fallbacks: Option<&FontFallbacks>,
511 ) -> Option<FontId> {
512 // try to find target font in custom font collection first
513 unsafe {
514 self.get_font_id_from_font_collection(
515 family_name,
516 weight,
517 style,
518 features,
519 fallbacks,
520 false,
521 )
522 .or_else(|| {
523 self.get_font_id_from_font_collection(
524 family_name,
525 weight,
526 style,
527 features,
528 fallbacks,
529 true,
530 )
531 })
532 .or_else(|| {
533 self.update_system_font_collection();
534 self.get_font_id_from_font_collection(
535 family_name,
536 weight,
537 style,
538 features,
539 fallbacks,
540 true,
541 )
542 })
543 }
544 }
545
546 fn layout_line(
547 &mut self,
548 text: &str,
549 font_size: Pixels,
550 font_runs: &[FontRun],
551 ) -> Result<LineLayout> {
552 if font_runs.is_empty() {
553 return Ok(LineLayout {
554 font_size,
555 ..Default::default()
556 });
557 }
558 unsafe {
559 let text_renderer = self.components.text_renderer.clone();
560 let text_wide = text.encode_utf16().collect_vec();
561
562 let mut utf8_offset = 0usize;
563 let mut utf16_offset = 0u32;
564 let text_layout = {
565 let first_run = &font_runs[0];
566 let font_info = &self.fonts[first_run.font_id.0];
567 let collection = if font_info.is_system_font {
568 &self.system_font_collection
569 } else {
570 &self.custom_font_collection
571 };
572 let format: IDWriteTextFormat1 = self
573 .components
574 .factory
575 .CreateTextFormat(
576 &HSTRING::from(&font_info.font_family),
577 collection,
578 font_info.font_face.GetWeight(),
579 font_info.font_face.GetStyle(),
580 DWRITE_FONT_STRETCH_NORMAL,
581 font_size.0,
582 &HSTRING::from(&self.components.locale),
583 )?
584 .cast()?;
585 if let Some(ref fallbacks) = font_info.fallbacks {
586 format.SetFontFallback(fallbacks)?;
587 }
588
589 let layout = self.components.factory.CreateTextLayout(
590 &text_wide,
591 &format,
592 f32::INFINITY,
593 f32::INFINITY,
594 )?;
595 let current_text = &text[utf8_offset..(utf8_offset + first_run.len)];
596 utf8_offset += first_run.len;
597 let current_text_utf16_length = current_text.encode_utf16().count() as u32;
598 let text_range = DWRITE_TEXT_RANGE {
599 startPosition: utf16_offset,
600 length: current_text_utf16_length,
601 };
602 layout.SetTypography(&font_info.features, text_range)?;
603 utf16_offset += current_text_utf16_length;
604
605 layout
606 };
607
608 let mut first_run = true;
609 let mut max_ascent = 0.0_f32;
610 let mut max_descent = 0.0_f32;
611 for run in font_runs {
612 let font_info = &self.fonts[run.font_id.0];
613 let mut metrics = std::mem::zeroed();
614 font_info.font_face.GetMetrics(&mut metrics);
615 let font_scale = font_size.0 / metrics.Base.designUnitsPerEm as f32;
616 max_ascent = max_ascent.max(metrics.Base.ascent as f32 * font_scale);
617 max_descent = max_descent.max(-(metrics.Base.descent as f32 * font_scale));
618
619 if first_run {
620 first_run = false;
621 continue;
622 }
623
624 let current_text = &text[utf8_offset..(utf8_offset + run.len)];
625 utf8_offset += run.len;
626 let current_text_utf16_length = current_text.encode_utf16().count() as u32;
627
628 let collection = if font_info.is_system_font {
629 &self.system_font_collection
630 } else {
631 &self.custom_font_collection
632 };
633 let text_range = DWRITE_TEXT_RANGE {
634 startPosition: utf16_offset,
635 length: current_text_utf16_length,
636 };
637 utf16_offset += current_text_utf16_length;
638 text_layout.SetFontCollection(collection, text_range)?;
639 text_layout
640 .SetFontFamilyName(&HSTRING::from(&font_info.font_family), text_range)?;
641 text_layout.SetFontSize(font_size.0, text_range)?;
642 text_layout.SetFontStyle(font_info.font_face.GetStyle(), text_range)?;
643 text_layout.SetFontWeight(font_info.font_face.GetWeight(), text_range)?;
644 text_layout.SetTypography(&font_info.features, text_range)?;
645 }
646
647 let mut runs = Vec::new();
648 let renderer_context = RendererContext {
649 text_system: self,
650 index_converter: StringIndexConverter::new(text),
651 runs: &mut runs,
652 width: 0.0,
653 };
654 text_layout.Draw(
655 Some(&renderer_context as *const _ as _),
656 &text_renderer.0,
657 0.0,
658 0.0,
659 )?;
660 let width = px(renderer_context.width);
661
662 Ok(LineLayout {
663 font_size,
664 width,
665 ascent: max_ascent.into(),
666 descent: max_descent.into(),
667 runs,
668 len: text.len(),
669 })
670 }
671 }
672
673 fn font_metrics(&self, font_id: FontId) -> FontMetrics {
674 unsafe {
675 let font_info = &self.fonts[font_id.0];
676 let mut metrics = std::mem::zeroed();
677 font_info.font_face.GetMetrics(&mut metrics);
678
679 FontMetrics {
680 units_per_em: metrics.Base.designUnitsPerEm as _,
681 ascent: metrics.Base.ascent as _,
682 descent: -(metrics.Base.descent as f32),
683 line_gap: metrics.Base.lineGap as _,
684 underline_position: metrics.Base.underlinePosition as _,
685 underline_thickness: metrics.Base.underlineThickness as _,
686 cap_height: metrics.Base.capHeight as _,
687 x_height: metrics.Base.xHeight as _,
688 bounding_box: Bounds {
689 origin: Point {
690 x: metrics.glyphBoxLeft as _,
691 y: metrics.glyphBoxBottom as _,
692 },
693 size: Size {
694 width: (metrics.glyphBoxRight - metrics.glyphBoxLeft) as _,
695 height: (metrics.glyphBoxTop - metrics.glyphBoxBottom) as _,
696 },
697 },
698 }
699 }
700 }
701
702 fn create_glyph_run_analysis(
703 &self,
704 params: &RenderGlyphParams,
705 ) -> Result<IDWriteGlyphRunAnalysis> {
706 let font = &self.fonts[params.font_id.0];
707 let glyph_id = [params.glyph_id.0 as u16];
708 let advance = [0.0];
709 let offset = [DWRITE_GLYPH_OFFSET::default()];
710 let glyph_run = DWRITE_GLYPH_RUN {
711 fontFace: unsafe { std::mem::transmute_copy(&font.font_face) },
712 fontEmSize: params.font_size.0,
713 glyphCount: 1,
714 glyphIndices: glyph_id.as_ptr(),
715 glyphAdvances: advance.as_ptr(),
716 glyphOffsets: offset.as_ptr(),
717 isSideways: BOOL(0),
718 bidiLevel: 0,
719 };
720 let transform = DWRITE_MATRIX {
721 m11: params.scale_factor,
722 m12: 0.0,
723 m21: 0.0,
724 m22: params.scale_factor,
725 dx: 0.0,
726 dy: 0.0,
727 };
728 let baseline_origin_x =
729 params.subpixel_variant.x as f32 / SUBPIXEL_VARIANTS_X as f32 / params.scale_factor;
730 let baseline_origin_y =
731 params.subpixel_variant.y as f32 / SUBPIXEL_VARIANTS_Y as f32 / params.scale_factor;
732
733 let mut rendering_mode = DWRITE_RENDERING_MODE1::default();
734 let mut grid_fit_mode = DWRITE_GRID_FIT_MODE::default();
735 unsafe {
736 font.font_face.GetRecommendedRenderingMode(
737 params.font_size.0,
738 // Using 96 as scale is applied by the transform
739 96.0,
740 96.0,
741 Some(&transform),
742 false,
743 DWRITE_OUTLINE_THRESHOLD_ANTIALIASED,
744 DWRITE_MEASURING_MODE_NATURAL,
745 None,
746 &mut rendering_mode,
747 &mut grid_fit_mode,
748 )?;
749 }
750 let rendering_mode = match rendering_mode {
751 DWRITE_RENDERING_MODE1_OUTLINE => DWRITE_RENDERING_MODE1_NATURAL_SYMMETRIC,
752 m => m,
753 };
754
755 let glyph_analysis = unsafe {
756 self.components.factory.CreateGlyphRunAnalysis(
757 &glyph_run,
758 Some(&transform),
759 rendering_mode,
760 DWRITE_MEASURING_MODE_NATURAL,
761 grid_fit_mode,
762 DWRITE_TEXT_ANTIALIAS_MODE_GRAYSCALE,
763 baseline_origin_x,
764 baseline_origin_y,
765 )
766 }?;
767 Ok(glyph_analysis)
768 }
769
770 fn raster_bounds(&self, params: &RenderGlyphParams) -> Result<Bounds<DevicePixels>> {
771 let glyph_analysis = self.create_glyph_run_analysis(params)?;
772
773 let bounds = unsafe { glyph_analysis.GetAlphaTextureBounds(DWRITE_TEXTURE_ALIASED_1x1)? };
774
775 if bounds.right < bounds.left {
776 Ok(Bounds {
777 origin: point(0.into(), 0.into()),
778 size: size(0.into(), 0.into()),
779 })
780 } else {
781 Ok(Bounds {
782 origin: point(bounds.left.into(), bounds.top.into()),
783 size: size(
784 (bounds.right - bounds.left).into(),
785 (bounds.bottom - bounds.top).into(),
786 ),
787 })
788 }
789 }
790
791 fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
792 let font_info = &self.fonts[font_id.0];
793 let codepoints = [ch as u32];
794 let mut glyph_indices = vec![0u16; 1];
795 unsafe {
796 font_info
797 .font_face
798 .GetGlyphIndices(codepoints.as_ptr(), 1, glyph_indices.as_mut_ptr())
799 .log_err()
800 }
801 .map(|_| GlyphId(glyph_indices[0] as u32))
802 }
803
804 fn rasterize_glyph(
805 &self,
806 params: &RenderGlyphParams,
807 glyph_bounds: Bounds<DevicePixels>,
808 ) -> Result<(Size<DevicePixels>, Vec<u8>)> {
809 if glyph_bounds.size.width.0 == 0 || glyph_bounds.size.height.0 == 0 {
810 anyhow::bail!("glyph bounds are empty");
811 }
812
813 let bitmap_data = if params.is_emoji {
814 if let Ok(color) = self.rasterize_color(params, glyph_bounds) {
815 color
816 } else {
817 let monochrome = self.rasterize_monochrome(params, glyph_bounds)?;
818 monochrome
819 .into_iter()
820 .flat_map(|pixel| [0, 0, 0, pixel])
821 .collect::<Vec<_>>()
822 }
823 } else {
824 self.rasterize_monochrome(params, glyph_bounds)?
825 };
826
827 Ok((glyph_bounds.size, bitmap_data))
828 }
829
830 fn rasterize_monochrome(
831 &self,
832 params: &RenderGlyphParams,
833 glyph_bounds: Bounds<DevicePixels>,
834 ) -> Result<Vec<u8>> {
835 let mut bitmap_data =
836 vec![0u8; glyph_bounds.size.width.0 as usize * glyph_bounds.size.height.0 as usize];
837
838 let glyph_analysis = self.create_glyph_run_analysis(params)?;
839 unsafe {
840 glyph_analysis.CreateAlphaTexture(
841 DWRITE_TEXTURE_ALIASED_1x1,
842 &RECT {
843 left: glyph_bounds.origin.x.0,
844 top: glyph_bounds.origin.y.0,
845 right: glyph_bounds.size.width.0 + glyph_bounds.origin.x.0,
846 bottom: glyph_bounds.size.height.0 + glyph_bounds.origin.y.0,
847 },
848 &mut bitmap_data,
849 )?;
850 }
851
852 Ok(bitmap_data)
853 }
854
855 fn rasterize_color(
856 &self,
857 params: &RenderGlyphParams,
858 glyph_bounds: Bounds<DevicePixels>,
859 ) -> Result<Vec<u8>> {
860 let bitmap_size = glyph_bounds.size;
861 let subpixel_shift = params
862 .subpixel_variant
863 .map(|v| v as f32 / SUBPIXEL_VARIANTS_X as f32);
864 let baseline_origin_x = subpixel_shift.x / params.scale_factor;
865 let baseline_origin_y = subpixel_shift.y / params.scale_factor;
866
867 let transform = DWRITE_MATRIX {
868 m11: params.scale_factor,
869 m12: 0.0,
870 m21: 0.0,
871 m22: params.scale_factor,
872 dx: 0.0,
873 dy: 0.0,
874 };
875
876 let font = &self.fonts[params.font_id.0];
877 let glyph_id = [params.glyph_id.0 as u16];
878 let advance = [glyph_bounds.size.width.0 as f32];
879 let offset = [DWRITE_GLYPH_OFFSET {
880 advanceOffset: -glyph_bounds.origin.x.0 as f32 / params.scale_factor,
881 ascenderOffset: glyph_bounds.origin.y.0 as f32 / params.scale_factor,
882 }];
883 let glyph_run = DWRITE_GLYPH_RUN {
884 fontFace: unsafe { std::mem::transmute_copy(&font.font_face) },
885 fontEmSize: params.font_size.0,
886 glyphCount: 1,
887 glyphIndices: glyph_id.as_ptr(),
888 glyphAdvances: advance.as_ptr(),
889 glyphOffsets: offset.as_ptr(),
890 isSideways: BOOL(0),
891 bidiLevel: 0,
892 };
893
894 // todo: support formats other than COLR
895 let color_enumerator = unsafe {
896 self.components.factory.TranslateColorGlyphRun(
897 Vector2::new(baseline_origin_x, baseline_origin_y),
898 &glyph_run,
899 None,
900 DWRITE_GLYPH_IMAGE_FORMATS_COLR,
901 DWRITE_MEASURING_MODE_NATURAL,
902 Some(&transform),
903 0,
904 )
905 }?;
906
907 let mut glyph_layers = Vec::new();
908 loop {
909 let color_run = unsafe { color_enumerator.GetCurrentRun() }?;
910 let color_run = unsafe { &*color_run };
911 let image_format = color_run.glyphImageFormat & !DWRITE_GLYPH_IMAGE_FORMATS_TRUETYPE;
912 if image_format == DWRITE_GLYPH_IMAGE_FORMATS_COLR {
913 let color_analysis = unsafe {
914 self.components.factory.CreateGlyphRunAnalysis(
915 &color_run.Base.glyphRun as *const _,
916 Some(&transform),
917 DWRITE_RENDERING_MODE1_NATURAL_SYMMETRIC,
918 DWRITE_MEASURING_MODE_NATURAL,
919 DWRITE_GRID_FIT_MODE_DEFAULT,
920 DWRITE_TEXT_ANTIALIAS_MODE_GRAYSCALE,
921 baseline_origin_x,
922 baseline_origin_y,
923 )
924 }?;
925
926 let color_bounds =
927 unsafe { color_analysis.GetAlphaTextureBounds(DWRITE_TEXTURE_ALIASED_1x1) }?;
928
929 let color_size = size(
930 color_bounds.right - color_bounds.left,
931 color_bounds.bottom - color_bounds.top,
932 );
933 if color_size.width > 0 && color_size.height > 0 {
934 let mut alpha_data = vec![0u8; (color_size.width * color_size.height) as usize];
935 unsafe {
936 color_analysis.CreateAlphaTexture(
937 DWRITE_TEXTURE_ALIASED_1x1,
938 &color_bounds,
939 &mut alpha_data,
940 )
941 }?;
942
943 let run_color = {
944 let run_color = color_run.Base.runColor;
945 Rgba {
946 r: run_color.r,
947 g: run_color.g,
948 b: run_color.b,
949 a: run_color.a,
950 }
951 };
952 let bounds = bounds(point(color_bounds.left, color_bounds.top), color_size);
953 glyph_layers.push(GlyphLayerTexture::new(
954 &self.components.gpu_state,
955 run_color,
956 bounds,
957 &alpha_data,
958 )?);
959 }
960 }
961
962 let has_next = unsafe { color_enumerator.MoveNext() }
963 .map(|e| e.as_bool())
964 .unwrap_or(false);
965 if !has_next {
966 break;
967 }
968 }
969
970 let gpu_state = &self.components.gpu_state;
971 let params_buffer = {
972 let desc = D3D11_BUFFER_DESC {
973 ByteWidth: std::mem::size_of::<GlyphLayerTextureParams>() as u32,
974 Usage: D3D11_USAGE_DYNAMIC,
975 BindFlags: D3D11_BIND_CONSTANT_BUFFER.0 as u32,
976 CPUAccessFlags: D3D11_CPU_ACCESS_WRITE.0 as u32,
977 MiscFlags: 0,
978 StructureByteStride: 0,
979 };
980
981 let mut buffer = None;
982 unsafe {
983 gpu_state
984 .device
985 .CreateBuffer(&desc, None, Some(&mut buffer))
986 }?;
987 [buffer]
988 };
989
990 let render_target_texture = {
991 let mut texture = None;
992 let desc = D3D11_TEXTURE2D_DESC {
993 Width: bitmap_size.width.0 as u32,
994 Height: bitmap_size.height.0 as u32,
995 MipLevels: 1,
996 ArraySize: 1,
997 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
998 SampleDesc: DXGI_SAMPLE_DESC {
999 Count: 1,
1000 Quality: 0,
1001 },
1002 Usage: D3D11_USAGE_DEFAULT,
1003 BindFlags: D3D11_BIND_RENDER_TARGET.0 as u32,
1004 CPUAccessFlags: 0,
1005 MiscFlags: 0,
1006 };
1007 unsafe {
1008 gpu_state
1009 .device
1010 .CreateTexture2D(&desc, None, Some(&mut texture))
1011 }?;
1012 texture.unwrap()
1013 };
1014
1015 let render_target_view = {
1016 let desc = D3D11_RENDER_TARGET_VIEW_DESC {
1017 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
1018 ViewDimension: D3D11_RTV_DIMENSION_TEXTURE2D,
1019 Anonymous: D3D11_RENDER_TARGET_VIEW_DESC_0 {
1020 Texture2D: D3D11_TEX2D_RTV { MipSlice: 0 },
1021 },
1022 };
1023 let mut rtv = None;
1024 unsafe {
1025 gpu_state.device.CreateRenderTargetView(
1026 &render_target_texture,
1027 Some(&desc),
1028 Some(&mut rtv),
1029 )
1030 }?;
1031 [rtv]
1032 };
1033
1034 let staging_texture = {
1035 let mut texture = None;
1036 let desc = D3D11_TEXTURE2D_DESC {
1037 Width: bitmap_size.width.0 as u32,
1038 Height: bitmap_size.height.0 as u32,
1039 MipLevels: 1,
1040 ArraySize: 1,
1041 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
1042 SampleDesc: DXGI_SAMPLE_DESC {
1043 Count: 1,
1044 Quality: 0,
1045 },
1046 Usage: D3D11_USAGE_STAGING,
1047 BindFlags: 0,
1048 CPUAccessFlags: D3D11_CPU_ACCESS_READ.0 as u32,
1049 MiscFlags: 0,
1050 };
1051 unsafe {
1052 gpu_state
1053 .device
1054 .CreateTexture2D(&desc, None, Some(&mut texture))
1055 }?;
1056 texture.unwrap()
1057 };
1058
1059 let device_context = &gpu_state.device_context;
1060 unsafe { device_context.IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP) };
1061 unsafe { device_context.VSSetShader(&gpu_state.vertex_shader, None) };
1062 unsafe { device_context.PSSetShader(&gpu_state.pixel_shader, None) };
1063 unsafe { device_context.VSSetConstantBuffers(0, Some(¶ms_buffer)) };
1064 unsafe { device_context.PSSetConstantBuffers(0, Some(¶ms_buffer)) };
1065 unsafe { device_context.OMSetRenderTargets(Some(&render_target_view), None) };
1066 unsafe { device_context.PSSetSamplers(0, Some(&gpu_state.sampler)) };
1067 unsafe { device_context.OMSetBlendState(&gpu_state.blend_state, None, 0xffffffff) };
1068
1069 let crate::FontInfo {
1070 gamma_ratios,
1071 grayscale_enhanced_contrast,
1072 } = DirectXRenderer::get_font_info();
1073
1074 for layer in glyph_layers {
1075 let params = GlyphLayerTextureParams {
1076 run_color: layer.run_color,
1077 bounds: layer.bounds,
1078 gamma_ratios: *gamma_ratios,
1079 grayscale_enhanced_contrast: *grayscale_enhanced_contrast,
1080 _pad: [0f32; 3],
1081 };
1082 unsafe {
1083 let mut dest = std::mem::zeroed();
1084 gpu_state.device_context.Map(
1085 params_buffer[0].as_ref().unwrap(),
1086 0,
1087 D3D11_MAP_WRITE_DISCARD,
1088 0,
1089 Some(&mut dest),
1090 )?;
1091 std::ptr::copy_nonoverlapping(¶ms as *const _, dest.pData as *mut _, 1);
1092 gpu_state
1093 .device_context
1094 .Unmap(params_buffer[0].as_ref().unwrap(), 0);
1095 };
1096
1097 let texture = [Some(layer.texture_view)];
1098 unsafe { device_context.PSSetShaderResources(0, Some(&texture)) };
1099
1100 let viewport = [D3D11_VIEWPORT {
1101 TopLeftX: layer.bounds.origin.x as f32,
1102 TopLeftY: layer.bounds.origin.y as f32,
1103 Width: layer.bounds.size.width as f32,
1104 Height: layer.bounds.size.height as f32,
1105 MinDepth: 0.0,
1106 MaxDepth: 1.0,
1107 }];
1108 unsafe { device_context.RSSetViewports(Some(&viewport)) };
1109
1110 unsafe { device_context.Draw(4, 0) };
1111 }
1112
1113 unsafe { device_context.CopyResource(&staging_texture, &render_target_texture) };
1114
1115 let mapped_data = {
1116 let mut mapped_data = D3D11_MAPPED_SUBRESOURCE::default();
1117 unsafe {
1118 device_context.Map(
1119 &staging_texture,
1120 0,
1121 D3D11_MAP_READ,
1122 0,
1123 Some(&mut mapped_data),
1124 )
1125 }?;
1126 mapped_data
1127 };
1128 let mut rasterized =
1129 vec![0u8; (bitmap_size.width.0 as u32 * bitmap_size.height.0 as u32 * 4) as usize];
1130
1131 for y in 0..bitmap_size.height.0 as usize {
1132 let width = bitmap_size.width.0 as usize;
1133 unsafe {
1134 std::ptr::copy_nonoverlapping::<u8>(
1135 (mapped_data.pData as *const u8).byte_add(mapped_data.RowPitch as usize * y),
1136 rasterized
1137 .as_mut_ptr()
1138 .byte_add(width * y * std::mem::size_of::<u32>()),
1139 width * std::mem::size_of::<u32>(),
1140 )
1141 };
1142 }
1143
1144 // Convert from premultiplied to straight alpha
1145 for chunk in rasterized.chunks_exact_mut(4) {
1146 let b = chunk[0] as f32;
1147 let g = chunk[1] as f32;
1148 let r = chunk[2] as f32;
1149 let a = chunk[3] as f32;
1150 if a > 0.0 {
1151 let inv_a = 255.0 / a;
1152 chunk[0] = (b * inv_a).clamp(0.0, 255.0) as u8;
1153 chunk[1] = (g * inv_a).clamp(0.0, 255.0) as u8;
1154 chunk[2] = (r * inv_a).clamp(0.0, 255.0) as u8;
1155 }
1156 }
1157
1158 Ok(rasterized)
1159 }
1160
1161 fn get_typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>> {
1162 unsafe {
1163 let font = &self.fonts[font_id.0].font_face;
1164 let glyph_indices = [glyph_id.0 as u16];
1165 let mut metrics = [DWRITE_GLYPH_METRICS::default()];
1166 font.GetDesignGlyphMetrics(glyph_indices.as_ptr(), 1, metrics.as_mut_ptr(), false)?;
1167
1168 let metrics = &metrics[0];
1169 let advance_width = metrics.advanceWidth as i32;
1170 let advance_height = metrics.advanceHeight as i32;
1171 let left_side_bearing = metrics.leftSideBearing;
1172 let right_side_bearing = metrics.rightSideBearing;
1173 let top_side_bearing = metrics.topSideBearing;
1174 let bottom_side_bearing = metrics.bottomSideBearing;
1175 let vertical_origin_y = metrics.verticalOriginY;
1176
1177 let y_offset = vertical_origin_y + bottom_side_bearing - advance_height;
1178 let width = advance_width - (left_side_bearing + right_side_bearing);
1179 let height = advance_height - (top_side_bearing + bottom_side_bearing);
1180
1181 Ok(Bounds {
1182 origin: Point {
1183 x: left_side_bearing as f32,
1184 y: y_offset as f32,
1185 },
1186 size: Size {
1187 width: width as f32,
1188 height: height as f32,
1189 },
1190 })
1191 }
1192 }
1193
1194 fn get_advance(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Size<f32>> {
1195 unsafe {
1196 let font = &self.fonts[font_id.0].font_face;
1197 let glyph_indices = [glyph_id.0 as u16];
1198 let mut metrics = [DWRITE_GLYPH_METRICS::default()];
1199 font.GetDesignGlyphMetrics(glyph_indices.as_ptr(), 1, metrics.as_mut_ptr(), false)?;
1200
1201 let metrics = &metrics[0];
1202
1203 Ok(Size {
1204 width: metrics.advanceWidth as f32,
1205 height: 0.0,
1206 })
1207 }
1208 }
1209
1210 fn all_font_names(&self) -> Vec<String> {
1211 let mut result =
1212 get_font_names_from_collection(&self.system_font_collection, &self.components.locale);
1213 result.extend(get_font_names_from_collection(
1214 &self.custom_font_collection,
1215 &self.components.locale,
1216 ));
1217 result
1218 }
1219
1220 fn handle_gpu_lost(&mut self, directx_devices: &DirectXDevices) {
1221 try_to_recover_from_device_lost(
1222 || GPUState::new(directx_devices).context("Recreating GPU state for DirectWrite"),
1223 |gpu_state| self.components.gpu_state = gpu_state,
1224 || {
1225 log::error!(
1226 "Failed to recreate GPU state for DirectWrite after multiple attempts."
1227 );
1228 // Do something here?
1229 // At this point, the device loss is considered unrecoverable.
1230 },
1231 );
1232 }
1233}
1234
1235impl Drop for DirectWriteState {
1236 fn drop(&mut self) {
1237 unsafe {
1238 let _ = self
1239 .components
1240 .factory
1241 .UnregisterFontFileLoader(&self.components.in_memory_loader);
1242 }
1243 }
1244}
1245
1246struct GlyphLayerTexture {
1247 run_color: Rgba,
1248 bounds: Bounds<i32>,
1249 texture_view: ID3D11ShaderResourceView,
1250 // holding on to the texture to not RAII drop it
1251 _texture: ID3D11Texture2D,
1252}
1253
1254impl GlyphLayerTexture {
1255 pub fn new(
1256 gpu_state: &GPUState,
1257 run_color: Rgba,
1258 bounds: Bounds<i32>,
1259 alpha_data: &[u8],
1260 ) -> Result<Self> {
1261 let texture_size = bounds.size;
1262
1263 let desc = D3D11_TEXTURE2D_DESC {
1264 Width: texture_size.width as u32,
1265 Height: texture_size.height as u32,
1266 MipLevels: 1,
1267 ArraySize: 1,
1268 Format: DXGI_FORMAT_R8_UNORM,
1269 SampleDesc: DXGI_SAMPLE_DESC {
1270 Count: 1,
1271 Quality: 0,
1272 },
1273 Usage: D3D11_USAGE_DEFAULT,
1274 BindFlags: D3D11_BIND_SHADER_RESOURCE.0 as u32,
1275 CPUAccessFlags: 0,
1276 MiscFlags: 0,
1277 };
1278
1279 let texture = {
1280 let mut texture: Option<ID3D11Texture2D> = None;
1281 unsafe {
1282 gpu_state
1283 .device
1284 .CreateTexture2D(&desc, None, Some(&mut texture))?
1285 };
1286 texture.unwrap()
1287 };
1288 let texture_view = {
1289 let mut view: Option<ID3D11ShaderResourceView> = None;
1290 unsafe {
1291 gpu_state
1292 .device
1293 .CreateShaderResourceView(&texture, None, Some(&mut view))?
1294 };
1295 view.unwrap()
1296 };
1297
1298 unsafe {
1299 gpu_state.device_context.UpdateSubresource(
1300 &texture,
1301 0,
1302 None,
1303 alpha_data.as_ptr() as _,
1304 texture_size.width as u32,
1305 0,
1306 )
1307 };
1308
1309 Ok(GlyphLayerTexture {
1310 run_color,
1311 bounds,
1312 texture_view,
1313 _texture: texture,
1314 })
1315 }
1316}
1317
1318#[repr(C)]
1319struct GlyphLayerTextureParams {
1320 bounds: Bounds<i32>,
1321 run_color: Rgba,
1322 gamma_ratios: [f32; 4],
1323 grayscale_enhanced_contrast: f32,
1324 _pad: [f32; 3],
1325}
1326
1327struct TextRendererWrapper(pub IDWriteTextRenderer);
1328
1329impl TextRendererWrapper {
1330 pub fn new(locale_str: &str) -> Self {
1331 let inner = TextRenderer::new(locale_str);
1332 TextRendererWrapper(inner.into())
1333 }
1334}
1335
1336#[implement(IDWriteTextRenderer)]
1337struct TextRenderer {
1338 locale: String,
1339}
1340
1341impl TextRenderer {
1342 pub fn new(locale_str: &str) -> Self {
1343 TextRenderer {
1344 locale: locale_str.to_owned(),
1345 }
1346 }
1347}
1348
1349struct RendererContext<'t, 'a, 'b> {
1350 text_system: &'t mut DirectWriteState,
1351 index_converter: StringIndexConverter<'a>,
1352 runs: &'b mut Vec<ShapedRun>,
1353 width: f32,
1354}
1355
1356#[derive(Debug)]
1357struct ClusterAnalyzer<'t> {
1358 utf16_idx: usize,
1359 glyph_idx: usize,
1360 glyph_count: usize,
1361 cluster_map: &'t [u16],
1362}
1363
1364impl<'t> ClusterAnalyzer<'t> {
1365 pub fn new(cluster_map: &'t [u16], glyph_count: usize) -> Self {
1366 ClusterAnalyzer {
1367 utf16_idx: 0,
1368 glyph_idx: 0,
1369 glyph_count,
1370 cluster_map,
1371 }
1372 }
1373}
1374
1375impl Iterator for ClusterAnalyzer<'_> {
1376 type Item = (usize, usize);
1377
1378 fn next(&mut self) -> Option<(usize, usize)> {
1379 if self.utf16_idx >= self.cluster_map.len() {
1380 return None; // No more clusters
1381 }
1382 let start_utf16_idx = self.utf16_idx;
1383 let current_glyph = self.cluster_map[start_utf16_idx] as usize;
1384
1385 // Find the end of current cluster (where glyph index changes)
1386 let mut end_utf16_idx = start_utf16_idx + 1;
1387 while end_utf16_idx < self.cluster_map.len()
1388 && self.cluster_map[end_utf16_idx] as usize == current_glyph
1389 {
1390 end_utf16_idx += 1;
1391 }
1392
1393 let utf16_len = end_utf16_idx - start_utf16_idx;
1394
1395 // Calculate glyph count for this cluster
1396 let next_glyph = if end_utf16_idx < self.cluster_map.len() {
1397 self.cluster_map[end_utf16_idx] as usize
1398 } else {
1399 self.glyph_count
1400 };
1401
1402 let glyph_count = next_glyph - current_glyph;
1403
1404 // Update state for next call
1405 self.utf16_idx = end_utf16_idx;
1406 self.glyph_idx = next_glyph;
1407
1408 Some((utf16_len, glyph_count))
1409 }
1410}
1411
1412#[allow(non_snake_case)]
1413impl IDWritePixelSnapping_Impl for TextRenderer_Impl {
1414 fn IsPixelSnappingDisabled(
1415 &self,
1416 _clientdrawingcontext: *const ::core::ffi::c_void,
1417 ) -> windows::core::Result<BOOL> {
1418 Ok(BOOL(0))
1419 }
1420
1421 fn GetCurrentTransform(
1422 &self,
1423 _clientdrawingcontext: *const ::core::ffi::c_void,
1424 transform: *mut DWRITE_MATRIX,
1425 ) -> windows::core::Result<()> {
1426 unsafe {
1427 *transform = DWRITE_MATRIX {
1428 m11: 1.0,
1429 m12: 0.0,
1430 m21: 0.0,
1431 m22: 1.0,
1432 dx: 0.0,
1433 dy: 0.0,
1434 };
1435 }
1436 Ok(())
1437 }
1438
1439 fn GetPixelsPerDip(
1440 &self,
1441 _clientdrawingcontext: *const ::core::ffi::c_void,
1442 ) -> windows::core::Result<f32> {
1443 Ok(1.0)
1444 }
1445}
1446
1447#[allow(non_snake_case)]
1448impl IDWriteTextRenderer_Impl for TextRenderer_Impl {
1449 fn DrawGlyphRun(
1450 &self,
1451 clientdrawingcontext: *const ::core::ffi::c_void,
1452 _baselineoriginx: f32,
1453 _baselineoriginy: f32,
1454 _measuringmode: DWRITE_MEASURING_MODE,
1455 glyphrun: *const DWRITE_GLYPH_RUN,
1456 glyphrundescription: *const DWRITE_GLYPH_RUN_DESCRIPTION,
1457 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1458 ) -> windows::core::Result<()> {
1459 let glyphrun = unsafe { &*glyphrun };
1460 let glyph_count = glyphrun.glyphCount as usize;
1461 if glyph_count == 0 || glyphrun.fontFace.is_none() {
1462 return Ok(());
1463 }
1464 let desc = unsafe { &*glyphrundescription };
1465 let context = unsafe {
1466 &mut *(clientdrawingcontext as *const RendererContext as *mut RendererContext)
1467 };
1468 let font_face = glyphrun.fontFace.as_ref().unwrap();
1469 // This `cast()` action here should never fail since we are running on Win10+, and
1470 // `IDWriteFontFace3` requires Win10
1471 let font_face = &font_face.cast::<IDWriteFontFace3>().unwrap();
1472 let Some((font_identifier, font_struct, color_font)) =
1473 get_font_identifier_and_font_struct(font_face, &self.locale)
1474 else {
1475 return Ok(());
1476 };
1477
1478 let font_id = if let Some(id) = context
1479 .text_system
1480 .font_id_by_identifier
1481 .get(&font_identifier)
1482 {
1483 *id
1484 } else {
1485 context.text_system.select_font(&font_struct)
1486 };
1487
1488 let glyph_ids = unsafe { std::slice::from_raw_parts(glyphrun.glyphIndices, glyph_count) };
1489 let glyph_advances =
1490 unsafe { std::slice::from_raw_parts(glyphrun.glyphAdvances, glyph_count) };
1491 let glyph_offsets =
1492 unsafe { std::slice::from_raw_parts(glyphrun.glyphOffsets, glyph_count) };
1493 let cluster_map =
1494 unsafe { std::slice::from_raw_parts(desc.clusterMap, desc.stringLength as usize) };
1495
1496 let mut cluster_analyzer = ClusterAnalyzer::new(cluster_map, glyph_count);
1497 let mut utf16_idx = desc.textPosition as usize;
1498 let mut glyph_idx = 0;
1499 let mut glyphs = Vec::with_capacity(glyph_count);
1500 for (cluster_utf16_len, cluster_glyph_count) in cluster_analyzer {
1501 context.index_converter.advance_to_utf16_ix(utf16_idx);
1502 utf16_idx += cluster_utf16_len;
1503 for (cluster_glyph_idx, glyph_id) in glyph_ids
1504 [glyph_idx..(glyph_idx + cluster_glyph_count)]
1505 .iter()
1506 .enumerate()
1507 {
1508 let id = GlyphId(*glyph_id as u32);
1509 let is_emoji = color_font
1510 && is_color_glyph(font_face, id, &context.text_system.components.factory);
1511 let this_glyph_idx = glyph_idx + cluster_glyph_idx;
1512 glyphs.push(ShapedGlyph {
1513 id,
1514 position: point(
1515 px(context.width + glyph_offsets[this_glyph_idx].advanceOffset),
1516 px(0.0),
1517 ),
1518 index: context.index_converter.utf8_ix,
1519 is_emoji,
1520 });
1521 context.width += glyph_advances[this_glyph_idx];
1522 }
1523 glyph_idx += cluster_glyph_count;
1524 }
1525 context.runs.push(ShapedRun { font_id, glyphs });
1526 Ok(())
1527 }
1528
1529 fn DrawUnderline(
1530 &self,
1531 _clientdrawingcontext: *const ::core::ffi::c_void,
1532 _baselineoriginx: f32,
1533 _baselineoriginy: f32,
1534 _underline: *const DWRITE_UNDERLINE,
1535 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1536 ) -> windows::core::Result<()> {
1537 Err(windows::core::Error::new(
1538 E_NOTIMPL,
1539 "DrawUnderline unimplemented",
1540 ))
1541 }
1542
1543 fn DrawStrikethrough(
1544 &self,
1545 _clientdrawingcontext: *const ::core::ffi::c_void,
1546 _baselineoriginx: f32,
1547 _baselineoriginy: f32,
1548 _strikethrough: *const DWRITE_STRIKETHROUGH,
1549 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1550 ) -> windows::core::Result<()> {
1551 Err(windows::core::Error::new(
1552 E_NOTIMPL,
1553 "DrawStrikethrough unimplemented",
1554 ))
1555 }
1556
1557 fn DrawInlineObject(
1558 &self,
1559 _clientdrawingcontext: *const ::core::ffi::c_void,
1560 _originx: f32,
1561 _originy: f32,
1562 _inlineobject: windows::core::Ref<IDWriteInlineObject>,
1563 _issideways: BOOL,
1564 _isrighttoleft: BOOL,
1565 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1566 ) -> windows::core::Result<()> {
1567 Err(windows::core::Error::new(
1568 E_NOTIMPL,
1569 "DrawInlineObject unimplemented",
1570 ))
1571 }
1572}
1573
1574struct StringIndexConverter<'a> {
1575 text: &'a str,
1576 utf8_ix: usize,
1577 utf16_ix: usize,
1578}
1579
1580impl<'a> StringIndexConverter<'a> {
1581 fn new(text: &'a str) -> Self {
1582 Self {
1583 text,
1584 utf8_ix: 0,
1585 utf16_ix: 0,
1586 }
1587 }
1588
1589 #[allow(dead_code)]
1590 fn advance_to_utf8_ix(&mut self, utf8_target: usize) {
1591 for (ix, c) in self.text[self.utf8_ix..].char_indices() {
1592 if self.utf8_ix + ix >= utf8_target {
1593 self.utf8_ix += ix;
1594 return;
1595 }
1596 self.utf16_ix += c.len_utf16();
1597 }
1598 self.utf8_ix = self.text.len();
1599 }
1600
1601 fn advance_to_utf16_ix(&mut self, utf16_target: usize) {
1602 for (ix, c) in self.text[self.utf8_ix..].char_indices() {
1603 if self.utf16_ix >= utf16_target {
1604 self.utf8_ix += ix;
1605 return;
1606 }
1607 self.utf16_ix += c.len_utf16();
1608 }
1609 self.utf8_ix = self.text.len();
1610 }
1611}
1612
1613impl Into<DWRITE_FONT_STYLE> for FontStyle {
1614 fn into(self) -> DWRITE_FONT_STYLE {
1615 match self {
1616 FontStyle::Normal => DWRITE_FONT_STYLE_NORMAL,
1617 FontStyle::Italic => DWRITE_FONT_STYLE_ITALIC,
1618 FontStyle::Oblique => DWRITE_FONT_STYLE_OBLIQUE,
1619 }
1620 }
1621}
1622
1623impl From<DWRITE_FONT_STYLE> for FontStyle {
1624 fn from(value: DWRITE_FONT_STYLE) -> Self {
1625 match value.0 {
1626 0 => FontStyle::Normal,
1627 1 => FontStyle::Italic,
1628 2 => FontStyle::Oblique,
1629 _ => unreachable!(),
1630 }
1631 }
1632}
1633
1634impl Into<DWRITE_FONT_WEIGHT> for FontWeight {
1635 fn into(self) -> DWRITE_FONT_WEIGHT {
1636 DWRITE_FONT_WEIGHT(self.0 as i32)
1637 }
1638}
1639
1640impl From<DWRITE_FONT_WEIGHT> for FontWeight {
1641 fn from(value: DWRITE_FONT_WEIGHT) -> Self {
1642 FontWeight(value.0 as f32)
1643 }
1644}
1645
1646fn get_font_names_from_collection(
1647 collection: &IDWriteFontCollection1,
1648 locale: &str,
1649) -> Vec<String> {
1650 unsafe {
1651 let mut result = Vec::new();
1652 let family_count = collection.GetFontFamilyCount();
1653 for index in 0..family_count {
1654 let Some(font_family) = collection.GetFontFamily(index).log_err() else {
1655 continue;
1656 };
1657 let Some(localized_family_name) = font_family.GetFamilyNames().log_err() else {
1658 continue;
1659 };
1660 let Some(family_name) = get_name(localized_family_name, locale).log_err() else {
1661 continue;
1662 };
1663 result.push(family_name);
1664 }
1665
1666 result
1667 }
1668}
1669
1670fn get_font_identifier_and_font_struct(
1671 font_face: &IDWriteFontFace3,
1672 locale: &str,
1673) -> Option<(FontIdentifier, Font, bool)> {
1674 let postscript_name = get_postscript_name(font_face, locale).log_err()?;
1675 let localized_family_name = unsafe { font_face.GetFamilyNames().log_err() }?;
1676 let family_name = get_name(localized_family_name, locale).log_err()?;
1677 let weight = unsafe { font_face.GetWeight() };
1678 let style = unsafe { font_face.GetStyle() };
1679 let identifier = FontIdentifier {
1680 postscript_name,
1681 weight: weight.0,
1682 style: style.0,
1683 };
1684 let font_struct = Font {
1685 family: family_name.into(),
1686 features: FontFeatures::default(),
1687 weight: weight.into(),
1688 style: style.into(),
1689 fallbacks: None,
1690 };
1691 let is_emoji = unsafe { font_face.IsColorFont().as_bool() };
1692 Some((identifier, font_struct, is_emoji))
1693}
1694
1695#[inline]
1696fn get_font_identifier(font_face: &IDWriteFontFace3, locale: &str) -> Option<FontIdentifier> {
1697 let weight = unsafe { font_face.GetWeight().0 };
1698 let style = unsafe { font_face.GetStyle().0 };
1699 get_postscript_name(font_face, locale)
1700 .log_err()
1701 .map(|postscript_name| FontIdentifier {
1702 postscript_name,
1703 weight,
1704 style,
1705 })
1706}
1707
1708#[inline]
1709fn get_postscript_name(font_face: &IDWriteFontFace3, locale: &str) -> Result<String> {
1710 let mut info = None;
1711 let mut exists = BOOL(0);
1712 unsafe {
1713 font_face.GetInformationalStrings(
1714 DWRITE_INFORMATIONAL_STRING_POSTSCRIPT_NAME,
1715 &mut info,
1716 &mut exists,
1717 )?
1718 };
1719 if !exists.as_bool() || info.is_none() {
1720 anyhow::bail!("No postscript name found for font face");
1721 }
1722
1723 get_name(info.unwrap(), locale)
1724}
1725
1726// https://learn.microsoft.com/en-us/windows/win32/api/dwrite/ne-dwrite-dwrite_font_feature_tag
1727fn apply_font_features(
1728 direct_write_features: &IDWriteTypography,
1729 features: &FontFeatures,
1730) -> Result<()> {
1731 let tag_values = features.tag_value_list();
1732 if tag_values.is_empty() {
1733 return Ok(());
1734 }
1735
1736 // All of these features are enabled by default by DirectWrite.
1737 // If you want to (and can) peek into the source of DirectWrite
1738 let mut feature_liga = make_direct_write_feature("liga", 1);
1739 let mut feature_clig = make_direct_write_feature("clig", 1);
1740 let mut feature_calt = make_direct_write_feature("calt", 1);
1741
1742 for (tag, value) in tag_values {
1743 if tag.as_str() == "liga" && *value == 0 {
1744 feature_liga.parameter = 0;
1745 continue;
1746 }
1747 if tag.as_str() == "clig" && *value == 0 {
1748 feature_clig.parameter = 0;
1749 continue;
1750 }
1751 if tag.as_str() == "calt" && *value == 0 {
1752 feature_calt.parameter = 0;
1753 continue;
1754 }
1755
1756 unsafe {
1757 direct_write_features.AddFontFeature(make_direct_write_feature(tag, *value))?;
1758 }
1759 }
1760 unsafe {
1761 direct_write_features.AddFontFeature(feature_liga)?;
1762 direct_write_features.AddFontFeature(feature_clig)?;
1763 direct_write_features.AddFontFeature(feature_calt)?;
1764 }
1765
1766 Ok(())
1767}
1768
1769#[inline]
1770const fn make_direct_write_feature(feature_name: &str, parameter: u32) -> DWRITE_FONT_FEATURE {
1771 let tag = make_direct_write_tag(feature_name);
1772 DWRITE_FONT_FEATURE {
1773 nameTag: tag,
1774 parameter,
1775 }
1776}
1777
1778#[inline]
1779const fn make_open_type_tag(tag_name: &str) -> u32 {
1780 let bytes = tag_name.as_bytes();
1781 debug_assert!(bytes.len() == 4);
1782 u32::from_le_bytes([bytes[0], bytes[1], bytes[2], bytes[3]])
1783}
1784
1785#[inline]
1786const fn make_direct_write_tag(tag_name: &str) -> DWRITE_FONT_FEATURE_TAG {
1787 DWRITE_FONT_FEATURE_TAG(make_open_type_tag(tag_name))
1788}
1789
1790#[inline]
1791fn get_name(string: IDWriteLocalizedStrings, locale: &str) -> Result<String> {
1792 let mut locale_name_index = 0u32;
1793 let mut exists = BOOL(0);
1794 unsafe {
1795 string.FindLocaleName(
1796 &HSTRING::from(locale),
1797 &mut locale_name_index,
1798 &mut exists as _,
1799 )?
1800 };
1801 if !exists.as_bool() {
1802 unsafe {
1803 string.FindLocaleName(
1804 DEFAULT_LOCALE_NAME,
1805 &mut locale_name_index as _,
1806 &mut exists as _,
1807 )?
1808 };
1809 anyhow::ensure!(exists.as_bool(), "No localised string for {locale}");
1810 }
1811
1812 let name_length = unsafe { string.GetStringLength(locale_name_index) }? as usize;
1813 let mut name_vec = vec![0u16; name_length + 1];
1814 unsafe {
1815 string.GetString(locale_name_index, &mut name_vec)?;
1816 }
1817
1818 Ok(String::from_utf16_lossy(&name_vec[..name_length]))
1819}
1820
1821fn get_system_ui_font_name() -> SharedString {
1822 unsafe {
1823 let mut info: LOGFONTW = std::mem::zeroed();
1824 let font_family = if SystemParametersInfoW(
1825 SPI_GETICONTITLELOGFONT,
1826 std::mem::size_of::<LOGFONTW>() as u32,
1827 Some(&mut info as *mut _ as _),
1828 SYSTEM_PARAMETERS_INFO_UPDATE_FLAGS(0),
1829 )
1830 .log_err()
1831 .is_none()
1832 {
1833 // https://learn.microsoft.com/en-us/windows/win32/uxguide/vis-fonts
1834 // Segoe UI is the Windows font intended for user interface text strings.
1835 "Segoe UI".into()
1836 } else {
1837 let font_name = String::from_utf16_lossy(&info.lfFaceName);
1838 font_name.trim_matches(char::from(0)).to_owned().into()
1839 };
1840 log::info!("Use {} as UI font.", font_family);
1841 font_family
1842 }
1843}
1844
1845// One would think that with newer DirectWrite method: IDWriteFontFace4::GetGlyphImageFormats
1846// but that doesn't seem to work for some glyphs, say ❤
1847fn is_color_glyph(
1848 font_face: &IDWriteFontFace3,
1849 glyph_id: GlyphId,
1850 factory: &IDWriteFactory5,
1851) -> bool {
1852 let glyph_run = DWRITE_GLYPH_RUN {
1853 fontFace: unsafe { std::mem::transmute_copy(font_face) },
1854 fontEmSize: 14.0,
1855 glyphCount: 1,
1856 glyphIndices: &(glyph_id.0 as u16),
1857 glyphAdvances: &0.0,
1858 glyphOffsets: &DWRITE_GLYPH_OFFSET {
1859 advanceOffset: 0.0,
1860 ascenderOffset: 0.0,
1861 },
1862 isSideways: BOOL(0),
1863 bidiLevel: 0,
1864 };
1865 unsafe {
1866 factory.TranslateColorGlyphRun(
1867 Vector2::default(),
1868 &glyph_run as _,
1869 None,
1870 DWRITE_GLYPH_IMAGE_FORMATS_COLR
1871 | DWRITE_GLYPH_IMAGE_FORMATS_SVG
1872 | DWRITE_GLYPH_IMAGE_FORMATS_PNG
1873 | DWRITE_GLYPH_IMAGE_FORMATS_JPEG
1874 | DWRITE_GLYPH_IMAGE_FORMATS_PREMULTIPLIED_B8G8R8A8,
1875 DWRITE_MEASURING_MODE_NATURAL,
1876 None,
1877 0,
1878 )
1879 }
1880 .is_ok()
1881}
1882
1883const DEFAULT_LOCALE_NAME: PCWSTR = windows::core::w!("en-US");
1884
1885#[cfg(test)]
1886mod tests {
1887 use crate::platform::windows::direct_write::ClusterAnalyzer;
1888
1889 #[test]
1890 fn test_cluster_map() {
1891 let cluster_map = [0];
1892 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 1);
1893 let next = analyzer.next();
1894 assert_eq!(next, Some((1, 1)));
1895 let next = analyzer.next();
1896 assert_eq!(next, None);
1897
1898 let cluster_map = [0, 1, 2];
1899 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 3);
1900 let next = analyzer.next();
1901 assert_eq!(next, Some((1, 1)));
1902 let next = analyzer.next();
1903 assert_eq!(next, Some((1, 1)));
1904 let next = analyzer.next();
1905 assert_eq!(next, Some((1, 1)));
1906 let next = analyzer.next();
1907 assert_eq!(next, None);
1908 // 👨👩👧👦👩💻
1909 let cluster_map = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 4, 4, 4];
1910 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 5);
1911 let next = analyzer.next();
1912 assert_eq!(next, Some((11, 4)));
1913 let next = analyzer.next();
1914 assert_eq!(next, Some((5, 1)));
1915 let next = analyzer.next();
1916 assert_eq!(next, None);
1917 // 👩💻
1918 let cluster_map = [0, 0, 0, 0, 0];
1919 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 1);
1920 let next = analyzer.next();
1921 assert_eq!(next, Some((5, 1)));
1922 let next = analyzer.next();
1923 assert_eq!(next, None);
1924 }
1925}