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 ascent = Pixels::default();
610 let mut descent = Pixels::default();
611 for run in font_runs {
612 if first_run {
613 first_run = false;
614 let mut metrics = vec![DWRITE_LINE_METRICS::default(); 4];
615 let mut line_count = 0u32;
616 text_layout.GetLineMetrics(Some(&mut metrics), &mut line_count as _)?;
617 ascent = px(metrics[0].baseline);
618 descent = px(metrics[0].height - metrics[0].baseline);
619 continue;
620 }
621 let font_info = &self.fonts[run.font_id.0];
622 let current_text = &text[utf8_offset..(utf8_offset + run.len)];
623 utf8_offset += run.len;
624 let current_text_utf16_length = current_text.encode_utf16().count() as u32;
625
626 let collection = if font_info.is_system_font {
627 &self.system_font_collection
628 } else {
629 &self.custom_font_collection
630 };
631 let text_range = DWRITE_TEXT_RANGE {
632 startPosition: utf16_offset,
633 length: current_text_utf16_length,
634 };
635 utf16_offset += current_text_utf16_length;
636 text_layout.SetFontCollection(collection, text_range)?;
637 text_layout
638 .SetFontFamilyName(&HSTRING::from(&font_info.font_family), text_range)?;
639 text_layout.SetFontSize(font_size.0, text_range)?;
640 text_layout.SetFontStyle(font_info.font_face.GetStyle(), text_range)?;
641 text_layout.SetFontWeight(font_info.font_face.GetWeight(), text_range)?;
642 text_layout.SetTypography(&font_info.features, text_range)?;
643 }
644
645 let mut runs = Vec::new();
646 let renderer_context = RendererContext {
647 text_system: self,
648 index_converter: StringIndexConverter::new(text),
649 runs: &mut runs,
650 width: 0.0,
651 };
652 text_layout.Draw(
653 Some(&renderer_context as *const _ as _),
654 &text_renderer.0,
655 0.0,
656 0.0,
657 )?;
658 let width = px(renderer_context.width);
659
660 Ok(LineLayout {
661 font_size,
662 width,
663 ascent,
664 descent,
665 runs,
666 len: text.len(),
667 })
668 }
669 }
670
671 fn font_metrics(&self, font_id: FontId) -> FontMetrics {
672 unsafe {
673 let font_info = &self.fonts[font_id.0];
674 let mut metrics = std::mem::zeroed();
675 font_info.font_face.GetMetrics(&mut metrics);
676
677 FontMetrics {
678 units_per_em: metrics.Base.designUnitsPerEm as _,
679 ascent: metrics.Base.ascent as _,
680 descent: -(metrics.Base.descent as f32),
681 line_gap: metrics.Base.lineGap as _,
682 underline_position: metrics.Base.underlinePosition as _,
683 underline_thickness: metrics.Base.underlineThickness as _,
684 cap_height: metrics.Base.capHeight as _,
685 x_height: metrics.Base.xHeight as _,
686 bounding_box: Bounds {
687 origin: Point {
688 x: metrics.glyphBoxLeft as _,
689 y: metrics.glyphBoxBottom as _,
690 },
691 size: Size {
692 width: (metrics.glyphBoxRight - metrics.glyphBoxLeft) as _,
693 height: (metrics.glyphBoxTop - metrics.glyphBoxBottom) as _,
694 },
695 },
696 }
697 }
698 }
699
700 fn create_glyph_run_analysis(
701 &self,
702 params: &RenderGlyphParams,
703 ) -> Result<IDWriteGlyphRunAnalysis> {
704 let font = &self.fonts[params.font_id.0];
705 let glyph_id = [params.glyph_id.0 as u16];
706 let advance = [0.0];
707 let offset = [DWRITE_GLYPH_OFFSET::default()];
708 let glyph_run = DWRITE_GLYPH_RUN {
709 fontFace: unsafe { std::mem::transmute_copy(&font.font_face) },
710 fontEmSize: params.font_size.0,
711 glyphCount: 1,
712 glyphIndices: glyph_id.as_ptr(),
713 glyphAdvances: advance.as_ptr(),
714 glyphOffsets: offset.as_ptr(),
715 isSideways: BOOL(0),
716 bidiLevel: 0,
717 };
718 let transform = DWRITE_MATRIX {
719 m11: params.scale_factor,
720 m12: 0.0,
721 m21: 0.0,
722 m22: params.scale_factor,
723 dx: 0.0,
724 dy: 0.0,
725 };
726 let baseline_origin_x =
727 params.subpixel_variant.x as f32 / SUBPIXEL_VARIANTS_X as f32 / params.scale_factor;
728 let baseline_origin_y =
729 params.subpixel_variant.y as f32 / SUBPIXEL_VARIANTS_Y as f32 / params.scale_factor;
730
731 let mut rendering_mode = DWRITE_RENDERING_MODE1::default();
732 let mut grid_fit_mode = DWRITE_GRID_FIT_MODE::default();
733 unsafe {
734 font.font_face.GetRecommendedRenderingMode(
735 params.font_size.0,
736 // Using 96 as scale is applied by the transform
737 96.0,
738 96.0,
739 Some(&transform),
740 false,
741 DWRITE_OUTLINE_THRESHOLD_ANTIALIASED,
742 DWRITE_MEASURING_MODE_NATURAL,
743 None,
744 &mut rendering_mode,
745 &mut grid_fit_mode,
746 )?;
747 }
748 let rendering_mode = match rendering_mode {
749 DWRITE_RENDERING_MODE1_OUTLINE => DWRITE_RENDERING_MODE1_NATURAL_SYMMETRIC,
750 m => m,
751 };
752
753 let glyph_analysis = unsafe {
754 self.components.factory.CreateGlyphRunAnalysis(
755 &glyph_run,
756 Some(&transform),
757 rendering_mode,
758 DWRITE_MEASURING_MODE_NATURAL,
759 grid_fit_mode,
760 DWRITE_TEXT_ANTIALIAS_MODE_GRAYSCALE,
761 baseline_origin_x,
762 baseline_origin_y,
763 )
764 }?;
765 Ok(glyph_analysis)
766 }
767
768 fn raster_bounds(&self, params: &RenderGlyphParams) -> Result<Bounds<DevicePixels>> {
769 let glyph_analysis = self.create_glyph_run_analysis(params)?;
770
771 let bounds = unsafe { glyph_analysis.GetAlphaTextureBounds(DWRITE_TEXTURE_ALIASED_1x1)? };
772
773 if bounds.right < bounds.left {
774 Ok(Bounds {
775 origin: point(0.into(), 0.into()),
776 size: size(0.into(), 0.into()),
777 })
778 } else {
779 Ok(Bounds {
780 origin: point(bounds.left.into(), bounds.top.into()),
781 size: size(
782 (bounds.right - bounds.left).into(),
783 (bounds.bottom - bounds.top).into(),
784 ),
785 })
786 }
787 }
788
789 fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
790 let font_info = &self.fonts[font_id.0];
791 let codepoints = [ch as u32];
792 let mut glyph_indices = vec![0u16; 1];
793 unsafe {
794 font_info
795 .font_face
796 .GetGlyphIndices(codepoints.as_ptr(), 1, glyph_indices.as_mut_ptr())
797 .log_err()
798 }
799 .map(|_| GlyphId(glyph_indices[0] as u32))
800 }
801
802 fn rasterize_glyph(
803 &self,
804 params: &RenderGlyphParams,
805 glyph_bounds: Bounds<DevicePixels>,
806 ) -> Result<(Size<DevicePixels>, Vec<u8>)> {
807 if glyph_bounds.size.width.0 == 0 || glyph_bounds.size.height.0 == 0 {
808 anyhow::bail!("glyph bounds are empty");
809 }
810
811 let bitmap_data = if params.is_emoji {
812 if let Ok(color) = self.rasterize_color(params, glyph_bounds) {
813 color
814 } else {
815 let monochrome = self.rasterize_monochrome(params, glyph_bounds)?;
816 monochrome
817 .into_iter()
818 .flat_map(|pixel| [0, 0, 0, pixel])
819 .collect::<Vec<_>>()
820 }
821 } else {
822 self.rasterize_monochrome(params, glyph_bounds)?
823 };
824
825 Ok((glyph_bounds.size, bitmap_data))
826 }
827
828 fn rasterize_monochrome(
829 &self,
830 params: &RenderGlyphParams,
831 glyph_bounds: Bounds<DevicePixels>,
832 ) -> Result<Vec<u8>> {
833 let mut bitmap_data =
834 vec![0u8; glyph_bounds.size.width.0 as usize * glyph_bounds.size.height.0 as usize];
835
836 let glyph_analysis = self.create_glyph_run_analysis(params)?;
837 unsafe {
838 glyph_analysis.CreateAlphaTexture(
839 DWRITE_TEXTURE_ALIASED_1x1,
840 &RECT {
841 left: glyph_bounds.origin.x.0,
842 top: glyph_bounds.origin.y.0,
843 right: glyph_bounds.size.width.0 + glyph_bounds.origin.x.0,
844 bottom: glyph_bounds.size.height.0 + glyph_bounds.origin.y.0,
845 },
846 &mut bitmap_data,
847 )?;
848 }
849
850 Ok(bitmap_data)
851 }
852
853 fn rasterize_color(
854 &self,
855 params: &RenderGlyphParams,
856 glyph_bounds: Bounds<DevicePixels>,
857 ) -> Result<Vec<u8>> {
858 let bitmap_size = glyph_bounds.size;
859 let subpixel_shift = params
860 .subpixel_variant
861 .map(|v| v as f32 / SUBPIXEL_VARIANTS_X as f32);
862 let baseline_origin_x = subpixel_shift.x / params.scale_factor;
863 let baseline_origin_y = subpixel_shift.y / params.scale_factor;
864
865 let transform = DWRITE_MATRIX {
866 m11: params.scale_factor,
867 m12: 0.0,
868 m21: 0.0,
869 m22: params.scale_factor,
870 dx: 0.0,
871 dy: 0.0,
872 };
873
874 let font = &self.fonts[params.font_id.0];
875 let glyph_id = [params.glyph_id.0 as u16];
876 let advance = [glyph_bounds.size.width.0 as f32];
877 let offset = [DWRITE_GLYPH_OFFSET {
878 advanceOffset: -glyph_bounds.origin.x.0 as f32 / params.scale_factor,
879 ascenderOffset: glyph_bounds.origin.y.0 as f32 / params.scale_factor,
880 }];
881 let glyph_run = DWRITE_GLYPH_RUN {
882 fontFace: unsafe { std::mem::transmute_copy(&font.font_face) },
883 fontEmSize: params.font_size.0,
884 glyphCount: 1,
885 glyphIndices: glyph_id.as_ptr(),
886 glyphAdvances: advance.as_ptr(),
887 glyphOffsets: offset.as_ptr(),
888 isSideways: BOOL(0),
889 bidiLevel: 0,
890 };
891
892 // todo: support formats other than COLR
893 let color_enumerator = unsafe {
894 self.components.factory.TranslateColorGlyphRun(
895 Vector2::new(baseline_origin_x, baseline_origin_y),
896 &glyph_run,
897 None,
898 DWRITE_GLYPH_IMAGE_FORMATS_COLR,
899 DWRITE_MEASURING_MODE_NATURAL,
900 Some(&transform),
901 0,
902 )
903 }?;
904
905 let mut glyph_layers = Vec::new();
906 loop {
907 let color_run = unsafe { color_enumerator.GetCurrentRun() }?;
908 let color_run = unsafe { &*color_run };
909 let image_format = color_run.glyphImageFormat & !DWRITE_GLYPH_IMAGE_FORMATS_TRUETYPE;
910 if image_format == DWRITE_GLYPH_IMAGE_FORMATS_COLR {
911 let color_analysis = unsafe {
912 self.components.factory.CreateGlyphRunAnalysis(
913 &color_run.Base.glyphRun as *const _,
914 Some(&transform),
915 DWRITE_RENDERING_MODE1_NATURAL_SYMMETRIC,
916 DWRITE_MEASURING_MODE_NATURAL,
917 DWRITE_GRID_FIT_MODE_DEFAULT,
918 DWRITE_TEXT_ANTIALIAS_MODE_GRAYSCALE,
919 baseline_origin_x,
920 baseline_origin_y,
921 )
922 }?;
923
924 let color_bounds =
925 unsafe { color_analysis.GetAlphaTextureBounds(DWRITE_TEXTURE_ALIASED_1x1) }?;
926
927 let color_size = size(
928 color_bounds.right - color_bounds.left,
929 color_bounds.bottom - color_bounds.top,
930 );
931 if color_size.width > 0 && color_size.height > 0 {
932 let mut alpha_data = vec![0u8; (color_size.width * color_size.height) as usize];
933 unsafe {
934 color_analysis.CreateAlphaTexture(
935 DWRITE_TEXTURE_ALIASED_1x1,
936 &color_bounds,
937 &mut alpha_data,
938 )
939 }?;
940
941 let run_color = {
942 let run_color = color_run.Base.runColor;
943 Rgba {
944 r: run_color.r,
945 g: run_color.g,
946 b: run_color.b,
947 a: run_color.a,
948 }
949 };
950 let bounds = bounds(point(color_bounds.left, color_bounds.top), color_size);
951 glyph_layers.push(GlyphLayerTexture::new(
952 &self.components.gpu_state,
953 run_color,
954 bounds,
955 &alpha_data,
956 )?);
957 }
958 }
959
960 let has_next = unsafe { color_enumerator.MoveNext() }
961 .map(|e| e.as_bool())
962 .unwrap_or(false);
963 if !has_next {
964 break;
965 }
966 }
967
968 let gpu_state = &self.components.gpu_state;
969 let params_buffer = {
970 let desc = D3D11_BUFFER_DESC {
971 ByteWidth: std::mem::size_of::<GlyphLayerTextureParams>() as u32,
972 Usage: D3D11_USAGE_DYNAMIC,
973 BindFlags: D3D11_BIND_CONSTANT_BUFFER.0 as u32,
974 CPUAccessFlags: D3D11_CPU_ACCESS_WRITE.0 as u32,
975 MiscFlags: 0,
976 StructureByteStride: 0,
977 };
978
979 let mut buffer = None;
980 unsafe {
981 gpu_state
982 .device
983 .CreateBuffer(&desc, None, Some(&mut buffer))
984 }?;
985 [buffer]
986 };
987
988 let render_target_texture = {
989 let mut texture = None;
990 let desc = D3D11_TEXTURE2D_DESC {
991 Width: bitmap_size.width.0 as u32,
992 Height: bitmap_size.height.0 as u32,
993 MipLevels: 1,
994 ArraySize: 1,
995 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
996 SampleDesc: DXGI_SAMPLE_DESC {
997 Count: 1,
998 Quality: 0,
999 },
1000 Usage: D3D11_USAGE_DEFAULT,
1001 BindFlags: D3D11_BIND_RENDER_TARGET.0 as u32,
1002 CPUAccessFlags: 0,
1003 MiscFlags: 0,
1004 };
1005 unsafe {
1006 gpu_state
1007 .device
1008 .CreateTexture2D(&desc, None, Some(&mut texture))
1009 }?;
1010 texture.unwrap()
1011 };
1012
1013 let render_target_view = {
1014 let desc = D3D11_RENDER_TARGET_VIEW_DESC {
1015 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
1016 ViewDimension: D3D11_RTV_DIMENSION_TEXTURE2D,
1017 Anonymous: D3D11_RENDER_TARGET_VIEW_DESC_0 {
1018 Texture2D: D3D11_TEX2D_RTV { MipSlice: 0 },
1019 },
1020 };
1021 let mut rtv = None;
1022 unsafe {
1023 gpu_state.device.CreateRenderTargetView(
1024 &render_target_texture,
1025 Some(&desc),
1026 Some(&mut rtv),
1027 )
1028 }?;
1029 [rtv]
1030 };
1031
1032 let staging_texture = {
1033 let mut texture = None;
1034 let desc = D3D11_TEXTURE2D_DESC {
1035 Width: bitmap_size.width.0 as u32,
1036 Height: bitmap_size.height.0 as u32,
1037 MipLevels: 1,
1038 ArraySize: 1,
1039 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
1040 SampleDesc: DXGI_SAMPLE_DESC {
1041 Count: 1,
1042 Quality: 0,
1043 },
1044 Usage: D3D11_USAGE_STAGING,
1045 BindFlags: 0,
1046 CPUAccessFlags: D3D11_CPU_ACCESS_READ.0 as u32,
1047 MiscFlags: 0,
1048 };
1049 unsafe {
1050 gpu_state
1051 .device
1052 .CreateTexture2D(&desc, None, Some(&mut texture))
1053 }?;
1054 texture.unwrap()
1055 };
1056
1057 let device_context = &gpu_state.device_context;
1058 unsafe { device_context.IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP) };
1059 unsafe { device_context.VSSetShader(&gpu_state.vertex_shader, None) };
1060 unsafe { device_context.PSSetShader(&gpu_state.pixel_shader, None) };
1061 unsafe { device_context.VSSetConstantBuffers(0, Some(¶ms_buffer)) };
1062 unsafe { device_context.PSSetConstantBuffers(0, Some(¶ms_buffer)) };
1063 unsafe { device_context.OMSetRenderTargets(Some(&render_target_view), None) };
1064 unsafe { device_context.PSSetSamplers(0, Some(&gpu_state.sampler)) };
1065 unsafe { device_context.OMSetBlendState(&gpu_state.blend_state, None, 0xffffffff) };
1066
1067 let crate::FontInfo {
1068 gamma_ratios,
1069 grayscale_enhanced_contrast,
1070 } = DirectXRenderer::get_font_info();
1071
1072 for layer in glyph_layers {
1073 let params = GlyphLayerTextureParams {
1074 run_color: layer.run_color,
1075 bounds: layer.bounds,
1076 gamma_ratios: *gamma_ratios,
1077 grayscale_enhanced_contrast: *grayscale_enhanced_contrast,
1078 _pad: [0f32; 3],
1079 };
1080 unsafe {
1081 let mut dest = std::mem::zeroed();
1082 gpu_state.device_context.Map(
1083 params_buffer[0].as_ref().unwrap(),
1084 0,
1085 D3D11_MAP_WRITE_DISCARD,
1086 0,
1087 Some(&mut dest),
1088 )?;
1089 std::ptr::copy_nonoverlapping(¶ms as *const _, dest.pData as *mut _, 1);
1090 gpu_state
1091 .device_context
1092 .Unmap(params_buffer[0].as_ref().unwrap(), 0);
1093 };
1094
1095 let texture = [Some(layer.texture_view)];
1096 unsafe { device_context.PSSetShaderResources(0, Some(&texture)) };
1097
1098 let viewport = [D3D11_VIEWPORT {
1099 TopLeftX: layer.bounds.origin.x as f32,
1100 TopLeftY: layer.bounds.origin.y as f32,
1101 Width: layer.bounds.size.width as f32,
1102 Height: layer.bounds.size.height as f32,
1103 MinDepth: 0.0,
1104 MaxDepth: 1.0,
1105 }];
1106 unsafe { device_context.RSSetViewports(Some(&viewport)) };
1107
1108 unsafe { device_context.Draw(4, 0) };
1109 }
1110
1111 unsafe { device_context.CopyResource(&staging_texture, &render_target_texture) };
1112
1113 let mapped_data = {
1114 let mut mapped_data = D3D11_MAPPED_SUBRESOURCE::default();
1115 unsafe {
1116 device_context.Map(
1117 &staging_texture,
1118 0,
1119 D3D11_MAP_READ,
1120 0,
1121 Some(&mut mapped_data),
1122 )
1123 }?;
1124 mapped_data
1125 };
1126 let mut rasterized =
1127 vec![0u8; (bitmap_size.width.0 as u32 * bitmap_size.height.0 as u32 * 4) as usize];
1128
1129 for y in 0..bitmap_size.height.0 as usize {
1130 let width = bitmap_size.width.0 as usize;
1131 unsafe {
1132 std::ptr::copy_nonoverlapping::<u8>(
1133 (mapped_data.pData as *const u8).byte_add(mapped_data.RowPitch as usize * y),
1134 rasterized
1135 .as_mut_ptr()
1136 .byte_add(width * y * std::mem::size_of::<u32>()),
1137 width * std::mem::size_of::<u32>(),
1138 )
1139 };
1140 }
1141
1142 // Convert from premultiplied to straight alpha
1143 for chunk in rasterized.chunks_exact_mut(4) {
1144 let b = chunk[0] as f32;
1145 let g = chunk[1] as f32;
1146 let r = chunk[2] as f32;
1147 let a = chunk[3] as f32;
1148 if a > 0.0 {
1149 let inv_a = 255.0 / a;
1150 chunk[0] = (b * inv_a).clamp(0.0, 255.0) as u8;
1151 chunk[1] = (g * inv_a).clamp(0.0, 255.0) as u8;
1152 chunk[2] = (r * inv_a).clamp(0.0, 255.0) as u8;
1153 }
1154 }
1155
1156 Ok(rasterized)
1157 }
1158
1159 fn get_typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>> {
1160 unsafe {
1161 let font = &self.fonts[font_id.0].font_face;
1162 let glyph_indices = [glyph_id.0 as u16];
1163 let mut metrics = [DWRITE_GLYPH_METRICS::default()];
1164 font.GetDesignGlyphMetrics(glyph_indices.as_ptr(), 1, metrics.as_mut_ptr(), false)?;
1165
1166 let metrics = &metrics[0];
1167 let advance_width = metrics.advanceWidth as i32;
1168 let advance_height = metrics.advanceHeight as i32;
1169 let left_side_bearing = metrics.leftSideBearing;
1170 let right_side_bearing = metrics.rightSideBearing;
1171 let top_side_bearing = metrics.topSideBearing;
1172 let bottom_side_bearing = metrics.bottomSideBearing;
1173 let vertical_origin_y = metrics.verticalOriginY;
1174
1175 let y_offset = vertical_origin_y + bottom_side_bearing - advance_height;
1176 let width = advance_width - (left_side_bearing + right_side_bearing);
1177 let height = advance_height - (top_side_bearing + bottom_side_bearing);
1178
1179 Ok(Bounds {
1180 origin: Point {
1181 x: left_side_bearing as f32,
1182 y: y_offset as f32,
1183 },
1184 size: Size {
1185 width: width as f32,
1186 height: height as f32,
1187 },
1188 })
1189 }
1190 }
1191
1192 fn get_advance(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Size<f32>> {
1193 unsafe {
1194 let font = &self.fonts[font_id.0].font_face;
1195 let glyph_indices = [glyph_id.0 as u16];
1196 let mut metrics = [DWRITE_GLYPH_METRICS::default()];
1197 font.GetDesignGlyphMetrics(glyph_indices.as_ptr(), 1, metrics.as_mut_ptr(), false)?;
1198
1199 let metrics = &metrics[0];
1200
1201 Ok(Size {
1202 width: metrics.advanceWidth as f32,
1203 height: 0.0,
1204 })
1205 }
1206 }
1207
1208 fn all_font_names(&self) -> Vec<String> {
1209 let mut result =
1210 get_font_names_from_collection(&self.system_font_collection, &self.components.locale);
1211 result.extend(get_font_names_from_collection(
1212 &self.custom_font_collection,
1213 &self.components.locale,
1214 ));
1215 result
1216 }
1217
1218 fn handle_gpu_lost(&mut self, directx_devices: &DirectXDevices) {
1219 try_to_recover_from_device_lost(
1220 || GPUState::new(directx_devices).context("Recreating GPU state for DirectWrite"),
1221 |gpu_state| self.components.gpu_state = gpu_state,
1222 || {
1223 log::error!(
1224 "Failed to recreate GPU state for DirectWrite after multiple attempts."
1225 );
1226 // Do something here?
1227 // At this point, the device loss is considered unrecoverable.
1228 },
1229 );
1230 }
1231}
1232
1233impl Drop for DirectWriteState {
1234 fn drop(&mut self) {
1235 unsafe {
1236 let _ = self
1237 .components
1238 .factory
1239 .UnregisterFontFileLoader(&self.components.in_memory_loader);
1240 }
1241 }
1242}
1243
1244struct GlyphLayerTexture {
1245 run_color: Rgba,
1246 bounds: Bounds<i32>,
1247 texture_view: ID3D11ShaderResourceView,
1248 // holding on to the texture to not RAII drop it
1249 _texture: ID3D11Texture2D,
1250}
1251
1252impl GlyphLayerTexture {
1253 pub fn new(
1254 gpu_state: &GPUState,
1255 run_color: Rgba,
1256 bounds: Bounds<i32>,
1257 alpha_data: &[u8],
1258 ) -> Result<Self> {
1259 let texture_size = bounds.size;
1260
1261 let desc = D3D11_TEXTURE2D_DESC {
1262 Width: texture_size.width as u32,
1263 Height: texture_size.height as u32,
1264 MipLevels: 1,
1265 ArraySize: 1,
1266 Format: DXGI_FORMAT_R8_UNORM,
1267 SampleDesc: DXGI_SAMPLE_DESC {
1268 Count: 1,
1269 Quality: 0,
1270 },
1271 Usage: D3D11_USAGE_DEFAULT,
1272 BindFlags: D3D11_BIND_SHADER_RESOURCE.0 as u32,
1273 CPUAccessFlags: 0,
1274 MiscFlags: 0,
1275 };
1276
1277 let texture = {
1278 let mut texture: Option<ID3D11Texture2D> = None;
1279 unsafe {
1280 gpu_state
1281 .device
1282 .CreateTexture2D(&desc, None, Some(&mut texture))?
1283 };
1284 texture.unwrap()
1285 };
1286 let texture_view = {
1287 let mut view: Option<ID3D11ShaderResourceView> = None;
1288 unsafe {
1289 gpu_state
1290 .device
1291 .CreateShaderResourceView(&texture, None, Some(&mut view))?
1292 };
1293 view.unwrap()
1294 };
1295
1296 unsafe {
1297 gpu_state.device_context.UpdateSubresource(
1298 &texture,
1299 0,
1300 None,
1301 alpha_data.as_ptr() as _,
1302 texture_size.width as u32,
1303 0,
1304 )
1305 };
1306
1307 Ok(GlyphLayerTexture {
1308 run_color,
1309 bounds,
1310 texture_view,
1311 _texture: texture,
1312 })
1313 }
1314}
1315
1316#[repr(C)]
1317struct GlyphLayerTextureParams {
1318 bounds: Bounds<i32>,
1319 run_color: Rgba,
1320 gamma_ratios: [f32; 4],
1321 grayscale_enhanced_contrast: f32,
1322 _pad: [f32; 3],
1323}
1324
1325struct TextRendererWrapper(pub IDWriteTextRenderer);
1326
1327impl TextRendererWrapper {
1328 pub fn new(locale_str: &str) -> Self {
1329 let inner = TextRenderer::new(locale_str);
1330 TextRendererWrapper(inner.into())
1331 }
1332}
1333
1334#[implement(IDWriteTextRenderer)]
1335struct TextRenderer {
1336 locale: String,
1337}
1338
1339impl TextRenderer {
1340 pub fn new(locale_str: &str) -> Self {
1341 TextRenderer {
1342 locale: locale_str.to_owned(),
1343 }
1344 }
1345}
1346
1347struct RendererContext<'t, 'a, 'b> {
1348 text_system: &'t mut DirectWriteState,
1349 index_converter: StringIndexConverter<'a>,
1350 runs: &'b mut Vec<ShapedRun>,
1351 width: f32,
1352}
1353
1354#[derive(Debug)]
1355struct ClusterAnalyzer<'t> {
1356 utf16_idx: usize,
1357 glyph_idx: usize,
1358 glyph_count: usize,
1359 cluster_map: &'t [u16],
1360}
1361
1362impl<'t> ClusterAnalyzer<'t> {
1363 pub fn new(cluster_map: &'t [u16], glyph_count: usize) -> Self {
1364 ClusterAnalyzer {
1365 utf16_idx: 0,
1366 glyph_idx: 0,
1367 glyph_count,
1368 cluster_map,
1369 }
1370 }
1371}
1372
1373impl Iterator for ClusterAnalyzer<'_> {
1374 type Item = (usize, usize);
1375
1376 fn next(&mut self) -> Option<(usize, usize)> {
1377 if self.utf16_idx >= self.cluster_map.len() {
1378 return None; // No more clusters
1379 }
1380 let start_utf16_idx = self.utf16_idx;
1381 let current_glyph = self.cluster_map[start_utf16_idx] as usize;
1382
1383 // Find the end of current cluster (where glyph index changes)
1384 let mut end_utf16_idx = start_utf16_idx + 1;
1385 while end_utf16_idx < self.cluster_map.len()
1386 && self.cluster_map[end_utf16_idx] as usize == current_glyph
1387 {
1388 end_utf16_idx += 1;
1389 }
1390
1391 let utf16_len = end_utf16_idx - start_utf16_idx;
1392
1393 // Calculate glyph count for this cluster
1394 let next_glyph = if end_utf16_idx < self.cluster_map.len() {
1395 self.cluster_map[end_utf16_idx] as usize
1396 } else {
1397 self.glyph_count
1398 };
1399
1400 let glyph_count = next_glyph - current_glyph;
1401
1402 // Update state for next call
1403 self.utf16_idx = end_utf16_idx;
1404 self.glyph_idx = next_glyph;
1405
1406 Some((utf16_len, glyph_count))
1407 }
1408}
1409
1410#[allow(non_snake_case)]
1411impl IDWritePixelSnapping_Impl for TextRenderer_Impl {
1412 fn IsPixelSnappingDisabled(
1413 &self,
1414 _clientdrawingcontext: *const ::core::ffi::c_void,
1415 ) -> windows::core::Result<BOOL> {
1416 Ok(BOOL(0))
1417 }
1418
1419 fn GetCurrentTransform(
1420 &self,
1421 _clientdrawingcontext: *const ::core::ffi::c_void,
1422 transform: *mut DWRITE_MATRIX,
1423 ) -> windows::core::Result<()> {
1424 unsafe {
1425 *transform = DWRITE_MATRIX {
1426 m11: 1.0,
1427 m12: 0.0,
1428 m21: 0.0,
1429 m22: 1.0,
1430 dx: 0.0,
1431 dy: 0.0,
1432 };
1433 }
1434 Ok(())
1435 }
1436
1437 fn GetPixelsPerDip(
1438 &self,
1439 _clientdrawingcontext: *const ::core::ffi::c_void,
1440 ) -> windows::core::Result<f32> {
1441 Ok(1.0)
1442 }
1443}
1444
1445#[allow(non_snake_case)]
1446impl IDWriteTextRenderer_Impl for TextRenderer_Impl {
1447 fn DrawGlyphRun(
1448 &self,
1449 clientdrawingcontext: *const ::core::ffi::c_void,
1450 _baselineoriginx: f32,
1451 _baselineoriginy: f32,
1452 _measuringmode: DWRITE_MEASURING_MODE,
1453 glyphrun: *const DWRITE_GLYPH_RUN,
1454 glyphrundescription: *const DWRITE_GLYPH_RUN_DESCRIPTION,
1455 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1456 ) -> windows::core::Result<()> {
1457 let glyphrun = unsafe { &*glyphrun };
1458 let glyph_count = glyphrun.glyphCount as usize;
1459 if glyph_count == 0 || glyphrun.fontFace.is_none() {
1460 return Ok(());
1461 }
1462 let desc = unsafe { &*glyphrundescription };
1463 let context = unsafe {
1464 &mut *(clientdrawingcontext as *const RendererContext as *mut RendererContext)
1465 };
1466 let font_face = glyphrun.fontFace.as_ref().unwrap();
1467 // This `cast()` action here should never fail since we are running on Win10+, and
1468 // `IDWriteFontFace3` requires Win10
1469 let font_face = &font_face.cast::<IDWriteFontFace3>().unwrap();
1470 let Some((font_identifier, font_struct, color_font)) =
1471 get_font_identifier_and_font_struct(font_face, &self.locale)
1472 else {
1473 return Ok(());
1474 };
1475
1476 let font_id = if let Some(id) = context
1477 .text_system
1478 .font_id_by_identifier
1479 .get(&font_identifier)
1480 {
1481 *id
1482 } else {
1483 context.text_system.select_font(&font_struct)
1484 };
1485
1486 let glyph_ids = unsafe { std::slice::from_raw_parts(glyphrun.glyphIndices, glyph_count) };
1487 let glyph_advances =
1488 unsafe { std::slice::from_raw_parts(glyphrun.glyphAdvances, glyph_count) };
1489 let glyph_offsets =
1490 unsafe { std::slice::from_raw_parts(glyphrun.glyphOffsets, glyph_count) };
1491 let cluster_map =
1492 unsafe { std::slice::from_raw_parts(desc.clusterMap, desc.stringLength as usize) };
1493
1494 let mut cluster_analyzer = ClusterAnalyzer::new(cluster_map, glyph_count);
1495 let mut utf16_idx = desc.textPosition as usize;
1496 let mut glyph_idx = 0;
1497 let mut glyphs = Vec::with_capacity(glyph_count);
1498 for (cluster_utf16_len, cluster_glyph_count) in cluster_analyzer {
1499 context.index_converter.advance_to_utf16_ix(utf16_idx);
1500 utf16_idx += cluster_utf16_len;
1501 for (cluster_glyph_idx, glyph_id) in glyph_ids
1502 [glyph_idx..(glyph_idx + cluster_glyph_count)]
1503 .iter()
1504 .enumerate()
1505 {
1506 let id = GlyphId(*glyph_id as u32);
1507 let is_emoji = color_font
1508 && is_color_glyph(font_face, id, &context.text_system.components.factory);
1509 let this_glyph_idx = glyph_idx + cluster_glyph_idx;
1510 glyphs.push(ShapedGlyph {
1511 id,
1512 position: point(
1513 px(context.width + glyph_offsets[this_glyph_idx].advanceOffset),
1514 px(0.0),
1515 ),
1516 index: context.index_converter.utf8_ix,
1517 is_emoji,
1518 });
1519 context.width += glyph_advances[this_glyph_idx];
1520 }
1521 glyph_idx += cluster_glyph_count;
1522 }
1523 context.runs.push(ShapedRun { font_id, glyphs });
1524 Ok(())
1525 }
1526
1527 fn DrawUnderline(
1528 &self,
1529 _clientdrawingcontext: *const ::core::ffi::c_void,
1530 _baselineoriginx: f32,
1531 _baselineoriginy: f32,
1532 _underline: *const DWRITE_UNDERLINE,
1533 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1534 ) -> windows::core::Result<()> {
1535 Err(windows::core::Error::new(
1536 E_NOTIMPL,
1537 "DrawUnderline unimplemented",
1538 ))
1539 }
1540
1541 fn DrawStrikethrough(
1542 &self,
1543 _clientdrawingcontext: *const ::core::ffi::c_void,
1544 _baselineoriginx: f32,
1545 _baselineoriginy: f32,
1546 _strikethrough: *const DWRITE_STRIKETHROUGH,
1547 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1548 ) -> windows::core::Result<()> {
1549 Err(windows::core::Error::new(
1550 E_NOTIMPL,
1551 "DrawStrikethrough unimplemented",
1552 ))
1553 }
1554
1555 fn DrawInlineObject(
1556 &self,
1557 _clientdrawingcontext: *const ::core::ffi::c_void,
1558 _originx: f32,
1559 _originy: f32,
1560 _inlineobject: windows::core::Ref<IDWriteInlineObject>,
1561 _issideways: BOOL,
1562 _isrighttoleft: BOOL,
1563 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1564 ) -> windows::core::Result<()> {
1565 Err(windows::core::Error::new(
1566 E_NOTIMPL,
1567 "DrawInlineObject unimplemented",
1568 ))
1569 }
1570}
1571
1572struct StringIndexConverter<'a> {
1573 text: &'a str,
1574 utf8_ix: usize,
1575 utf16_ix: usize,
1576}
1577
1578impl<'a> StringIndexConverter<'a> {
1579 fn new(text: &'a str) -> Self {
1580 Self {
1581 text,
1582 utf8_ix: 0,
1583 utf16_ix: 0,
1584 }
1585 }
1586
1587 #[allow(dead_code)]
1588 fn advance_to_utf8_ix(&mut self, utf8_target: usize) {
1589 for (ix, c) in self.text[self.utf8_ix..].char_indices() {
1590 if self.utf8_ix + ix >= utf8_target {
1591 self.utf8_ix += ix;
1592 return;
1593 }
1594 self.utf16_ix += c.len_utf16();
1595 }
1596 self.utf8_ix = self.text.len();
1597 }
1598
1599 fn advance_to_utf16_ix(&mut self, utf16_target: usize) {
1600 for (ix, c) in self.text[self.utf8_ix..].char_indices() {
1601 if self.utf16_ix >= utf16_target {
1602 self.utf8_ix += ix;
1603 return;
1604 }
1605 self.utf16_ix += c.len_utf16();
1606 }
1607 self.utf8_ix = self.text.len();
1608 }
1609}
1610
1611impl Into<DWRITE_FONT_STYLE> for FontStyle {
1612 fn into(self) -> DWRITE_FONT_STYLE {
1613 match self {
1614 FontStyle::Normal => DWRITE_FONT_STYLE_NORMAL,
1615 FontStyle::Italic => DWRITE_FONT_STYLE_ITALIC,
1616 FontStyle::Oblique => DWRITE_FONT_STYLE_OBLIQUE,
1617 }
1618 }
1619}
1620
1621impl From<DWRITE_FONT_STYLE> for FontStyle {
1622 fn from(value: DWRITE_FONT_STYLE) -> Self {
1623 match value.0 {
1624 0 => FontStyle::Normal,
1625 1 => FontStyle::Italic,
1626 2 => FontStyle::Oblique,
1627 _ => unreachable!(),
1628 }
1629 }
1630}
1631
1632impl Into<DWRITE_FONT_WEIGHT> for FontWeight {
1633 fn into(self) -> DWRITE_FONT_WEIGHT {
1634 DWRITE_FONT_WEIGHT(self.0 as i32)
1635 }
1636}
1637
1638impl From<DWRITE_FONT_WEIGHT> for FontWeight {
1639 fn from(value: DWRITE_FONT_WEIGHT) -> Self {
1640 FontWeight(value.0 as f32)
1641 }
1642}
1643
1644fn get_font_names_from_collection(
1645 collection: &IDWriteFontCollection1,
1646 locale: &str,
1647) -> Vec<String> {
1648 unsafe {
1649 let mut result = Vec::new();
1650 let family_count = collection.GetFontFamilyCount();
1651 for index in 0..family_count {
1652 let Some(font_family) = collection.GetFontFamily(index).log_err() else {
1653 continue;
1654 };
1655 let Some(localized_family_name) = font_family.GetFamilyNames().log_err() else {
1656 continue;
1657 };
1658 let Some(family_name) = get_name(localized_family_name, locale).log_err() else {
1659 continue;
1660 };
1661 result.push(family_name);
1662 }
1663
1664 result
1665 }
1666}
1667
1668fn get_font_identifier_and_font_struct(
1669 font_face: &IDWriteFontFace3,
1670 locale: &str,
1671) -> Option<(FontIdentifier, Font, bool)> {
1672 let postscript_name = get_postscript_name(font_face, locale).log_err()?;
1673 let localized_family_name = unsafe { font_face.GetFamilyNames().log_err() }?;
1674 let family_name = get_name(localized_family_name, locale).log_err()?;
1675 let weight = unsafe { font_face.GetWeight() };
1676 let style = unsafe { font_face.GetStyle() };
1677 let identifier = FontIdentifier {
1678 postscript_name,
1679 weight: weight.0,
1680 style: style.0,
1681 };
1682 let font_struct = Font {
1683 family: family_name.into(),
1684 features: FontFeatures::default(),
1685 weight: weight.into(),
1686 style: style.into(),
1687 fallbacks: None,
1688 };
1689 let is_emoji = unsafe { font_face.IsColorFont().as_bool() };
1690 Some((identifier, font_struct, is_emoji))
1691}
1692
1693#[inline]
1694fn get_font_identifier(font_face: &IDWriteFontFace3, locale: &str) -> Option<FontIdentifier> {
1695 let weight = unsafe { font_face.GetWeight().0 };
1696 let style = unsafe { font_face.GetStyle().0 };
1697 get_postscript_name(font_face, locale)
1698 .log_err()
1699 .map(|postscript_name| FontIdentifier {
1700 postscript_name,
1701 weight,
1702 style,
1703 })
1704}
1705
1706#[inline]
1707fn get_postscript_name(font_face: &IDWriteFontFace3, locale: &str) -> Result<String> {
1708 let mut info = None;
1709 let mut exists = BOOL(0);
1710 unsafe {
1711 font_face.GetInformationalStrings(
1712 DWRITE_INFORMATIONAL_STRING_POSTSCRIPT_NAME,
1713 &mut info,
1714 &mut exists,
1715 )?
1716 };
1717 if !exists.as_bool() || info.is_none() {
1718 anyhow::bail!("No postscript name found for font face");
1719 }
1720
1721 get_name(info.unwrap(), locale)
1722}
1723
1724// https://learn.microsoft.com/en-us/windows/win32/api/dwrite/ne-dwrite-dwrite_font_feature_tag
1725fn apply_font_features(
1726 direct_write_features: &IDWriteTypography,
1727 features: &FontFeatures,
1728) -> Result<()> {
1729 let tag_values = features.tag_value_list();
1730 if tag_values.is_empty() {
1731 return Ok(());
1732 }
1733
1734 // All of these features are enabled by default by DirectWrite.
1735 // If you want to (and can) peek into the source of DirectWrite
1736 let mut feature_liga = make_direct_write_feature("liga", 1);
1737 let mut feature_clig = make_direct_write_feature("clig", 1);
1738 let mut feature_calt = make_direct_write_feature("calt", 1);
1739
1740 for (tag, value) in tag_values {
1741 if tag.as_str() == "liga" && *value == 0 {
1742 feature_liga.parameter = 0;
1743 continue;
1744 }
1745 if tag.as_str() == "clig" && *value == 0 {
1746 feature_clig.parameter = 0;
1747 continue;
1748 }
1749 if tag.as_str() == "calt" && *value == 0 {
1750 feature_calt.parameter = 0;
1751 continue;
1752 }
1753
1754 unsafe {
1755 direct_write_features.AddFontFeature(make_direct_write_feature(tag, *value))?;
1756 }
1757 }
1758 unsafe {
1759 direct_write_features.AddFontFeature(feature_liga)?;
1760 direct_write_features.AddFontFeature(feature_clig)?;
1761 direct_write_features.AddFontFeature(feature_calt)?;
1762 }
1763
1764 Ok(())
1765}
1766
1767#[inline]
1768const fn make_direct_write_feature(feature_name: &str, parameter: u32) -> DWRITE_FONT_FEATURE {
1769 let tag = make_direct_write_tag(feature_name);
1770 DWRITE_FONT_FEATURE {
1771 nameTag: tag,
1772 parameter,
1773 }
1774}
1775
1776#[inline]
1777const fn make_open_type_tag(tag_name: &str) -> u32 {
1778 let bytes = tag_name.as_bytes();
1779 debug_assert!(bytes.len() == 4);
1780 u32::from_le_bytes([bytes[0], bytes[1], bytes[2], bytes[3]])
1781}
1782
1783#[inline]
1784const fn make_direct_write_tag(tag_name: &str) -> DWRITE_FONT_FEATURE_TAG {
1785 DWRITE_FONT_FEATURE_TAG(make_open_type_tag(tag_name))
1786}
1787
1788#[inline]
1789fn get_name(string: IDWriteLocalizedStrings, locale: &str) -> Result<String> {
1790 let mut locale_name_index = 0u32;
1791 let mut exists = BOOL(0);
1792 unsafe {
1793 string.FindLocaleName(
1794 &HSTRING::from(locale),
1795 &mut locale_name_index,
1796 &mut exists as _,
1797 )?
1798 };
1799 if !exists.as_bool() {
1800 unsafe {
1801 string.FindLocaleName(
1802 DEFAULT_LOCALE_NAME,
1803 &mut locale_name_index as _,
1804 &mut exists as _,
1805 )?
1806 };
1807 anyhow::ensure!(exists.as_bool(), "No localised string for {locale}");
1808 }
1809
1810 let name_length = unsafe { string.GetStringLength(locale_name_index) }? as usize;
1811 let mut name_vec = vec![0u16; name_length + 1];
1812 unsafe {
1813 string.GetString(locale_name_index, &mut name_vec)?;
1814 }
1815
1816 Ok(String::from_utf16_lossy(&name_vec[..name_length]))
1817}
1818
1819fn get_system_ui_font_name() -> SharedString {
1820 unsafe {
1821 let mut info: LOGFONTW = std::mem::zeroed();
1822 let font_family = if SystemParametersInfoW(
1823 SPI_GETICONTITLELOGFONT,
1824 std::mem::size_of::<LOGFONTW>() as u32,
1825 Some(&mut info as *mut _ as _),
1826 SYSTEM_PARAMETERS_INFO_UPDATE_FLAGS(0),
1827 )
1828 .log_err()
1829 .is_none()
1830 {
1831 // https://learn.microsoft.com/en-us/windows/win32/uxguide/vis-fonts
1832 // Segoe UI is the Windows font intended for user interface text strings.
1833 "Segoe UI".into()
1834 } else {
1835 let font_name = String::from_utf16_lossy(&info.lfFaceName);
1836 font_name.trim_matches(char::from(0)).to_owned().into()
1837 };
1838 log::info!("Use {} as UI font.", font_family);
1839 font_family
1840 }
1841}
1842
1843// One would think that with newer DirectWrite method: IDWriteFontFace4::GetGlyphImageFormats
1844// but that doesn't seem to work for some glyphs, say ❤
1845fn is_color_glyph(
1846 font_face: &IDWriteFontFace3,
1847 glyph_id: GlyphId,
1848 factory: &IDWriteFactory5,
1849) -> bool {
1850 let glyph_run = DWRITE_GLYPH_RUN {
1851 fontFace: unsafe { std::mem::transmute_copy(font_face) },
1852 fontEmSize: 14.0,
1853 glyphCount: 1,
1854 glyphIndices: &(glyph_id.0 as u16),
1855 glyphAdvances: &0.0,
1856 glyphOffsets: &DWRITE_GLYPH_OFFSET {
1857 advanceOffset: 0.0,
1858 ascenderOffset: 0.0,
1859 },
1860 isSideways: BOOL(0),
1861 bidiLevel: 0,
1862 };
1863 unsafe {
1864 factory.TranslateColorGlyphRun(
1865 Vector2::default(),
1866 &glyph_run as _,
1867 None,
1868 DWRITE_GLYPH_IMAGE_FORMATS_COLR
1869 | DWRITE_GLYPH_IMAGE_FORMATS_SVG
1870 | DWRITE_GLYPH_IMAGE_FORMATS_PNG
1871 | DWRITE_GLYPH_IMAGE_FORMATS_JPEG
1872 | DWRITE_GLYPH_IMAGE_FORMATS_PREMULTIPLIED_B8G8R8A8,
1873 DWRITE_MEASURING_MODE_NATURAL,
1874 None,
1875 0,
1876 )
1877 }
1878 .is_ok()
1879}
1880
1881const DEFAULT_LOCALE_NAME: PCWSTR = windows::core::w!("en-US");
1882
1883#[cfg(test)]
1884mod tests {
1885 use crate::platform::windows::direct_write::ClusterAnalyzer;
1886
1887 #[test]
1888 fn test_cluster_map() {
1889 let cluster_map = [0];
1890 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 1);
1891 let next = analyzer.next();
1892 assert_eq!(next, Some((1, 1)));
1893 let next = analyzer.next();
1894 assert_eq!(next, None);
1895
1896 let cluster_map = [0, 1, 2];
1897 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 3);
1898 let next = analyzer.next();
1899 assert_eq!(next, Some((1, 1)));
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, None);
1906 // 👨👩👧👦👩💻
1907 let cluster_map = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 4, 4, 4];
1908 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 5);
1909 let next = analyzer.next();
1910 assert_eq!(next, Some((11, 4)));
1911 let next = analyzer.next();
1912 assert_eq!(next, Some((5, 1)));
1913 let next = analyzer.next();
1914 assert_eq!(next, None);
1915 // 👩💻
1916 let cluster_map = [0, 0, 0, 0, 0];
1917 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 1);
1918 let next = analyzer.next();
1919 assert_eq!(next, Some((5, 1)));
1920 let next = analyzer.next();
1921 assert_eq!(next, None);
1922 }
1923}