1use std::{borrow::Cow, sync::Arc};
2
3use ::util::ResultExt;
4use anyhow::Result;
5use collections::HashMap;
6use itertools::Itertools;
7use parking_lot::{RwLock, RwLockUpgradableReadGuard};
8use windows::{
9 Win32::{
10 Foundation::*,
11 Globalization::GetUserDefaultLocaleName,
12 Graphics::{
13 Direct3D::D3D_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP, 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(gpu_context: &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(gpu_context)?;
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(gpu_context: &DirectXDevices) -> Result<Self> {
104 let device = gpu_context.device.clone();
105 let device_context = gpu_context.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(gpu_context: &DirectXDevices) -> Result<Self> {
187 let components = DirectWriteComponent::new(gpu_context)?;
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
215impl PlatformTextSystem for DirectWriteTextSystem {
216 fn add_fonts(&self, fonts: Vec<Cow<'static, [u8]>>) -> Result<()> {
217 self.0.write().add_fonts(fonts)
218 }
219
220 fn all_font_names(&self) -> Vec<String> {
221 self.0.read().all_font_names()
222 }
223
224 fn font_id(&self, font: &Font) -> Result<FontId> {
225 let lock = self.0.upgradable_read();
226 if let Some(font_id) = lock.font_selections.get(font) {
227 Ok(*font_id)
228 } else {
229 let mut lock = RwLockUpgradableReadGuard::upgrade(lock);
230 let font_id = lock.select_font(font);
231 lock.font_selections.insert(font.clone(), font_id);
232 Ok(font_id)
233 }
234 }
235
236 fn font_metrics(&self, font_id: FontId) -> FontMetrics {
237 self.0.read().font_metrics(font_id)
238 }
239
240 fn typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>> {
241 self.0.read().get_typographic_bounds(font_id, glyph_id)
242 }
243
244 fn advance(&self, font_id: FontId, glyph_id: GlyphId) -> anyhow::Result<Size<f32>> {
245 self.0.read().get_advance(font_id, glyph_id)
246 }
247
248 fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
249 self.0.read().glyph_for_char(font_id, ch)
250 }
251
252 fn glyph_raster_bounds(
253 &self,
254 params: &RenderGlyphParams,
255 ) -> anyhow::Result<Bounds<DevicePixels>> {
256 self.0.read().raster_bounds(params)
257 }
258
259 fn rasterize_glyph(
260 &self,
261 params: &RenderGlyphParams,
262 raster_bounds: Bounds<DevicePixels>,
263 ) -> anyhow::Result<(Size<DevicePixels>, Vec<u8>)> {
264 self.0.read().rasterize_glyph(params, raster_bounds)
265 }
266
267 fn layout_line(&self, text: &str, font_size: Pixels, runs: &[FontRun]) -> LineLayout {
268 self.0
269 .write()
270 .layout_line(text, font_size, runs)
271 .log_err()
272 .unwrap_or(LineLayout {
273 font_size,
274 ..Default::default()
275 })
276 }
277}
278
279impl DirectWriteState {
280 fn add_fonts(&mut self, fonts: Vec<Cow<'static, [u8]>>) -> Result<()> {
281 for font_data in fonts {
282 match font_data {
283 Cow::Borrowed(data) => unsafe {
284 let font_file = self
285 .components
286 .in_memory_loader
287 .CreateInMemoryFontFileReference(
288 &self.components.factory,
289 data.as_ptr() as _,
290 data.len() as _,
291 None,
292 )?;
293 self.components.builder.AddFontFile(&font_file)?;
294 },
295 Cow::Owned(data) => unsafe {
296 let font_file = self
297 .components
298 .in_memory_loader
299 .CreateInMemoryFontFileReference(
300 &self.components.factory,
301 data.as_ptr() as _,
302 data.len() as _,
303 None,
304 )?;
305 self.components.builder.AddFontFile(&font_file)?;
306 },
307 }
308 }
309 let set = unsafe { self.components.builder.CreateFontSet()? };
310 let collection = unsafe {
311 self.components
312 .factory
313 .CreateFontCollectionFromFontSet(&set)?
314 };
315 self.custom_font_collection = collection;
316
317 Ok(())
318 }
319
320 fn generate_font_fallbacks(
321 &self,
322 fallbacks: &FontFallbacks,
323 ) -> Result<Option<IDWriteFontFallback>> {
324 if fallbacks.fallback_list().is_empty() {
325 return Ok(None);
326 }
327 unsafe {
328 let builder = self.components.factory.CreateFontFallbackBuilder()?;
329 let font_set = &self.system_font_collection.GetFontSet()?;
330 for family_name in fallbacks.fallback_list() {
331 let Some(fonts) = font_set
332 .GetMatchingFonts(
333 &HSTRING::from(family_name),
334 DWRITE_FONT_WEIGHT_NORMAL,
335 DWRITE_FONT_STRETCH_NORMAL,
336 DWRITE_FONT_STYLE_NORMAL,
337 )
338 .log_err()
339 else {
340 continue;
341 };
342 if fonts.GetFontCount() == 0 {
343 log::error!("No matching font found for {}", family_name);
344 continue;
345 }
346 let font = fonts.GetFontFaceReference(0)?.CreateFontFace()?;
347 let mut count = 0;
348 font.GetUnicodeRanges(None, &mut count).ok();
349 if count == 0 {
350 continue;
351 }
352 let mut unicode_ranges = vec![DWRITE_UNICODE_RANGE::default(); count as usize];
353 let Some(_) = font
354 .GetUnicodeRanges(Some(&mut unicode_ranges), &mut count)
355 .log_err()
356 else {
357 continue;
358 };
359 let target_family_name = HSTRING::from(family_name);
360 builder.AddMapping(
361 &unicode_ranges,
362 &[target_family_name.as_ptr()],
363 None,
364 None,
365 None,
366 1.0,
367 )?;
368 }
369 let system_fallbacks = self.components.factory.GetSystemFontFallback()?;
370 builder.AddMappings(&system_fallbacks)?;
371 Ok(Some(builder.CreateFontFallback()?))
372 }
373 }
374
375 unsafe fn generate_font_features(
376 &self,
377 font_features: &FontFeatures,
378 ) -> Result<IDWriteTypography> {
379 let direct_write_features = unsafe { self.components.factory.CreateTypography()? };
380 apply_font_features(&direct_write_features, font_features)?;
381 Ok(direct_write_features)
382 }
383
384 unsafe fn get_font_id_from_font_collection(
385 &mut self,
386 family_name: &str,
387 font_weight: FontWeight,
388 font_style: FontStyle,
389 font_features: &FontFeatures,
390 font_fallbacks: Option<&FontFallbacks>,
391 is_system_font: bool,
392 ) -> Option<FontId> {
393 let collection = if is_system_font {
394 &self.system_font_collection
395 } else {
396 &self.custom_font_collection
397 };
398 let fontset = unsafe { collection.GetFontSet().log_err()? };
399 let font = unsafe {
400 fontset
401 .GetMatchingFonts(
402 &HSTRING::from(family_name),
403 font_weight.into(),
404 DWRITE_FONT_STRETCH_NORMAL,
405 font_style.into(),
406 )
407 .log_err()?
408 };
409 let total_number = unsafe { font.GetFontCount() };
410 for index in 0..total_number {
411 let Some(font_face_ref) = (unsafe { font.GetFontFaceReference(index).log_err() })
412 else {
413 continue;
414 };
415 let Some(font_face) = (unsafe { font_face_ref.CreateFontFace().log_err() }) else {
416 continue;
417 };
418 let Some(identifier) = get_font_identifier(&font_face, &self.components.locale) else {
419 continue;
420 };
421 let Some(direct_write_features) =
422 (unsafe { self.generate_font_features(font_features).log_err() })
423 else {
424 continue;
425 };
426 let fallbacks = font_fallbacks
427 .and_then(|fallbacks| self.generate_font_fallbacks(fallbacks).log_err().flatten());
428 let font_info = FontInfo {
429 font_family: family_name.to_owned(),
430 font_face,
431 features: direct_write_features,
432 fallbacks,
433 is_system_font,
434 };
435 let font_id = FontId(self.fonts.len());
436 self.fonts.push(font_info);
437 self.font_id_by_identifier.insert(identifier, font_id);
438 return Some(font_id);
439 }
440 None
441 }
442
443 unsafe fn update_system_font_collection(&mut self) {
444 let mut collection = unsafe { std::mem::zeroed() };
445 if unsafe {
446 self.components
447 .factory
448 .GetSystemFontCollection(false, &mut collection, true)
449 .log_err()
450 .is_some()
451 } {
452 self.system_font_collection = collection.unwrap();
453 }
454 }
455
456 fn select_font(&mut self, target_font: &Font) -> FontId {
457 unsafe {
458 if target_font.family == ".SystemUIFont" {
459 let family = self.system_ui_font_name.clone();
460 self.find_font_id(
461 family.as_ref(),
462 target_font.weight,
463 target_font.style,
464 &target_font.features,
465 target_font.fallbacks.as_ref(),
466 )
467 .unwrap()
468 } else {
469 let family = self.system_ui_font_name.clone();
470 self.find_font_id(
471 font_name_with_fallbacks(target_font.family.as_ref(), family.as_ref()),
472 target_font.weight,
473 target_font.style,
474 &target_font.features,
475 target_font.fallbacks.as_ref(),
476 )
477 .unwrap_or_else(|| {
478 #[cfg(any(test, feature = "test-support"))]
479 {
480 panic!("ERROR: {} font not found!", target_font.family);
481 }
482 #[cfg(not(any(test, feature = "test-support")))]
483 {
484 log::error!("{} not found, use {} instead.", target_font.family, family);
485 self.get_font_id_from_font_collection(
486 family.as_ref(),
487 target_font.weight,
488 target_font.style,
489 &target_font.features,
490 target_font.fallbacks.as_ref(),
491 true,
492 )
493 .unwrap()
494 }
495 })
496 }
497 }
498 }
499
500 unsafe fn find_font_id(
501 &mut self,
502 family_name: &str,
503 weight: FontWeight,
504 style: FontStyle,
505 features: &FontFeatures,
506 fallbacks: Option<&FontFallbacks>,
507 ) -> Option<FontId> {
508 // try to find target font in custom font collection first
509 unsafe {
510 self.get_font_id_from_font_collection(
511 family_name,
512 weight,
513 style,
514 features,
515 fallbacks,
516 false,
517 )
518 .or_else(|| {
519 self.get_font_id_from_font_collection(
520 family_name,
521 weight,
522 style,
523 features,
524 fallbacks,
525 true,
526 )
527 })
528 .or_else(|| {
529 self.update_system_font_collection();
530 self.get_font_id_from_font_collection(
531 family_name,
532 weight,
533 style,
534 features,
535 fallbacks,
536 true,
537 )
538 })
539 }
540 }
541
542 fn layout_line(
543 &mut self,
544 text: &str,
545 font_size: Pixels,
546 font_runs: &[FontRun],
547 ) -> Result<LineLayout> {
548 if font_runs.is_empty() {
549 return Ok(LineLayout {
550 font_size,
551 ..Default::default()
552 });
553 }
554 unsafe {
555 let text_renderer = self.components.text_renderer.clone();
556 let text_wide = text.encode_utf16().collect_vec();
557
558 let mut utf8_offset = 0usize;
559 let mut utf16_offset = 0u32;
560 let text_layout = {
561 let first_run = &font_runs[0];
562 let font_info = &self.fonts[first_run.font_id.0];
563 let collection = if font_info.is_system_font {
564 &self.system_font_collection
565 } else {
566 &self.custom_font_collection
567 };
568 let format: IDWriteTextFormat1 = self
569 .components
570 .factory
571 .CreateTextFormat(
572 &HSTRING::from(&font_info.font_family),
573 collection,
574 font_info.font_face.GetWeight(),
575 font_info.font_face.GetStyle(),
576 DWRITE_FONT_STRETCH_NORMAL,
577 font_size.0,
578 &HSTRING::from(&self.components.locale),
579 )?
580 .cast()?;
581 if let Some(ref fallbacks) = font_info.fallbacks {
582 format.SetFontFallback(fallbacks)?;
583 }
584
585 let layout = self.components.factory.CreateTextLayout(
586 &text_wide,
587 &format,
588 f32::INFINITY,
589 f32::INFINITY,
590 )?;
591 let current_text = &text[utf8_offset..(utf8_offset + first_run.len)];
592 utf8_offset += first_run.len;
593 let current_text_utf16_length = current_text.encode_utf16().count() as u32;
594 let text_range = DWRITE_TEXT_RANGE {
595 startPosition: utf16_offset,
596 length: current_text_utf16_length,
597 };
598 layout.SetTypography(&font_info.features, text_range)?;
599 utf16_offset += current_text_utf16_length;
600
601 layout
602 };
603
604 let mut first_run = true;
605 let mut ascent = Pixels::default();
606 let mut descent = Pixels::default();
607 for run in font_runs {
608 if first_run {
609 first_run = false;
610 let mut metrics = vec![DWRITE_LINE_METRICS::default(); 4];
611 let mut line_count = 0u32;
612 text_layout.GetLineMetrics(Some(&mut metrics), &mut line_count as _)?;
613 ascent = px(metrics[0].baseline);
614 descent = px(metrics[0].height - metrics[0].baseline);
615 continue;
616 }
617 let font_info = &self.fonts[run.font_id.0];
618 let current_text = &text[utf8_offset..(utf8_offset + run.len)];
619 utf8_offset += run.len;
620 let current_text_utf16_length = current_text.encode_utf16().count() as u32;
621
622 let collection = if font_info.is_system_font {
623 &self.system_font_collection
624 } else {
625 &self.custom_font_collection
626 };
627 let text_range = DWRITE_TEXT_RANGE {
628 startPosition: utf16_offset,
629 length: current_text_utf16_length,
630 };
631 utf16_offset += current_text_utf16_length;
632 text_layout.SetFontCollection(collection, text_range)?;
633 text_layout
634 .SetFontFamilyName(&HSTRING::from(&font_info.font_family), text_range)?;
635 text_layout.SetFontSize(font_size.0, text_range)?;
636 text_layout.SetFontStyle(font_info.font_face.GetStyle(), text_range)?;
637 text_layout.SetFontWeight(font_info.font_face.GetWeight(), text_range)?;
638 text_layout.SetTypography(&font_info.features, text_range)?;
639 }
640
641 let mut runs = Vec::new();
642 let renderer_context = RendererContext {
643 text_system: self,
644 index_converter: StringIndexConverter::new(text),
645 runs: &mut runs,
646 width: 0.0,
647 };
648 text_layout.Draw(
649 Some(&renderer_context as *const _ as _),
650 &text_renderer.0,
651 0.0,
652 0.0,
653 )?;
654 let width = px(renderer_context.width);
655
656 Ok(LineLayout {
657 font_size,
658 width,
659 ascent,
660 descent,
661 runs,
662 len: text.len(),
663 })
664 }
665 }
666
667 fn font_metrics(&self, font_id: FontId) -> FontMetrics {
668 unsafe {
669 let font_info = &self.fonts[font_id.0];
670 let mut metrics = std::mem::zeroed();
671 font_info.font_face.GetMetrics(&mut metrics);
672
673 FontMetrics {
674 units_per_em: metrics.Base.designUnitsPerEm as _,
675 ascent: metrics.Base.ascent as _,
676 descent: -(metrics.Base.descent as f32),
677 line_gap: metrics.Base.lineGap as _,
678 underline_position: metrics.Base.underlinePosition as _,
679 underline_thickness: metrics.Base.underlineThickness as _,
680 cap_height: metrics.Base.capHeight as _,
681 x_height: metrics.Base.xHeight as _,
682 bounding_box: Bounds {
683 origin: Point {
684 x: metrics.glyphBoxLeft as _,
685 y: metrics.glyphBoxBottom as _,
686 },
687 size: Size {
688 width: (metrics.glyphBoxRight - metrics.glyphBoxLeft) as _,
689 height: (metrics.glyphBoxTop - metrics.glyphBoxBottom) as _,
690 },
691 },
692 }
693 }
694 }
695
696 fn create_glyph_run_analysis(
697 &self,
698 params: &RenderGlyphParams,
699 ) -> Result<IDWriteGlyphRunAnalysis> {
700 let font = &self.fonts[params.font_id.0];
701 let glyph_id = [params.glyph_id.0 as u16];
702 let advance = [0.0];
703 let offset = [DWRITE_GLYPH_OFFSET::default()];
704 let glyph_run = DWRITE_GLYPH_RUN {
705 fontFace: unsafe { std::mem::transmute_copy(&font.font_face) },
706 fontEmSize: params.font_size.0,
707 glyphCount: 1,
708 glyphIndices: glyph_id.as_ptr(),
709 glyphAdvances: advance.as_ptr(),
710 glyphOffsets: offset.as_ptr(),
711 isSideways: BOOL(0),
712 bidiLevel: 0,
713 };
714 let transform = DWRITE_MATRIX {
715 m11: params.scale_factor,
716 m12: 0.0,
717 m21: 0.0,
718 m22: params.scale_factor,
719 dx: 0.0,
720 dy: 0.0,
721 };
722 let subpixel_shift = params
723 .subpixel_variant
724 .map(|v| v as f32 / SUBPIXEL_VARIANTS as f32);
725 let baseline_origin_x = subpixel_shift.x / params.scale_factor;
726 let baseline_origin_y = subpixel_shift.y / params.scale_factor;
727
728 let mut rendering_mode = DWRITE_RENDERING_MODE1::default();
729 let mut grid_fit_mode = DWRITE_GRID_FIT_MODE::default();
730 unsafe {
731 font.font_face.GetRecommendedRenderingMode(
732 params.font_size.0,
733 // Using 96 as scale is applied by the transform
734 96.0,
735 96.0,
736 Some(&transform),
737 false,
738 DWRITE_OUTLINE_THRESHOLD_ANTIALIASED,
739 DWRITE_MEASURING_MODE_NATURAL,
740 None,
741 &mut rendering_mode,
742 &mut grid_fit_mode,
743 )?;
744 }
745 let rendering_mode = match rendering_mode {
746 DWRITE_RENDERING_MODE1_OUTLINE => DWRITE_RENDERING_MODE1_NATURAL_SYMMETRIC,
747 m => m,
748 };
749
750 let glyph_analysis = unsafe {
751 self.components.factory.CreateGlyphRunAnalysis(
752 &glyph_run,
753 Some(&transform),
754 rendering_mode,
755 DWRITE_MEASURING_MODE_NATURAL,
756 grid_fit_mode,
757 DWRITE_TEXT_ANTIALIAS_MODE_GRAYSCALE,
758 baseline_origin_x,
759 baseline_origin_y,
760 )
761 }?;
762 Ok(glyph_analysis)
763 }
764
765 fn raster_bounds(&self, params: &RenderGlyphParams) -> Result<Bounds<DevicePixels>> {
766 let glyph_analysis = self.create_glyph_run_analysis(params)?;
767
768 let bounds = unsafe { glyph_analysis.GetAlphaTextureBounds(DWRITE_TEXTURE_ALIASED_1x1)? };
769
770 if bounds.right < bounds.left {
771 Ok(Bounds {
772 origin: point(0.into(), 0.into()),
773 size: size(0.into(), 0.into()),
774 })
775 } else {
776 Ok(Bounds {
777 origin: point(bounds.left.into(), bounds.top.into()),
778 size: size(
779 (bounds.right - bounds.left).into(),
780 (bounds.bottom - bounds.top).into(),
781 ),
782 })
783 }
784 }
785
786 fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
787 let font_info = &self.fonts[font_id.0];
788 let codepoints = [ch as u32];
789 let mut glyph_indices = vec![0u16; 1];
790 unsafe {
791 font_info
792 .font_face
793 .GetGlyphIndices(codepoints.as_ptr(), 1, glyph_indices.as_mut_ptr())
794 .log_err()
795 }
796 .map(|_| GlyphId(glyph_indices[0] as u32))
797 }
798
799 fn rasterize_glyph(
800 &self,
801 params: &RenderGlyphParams,
802 glyph_bounds: Bounds<DevicePixels>,
803 ) -> Result<(Size<DevicePixels>, Vec<u8>)> {
804 if glyph_bounds.size.width.0 == 0 || glyph_bounds.size.height.0 == 0 {
805 anyhow::bail!("glyph bounds are empty");
806 }
807
808 let bitmap_data = if params.is_emoji {
809 if let Ok(color) = self.rasterize_color(params, glyph_bounds) {
810 color
811 } else {
812 let monochrome = self.rasterize_monochrome(params, glyph_bounds)?;
813 monochrome
814 .into_iter()
815 .flat_map(|pixel| [0, 0, 0, pixel])
816 .collect::<Vec<_>>()
817 }
818 } else {
819 self.rasterize_monochrome(params, glyph_bounds)?
820 };
821
822 Ok((glyph_bounds.size, bitmap_data))
823 }
824
825 fn rasterize_monochrome(
826 &self,
827 params: &RenderGlyphParams,
828 glyph_bounds: Bounds<DevicePixels>,
829 ) -> Result<Vec<u8>> {
830 let mut bitmap_data =
831 vec![0u8; glyph_bounds.size.width.0 as usize * glyph_bounds.size.height.0 as usize];
832
833 let glyph_analysis = self.create_glyph_run_analysis(params)?;
834 unsafe {
835 glyph_analysis.CreateAlphaTexture(
836 DWRITE_TEXTURE_ALIASED_1x1,
837 &RECT {
838 left: glyph_bounds.origin.x.0,
839 top: glyph_bounds.origin.y.0,
840 right: glyph_bounds.size.width.0 + glyph_bounds.origin.x.0,
841 bottom: glyph_bounds.size.height.0 + glyph_bounds.origin.y.0,
842 },
843 &mut bitmap_data,
844 )?;
845 }
846
847 Ok(bitmap_data)
848 }
849
850 fn rasterize_color(
851 &self,
852 params: &RenderGlyphParams,
853 glyph_bounds: Bounds<DevicePixels>,
854 ) -> Result<Vec<u8>> {
855 let bitmap_size = glyph_bounds.size;
856 let subpixel_shift = params
857 .subpixel_variant
858 .map(|v| v as f32 / SUBPIXEL_VARIANTS as f32);
859 let baseline_origin_x = subpixel_shift.x / params.scale_factor;
860 let baseline_origin_y = subpixel_shift.y / params.scale_factor;
861
862 let transform = DWRITE_MATRIX {
863 m11: params.scale_factor,
864 m12: 0.0,
865 m21: 0.0,
866 m22: params.scale_factor,
867 dx: 0.0,
868 dy: 0.0,
869 };
870
871 let font = &self.fonts[params.font_id.0];
872 let glyph_id = [params.glyph_id.0 as u16];
873 let advance = [glyph_bounds.size.width.0 as f32];
874 let offset = [DWRITE_GLYPH_OFFSET {
875 advanceOffset: -glyph_bounds.origin.x.0 as f32 / params.scale_factor,
876 ascenderOffset: glyph_bounds.origin.y.0 as f32 / params.scale_factor,
877 }];
878 let glyph_run = DWRITE_GLYPH_RUN {
879 fontFace: unsafe { std::mem::transmute_copy(&font.font_face) },
880 fontEmSize: params.font_size.0,
881 glyphCount: 1,
882 glyphIndices: glyph_id.as_ptr(),
883 glyphAdvances: advance.as_ptr(),
884 glyphOffsets: offset.as_ptr(),
885 isSideways: BOOL(0),
886 bidiLevel: 0,
887 };
888
889 // todo: support formats other than COLR
890 let color_enumerator = unsafe {
891 self.components.factory.TranslateColorGlyphRun(
892 Vector2::new(baseline_origin_x, baseline_origin_y),
893 &glyph_run,
894 None,
895 DWRITE_GLYPH_IMAGE_FORMATS_COLR,
896 DWRITE_MEASURING_MODE_NATURAL,
897 Some(&transform),
898 0,
899 )
900 }?;
901
902 let mut glyph_layers = Vec::new();
903 loop {
904 let color_run = unsafe { color_enumerator.GetCurrentRun() }?;
905 let color_run = unsafe { &*color_run };
906 let image_format = color_run.glyphImageFormat & !DWRITE_GLYPH_IMAGE_FORMATS_TRUETYPE;
907 if image_format == DWRITE_GLYPH_IMAGE_FORMATS_COLR {
908 let color_analysis = unsafe {
909 self.components.factory.CreateGlyphRunAnalysis(
910 &color_run.Base.glyphRun as *const _,
911 Some(&transform),
912 DWRITE_RENDERING_MODE1_NATURAL_SYMMETRIC,
913 DWRITE_MEASURING_MODE_NATURAL,
914 DWRITE_GRID_FIT_MODE_DEFAULT,
915 DWRITE_TEXT_ANTIALIAS_MODE_GRAYSCALE,
916 baseline_origin_x,
917 baseline_origin_y,
918 )
919 }?;
920
921 let color_bounds =
922 unsafe { color_analysis.GetAlphaTextureBounds(DWRITE_TEXTURE_ALIASED_1x1) }?;
923
924 let color_size = size(
925 color_bounds.right - color_bounds.left,
926 color_bounds.bottom - color_bounds.top,
927 );
928 if color_size.width > 0 && color_size.height > 0 {
929 let mut alpha_data = vec![0u8; (color_size.width * color_size.height) as usize];
930 unsafe {
931 color_analysis.CreateAlphaTexture(
932 DWRITE_TEXTURE_ALIASED_1x1,
933 &color_bounds,
934 &mut alpha_data,
935 )
936 }?;
937
938 let run_color = {
939 let run_color = color_run.Base.runColor;
940 Rgba {
941 r: run_color.r,
942 g: run_color.g,
943 b: run_color.b,
944 a: run_color.a,
945 }
946 };
947 let bounds = bounds(point(color_bounds.left, color_bounds.top), color_size);
948 glyph_layers.push(GlyphLayerTexture::new(
949 &self.components.gpu_state,
950 run_color,
951 bounds,
952 &alpha_data,
953 )?);
954 }
955 }
956
957 let has_next = unsafe { color_enumerator.MoveNext() }
958 .map(|e| e.as_bool())
959 .unwrap_or(false);
960 if !has_next {
961 break;
962 }
963 }
964
965 let gpu_state = &self.components.gpu_state;
966 let params_buffer = {
967 let desc = D3D11_BUFFER_DESC {
968 ByteWidth: std::mem::size_of::<GlyphLayerTextureParams>() as u32,
969 Usage: D3D11_USAGE_DYNAMIC,
970 BindFlags: D3D11_BIND_CONSTANT_BUFFER.0 as u32,
971 CPUAccessFlags: D3D11_CPU_ACCESS_WRITE.0 as u32,
972 MiscFlags: 0,
973 StructureByteStride: 0,
974 };
975
976 let mut buffer = None;
977 unsafe {
978 gpu_state
979 .device
980 .CreateBuffer(&desc, None, Some(&mut buffer))
981 }?;
982 [buffer]
983 };
984
985 let render_target_texture = {
986 let mut texture = None;
987 let desc = D3D11_TEXTURE2D_DESC {
988 Width: bitmap_size.width.0 as u32,
989 Height: bitmap_size.height.0 as u32,
990 MipLevels: 1,
991 ArraySize: 1,
992 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
993 SampleDesc: DXGI_SAMPLE_DESC {
994 Count: 1,
995 Quality: 0,
996 },
997 Usage: D3D11_USAGE_DEFAULT,
998 BindFlags: D3D11_BIND_RENDER_TARGET.0 as u32,
999 CPUAccessFlags: 0,
1000 MiscFlags: 0,
1001 };
1002 unsafe {
1003 gpu_state
1004 .device
1005 .CreateTexture2D(&desc, None, Some(&mut texture))
1006 }?;
1007 texture.unwrap()
1008 };
1009
1010 let render_target_view = {
1011 let desc = D3D11_RENDER_TARGET_VIEW_DESC {
1012 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
1013 ViewDimension: D3D11_RTV_DIMENSION_TEXTURE2D,
1014 Anonymous: D3D11_RENDER_TARGET_VIEW_DESC_0 {
1015 Texture2D: D3D11_TEX2D_RTV { MipSlice: 0 },
1016 },
1017 };
1018 let mut rtv = None;
1019 unsafe {
1020 gpu_state.device.CreateRenderTargetView(
1021 &render_target_texture,
1022 Some(&desc),
1023 Some(&mut rtv),
1024 )
1025 }?;
1026 [rtv]
1027 };
1028
1029 let staging_texture = {
1030 let mut texture = None;
1031 let desc = D3D11_TEXTURE2D_DESC {
1032 Width: bitmap_size.width.0 as u32,
1033 Height: bitmap_size.height.0 as u32,
1034 MipLevels: 1,
1035 ArraySize: 1,
1036 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
1037 SampleDesc: DXGI_SAMPLE_DESC {
1038 Count: 1,
1039 Quality: 0,
1040 },
1041 Usage: D3D11_USAGE_STAGING,
1042 BindFlags: 0,
1043 CPUAccessFlags: D3D11_CPU_ACCESS_READ.0 as u32,
1044 MiscFlags: 0,
1045 };
1046 unsafe {
1047 gpu_state
1048 .device
1049 .CreateTexture2D(&desc, None, Some(&mut texture))
1050 }?;
1051 texture.unwrap()
1052 };
1053
1054 let device_context = &gpu_state.device_context;
1055 unsafe { device_context.IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP) };
1056 unsafe { device_context.VSSetShader(&gpu_state.vertex_shader, None) };
1057 unsafe { device_context.PSSetShader(&gpu_state.pixel_shader, None) };
1058 unsafe { device_context.VSSetConstantBuffers(0, Some(¶ms_buffer)) };
1059 unsafe { device_context.PSSetConstantBuffers(0, Some(¶ms_buffer)) };
1060 unsafe { device_context.OMSetRenderTargets(Some(&render_target_view), None) };
1061 unsafe { device_context.PSSetSamplers(0, Some(&gpu_state.sampler)) };
1062 unsafe { device_context.OMSetBlendState(&gpu_state.blend_state, None, 0xffffffff) };
1063
1064 let crate::FontInfo {
1065 gamma_ratios,
1066 grayscale_enhanced_contrast,
1067 } = DirectXRenderer::get_font_info();
1068
1069 for layer in glyph_layers {
1070 let params = GlyphLayerTextureParams {
1071 run_color: layer.run_color,
1072 bounds: layer.bounds,
1073 gamma_ratios: *gamma_ratios,
1074 grayscale_enhanced_contrast: *grayscale_enhanced_contrast,
1075 _pad: [0f32; 3],
1076 };
1077 unsafe {
1078 let mut dest = std::mem::zeroed();
1079 gpu_state.device_context.Map(
1080 params_buffer[0].as_ref().unwrap(),
1081 0,
1082 D3D11_MAP_WRITE_DISCARD,
1083 0,
1084 Some(&mut dest),
1085 )?;
1086 std::ptr::copy_nonoverlapping(¶ms as *const _, dest.pData as *mut _, 1);
1087 gpu_state
1088 .device_context
1089 .Unmap(params_buffer[0].as_ref().unwrap(), 0);
1090 };
1091
1092 let texture = [Some(layer.texture_view)];
1093 unsafe { device_context.PSSetShaderResources(0, Some(&texture)) };
1094
1095 let viewport = [D3D11_VIEWPORT {
1096 TopLeftX: layer.bounds.origin.x as f32,
1097 TopLeftY: layer.bounds.origin.y as f32,
1098 Width: layer.bounds.size.width as f32,
1099 Height: layer.bounds.size.height as f32,
1100 MinDepth: 0.0,
1101 MaxDepth: 1.0,
1102 }];
1103 unsafe { device_context.RSSetViewports(Some(&viewport)) };
1104
1105 unsafe { device_context.Draw(4, 0) };
1106 }
1107
1108 unsafe { device_context.CopyResource(&staging_texture, &render_target_texture) };
1109
1110 let mapped_data = {
1111 let mut mapped_data = D3D11_MAPPED_SUBRESOURCE::default();
1112 unsafe {
1113 device_context.Map(
1114 &staging_texture,
1115 0,
1116 D3D11_MAP_READ,
1117 0,
1118 Some(&mut mapped_data),
1119 )
1120 }?;
1121 mapped_data
1122 };
1123 let mut rasterized =
1124 vec![0u8; (bitmap_size.width.0 as u32 * bitmap_size.height.0 as u32 * 4) as usize];
1125
1126 for y in 0..bitmap_size.height.0 as usize {
1127 let width = bitmap_size.width.0 as usize;
1128 unsafe {
1129 std::ptr::copy_nonoverlapping::<u8>(
1130 (mapped_data.pData as *const u8).byte_add(mapped_data.RowPitch as usize * y),
1131 rasterized
1132 .as_mut_ptr()
1133 .byte_add(width * y * std::mem::size_of::<u32>()),
1134 width * std::mem::size_of::<u32>(),
1135 )
1136 };
1137 }
1138
1139 // Convert from premultiplied to straight alpha
1140 for chunk in rasterized.chunks_exact_mut(4) {
1141 let b = chunk[0] as f32;
1142 let g = chunk[1] as f32;
1143 let r = chunk[2] as f32;
1144 let a = chunk[3] as f32;
1145 if a > 0.0 {
1146 let inv_a = 255.0 / a;
1147 chunk[0] = (b * inv_a).clamp(0.0, 255.0) as u8;
1148 chunk[1] = (g * inv_a).clamp(0.0, 255.0) as u8;
1149 chunk[2] = (r * inv_a).clamp(0.0, 255.0) as u8;
1150 }
1151 }
1152
1153 Ok(rasterized)
1154 }
1155
1156 fn get_typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>> {
1157 unsafe {
1158 let font = &self.fonts[font_id.0].font_face;
1159 let glyph_indices = [glyph_id.0 as u16];
1160 let mut metrics = [DWRITE_GLYPH_METRICS::default()];
1161 font.GetDesignGlyphMetrics(glyph_indices.as_ptr(), 1, metrics.as_mut_ptr(), false)?;
1162
1163 let metrics = &metrics[0];
1164 let advance_width = metrics.advanceWidth as i32;
1165 let advance_height = metrics.advanceHeight as i32;
1166 let left_side_bearing = metrics.leftSideBearing;
1167 let right_side_bearing = metrics.rightSideBearing;
1168 let top_side_bearing = metrics.topSideBearing;
1169 let bottom_side_bearing = metrics.bottomSideBearing;
1170 let vertical_origin_y = metrics.verticalOriginY;
1171
1172 let y_offset = vertical_origin_y + bottom_side_bearing - advance_height;
1173 let width = advance_width - (left_side_bearing + right_side_bearing);
1174 let height = advance_height - (top_side_bearing + bottom_side_bearing);
1175
1176 Ok(Bounds {
1177 origin: Point {
1178 x: left_side_bearing as f32,
1179 y: y_offset as f32,
1180 },
1181 size: Size {
1182 width: width as f32,
1183 height: height as f32,
1184 },
1185 })
1186 }
1187 }
1188
1189 fn get_advance(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Size<f32>> {
1190 unsafe {
1191 let font = &self.fonts[font_id.0].font_face;
1192 let glyph_indices = [glyph_id.0 as u16];
1193 let mut metrics = [DWRITE_GLYPH_METRICS::default()];
1194 font.GetDesignGlyphMetrics(glyph_indices.as_ptr(), 1, metrics.as_mut_ptr(), false)?;
1195
1196 let metrics = &metrics[0];
1197
1198 Ok(Size {
1199 width: metrics.advanceWidth as f32,
1200 height: 0.0,
1201 })
1202 }
1203 }
1204
1205 fn all_font_names(&self) -> Vec<String> {
1206 let mut result =
1207 get_font_names_from_collection(&self.system_font_collection, &self.components.locale);
1208 result.extend(get_font_names_from_collection(
1209 &self.custom_font_collection,
1210 &self.components.locale,
1211 ));
1212 result
1213 }
1214}
1215
1216impl Drop for DirectWriteState {
1217 fn drop(&mut self) {
1218 unsafe {
1219 let _ = self
1220 .components
1221 .factory
1222 .UnregisterFontFileLoader(&self.components.in_memory_loader);
1223 }
1224 }
1225}
1226
1227struct GlyphLayerTexture {
1228 run_color: Rgba,
1229 bounds: Bounds<i32>,
1230 texture_view: ID3D11ShaderResourceView,
1231 // holding on to the texture to not RAII drop it
1232 _texture: ID3D11Texture2D,
1233}
1234
1235impl GlyphLayerTexture {
1236 pub fn new(
1237 gpu_state: &GPUState,
1238 run_color: Rgba,
1239 bounds: Bounds<i32>,
1240 alpha_data: &[u8],
1241 ) -> Result<Self> {
1242 let texture_size = bounds.size;
1243
1244 let desc = D3D11_TEXTURE2D_DESC {
1245 Width: texture_size.width as u32,
1246 Height: texture_size.height as u32,
1247 MipLevels: 1,
1248 ArraySize: 1,
1249 Format: DXGI_FORMAT_R8_UNORM,
1250 SampleDesc: DXGI_SAMPLE_DESC {
1251 Count: 1,
1252 Quality: 0,
1253 },
1254 Usage: D3D11_USAGE_DEFAULT,
1255 BindFlags: D3D11_BIND_SHADER_RESOURCE.0 as u32,
1256 CPUAccessFlags: 0,
1257 MiscFlags: 0,
1258 };
1259
1260 let texture = {
1261 let mut texture: Option<ID3D11Texture2D> = None;
1262 unsafe {
1263 gpu_state
1264 .device
1265 .CreateTexture2D(&desc, None, Some(&mut texture))?
1266 };
1267 texture.unwrap()
1268 };
1269 let texture_view = {
1270 let mut view: Option<ID3D11ShaderResourceView> = None;
1271 unsafe {
1272 gpu_state
1273 .device
1274 .CreateShaderResourceView(&texture, None, Some(&mut view))?
1275 };
1276 view.unwrap()
1277 };
1278
1279 unsafe {
1280 gpu_state.device_context.UpdateSubresource(
1281 &texture,
1282 0,
1283 None,
1284 alpha_data.as_ptr() as _,
1285 texture_size.width as u32,
1286 0,
1287 )
1288 };
1289
1290 Ok(GlyphLayerTexture {
1291 run_color,
1292 bounds,
1293 texture_view,
1294 _texture: texture,
1295 })
1296 }
1297}
1298
1299#[repr(C)]
1300struct GlyphLayerTextureParams {
1301 bounds: Bounds<i32>,
1302 run_color: Rgba,
1303 gamma_ratios: [f32; 4],
1304 grayscale_enhanced_contrast: f32,
1305 _pad: [f32; 3],
1306}
1307
1308struct TextRendererWrapper(pub IDWriteTextRenderer);
1309
1310impl TextRendererWrapper {
1311 pub fn new(locale_str: &str) -> Self {
1312 let inner = TextRenderer::new(locale_str);
1313 TextRendererWrapper(inner.into())
1314 }
1315}
1316
1317#[implement(IDWriteTextRenderer)]
1318struct TextRenderer {
1319 locale: String,
1320}
1321
1322impl TextRenderer {
1323 pub fn new(locale_str: &str) -> Self {
1324 TextRenderer {
1325 locale: locale_str.to_owned(),
1326 }
1327 }
1328}
1329
1330struct RendererContext<'t, 'a, 'b> {
1331 text_system: &'t mut DirectWriteState,
1332 index_converter: StringIndexConverter<'a>,
1333 runs: &'b mut Vec<ShapedRun>,
1334 width: f32,
1335}
1336
1337#[derive(Debug)]
1338struct ClusterAnalyzer<'t> {
1339 utf16_idx: usize,
1340 glyph_idx: usize,
1341 glyph_count: usize,
1342 cluster_map: &'t [u16],
1343}
1344
1345impl<'t> ClusterAnalyzer<'t> {
1346 pub fn new(cluster_map: &'t [u16], glyph_count: usize) -> Self {
1347 ClusterAnalyzer {
1348 utf16_idx: 0,
1349 glyph_idx: 0,
1350 glyph_count,
1351 cluster_map,
1352 }
1353 }
1354}
1355
1356impl Iterator for ClusterAnalyzer<'_> {
1357 type Item = (usize, usize);
1358
1359 fn next(&mut self) -> Option<(usize, usize)> {
1360 if self.utf16_idx >= self.cluster_map.len() {
1361 return None; // No more clusters
1362 }
1363 let start_utf16_idx = self.utf16_idx;
1364 let current_glyph = self.cluster_map[start_utf16_idx] as usize;
1365
1366 // Find the end of current cluster (where glyph index changes)
1367 let mut end_utf16_idx = start_utf16_idx + 1;
1368 while end_utf16_idx < self.cluster_map.len()
1369 && self.cluster_map[end_utf16_idx] as usize == current_glyph
1370 {
1371 end_utf16_idx += 1;
1372 }
1373
1374 let utf16_len = end_utf16_idx - start_utf16_idx;
1375
1376 // Calculate glyph count for this cluster
1377 let next_glyph = if end_utf16_idx < self.cluster_map.len() {
1378 self.cluster_map[end_utf16_idx] as usize
1379 } else {
1380 self.glyph_count
1381 };
1382
1383 let glyph_count = next_glyph - current_glyph;
1384
1385 // Update state for next call
1386 self.utf16_idx = end_utf16_idx;
1387 self.glyph_idx = next_glyph;
1388
1389 Some((utf16_len, glyph_count))
1390 }
1391}
1392
1393#[allow(non_snake_case)]
1394impl IDWritePixelSnapping_Impl for TextRenderer_Impl {
1395 fn IsPixelSnappingDisabled(
1396 &self,
1397 _clientdrawingcontext: *const ::core::ffi::c_void,
1398 ) -> windows::core::Result<BOOL> {
1399 Ok(BOOL(0))
1400 }
1401
1402 fn GetCurrentTransform(
1403 &self,
1404 _clientdrawingcontext: *const ::core::ffi::c_void,
1405 transform: *mut DWRITE_MATRIX,
1406 ) -> windows::core::Result<()> {
1407 unsafe {
1408 *transform = DWRITE_MATRIX {
1409 m11: 1.0,
1410 m12: 0.0,
1411 m21: 0.0,
1412 m22: 1.0,
1413 dx: 0.0,
1414 dy: 0.0,
1415 };
1416 }
1417 Ok(())
1418 }
1419
1420 fn GetPixelsPerDip(
1421 &self,
1422 _clientdrawingcontext: *const ::core::ffi::c_void,
1423 ) -> windows::core::Result<f32> {
1424 Ok(1.0)
1425 }
1426}
1427
1428#[allow(non_snake_case)]
1429impl IDWriteTextRenderer_Impl for TextRenderer_Impl {
1430 fn DrawGlyphRun(
1431 &self,
1432 clientdrawingcontext: *const ::core::ffi::c_void,
1433 _baselineoriginx: f32,
1434 _baselineoriginy: f32,
1435 _measuringmode: DWRITE_MEASURING_MODE,
1436 glyphrun: *const DWRITE_GLYPH_RUN,
1437 glyphrundescription: *const DWRITE_GLYPH_RUN_DESCRIPTION,
1438 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1439 ) -> windows::core::Result<()> {
1440 let glyphrun = unsafe { &*glyphrun };
1441 let glyph_count = glyphrun.glyphCount as usize;
1442 if glyph_count == 0 || glyphrun.fontFace.is_none() {
1443 return Ok(());
1444 }
1445 let desc = unsafe { &*glyphrundescription };
1446 let context = unsafe {
1447 &mut *(clientdrawingcontext as *const RendererContext as *mut RendererContext)
1448 };
1449 let font_face = glyphrun.fontFace.as_ref().unwrap();
1450 // This `cast()` action here should never fail since we are running on Win10+, and
1451 // `IDWriteFontFace3` requires Win10
1452 let font_face = &font_face.cast::<IDWriteFontFace3>().unwrap();
1453 let Some((font_identifier, font_struct, color_font)) =
1454 get_font_identifier_and_font_struct(font_face, &self.locale)
1455 else {
1456 return Ok(());
1457 };
1458
1459 let font_id = if let Some(id) = context
1460 .text_system
1461 .font_id_by_identifier
1462 .get(&font_identifier)
1463 {
1464 *id
1465 } else {
1466 context.text_system.select_font(&font_struct)
1467 };
1468
1469 let glyph_ids = unsafe { std::slice::from_raw_parts(glyphrun.glyphIndices, glyph_count) };
1470 let glyph_advances =
1471 unsafe { std::slice::from_raw_parts(glyphrun.glyphAdvances, glyph_count) };
1472 let glyph_offsets =
1473 unsafe { std::slice::from_raw_parts(glyphrun.glyphOffsets, glyph_count) };
1474 let cluster_map =
1475 unsafe { std::slice::from_raw_parts(desc.clusterMap, desc.stringLength as usize) };
1476
1477 let mut cluster_analyzer = ClusterAnalyzer::new(cluster_map, glyph_count);
1478 let mut utf16_idx = desc.textPosition as usize;
1479 let mut glyph_idx = 0;
1480 let mut glyphs = Vec::with_capacity(glyph_count);
1481 for (cluster_utf16_len, cluster_glyph_count) in cluster_analyzer {
1482 context.index_converter.advance_to_utf16_ix(utf16_idx);
1483 utf16_idx += cluster_utf16_len;
1484 for (cluster_glyph_idx, glyph_id) in glyph_ids
1485 [glyph_idx..(glyph_idx + cluster_glyph_count)]
1486 .iter()
1487 .enumerate()
1488 {
1489 let id = GlyphId(*glyph_id as u32);
1490 let is_emoji = color_font
1491 && is_color_glyph(font_face, id, &context.text_system.components.factory);
1492 let this_glyph_idx = glyph_idx + cluster_glyph_idx;
1493 glyphs.push(ShapedGlyph {
1494 id,
1495 position: point(
1496 px(context.width + glyph_offsets[this_glyph_idx].advanceOffset),
1497 px(0.0),
1498 ),
1499 index: context.index_converter.utf8_ix,
1500 is_emoji,
1501 });
1502 context.width += glyph_advances[this_glyph_idx];
1503 }
1504 glyph_idx += cluster_glyph_count;
1505 }
1506 context.runs.push(ShapedRun { font_id, glyphs });
1507 Ok(())
1508 }
1509
1510 fn DrawUnderline(
1511 &self,
1512 _clientdrawingcontext: *const ::core::ffi::c_void,
1513 _baselineoriginx: f32,
1514 _baselineoriginy: f32,
1515 _underline: *const DWRITE_UNDERLINE,
1516 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1517 ) -> windows::core::Result<()> {
1518 Err(windows::core::Error::new(
1519 E_NOTIMPL,
1520 "DrawUnderline unimplemented",
1521 ))
1522 }
1523
1524 fn DrawStrikethrough(
1525 &self,
1526 _clientdrawingcontext: *const ::core::ffi::c_void,
1527 _baselineoriginx: f32,
1528 _baselineoriginy: f32,
1529 _strikethrough: *const DWRITE_STRIKETHROUGH,
1530 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1531 ) -> windows::core::Result<()> {
1532 Err(windows::core::Error::new(
1533 E_NOTIMPL,
1534 "DrawStrikethrough unimplemented",
1535 ))
1536 }
1537
1538 fn DrawInlineObject(
1539 &self,
1540 _clientdrawingcontext: *const ::core::ffi::c_void,
1541 _originx: f32,
1542 _originy: f32,
1543 _inlineobject: windows::core::Ref<IDWriteInlineObject>,
1544 _issideways: BOOL,
1545 _isrighttoleft: BOOL,
1546 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1547 ) -> windows::core::Result<()> {
1548 Err(windows::core::Error::new(
1549 E_NOTIMPL,
1550 "DrawInlineObject unimplemented",
1551 ))
1552 }
1553}
1554
1555struct StringIndexConverter<'a> {
1556 text: &'a str,
1557 utf8_ix: usize,
1558 utf16_ix: usize,
1559}
1560
1561impl<'a> StringIndexConverter<'a> {
1562 fn new(text: &'a str) -> Self {
1563 Self {
1564 text,
1565 utf8_ix: 0,
1566 utf16_ix: 0,
1567 }
1568 }
1569
1570 #[allow(dead_code)]
1571 fn advance_to_utf8_ix(&mut self, utf8_target: usize) {
1572 for (ix, c) in self.text[self.utf8_ix..].char_indices() {
1573 if self.utf8_ix + ix >= utf8_target {
1574 self.utf8_ix += ix;
1575 return;
1576 }
1577 self.utf16_ix += c.len_utf16();
1578 }
1579 self.utf8_ix = self.text.len();
1580 }
1581
1582 fn advance_to_utf16_ix(&mut self, utf16_target: usize) {
1583 for (ix, c) in self.text[self.utf8_ix..].char_indices() {
1584 if self.utf16_ix >= utf16_target {
1585 self.utf8_ix += ix;
1586 return;
1587 }
1588 self.utf16_ix += c.len_utf16();
1589 }
1590 self.utf8_ix = self.text.len();
1591 }
1592}
1593
1594impl Into<DWRITE_FONT_STYLE> for FontStyle {
1595 fn into(self) -> DWRITE_FONT_STYLE {
1596 match self {
1597 FontStyle::Normal => DWRITE_FONT_STYLE_NORMAL,
1598 FontStyle::Italic => DWRITE_FONT_STYLE_ITALIC,
1599 FontStyle::Oblique => DWRITE_FONT_STYLE_OBLIQUE,
1600 }
1601 }
1602}
1603
1604impl From<DWRITE_FONT_STYLE> for FontStyle {
1605 fn from(value: DWRITE_FONT_STYLE) -> Self {
1606 match value.0 {
1607 0 => FontStyle::Normal,
1608 1 => FontStyle::Italic,
1609 2 => FontStyle::Oblique,
1610 _ => unreachable!(),
1611 }
1612 }
1613}
1614
1615impl Into<DWRITE_FONT_WEIGHT> for FontWeight {
1616 fn into(self) -> DWRITE_FONT_WEIGHT {
1617 DWRITE_FONT_WEIGHT(self.0 as i32)
1618 }
1619}
1620
1621impl From<DWRITE_FONT_WEIGHT> for FontWeight {
1622 fn from(value: DWRITE_FONT_WEIGHT) -> Self {
1623 FontWeight(value.0 as f32)
1624 }
1625}
1626
1627fn get_font_names_from_collection(
1628 collection: &IDWriteFontCollection1,
1629 locale: &str,
1630) -> Vec<String> {
1631 unsafe {
1632 let mut result = Vec::new();
1633 let family_count = collection.GetFontFamilyCount();
1634 for index in 0..family_count {
1635 let Some(font_family) = collection.GetFontFamily(index).log_err() else {
1636 continue;
1637 };
1638 let Some(localized_family_name) = font_family.GetFamilyNames().log_err() else {
1639 continue;
1640 };
1641 let Some(family_name) = get_name(localized_family_name, locale).log_err() else {
1642 continue;
1643 };
1644 result.push(family_name);
1645 }
1646
1647 result
1648 }
1649}
1650
1651fn get_font_identifier_and_font_struct(
1652 font_face: &IDWriteFontFace3,
1653 locale: &str,
1654) -> Option<(FontIdentifier, Font, bool)> {
1655 let postscript_name = get_postscript_name(font_face, locale).log_err()?;
1656 let localized_family_name = unsafe { font_face.GetFamilyNames().log_err() }?;
1657 let family_name = get_name(localized_family_name, locale).log_err()?;
1658 let weight = unsafe { font_face.GetWeight() };
1659 let style = unsafe { font_face.GetStyle() };
1660 let identifier = FontIdentifier {
1661 postscript_name,
1662 weight: weight.0,
1663 style: style.0,
1664 };
1665 let font_struct = Font {
1666 family: family_name.into(),
1667 features: FontFeatures::default(),
1668 weight: weight.into(),
1669 style: style.into(),
1670 fallbacks: None,
1671 };
1672 let is_emoji = unsafe { font_face.IsColorFont().as_bool() };
1673 Some((identifier, font_struct, is_emoji))
1674}
1675
1676#[inline]
1677fn get_font_identifier(font_face: &IDWriteFontFace3, locale: &str) -> Option<FontIdentifier> {
1678 let weight = unsafe { font_face.GetWeight().0 };
1679 let style = unsafe { font_face.GetStyle().0 };
1680 get_postscript_name(font_face, locale)
1681 .log_err()
1682 .map(|postscript_name| FontIdentifier {
1683 postscript_name,
1684 weight,
1685 style,
1686 })
1687}
1688
1689#[inline]
1690fn get_postscript_name(font_face: &IDWriteFontFace3, locale: &str) -> Result<String> {
1691 let mut info = None;
1692 let mut exists = BOOL(0);
1693 unsafe {
1694 font_face.GetInformationalStrings(
1695 DWRITE_INFORMATIONAL_STRING_POSTSCRIPT_NAME,
1696 &mut info,
1697 &mut exists,
1698 )?
1699 };
1700 if !exists.as_bool() || info.is_none() {
1701 anyhow::bail!("No postscript name found for font face");
1702 }
1703
1704 get_name(info.unwrap(), locale)
1705}
1706
1707// https://learn.microsoft.com/en-us/windows/win32/api/dwrite/ne-dwrite-dwrite_font_feature_tag
1708fn apply_font_features(
1709 direct_write_features: &IDWriteTypography,
1710 features: &FontFeatures,
1711) -> Result<()> {
1712 let tag_values = features.tag_value_list();
1713 if tag_values.is_empty() {
1714 return Ok(());
1715 }
1716
1717 // All of these features are enabled by default by DirectWrite.
1718 // If you want to (and can) peek into the source of DirectWrite
1719 let mut feature_liga = make_direct_write_feature("liga", 1);
1720 let mut feature_clig = make_direct_write_feature("clig", 1);
1721 let mut feature_calt = make_direct_write_feature("calt", 1);
1722
1723 for (tag, value) in tag_values {
1724 if tag.as_str() == "liga" && *value == 0 {
1725 feature_liga.parameter = 0;
1726 continue;
1727 }
1728 if tag.as_str() == "clig" && *value == 0 {
1729 feature_clig.parameter = 0;
1730 continue;
1731 }
1732 if tag.as_str() == "calt" && *value == 0 {
1733 feature_calt.parameter = 0;
1734 continue;
1735 }
1736
1737 unsafe {
1738 direct_write_features.AddFontFeature(make_direct_write_feature(tag, *value))?;
1739 }
1740 }
1741 unsafe {
1742 direct_write_features.AddFontFeature(feature_liga)?;
1743 direct_write_features.AddFontFeature(feature_clig)?;
1744 direct_write_features.AddFontFeature(feature_calt)?;
1745 }
1746
1747 Ok(())
1748}
1749
1750#[inline]
1751const fn make_direct_write_feature(feature_name: &str, parameter: u32) -> DWRITE_FONT_FEATURE {
1752 let tag = make_direct_write_tag(feature_name);
1753 DWRITE_FONT_FEATURE {
1754 nameTag: tag,
1755 parameter,
1756 }
1757}
1758
1759#[inline]
1760const fn make_open_type_tag(tag_name: &str) -> u32 {
1761 let bytes = tag_name.as_bytes();
1762 debug_assert!(bytes.len() == 4);
1763 u32::from_le_bytes([bytes[0], bytes[1], bytes[2], bytes[3]])
1764}
1765
1766#[inline]
1767const fn make_direct_write_tag(tag_name: &str) -> DWRITE_FONT_FEATURE_TAG {
1768 DWRITE_FONT_FEATURE_TAG(make_open_type_tag(tag_name))
1769}
1770
1771#[inline]
1772fn get_name(string: IDWriteLocalizedStrings, locale: &str) -> Result<String> {
1773 let mut locale_name_index = 0u32;
1774 let mut exists = BOOL(0);
1775 unsafe {
1776 string.FindLocaleName(
1777 &HSTRING::from(locale),
1778 &mut locale_name_index,
1779 &mut exists as _,
1780 )?
1781 };
1782 if !exists.as_bool() {
1783 unsafe {
1784 string.FindLocaleName(
1785 DEFAULT_LOCALE_NAME,
1786 &mut locale_name_index as _,
1787 &mut exists as _,
1788 )?
1789 };
1790 anyhow::ensure!(exists.as_bool(), "No localised string for {locale}");
1791 }
1792
1793 let name_length = unsafe { string.GetStringLength(locale_name_index) }? as usize;
1794 let mut name_vec = vec![0u16; name_length + 1];
1795 unsafe {
1796 string.GetString(locale_name_index, &mut name_vec)?;
1797 }
1798
1799 Ok(String::from_utf16_lossy(&name_vec[..name_length]))
1800}
1801
1802fn get_system_ui_font_name() -> SharedString {
1803 unsafe {
1804 let mut info: LOGFONTW = std::mem::zeroed();
1805 let font_family = if SystemParametersInfoW(
1806 SPI_GETICONTITLELOGFONT,
1807 std::mem::size_of::<LOGFONTW>() as u32,
1808 Some(&mut info as *mut _ as _),
1809 SYSTEM_PARAMETERS_INFO_UPDATE_FLAGS(0),
1810 )
1811 .log_err()
1812 .is_none()
1813 {
1814 // https://learn.microsoft.com/en-us/windows/win32/uxguide/vis-fonts
1815 // Segoe UI is the Windows font intended for user interface text strings.
1816 "Segoe UI".into()
1817 } else {
1818 let font_name = String::from_utf16_lossy(&info.lfFaceName);
1819 font_name.trim_matches(char::from(0)).to_owned().into()
1820 };
1821 log::info!("Use {} as UI font.", font_family);
1822 font_family
1823 }
1824}
1825
1826// One would think that with newer DirectWrite method: IDWriteFontFace4::GetGlyphImageFormats
1827// but that doesn't seem to work for some glyphs, say ❤
1828fn is_color_glyph(
1829 font_face: &IDWriteFontFace3,
1830 glyph_id: GlyphId,
1831 factory: &IDWriteFactory5,
1832) -> bool {
1833 let glyph_run = DWRITE_GLYPH_RUN {
1834 fontFace: unsafe { std::mem::transmute_copy(font_face) },
1835 fontEmSize: 14.0,
1836 glyphCount: 1,
1837 glyphIndices: &(glyph_id.0 as u16),
1838 glyphAdvances: &0.0,
1839 glyphOffsets: &DWRITE_GLYPH_OFFSET {
1840 advanceOffset: 0.0,
1841 ascenderOffset: 0.0,
1842 },
1843 isSideways: BOOL(0),
1844 bidiLevel: 0,
1845 };
1846 unsafe {
1847 factory.TranslateColorGlyphRun(
1848 Vector2::default(),
1849 &glyph_run as _,
1850 None,
1851 DWRITE_GLYPH_IMAGE_FORMATS_COLR
1852 | DWRITE_GLYPH_IMAGE_FORMATS_SVG
1853 | DWRITE_GLYPH_IMAGE_FORMATS_PNG
1854 | DWRITE_GLYPH_IMAGE_FORMATS_JPEG
1855 | DWRITE_GLYPH_IMAGE_FORMATS_PREMULTIPLIED_B8G8R8A8,
1856 DWRITE_MEASURING_MODE_NATURAL,
1857 None,
1858 0,
1859 )
1860 }
1861 .is_ok()
1862}
1863
1864const DEFAULT_LOCALE_NAME: PCWSTR = windows::core::w!("en-US");
1865
1866#[cfg(test)]
1867mod tests {
1868 use crate::platform::windows::direct_write::ClusterAnalyzer;
1869
1870 #[test]
1871 fn test_cluster_map() {
1872 let cluster_map = [0];
1873 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 1);
1874 let next = analyzer.next();
1875 assert_eq!(next, Some((1, 1)));
1876 let next = analyzer.next();
1877 assert_eq!(next, None);
1878
1879 let cluster_map = [0, 1, 2];
1880 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 3);
1881 let next = analyzer.next();
1882 assert_eq!(next, Some((1, 1)));
1883 let next = analyzer.next();
1884 assert_eq!(next, Some((1, 1)));
1885 let next = analyzer.next();
1886 assert_eq!(next, Some((1, 1)));
1887 let next = analyzer.next();
1888 assert_eq!(next, None);
1889 // 👨👩👧👦👩💻
1890 let cluster_map = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 4, 4, 4];
1891 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 5);
1892 let next = analyzer.next();
1893 assert_eq!(next, Some((11, 4)));
1894 let next = analyzer.next();
1895 assert_eq!(next, Some((5, 1)));
1896 let next = analyzer.next();
1897 assert_eq!(next, None);
1898 // 👩💻
1899 let cluster_map = [0, 0, 0, 0, 0];
1900 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 1);
1901 let next = analyzer.next();
1902 assert_eq!(next, Some((5, 1)));
1903 let next = analyzer.next();
1904 assert_eq!(next, None);
1905 }
1906}