1use std::{borrow::Cow, mem::ManuallyDrop, sync::Arc};
2
3use ::util::ResultExt;
4use anyhow::Result;
5use collections::HashMap;
6use itertools::Itertools;
7use parking_lot::{RwLock, RwLockUpgradableReadGuard};
8use windows::{
9 Win32::{
10 Foundation::*,
11 Globalization::GetUserDefaultLocaleName,
12 Graphics::{
13 Direct3D::D3D_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP,
14 Direct3D11::*,
15 DirectWrite::*,
16 Dxgi::Common::*,
17 Gdi::{IsRectEmpty, LOGFONTW},
18 Imaging::*,
19 },
20 System::SystemServices::LOCALE_NAME_MAX_LENGTH,
21 UI::WindowsAndMessaging::*,
22 },
23 core::*,
24};
25use windows_numerics::Vector2;
26
27use crate::*;
28
29#[derive(Debug)]
30struct FontInfo {
31 font_family: String,
32 font_face: IDWriteFontFace3,
33 features: IDWriteTypography,
34 fallbacks: Option<IDWriteFontFallback>,
35 is_system_font: bool,
36}
37
38pub(crate) struct DirectWriteTextSystem(RwLock<DirectWriteState>);
39
40struct DirectWriteComponent {
41 locale: String,
42 factory: IDWriteFactory5,
43 bitmap_factory: AgileReference<IWICImagingFactory>,
44 in_memory_loader: IDWriteInMemoryFontFileLoader,
45 builder: IDWriteFontSetBuilder1,
46 text_renderer: Arc<TextRendererWrapper>,
47
48 render_params: IDWriteRenderingParams,
49 gpu_state: GPUState,
50}
51
52struct GPUState {
53 device: ID3D11Device,
54 device_context: ID3D11DeviceContext,
55 sampler: [Option<ID3D11SamplerState>; 1],
56 blend_state: ID3D11BlendState,
57 vertex_shader: ID3D11VertexShader,
58 pixel_shader: ID3D11PixelShader,
59}
60
61struct DirectWriteState {
62 components: DirectWriteComponent,
63 system_ui_font_name: SharedString,
64 system_font_collection: IDWriteFontCollection1,
65 custom_font_collection: IDWriteFontCollection1,
66 fonts: Vec<FontInfo>,
67 font_selections: HashMap<Font, FontId>,
68 font_id_by_identifier: HashMap<FontIdentifier, FontId>,
69}
70
71#[derive(Debug, Clone, Hash, PartialEq, Eq)]
72struct FontIdentifier {
73 postscript_name: String,
74 weight: i32,
75 style: i32,
76}
77
78impl DirectWriteComponent {
79 pub fn new(bitmap_factory: &IWICImagingFactory, gpu_context: &DirectXDevices) -> Result<Self> {
80 // todo: ideally this would not be a large unsafe block but smaller isolated ones for easier auditing
81 unsafe {
82 let factory: IDWriteFactory5 = DWriteCreateFactory(DWRITE_FACTORY_TYPE_SHARED)?;
83 let bitmap_factory = AgileReference::new(bitmap_factory)?;
84 // The `IDWriteInMemoryFontFileLoader` here is supported starting from
85 // Windows 10 Creators Update, which consequently requires the entire
86 // `DirectWriteTextSystem` to run on `win10 1703`+.
87 let in_memory_loader = factory.CreateInMemoryFontFileLoader()?;
88 factory.RegisterFontFileLoader(&in_memory_loader)?;
89 let builder = factory.CreateFontSetBuilder()?;
90 let mut locale_vec = vec![0u16; LOCALE_NAME_MAX_LENGTH as usize];
91 GetUserDefaultLocaleName(&mut locale_vec);
92 let locale = String::from_utf16_lossy(&locale_vec);
93 let text_renderer = Arc::new(TextRendererWrapper::new(&locale));
94
95 let render_params = factory.CreateRenderingParams()?;
96
97 let gpu_state = GPUState::new(gpu_context)?;
98
99 Ok(DirectWriteComponent {
100 locale,
101 factory,
102 bitmap_factory,
103 in_memory_loader,
104 builder,
105 text_renderer,
106 render_params,
107 gpu_state,
108 })
109 }
110 }
111}
112
113impl GPUState {
114 fn new(gpu_context: &DirectXDevices) -> Result<Self> {
115 let device = gpu_context.device.clone();
116 let device_context = gpu_context.device_context.clone();
117
118 let blend_state = {
119 let mut blend_state = None;
120 let desc = D3D11_BLEND_DESC {
121 AlphaToCoverageEnable: false.into(),
122 IndependentBlendEnable: false.into(),
123 RenderTarget: [
124 D3D11_RENDER_TARGET_BLEND_DESC {
125 BlendEnable: true.into(),
126 SrcBlend: D3D11_BLEND_SRC_ALPHA,
127 DestBlend: D3D11_BLEND_INV_SRC_ALPHA,
128 BlendOp: D3D11_BLEND_OP_ADD,
129 SrcBlendAlpha: D3D11_BLEND_SRC_ALPHA,
130 DestBlendAlpha: D3D11_BLEND_INV_SRC_ALPHA,
131 BlendOpAlpha: D3D11_BLEND_OP_ADD,
132 RenderTargetWriteMask: D3D11_COLOR_WRITE_ENABLE_ALL.0 as u8,
133 },
134 Default::default(),
135 Default::default(),
136 Default::default(),
137 Default::default(),
138 Default::default(),
139 Default::default(),
140 Default::default(),
141 ],
142 };
143 unsafe { device.CreateBlendState(&desc, Some(&mut blend_state)) }?;
144 blend_state.unwrap()
145 };
146
147 let sampler = {
148 let mut sampler = None;
149 let desc = D3D11_SAMPLER_DESC {
150 Filter: D3D11_FILTER_MIN_MAG_MIP_POINT,
151 AddressU: D3D11_TEXTURE_ADDRESS_BORDER,
152 AddressV: D3D11_TEXTURE_ADDRESS_BORDER,
153 AddressW: D3D11_TEXTURE_ADDRESS_BORDER,
154 MipLODBias: 0.0,
155 MaxAnisotropy: 1,
156 ComparisonFunc: D3D11_COMPARISON_ALWAYS,
157 BorderColor: [0.0, 0.0, 0.0, 0.0],
158 MinLOD: 0.0,
159 MaxLOD: 0.0,
160 };
161 unsafe { device.CreateSamplerState(&desc, Some(&mut sampler)) }?;
162 [sampler]
163 };
164
165 let vertex_shader = {
166 let source = shader_resources::RawShaderBytes::new(
167 shader_resources::ShaderModule::EmojiRasterization,
168 shader_resources::ShaderTarget::Vertex,
169 )?;
170 let mut shader = None;
171 unsafe { device.CreateVertexShader(source.as_bytes(), None, Some(&mut shader)) }?;
172 shader.unwrap()
173 };
174
175 let pixel_shader = {
176 let source = shader_resources::RawShaderBytes::new(
177 shader_resources::ShaderModule::EmojiRasterization,
178 shader_resources::ShaderTarget::Fragment,
179 )?;
180 let mut shader = None;
181 unsafe { device.CreatePixelShader(source.as_bytes(), None, Some(&mut shader)) }?;
182 shader.unwrap()
183 };
184
185 Ok(Self {
186 device,
187 device_context,
188 sampler,
189 blend_state,
190 vertex_shader,
191 pixel_shader,
192 })
193 }
194}
195
196impl DirectWriteTextSystem {
197 pub(crate) fn new(
198 gpu_context: &DirectXDevices,
199 bitmap_factory: &IWICImagingFactory,
200 ) -> Result<Self> {
201 let components = DirectWriteComponent::new(bitmap_factory, gpu_context)?;
202 let system_font_collection = unsafe {
203 let mut result = std::mem::zeroed();
204 components
205 .factory
206 .GetSystemFontCollection(false, &mut result, true)?;
207 result.unwrap()
208 };
209 let custom_font_set = unsafe { components.builder.CreateFontSet()? };
210 let custom_font_collection = unsafe {
211 components
212 .factory
213 .CreateFontCollectionFromFontSet(&custom_font_set)?
214 };
215 let system_ui_font_name = get_system_ui_font_name();
216
217 Ok(Self(RwLock::new(DirectWriteState {
218 components,
219 system_ui_font_name,
220 system_font_collection,
221 custom_font_collection,
222 fonts: Vec::new(),
223 font_selections: HashMap::default(),
224 font_id_by_identifier: HashMap::default(),
225 })))
226 }
227}
228
229impl PlatformTextSystem for DirectWriteTextSystem {
230 fn add_fonts(&self, fonts: Vec<Cow<'static, [u8]>>) -> Result<()> {
231 self.0.write().add_fonts(fonts)
232 }
233
234 fn all_font_names(&self) -> Vec<String> {
235 self.0.read().all_font_names()
236 }
237
238 fn font_id(&self, font: &Font) -> Result<FontId> {
239 let lock = self.0.upgradable_read();
240 if let Some(font_id) = lock.font_selections.get(font) {
241 Ok(*font_id)
242 } else {
243 let mut lock = RwLockUpgradableReadGuard::upgrade(lock);
244 let font_id = lock.select_font(font);
245 lock.font_selections.insert(font.clone(), font_id);
246 Ok(font_id)
247 }
248 }
249
250 fn font_metrics(&self, font_id: FontId) -> FontMetrics {
251 self.0.read().font_metrics(font_id)
252 }
253
254 fn typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>> {
255 self.0.read().get_typographic_bounds(font_id, glyph_id)
256 }
257
258 fn advance(&self, font_id: FontId, glyph_id: GlyphId) -> anyhow::Result<Size<f32>> {
259 self.0.read().get_advance(font_id, glyph_id)
260 }
261
262 fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
263 self.0.read().glyph_for_char(font_id, ch)
264 }
265
266 fn glyph_raster_bounds(
267 &self,
268 params: &RenderGlyphParams,
269 ) -> anyhow::Result<Bounds<DevicePixels>> {
270 self.0.read().raster_bounds(params)
271 }
272
273 fn rasterize_glyph(
274 &self,
275 params: &RenderGlyphParams,
276 raster_bounds: Bounds<DevicePixels>,
277 ) -> anyhow::Result<(Size<DevicePixels>, Vec<u8>)> {
278 self.0.read().rasterize_glyph(params, raster_bounds)
279 }
280
281 fn layout_line(&self, text: &str, font_size: Pixels, runs: &[FontRun]) -> LineLayout {
282 self.0
283 .write()
284 .layout_line(text, font_size, runs)
285 .log_err()
286 .unwrap_or(LineLayout {
287 font_size,
288 ..Default::default()
289 })
290 }
291}
292
293impl DirectWriteState {
294 fn add_fonts(&mut self, fonts: Vec<Cow<'static, [u8]>>) -> Result<()> {
295 for font_data in fonts {
296 match font_data {
297 Cow::Borrowed(data) => unsafe {
298 let font_file = self
299 .components
300 .in_memory_loader
301 .CreateInMemoryFontFileReference(
302 &self.components.factory,
303 data.as_ptr() as _,
304 data.len() as _,
305 None,
306 )?;
307 self.components.builder.AddFontFile(&font_file)?;
308 },
309 Cow::Owned(data) => unsafe {
310 let font_file = self
311 .components
312 .in_memory_loader
313 .CreateInMemoryFontFileReference(
314 &self.components.factory,
315 data.as_ptr() as _,
316 data.len() as _,
317 None,
318 )?;
319 self.components.builder.AddFontFile(&font_file)?;
320 },
321 }
322 }
323 let set = unsafe { self.components.builder.CreateFontSet()? };
324 let collection = unsafe {
325 self.components
326 .factory
327 .CreateFontCollectionFromFontSet(&set)?
328 };
329 self.custom_font_collection = collection;
330
331 Ok(())
332 }
333
334 fn generate_font_fallbacks(
335 &self,
336 fallbacks: &FontFallbacks,
337 ) -> Result<Option<IDWriteFontFallback>> {
338 if fallbacks.fallback_list().is_empty() {
339 return Ok(None);
340 }
341 unsafe {
342 let builder = self.components.factory.CreateFontFallbackBuilder()?;
343 let font_set = &self.system_font_collection.GetFontSet()?;
344 for family_name in fallbacks.fallback_list() {
345 let Some(fonts) = font_set
346 .GetMatchingFonts(
347 &HSTRING::from(family_name),
348 DWRITE_FONT_WEIGHT_NORMAL,
349 DWRITE_FONT_STRETCH_NORMAL,
350 DWRITE_FONT_STYLE_NORMAL,
351 )
352 .log_err()
353 else {
354 continue;
355 };
356 if fonts.GetFontCount() == 0 {
357 log::error!("No matching font found for {}", family_name);
358 continue;
359 }
360 let font = fonts.GetFontFaceReference(0)?.CreateFontFace()?;
361 let mut count = 0;
362 font.GetUnicodeRanges(None, &mut count).ok();
363 if count == 0 {
364 continue;
365 }
366 let mut unicode_ranges = vec![DWRITE_UNICODE_RANGE::default(); count as usize];
367 let Some(_) = font
368 .GetUnicodeRanges(Some(&mut unicode_ranges), &mut count)
369 .log_err()
370 else {
371 continue;
372 };
373 let target_family_name = HSTRING::from(family_name);
374 builder.AddMapping(
375 &unicode_ranges,
376 &[target_family_name.as_ptr()],
377 None,
378 None,
379 None,
380 1.0,
381 )?;
382 }
383 let system_fallbacks = self.components.factory.GetSystemFontFallback()?;
384 builder.AddMappings(&system_fallbacks)?;
385 Ok(Some(builder.CreateFontFallback()?))
386 }
387 }
388
389 unsafe fn generate_font_features(
390 &self,
391 font_features: &FontFeatures,
392 ) -> Result<IDWriteTypography> {
393 let direct_write_features = unsafe { self.components.factory.CreateTypography()? };
394 apply_font_features(&direct_write_features, font_features)?;
395 Ok(direct_write_features)
396 }
397
398 unsafe fn get_font_id_from_font_collection(
399 &mut self,
400 family_name: &str,
401 font_weight: FontWeight,
402 font_style: FontStyle,
403 font_features: &FontFeatures,
404 font_fallbacks: Option<&FontFallbacks>,
405 is_system_font: bool,
406 ) -> Option<FontId> {
407 let collection = if is_system_font {
408 &self.system_font_collection
409 } else {
410 &self.custom_font_collection
411 };
412 let fontset = unsafe { collection.GetFontSet().log_err()? };
413 let font = unsafe {
414 fontset
415 .GetMatchingFonts(
416 &HSTRING::from(family_name),
417 font_weight.into(),
418 DWRITE_FONT_STRETCH_NORMAL,
419 font_style.into(),
420 )
421 .log_err()?
422 };
423 let total_number = unsafe { font.GetFontCount() };
424 for index in 0..total_number {
425 let Some(font_face_ref) = (unsafe { font.GetFontFaceReference(index).log_err() })
426 else {
427 continue;
428 };
429 let Some(font_face) = (unsafe { font_face_ref.CreateFontFace().log_err() }) else {
430 continue;
431 };
432 let Some(identifier) = get_font_identifier(&font_face, &self.components.locale) else {
433 continue;
434 };
435 let Some(direct_write_features) =
436 (unsafe { self.generate_font_features(font_features).log_err() })
437 else {
438 continue;
439 };
440 let fallbacks = font_fallbacks
441 .and_then(|fallbacks| self.generate_font_fallbacks(fallbacks).log_err().flatten());
442 let font_info = FontInfo {
443 font_family: family_name.to_owned(),
444 font_face,
445 features: direct_write_features,
446 fallbacks,
447 is_system_font,
448 };
449 let font_id = FontId(self.fonts.len());
450 self.fonts.push(font_info);
451 self.font_id_by_identifier.insert(identifier, font_id);
452 return Some(font_id);
453 }
454 None
455 }
456
457 unsafe fn update_system_font_collection(&mut self) {
458 let mut collection = unsafe { std::mem::zeroed() };
459 if unsafe {
460 self.components
461 .factory
462 .GetSystemFontCollection(false, &mut collection, true)
463 .log_err()
464 .is_some()
465 } {
466 self.system_font_collection = collection.unwrap();
467 }
468 }
469
470 fn select_font(&mut self, target_font: &Font) -> FontId {
471 unsafe {
472 if target_font.family == ".SystemUIFont" {
473 let family = self.system_ui_font_name.clone();
474 self.find_font_id(
475 family.as_ref(),
476 target_font.weight,
477 target_font.style,
478 &target_font.features,
479 target_font.fallbacks.as_ref(),
480 )
481 .unwrap()
482 } else {
483 self.find_font_id(
484 target_font.family.as_ref(),
485 target_font.weight,
486 target_font.style,
487 &target_font.features,
488 target_font.fallbacks.as_ref(),
489 )
490 .unwrap_or_else(|| {
491 #[cfg(any(test, feature = "test-support"))]
492 {
493 panic!("ERROR: {} font not found!", target_font.family);
494 }
495 #[cfg(not(any(test, feature = "test-support")))]
496 {
497 let family = self.system_ui_font_name.clone();
498 log::error!("{} not found, use {} instead.", target_font.family, family);
499 self.get_font_id_from_font_collection(
500 family.as_ref(),
501 target_font.weight,
502 target_font.style,
503 &target_font.features,
504 target_font.fallbacks.as_ref(),
505 true,
506 )
507 .unwrap()
508 }
509 })
510 }
511 }
512 }
513
514 unsafe fn find_font_id(
515 &mut self,
516 family_name: &str,
517 weight: FontWeight,
518 style: FontStyle,
519 features: &FontFeatures,
520 fallbacks: Option<&FontFallbacks>,
521 ) -> Option<FontId> {
522 // try to find target font in custom font collection first
523 unsafe {
524 self.get_font_id_from_font_collection(
525 family_name,
526 weight,
527 style,
528 features,
529 fallbacks,
530 false,
531 )
532 .or_else(|| {
533 self.get_font_id_from_font_collection(
534 family_name,
535 weight,
536 style,
537 features,
538 fallbacks,
539 true,
540 )
541 })
542 .or_else(|| {
543 self.update_system_font_collection();
544 self.get_font_id_from_font_collection(
545 family_name,
546 weight,
547 style,
548 features,
549 fallbacks,
550 true,
551 )
552 })
553 }
554 }
555
556 fn layout_line(
557 &mut self,
558 text: &str,
559 font_size: Pixels,
560 font_runs: &[FontRun],
561 ) -> Result<LineLayout> {
562 if font_runs.is_empty() {
563 return Ok(LineLayout {
564 font_size,
565 ..Default::default()
566 });
567 }
568 unsafe {
569 let text_renderer = self.components.text_renderer.clone();
570 let text_wide = text.encode_utf16().collect_vec();
571
572 let mut utf8_offset = 0usize;
573 let mut utf16_offset = 0u32;
574 let text_layout = {
575 let first_run = &font_runs[0];
576 let font_info = &self.fonts[first_run.font_id.0];
577 let collection = if font_info.is_system_font {
578 &self.system_font_collection
579 } else {
580 &self.custom_font_collection
581 };
582 let format: IDWriteTextFormat1 = self
583 .components
584 .factory
585 .CreateTextFormat(
586 &HSTRING::from(&font_info.font_family),
587 collection,
588 font_info.font_face.GetWeight(),
589 font_info.font_face.GetStyle(),
590 DWRITE_FONT_STRETCH_NORMAL,
591 font_size.0,
592 &HSTRING::from(&self.components.locale),
593 )?
594 .cast()?;
595 if let Some(ref fallbacks) = font_info.fallbacks {
596 format.SetFontFallback(fallbacks)?;
597 }
598
599 let layout = self.components.factory.CreateTextLayout(
600 &text_wide,
601 &format,
602 f32::INFINITY,
603 f32::INFINITY,
604 )?;
605 let current_text = &text[utf8_offset..(utf8_offset + first_run.len)];
606 utf8_offset += first_run.len;
607 let current_text_utf16_length = current_text.encode_utf16().count() as u32;
608 let text_range = DWRITE_TEXT_RANGE {
609 startPosition: utf16_offset,
610 length: current_text_utf16_length,
611 };
612 layout.SetTypography(&font_info.features, text_range)?;
613 utf16_offset += current_text_utf16_length;
614
615 layout
616 };
617
618 let mut first_run = true;
619 let mut ascent = Pixels::default();
620 let mut descent = Pixels::default();
621 for run in font_runs {
622 if first_run {
623 first_run = false;
624 let mut metrics = vec![DWRITE_LINE_METRICS::default(); 4];
625 let mut line_count = 0u32;
626 text_layout.GetLineMetrics(Some(&mut metrics), &mut line_count as _)?;
627 ascent = px(metrics[0].baseline);
628 descent = px(metrics[0].height - metrics[0].baseline);
629 continue;
630 }
631 let font_info = &self.fonts[run.font_id.0];
632 let current_text = &text[utf8_offset..(utf8_offset + run.len)];
633 utf8_offset += run.len;
634 let current_text_utf16_length = current_text.encode_utf16().count() as u32;
635
636 let collection = if font_info.is_system_font {
637 &self.system_font_collection
638 } else {
639 &self.custom_font_collection
640 };
641 let text_range = DWRITE_TEXT_RANGE {
642 startPosition: utf16_offset,
643 length: current_text_utf16_length,
644 };
645 utf16_offset += current_text_utf16_length;
646 text_layout.SetFontCollection(collection, text_range)?;
647 text_layout
648 .SetFontFamilyName(&HSTRING::from(&font_info.font_family), text_range)?;
649 text_layout.SetFontSize(font_size.0, text_range)?;
650 text_layout.SetFontStyle(font_info.font_face.GetStyle(), text_range)?;
651 text_layout.SetFontWeight(font_info.font_face.GetWeight(), text_range)?;
652 text_layout.SetTypography(&font_info.features, text_range)?;
653 }
654
655 let mut runs = Vec::new();
656 let renderer_context = RendererContext {
657 text_system: self,
658 index_converter: StringIndexConverter::new(text),
659 runs: &mut runs,
660 width: 0.0,
661 };
662 text_layout.Draw(
663 Some(&renderer_context as *const _ as _),
664 &text_renderer.0,
665 0.0,
666 0.0,
667 )?;
668 let width = px(renderer_context.width);
669
670 Ok(LineLayout {
671 font_size,
672 width,
673 ascent,
674 descent,
675 runs,
676 len: text.len(),
677 })
678 }
679 }
680
681 fn font_metrics(&self, font_id: FontId) -> FontMetrics {
682 unsafe {
683 let font_info = &self.fonts[font_id.0];
684 let mut metrics = std::mem::zeroed();
685 font_info.font_face.GetMetrics(&mut metrics);
686
687 FontMetrics {
688 units_per_em: metrics.Base.designUnitsPerEm as _,
689 ascent: metrics.Base.ascent as _,
690 descent: -(metrics.Base.descent as f32),
691 line_gap: metrics.Base.lineGap as _,
692 underline_position: metrics.Base.underlinePosition as _,
693 underline_thickness: metrics.Base.underlineThickness as _,
694 cap_height: metrics.Base.capHeight as _,
695 x_height: metrics.Base.xHeight as _,
696 bounding_box: Bounds {
697 origin: Point {
698 x: metrics.glyphBoxLeft as _,
699 y: metrics.glyphBoxBottom as _,
700 },
701 size: Size {
702 width: (metrics.glyphBoxRight - metrics.glyphBoxLeft) as _,
703 height: (metrics.glyphBoxTop - metrics.glyphBoxBottom) as _,
704 },
705 },
706 }
707 }
708 }
709
710 fn create_glyph_run_analysis(
711 &self,
712 params: &RenderGlyphParams,
713 ) -> Result<IDWriteGlyphRunAnalysis> {
714 let font = &self.fonts[params.font_id.0];
715 let glyph_id = [params.glyph_id.0 as u16];
716 let advance = [0.0];
717 let offset = [DWRITE_GLYPH_OFFSET::default()];
718 let glyph_run = DWRITE_GLYPH_RUN {
719 fontFace: unsafe { std::mem::transmute_copy(&font.font_face) },
720 fontEmSize: params.font_size.0,
721 glyphCount: 1,
722 glyphIndices: glyph_id.as_ptr(),
723 glyphAdvances: advance.as_ptr(),
724 glyphOffsets: offset.as_ptr(),
725 isSideways: BOOL(0),
726 bidiLevel: 0,
727 };
728 let transform = DWRITE_MATRIX {
729 m11: params.scale_factor,
730 m12: 0.0,
731 m21: 0.0,
732 m22: params.scale_factor,
733 dx: 0.0,
734 dy: 0.0,
735 };
736 let subpixel_shift = params
737 .subpixel_variant
738 .map(|v| v as f32 / SUBPIXEL_VARIANTS as f32);
739 let baseline_origin_x = subpixel_shift.x / params.scale_factor;
740 let baseline_origin_y = subpixel_shift.y / params.scale_factor;
741
742 let mut rendering_mode = DWRITE_RENDERING_MODE1::default();
743 let mut grid_fit_mode = DWRITE_GRID_FIT_MODE::default();
744 unsafe {
745 font.font_face.GetRecommendedRenderingMode(
746 params.font_size.0,
747 // The dpi here seems that it has the same effect with `Some(&transform)`
748 1.0,
749 1.0,
750 Some(&transform),
751 false,
752 DWRITE_OUTLINE_THRESHOLD_ANTIALIASED,
753 DWRITE_MEASURING_MODE_NATURAL,
754 &self.components.render_params,
755 &mut rendering_mode,
756 &mut grid_fit_mode,
757 )?;
758 }
759
760 let antialias_mode = if params.is_emoji {
761 DWRITE_TEXT_ANTIALIAS_MODE_CLEARTYPE
762 } else {
763 DWRITE_TEXT_ANTIALIAS_MODE_GRAYSCALE
764 };
765
766 let glyph_analysis = unsafe {
767 self.components.factory.CreateGlyphRunAnalysis(
768 &glyph_run,
769 Some(&transform),
770 rendering_mode,
771 DWRITE_MEASURING_MODE_NATURAL,
772 grid_fit_mode,
773 antialias_mode,
774 baseline_origin_x,
775 baseline_origin_y,
776 )
777 }?;
778 Ok(glyph_analysis)
779 }
780
781 fn raster_bounds(&self, params: &RenderGlyphParams) -> Result<Bounds<DevicePixels>> {
782 let glyph_analysis = self.create_glyph_run_analysis(params)?;
783
784 if params.is_emoji {
785 let bounds =
786 unsafe { glyph_analysis.GetAlphaTextureBounds(DWRITE_TEXTURE_CLEARTYPE_3x1)? };
787 // If it's empty, retry with grayscale AA.
788 if !unsafe { IsRectEmpty(&bounds) }.as_bool() {
789 return Ok(Bounds {
790 origin: point((bounds.left as i32).into(), (bounds.top as i32).into()),
791 size: size(
792 (bounds.right - bounds.left).into(),
793 (bounds.bottom - bounds.top).into(),
794 ),
795 });
796 }
797 }
798
799 let bounds = unsafe { glyph_analysis.GetAlphaTextureBounds(DWRITE_TEXTURE_ALIASED_1x1)? };
800
801 if bounds.right < bounds.left {
802 Ok(Bounds {
803 origin: point(0.into(), 0.into()),
804 size: size(0.into(), 0.into()),
805 })
806 } else {
807 Ok(Bounds {
808 origin: point((bounds.left as i32).into(), (bounds.top as i32).into()),
809 size: size(
810 (bounds.right - bounds.left).into(),
811 (bounds.bottom - bounds.top).into(),
812 ),
813 })
814 }
815 }
816
817 fn glyph_for_char(&self, font_id: FontId, ch: char) -> Option<GlyphId> {
818 let font_info = &self.fonts[font_id.0];
819 let codepoints = [ch as u32];
820 let mut glyph_indices = vec![0u16; 1];
821 unsafe {
822 font_info
823 .font_face
824 .GetGlyphIndices(codepoints.as_ptr(), 1, glyph_indices.as_mut_ptr())
825 .log_err()
826 }
827 .map(|_| GlyphId(glyph_indices[0] as u32))
828 }
829
830 fn rasterize_glyph(
831 &self,
832 params: &RenderGlyphParams,
833 glyph_bounds: Bounds<DevicePixels>,
834 ) -> Result<(Size<DevicePixels>, Vec<u8>)> {
835 if glyph_bounds.size.width.0 == 0 || glyph_bounds.size.height.0 == 0 {
836 anyhow::bail!("glyph bounds are empty");
837 }
838
839 // Add an extra pixel when the subpixel variant isn't zero to make room for anti-aliasing.
840 let bitmap_size = glyph_bounds.size;
841
842 let subpixel_shift = params
843 .subpixel_variant
844 .map(|v| v as f32 / SUBPIXEL_VARIANTS as f32);
845 let baseline_origin_x = subpixel_shift.x / params.scale_factor;
846 let baseline_origin_y = subpixel_shift.y / params.scale_factor;
847
848 let glyph_analysis = self.create_glyph_run_analysis(params)?;
849
850 let font = &self.fonts[params.font_id.0];
851 let glyph_id = [params.glyph_id.0 as u16];
852 let advance = [glyph_bounds.size.width.0 as f32];
853 let offset = [DWRITE_GLYPH_OFFSET {
854 advanceOffset: -glyph_bounds.origin.x.0 as f32 / params.scale_factor,
855 ascenderOffset: glyph_bounds.origin.y.0 as f32 / params.scale_factor,
856 }];
857 let glyph_run = DWRITE_GLYPH_RUN {
858 fontFace: unsafe { std::mem::transmute_copy(&font.font_face) },
859 fontEmSize: params.font_size.0,
860 glyphCount: 1,
861 glyphIndices: glyph_id.as_ptr(),
862 glyphAdvances: advance.as_ptr(),
863 glyphOffsets: offset.as_ptr(),
864 isSideways: BOOL(0),
865 bidiLevel: 0,
866 };
867 let transform = DWRITE_MATRIX {
868 m11: params.scale_factor,
869 m12: 0.0,
870 m21: 0.0,
871 m22: params.scale_factor,
872 dx: 0.0,
873 dy: 0.0,
874 };
875
876 let mut bitmap_data: Vec<u8>;
877 if params.is_emoji {
878 if let Ok(color) = self.rasterize_color(
879 &glyph_run,
880 &transform,
881 point(baseline_origin_x, baseline_origin_y),
882 bitmap_size,
883 ) {
884 bitmap_data = color;
885 } else {
886 let monochrome = Self::rasterize_monochrome(&glyph_analysis, glyph_bounds)?;
887 bitmap_data = monochrome
888 .into_iter()
889 .flat_map(|pixel| [0, 0, 0, pixel])
890 .collect::<Vec<_>>();
891 }
892 } else {
893 bitmap_data = Self::rasterize_monochrome(&glyph_analysis, glyph_bounds)?;
894 }
895
896 Ok((bitmap_size, bitmap_data))
897 }
898
899 fn rasterize_monochrome(
900 glyph_analysis: &IDWriteGlyphRunAnalysis,
901 glyph_bounds: Bounds<DevicePixels>,
902 ) -> Result<Vec<u8>> {
903 let mut bitmap_data =
904 vec![0u8; glyph_bounds.size.width.0 as usize * glyph_bounds.size.height.0 as usize];
905
906 unsafe {
907 glyph_analysis.CreateAlphaTexture(
908 DWRITE_TEXTURE_ALIASED_1x1,
909 &RECT {
910 left: glyph_bounds.origin.x.0,
911 top: glyph_bounds.origin.y.0,
912 right: glyph_bounds.size.width.0 + glyph_bounds.origin.x.0,
913 bottom: glyph_bounds.size.height.0 + glyph_bounds.origin.y.0,
914 },
915 &mut bitmap_data,
916 )?;
917 }
918
919 Ok(bitmap_data)
920 }
921
922 fn rasterize_color(
923 &self,
924 glyph_run: &DWRITE_GLYPH_RUN,
925 transform: &DWRITE_MATRIX,
926 baseline_origin: Point<f32>,
927 bitmap_size: Size<DevicePixels>,
928 ) -> Result<Vec<u8>> {
929 // todo: support formats other than COLR
930 let color_enumerator = unsafe {
931 self.components.factory.TranslateColorGlyphRun(
932 Vector2::new(baseline_origin.x, baseline_origin.y),
933 glyph_run,
934 None,
935 DWRITE_GLYPH_IMAGE_FORMATS_COLR,
936 DWRITE_MEASURING_MODE_NATURAL,
937 Some(transform),
938 0,
939 )
940 }?;
941
942 let mut glyph_layers = Vec::new();
943 loop {
944 let color_run = unsafe { color_enumerator.GetCurrentRun() }?;
945 let color_run = unsafe { &*color_run };
946 let image_format = color_run.glyphImageFormat & !DWRITE_GLYPH_IMAGE_FORMATS_TRUETYPE;
947 if image_format == DWRITE_GLYPH_IMAGE_FORMATS_COLR {
948 let color_analysis = unsafe {
949 self.components.factory.CreateGlyphRunAnalysis(
950 &color_run.Base.glyphRun as *const _,
951 Some(transform),
952 DWRITE_RENDERING_MODE1_NATURAL_SYMMETRIC,
953 DWRITE_MEASURING_MODE_NATURAL,
954 DWRITE_GRID_FIT_MODE_DEFAULT,
955 DWRITE_TEXT_ANTIALIAS_MODE_CLEARTYPE,
956 baseline_origin.x,
957 baseline_origin.y,
958 )
959 }?;
960
961 let color_bounds =
962 unsafe { color_analysis.GetAlphaTextureBounds(DWRITE_TEXTURE_CLEARTYPE_3x1) }?;
963
964 let color_size = size(
965 color_bounds.right - color_bounds.left,
966 color_bounds.bottom - color_bounds.top,
967 );
968 if color_size.width > 0 && color_size.height > 0 {
969 let mut alpha_data =
970 vec![0u8; (color_size.width * color_size.height * 3) as usize];
971 unsafe {
972 color_analysis.CreateAlphaTexture(
973 DWRITE_TEXTURE_CLEARTYPE_3x1,
974 &color_bounds,
975 &mut alpha_data,
976 )
977 }?;
978
979 let run_color = {
980 let run_color = color_run.Base.runColor;
981 Rgba {
982 r: run_color.r,
983 g: run_color.g,
984 b: run_color.b,
985 a: run_color.a,
986 }
987 };
988 let bounds = bounds(point(color_bounds.left, color_bounds.top), color_size);
989 let alpha_data = alpha_data
990 .chunks_exact(3)
991 .flat_map(|chunk| [chunk[0], chunk[1], chunk[2], 255])
992 .collect::<Vec<_>>();
993 glyph_layers.push(GlyphLayerTexture::new(
994 &self.components.gpu_state,
995 run_color,
996 bounds,
997 &alpha_data,
998 )?);
999 }
1000 }
1001
1002 let has_next = unsafe { color_enumerator.MoveNext() }
1003 .map(|e| e.as_bool())
1004 .unwrap_or(false);
1005 if !has_next {
1006 break;
1007 }
1008 }
1009
1010 let gpu_state = &self.components.gpu_state;
1011 let params_buffer = {
1012 let desc = D3D11_BUFFER_DESC {
1013 ByteWidth: std::mem::size_of::<GlyphLayerTextureParams>() as u32,
1014 Usage: D3D11_USAGE_DYNAMIC,
1015 BindFlags: D3D11_BIND_CONSTANT_BUFFER.0 as u32,
1016 CPUAccessFlags: D3D11_CPU_ACCESS_WRITE.0 as u32,
1017 MiscFlags: 0,
1018 StructureByteStride: 0,
1019 };
1020
1021 let mut buffer = None;
1022 unsafe {
1023 gpu_state
1024 .device
1025 .CreateBuffer(&desc, None, Some(&mut buffer))
1026 }?;
1027 [buffer]
1028 };
1029
1030 let render_target_texture = {
1031 let mut texture = None;
1032 let desc = D3D11_TEXTURE2D_DESC {
1033 Width: bitmap_size.width.0 as u32,
1034 Height: bitmap_size.height.0 as u32,
1035 MipLevels: 1,
1036 ArraySize: 1,
1037 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
1038 SampleDesc: DXGI_SAMPLE_DESC {
1039 Count: 1,
1040 Quality: 0,
1041 },
1042 Usage: D3D11_USAGE_DEFAULT,
1043 BindFlags: D3D11_BIND_RENDER_TARGET.0 as u32,
1044 CPUAccessFlags: 0,
1045 MiscFlags: 0,
1046 };
1047 unsafe {
1048 gpu_state
1049 .device
1050 .CreateTexture2D(&desc, None, Some(&mut texture))
1051 }?;
1052 texture.unwrap()
1053 };
1054
1055 let render_target_view = {
1056 let desc = D3D11_RENDER_TARGET_VIEW_DESC {
1057 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
1058 ViewDimension: D3D11_RTV_DIMENSION_TEXTURE2D,
1059 Anonymous: D3D11_RENDER_TARGET_VIEW_DESC_0 {
1060 Texture2D: D3D11_TEX2D_RTV { MipSlice: 0 },
1061 },
1062 };
1063 let mut rtv = None;
1064 unsafe {
1065 gpu_state.device.CreateRenderTargetView(
1066 &render_target_texture,
1067 Some(&desc),
1068 Some(&mut rtv),
1069 )
1070 }?;
1071 [rtv]
1072 };
1073
1074 let staging_texture = {
1075 let mut texture = None;
1076 let desc = D3D11_TEXTURE2D_DESC {
1077 Width: bitmap_size.width.0 as u32,
1078 Height: bitmap_size.height.0 as u32,
1079 MipLevels: 1,
1080 ArraySize: 1,
1081 Format: DXGI_FORMAT_B8G8R8A8_UNORM,
1082 SampleDesc: DXGI_SAMPLE_DESC {
1083 Count: 1,
1084 Quality: 0,
1085 },
1086 Usage: D3D11_USAGE_STAGING,
1087 BindFlags: 0,
1088 CPUAccessFlags: D3D11_CPU_ACCESS_READ.0 as u32,
1089 MiscFlags: 0,
1090 };
1091 unsafe {
1092 gpu_state
1093 .device
1094 .CreateTexture2D(&desc, None, Some(&mut texture))
1095 }?;
1096 texture.unwrap()
1097 };
1098
1099 let device_context = &gpu_state.device_context;
1100 unsafe { device_context.IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP) };
1101 unsafe { device_context.VSSetShader(&gpu_state.vertex_shader, None) };
1102 unsafe { device_context.PSSetShader(&gpu_state.pixel_shader, None) };
1103 unsafe { device_context.VSSetConstantBuffers(0, Some(¶ms_buffer)) };
1104 unsafe { device_context.PSSetConstantBuffers(0, Some(¶ms_buffer)) };
1105 unsafe { device_context.OMSetRenderTargets(Some(&render_target_view), None) };
1106 unsafe { device_context.PSSetSamplers(0, Some(&gpu_state.sampler)) };
1107 unsafe { device_context.OMSetBlendState(&gpu_state.blend_state, None, 0xffffffff) };
1108
1109 for layer in glyph_layers {
1110 let params = GlyphLayerTextureParams {
1111 run_color: layer.run_color,
1112 bounds: layer.bounds,
1113 };
1114 unsafe {
1115 let mut dest = std::mem::zeroed();
1116 gpu_state.device_context.Map(
1117 params_buffer[0].as_ref().unwrap(),
1118 0,
1119 D3D11_MAP_WRITE_DISCARD,
1120 0,
1121 Some(&mut dest),
1122 )?;
1123 std::ptr::copy_nonoverlapping(¶ms as *const _, dest.pData as *mut _, 1);
1124 gpu_state
1125 .device_context
1126 .Unmap(params_buffer[0].as_ref().unwrap(), 0);
1127 };
1128
1129 let texture = [Some(layer.texture_view)];
1130 unsafe { device_context.PSSetShaderResources(0, Some(&texture)) };
1131
1132 let viewport = [D3D11_VIEWPORT {
1133 TopLeftX: layer.bounds.origin.x as f32,
1134 TopLeftY: layer.bounds.origin.y as f32,
1135 Width: layer.bounds.size.width as f32,
1136 Height: layer.bounds.size.height as f32,
1137 MinDepth: 0.0,
1138 MaxDepth: 1.0,
1139 }];
1140 unsafe { device_context.RSSetViewports(Some(&viewport)) };
1141
1142 unsafe { device_context.Draw(4, 0) };
1143 }
1144
1145 unsafe { device_context.CopyResource(&staging_texture, &render_target_texture) };
1146
1147 let mapped_data = {
1148 let mut mapped_data = D3D11_MAPPED_SUBRESOURCE::default();
1149 unsafe {
1150 device_context.Map(
1151 &staging_texture,
1152 0,
1153 D3D11_MAP_READ,
1154 0,
1155 Some(&mut mapped_data),
1156 )
1157 }?;
1158 mapped_data
1159 };
1160 let mut rasterized =
1161 vec![0u8; (bitmap_size.width.0 as u32 * bitmap_size.height.0 as u32 * 4) as usize];
1162
1163 for y in 0..bitmap_size.height.0 as usize {
1164 let width = bitmap_size.width.0 as usize;
1165 unsafe {
1166 std::ptr::copy_nonoverlapping::<u8>(
1167 (mapped_data.pData as *const u8).byte_add(mapped_data.RowPitch as usize * y),
1168 rasterized
1169 .as_mut_ptr()
1170 .byte_add(width * y * std::mem::size_of::<u32>()),
1171 width * std::mem::size_of::<u32>(),
1172 )
1173 };
1174 }
1175
1176 Ok(rasterized)
1177 }
1178
1179 fn get_typographic_bounds(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Bounds<f32>> {
1180 unsafe {
1181 let font = &self.fonts[font_id.0].font_face;
1182 let glyph_indices = [glyph_id.0 as u16];
1183 let mut metrics = [DWRITE_GLYPH_METRICS::default()];
1184 font.GetDesignGlyphMetrics(glyph_indices.as_ptr(), 1, metrics.as_mut_ptr(), false)?;
1185
1186 let metrics = &metrics[0];
1187 let advance_width = metrics.advanceWidth as i32;
1188 let advance_height = metrics.advanceHeight as i32;
1189 let left_side_bearing = metrics.leftSideBearing;
1190 let right_side_bearing = metrics.rightSideBearing;
1191 let top_side_bearing = metrics.topSideBearing;
1192 let bottom_side_bearing = metrics.bottomSideBearing;
1193 let vertical_origin_y = metrics.verticalOriginY;
1194
1195 let y_offset = vertical_origin_y + bottom_side_bearing - advance_height;
1196 let width = advance_width - (left_side_bearing + right_side_bearing);
1197 let height = advance_height - (top_side_bearing + bottom_side_bearing);
1198
1199 Ok(Bounds {
1200 origin: Point {
1201 x: left_side_bearing as f32,
1202 y: y_offset as f32,
1203 },
1204 size: Size {
1205 width: width as f32,
1206 height: height as f32,
1207 },
1208 })
1209 }
1210 }
1211
1212 fn get_advance(&self, font_id: FontId, glyph_id: GlyphId) -> Result<Size<f32>> {
1213 unsafe {
1214 let font = &self.fonts[font_id.0].font_face;
1215 let glyph_indices = [glyph_id.0 as u16];
1216 let mut metrics = [DWRITE_GLYPH_METRICS::default()];
1217 font.GetDesignGlyphMetrics(glyph_indices.as_ptr(), 1, metrics.as_mut_ptr(), false)?;
1218
1219 let metrics = &metrics[0];
1220
1221 Ok(Size {
1222 width: metrics.advanceWidth as f32,
1223 height: 0.0,
1224 })
1225 }
1226 }
1227
1228 fn all_font_names(&self) -> Vec<String> {
1229 let mut result =
1230 get_font_names_from_collection(&self.system_font_collection, &self.components.locale);
1231 result.extend(get_font_names_from_collection(
1232 &self.custom_font_collection,
1233 &self.components.locale,
1234 ));
1235 result
1236 }
1237}
1238
1239impl Drop for DirectWriteState {
1240 fn drop(&mut self) {
1241 unsafe {
1242 let _ = self
1243 .components
1244 .factory
1245 .UnregisterFontFileLoader(&self.components.in_memory_loader);
1246 }
1247 }
1248}
1249
1250struct GlyphLayerTexture {
1251 run_color: Rgba,
1252 bounds: Bounds<i32>,
1253 texture: ID3D11Texture2D,
1254 texture_view: ID3D11ShaderResourceView,
1255}
1256
1257impl GlyphLayerTexture {
1258 pub fn new(
1259 gpu_state: &GPUState,
1260 run_color: Rgba,
1261 bounds: Bounds<i32>,
1262 alpha_data: &[u8],
1263 ) -> Result<Self> {
1264 let texture_size = bounds.size;
1265
1266 let desc = D3D11_TEXTURE2D_DESC {
1267 Width: texture_size.width as u32,
1268 Height: texture_size.height as u32,
1269 MipLevels: 1,
1270 ArraySize: 1,
1271 Format: DXGI_FORMAT_R8G8B8A8_UNORM,
1272 SampleDesc: DXGI_SAMPLE_DESC {
1273 Count: 1,
1274 Quality: 0,
1275 },
1276 Usage: D3D11_USAGE_DEFAULT,
1277 BindFlags: D3D11_BIND_SHADER_RESOURCE.0 as u32,
1278 CPUAccessFlags: D3D11_CPU_ACCESS_WRITE.0 as u32,
1279 MiscFlags: 0,
1280 };
1281
1282 let texture = {
1283 let mut texture: Option<ID3D11Texture2D> = None;
1284 unsafe {
1285 gpu_state
1286 .device
1287 .CreateTexture2D(&desc, None, Some(&mut texture))?
1288 };
1289 texture.unwrap()
1290 };
1291 let texture_view = {
1292 let mut view: Option<ID3D11ShaderResourceView> = None;
1293 unsafe {
1294 gpu_state
1295 .device
1296 .CreateShaderResourceView(&texture, None, Some(&mut view))?
1297 };
1298 view.unwrap()
1299 };
1300
1301 unsafe {
1302 gpu_state.device_context.UpdateSubresource(
1303 &texture,
1304 0,
1305 None,
1306 alpha_data.as_ptr() as _,
1307 (texture_size.width * 4) as u32,
1308 0,
1309 )
1310 };
1311
1312 Ok(GlyphLayerTexture {
1313 run_color,
1314 bounds,
1315 texture,
1316 texture_view,
1317 })
1318 }
1319}
1320
1321#[repr(C)]
1322struct GlyphLayerTextureParams {
1323 bounds: Bounds<i32>,
1324 run_color: Rgba,
1325}
1326
1327struct TextRendererWrapper(pub IDWriteTextRenderer);
1328
1329impl TextRendererWrapper {
1330 pub fn new(locale_str: &str) -> Self {
1331 let inner = TextRenderer::new(locale_str);
1332 TextRendererWrapper(inner.into())
1333 }
1334}
1335
1336#[implement(IDWriteTextRenderer)]
1337struct TextRenderer {
1338 locale: String,
1339}
1340
1341impl TextRenderer {
1342 pub fn new(locale_str: &str) -> Self {
1343 TextRenderer {
1344 locale: locale_str.to_owned(),
1345 }
1346 }
1347}
1348
1349struct RendererContext<'t, 'a, 'b> {
1350 text_system: &'t mut DirectWriteState,
1351 index_converter: StringIndexConverter<'a>,
1352 runs: &'b mut Vec<ShapedRun>,
1353 width: f32,
1354}
1355
1356#[derive(Debug)]
1357struct ClusterAnalyzer<'t> {
1358 utf16_idx: usize,
1359 glyph_idx: usize,
1360 glyph_count: usize,
1361 cluster_map: &'t [u16],
1362}
1363
1364impl<'t> ClusterAnalyzer<'t> {
1365 pub fn new(cluster_map: &'t [u16], glyph_count: usize) -> Self {
1366 ClusterAnalyzer {
1367 utf16_idx: 0,
1368 glyph_idx: 0,
1369 glyph_count,
1370 cluster_map,
1371 }
1372 }
1373}
1374
1375impl Iterator for ClusterAnalyzer<'_> {
1376 type Item = (usize, usize);
1377
1378 fn next(&mut self) -> Option<(usize, usize)> {
1379 if self.utf16_idx >= self.cluster_map.len() {
1380 return None; // No more clusters
1381 }
1382 let start_utf16_idx = self.utf16_idx;
1383 let current_glyph = self.cluster_map[start_utf16_idx] as usize;
1384
1385 // Find the end of current cluster (where glyph index changes)
1386 let mut end_utf16_idx = start_utf16_idx + 1;
1387 while end_utf16_idx < self.cluster_map.len()
1388 && self.cluster_map[end_utf16_idx] as usize == current_glyph
1389 {
1390 end_utf16_idx += 1;
1391 }
1392
1393 let utf16_len = end_utf16_idx - start_utf16_idx;
1394
1395 // Calculate glyph count for this cluster
1396 let next_glyph = if end_utf16_idx < self.cluster_map.len() {
1397 self.cluster_map[end_utf16_idx] as usize
1398 } else {
1399 self.glyph_count
1400 };
1401
1402 let glyph_count = next_glyph - current_glyph;
1403
1404 // Update state for next call
1405 self.utf16_idx = end_utf16_idx;
1406 self.glyph_idx = next_glyph;
1407
1408 Some((utf16_len, glyph_count))
1409 }
1410}
1411
1412#[allow(non_snake_case)]
1413impl IDWritePixelSnapping_Impl for TextRenderer_Impl {
1414 fn IsPixelSnappingDisabled(
1415 &self,
1416 _clientdrawingcontext: *const ::core::ffi::c_void,
1417 ) -> windows::core::Result<BOOL> {
1418 Ok(BOOL(0))
1419 }
1420
1421 fn GetCurrentTransform(
1422 &self,
1423 _clientdrawingcontext: *const ::core::ffi::c_void,
1424 transform: *mut DWRITE_MATRIX,
1425 ) -> windows::core::Result<()> {
1426 unsafe {
1427 *transform = DWRITE_MATRIX {
1428 m11: 1.0,
1429 m12: 0.0,
1430 m21: 0.0,
1431 m22: 1.0,
1432 dx: 0.0,
1433 dy: 0.0,
1434 };
1435 }
1436 Ok(())
1437 }
1438
1439 fn GetPixelsPerDip(
1440 &self,
1441 _clientdrawingcontext: *const ::core::ffi::c_void,
1442 ) -> windows::core::Result<f32> {
1443 Ok(1.0)
1444 }
1445}
1446
1447#[allow(non_snake_case)]
1448impl IDWriteTextRenderer_Impl for TextRenderer_Impl {
1449 fn DrawGlyphRun(
1450 &self,
1451 clientdrawingcontext: *const ::core::ffi::c_void,
1452 _baselineoriginx: f32,
1453 _baselineoriginy: f32,
1454 _measuringmode: DWRITE_MEASURING_MODE,
1455 glyphrun: *const DWRITE_GLYPH_RUN,
1456 glyphrundescription: *const DWRITE_GLYPH_RUN_DESCRIPTION,
1457 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1458 ) -> windows::core::Result<()> {
1459 let glyphrun = unsafe { &*glyphrun };
1460 let glyph_count = glyphrun.glyphCount as usize;
1461 if glyph_count == 0 || glyphrun.fontFace.is_none() {
1462 return Ok(());
1463 }
1464 let desc = unsafe { &*glyphrundescription };
1465 let context = unsafe {
1466 &mut *(clientdrawingcontext as *const RendererContext as *mut RendererContext)
1467 };
1468 let font_face = glyphrun.fontFace.as_ref().unwrap();
1469 // This `cast()` action here should never fail since we are running on Win10+, and
1470 // `IDWriteFontFace3` requires Win10
1471 let font_face = &font_face.cast::<IDWriteFontFace3>().unwrap();
1472 let Some((font_identifier, font_struct, color_font)) =
1473 get_font_identifier_and_font_struct(font_face, &self.locale)
1474 else {
1475 return Ok(());
1476 };
1477
1478 let font_id = if let Some(id) = context
1479 .text_system
1480 .font_id_by_identifier
1481 .get(&font_identifier)
1482 {
1483 *id
1484 } else {
1485 context.text_system.select_font(&font_struct)
1486 };
1487
1488 let glyph_ids = unsafe { std::slice::from_raw_parts(glyphrun.glyphIndices, glyph_count) };
1489 let glyph_advances =
1490 unsafe { std::slice::from_raw_parts(glyphrun.glyphAdvances, glyph_count) };
1491 let glyph_offsets =
1492 unsafe { std::slice::from_raw_parts(glyphrun.glyphOffsets, glyph_count) };
1493 let cluster_map =
1494 unsafe { std::slice::from_raw_parts(desc.clusterMap, desc.stringLength as usize) };
1495
1496 let mut cluster_analyzer = ClusterAnalyzer::new(cluster_map, glyph_count);
1497 let mut utf16_idx = desc.textPosition as usize;
1498 let mut glyph_idx = 0;
1499 let mut glyphs = Vec::with_capacity(glyph_count);
1500 for (cluster_utf16_len, cluster_glyph_count) in cluster_analyzer {
1501 context.index_converter.advance_to_utf16_ix(utf16_idx);
1502 utf16_idx += cluster_utf16_len;
1503 for (cluster_glyph_idx, glyph_id) in glyph_ids
1504 [glyph_idx..(glyph_idx + cluster_glyph_count)]
1505 .iter()
1506 .enumerate()
1507 {
1508 let id = GlyphId(*glyph_id as u32);
1509 let is_emoji = color_font
1510 && is_color_glyph(font_face, id, &context.text_system.components.factory);
1511 let this_glyph_idx = glyph_idx + cluster_glyph_idx;
1512 glyphs.push(ShapedGlyph {
1513 id,
1514 position: point(
1515 px(context.width + glyph_offsets[this_glyph_idx].advanceOffset),
1516 px(0.0),
1517 ),
1518 index: context.index_converter.utf8_ix,
1519 is_emoji,
1520 });
1521 context.width += glyph_advances[this_glyph_idx];
1522 }
1523 glyph_idx += cluster_glyph_count;
1524 }
1525 context.runs.push(ShapedRun { font_id, glyphs });
1526 Ok(())
1527 }
1528
1529 fn DrawUnderline(
1530 &self,
1531 _clientdrawingcontext: *const ::core::ffi::c_void,
1532 _baselineoriginx: f32,
1533 _baselineoriginy: f32,
1534 _underline: *const DWRITE_UNDERLINE,
1535 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1536 ) -> windows::core::Result<()> {
1537 Err(windows::core::Error::new(
1538 E_NOTIMPL,
1539 "DrawUnderline unimplemented",
1540 ))
1541 }
1542
1543 fn DrawStrikethrough(
1544 &self,
1545 _clientdrawingcontext: *const ::core::ffi::c_void,
1546 _baselineoriginx: f32,
1547 _baselineoriginy: f32,
1548 _strikethrough: *const DWRITE_STRIKETHROUGH,
1549 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1550 ) -> windows::core::Result<()> {
1551 Err(windows::core::Error::new(
1552 E_NOTIMPL,
1553 "DrawStrikethrough unimplemented",
1554 ))
1555 }
1556
1557 fn DrawInlineObject(
1558 &self,
1559 _clientdrawingcontext: *const ::core::ffi::c_void,
1560 _originx: f32,
1561 _originy: f32,
1562 _inlineobject: windows::core::Ref<IDWriteInlineObject>,
1563 _issideways: BOOL,
1564 _isrighttoleft: BOOL,
1565 _clientdrawingeffect: windows::core::Ref<windows::core::IUnknown>,
1566 ) -> windows::core::Result<()> {
1567 Err(windows::core::Error::new(
1568 E_NOTIMPL,
1569 "DrawInlineObject unimplemented",
1570 ))
1571 }
1572}
1573
1574struct StringIndexConverter<'a> {
1575 text: &'a str,
1576 utf8_ix: usize,
1577 utf16_ix: usize,
1578}
1579
1580impl<'a> StringIndexConverter<'a> {
1581 fn new(text: &'a str) -> Self {
1582 Self {
1583 text,
1584 utf8_ix: 0,
1585 utf16_ix: 0,
1586 }
1587 }
1588
1589 #[allow(dead_code)]
1590 fn advance_to_utf8_ix(&mut self, utf8_target: usize) {
1591 for (ix, c) in self.text[self.utf8_ix..].char_indices() {
1592 if self.utf8_ix + ix >= utf8_target {
1593 self.utf8_ix += ix;
1594 return;
1595 }
1596 self.utf16_ix += c.len_utf16();
1597 }
1598 self.utf8_ix = self.text.len();
1599 }
1600
1601 fn advance_to_utf16_ix(&mut self, utf16_target: usize) {
1602 for (ix, c) in self.text[self.utf8_ix..].char_indices() {
1603 if self.utf16_ix >= utf16_target {
1604 self.utf8_ix += ix;
1605 return;
1606 }
1607 self.utf16_ix += c.len_utf16();
1608 }
1609 self.utf8_ix = self.text.len();
1610 }
1611}
1612
1613impl Into<DWRITE_FONT_STYLE> for FontStyle {
1614 fn into(self) -> DWRITE_FONT_STYLE {
1615 match self {
1616 FontStyle::Normal => DWRITE_FONT_STYLE_NORMAL,
1617 FontStyle::Italic => DWRITE_FONT_STYLE_ITALIC,
1618 FontStyle::Oblique => DWRITE_FONT_STYLE_OBLIQUE,
1619 }
1620 }
1621}
1622
1623impl From<DWRITE_FONT_STYLE> for FontStyle {
1624 fn from(value: DWRITE_FONT_STYLE) -> Self {
1625 match value.0 {
1626 0 => FontStyle::Normal,
1627 1 => FontStyle::Italic,
1628 2 => FontStyle::Oblique,
1629 _ => unreachable!(),
1630 }
1631 }
1632}
1633
1634impl Into<DWRITE_FONT_WEIGHT> for FontWeight {
1635 fn into(self) -> DWRITE_FONT_WEIGHT {
1636 DWRITE_FONT_WEIGHT(self.0 as i32)
1637 }
1638}
1639
1640impl From<DWRITE_FONT_WEIGHT> for FontWeight {
1641 fn from(value: DWRITE_FONT_WEIGHT) -> Self {
1642 FontWeight(value.0 as f32)
1643 }
1644}
1645
1646fn get_font_names_from_collection(
1647 collection: &IDWriteFontCollection1,
1648 locale: &str,
1649) -> Vec<String> {
1650 unsafe {
1651 let mut result = Vec::new();
1652 let family_count = collection.GetFontFamilyCount();
1653 for index in 0..family_count {
1654 let Some(font_family) = collection.GetFontFamily(index).log_err() else {
1655 continue;
1656 };
1657 let Some(localized_family_name) = font_family.GetFamilyNames().log_err() else {
1658 continue;
1659 };
1660 let Some(family_name) = get_name(localized_family_name, locale).log_err() else {
1661 continue;
1662 };
1663 result.push(family_name);
1664 }
1665
1666 result
1667 }
1668}
1669
1670fn get_font_identifier_and_font_struct(
1671 font_face: &IDWriteFontFace3,
1672 locale: &str,
1673) -> Option<(FontIdentifier, Font, bool)> {
1674 let postscript_name = get_postscript_name(font_face, locale).log_err()?;
1675 let localized_family_name = unsafe { font_face.GetFamilyNames().log_err() }?;
1676 let family_name = get_name(localized_family_name, locale).log_err()?;
1677 let weight = unsafe { font_face.GetWeight() };
1678 let style = unsafe { font_face.GetStyle() };
1679 let identifier = FontIdentifier {
1680 postscript_name,
1681 weight: weight.0,
1682 style: style.0,
1683 };
1684 let font_struct = Font {
1685 family: family_name.into(),
1686 features: FontFeatures::default(),
1687 weight: weight.into(),
1688 style: style.into(),
1689 fallbacks: None,
1690 };
1691 let is_emoji = unsafe { font_face.IsColorFont().as_bool() };
1692 Some((identifier, font_struct, is_emoji))
1693}
1694
1695#[inline]
1696fn get_font_identifier(font_face: &IDWriteFontFace3, locale: &str) -> Option<FontIdentifier> {
1697 let weight = unsafe { font_face.GetWeight().0 };
1698 let style = unsafe { font_face.GetStyle().0 };
1699 get_postscript_name(font_face, locale)
1700 .log_err()
1701 .map(|postscript_name| FontIdentifier {
1702 postscript_name,
1703 weight,
1704 style,
1705 })
1706}
1707
1708#[inline]
1709fn get_postscript_name(font_face: &IDWriteFontFace3, locale: &str) -> Result<String> {
1710 let mut info = None;
1711 let mut exists = BOOL(0);
1712 unsafe {
1713 font_face.GetInformationalStrings(
1714 DWRITE_INFORMATIONAL_STRING_POSTSCRIPT_NAME,
1715 &mut info,
1716 &mut exists,
1717 )?
1718 };
1719 if !exists.as_bool() || info.is_none() {
1720 anyhow::bail!("No postscript name found for font face");
1721 }
1722
1723 get_name(info.unwrap(), locale)
1724}
1725
1726// https://learn.microsoft.com/en-us/windows/win32/api/dwrite/ne-dwrite-dwrite_font_feature_tag
1727fn apply_font_features(
1728 direct_write_features: &IDWriteTypography,
1729 features: &FontFeatures,
1730) -> Result<()> {
1731 let tag_values = features.tag_value_list();
1732 if tag_values.is_empty() {
1733 return Ok(());
1734 }
1735
1736 // All of these features are enabled by default by DirectWrite.
1737 // If you want to (and can) peek into the source of DirectWrite
1738 let mut feature_liga = make_direct_write_feature("liga", 1);
1739 let mut feature_clig = make_direct_write_feature("clig", 1);
1740 let mut feature_calt = make_direct_write_feature("calt", 1);
1741
1742 for (tag, value) in tag_values {
1743 if tag.as_str() == "liga" && *value == 0 {
1744 feature_liga.parameter = 0;
1745 continue;
1746 }
1747 if tag.as_str() == "clig" && *value == 0 {
1748 feature_clig.parameter = 0;
1749 continue;
1750 }
1751 if tag.as_str() == "calt" && *value == 0 {
1752 feature_calt.parameter = 0;
1753 continue;
1754 }
1755
1756 unsafe {
1757 direct_write_features.AddFontFeature(make_direct_write_feature(&tag, *value))?;
1758 }
1759 }
1760 unsafe {
1761 direct_write_features.AddFontFeature(feature_liga)?;
1762 direct_write_features.AddFontFeature(feature_clig)?;
1763 direct_write_features.AddFontFeature(feature_calt)?;
1764 }
1765
1766 Ok(())
1767}
1768
1769#[inline]
1770const fn make_direct_write_feature(feature_name: &str, parameter: u32) -> DWRITE_FONT_FEATURE {
1771 let tag = make_direct_write_tag(feature_name);
1772 DWRITE_FONT_FEATURE {
1773 nameTag: tag,
1774 parameter,
1775 }
1776}
1777
1778#[inline]
1779const fn make_open_type_tag(tag_name: &str) -> u32 {
1780 let bytes = tag_name.as_bytes();
1781 debug_assert!(bytes.len() == 4);
1782 u32::from_le_bytes([bytes[0], bytes[1], bytes[2], bytes[3]])
1783}
1784
1785#[inline]
1786const fn make_direct_write_tag(tag_name: &str) -> DWRITE_FONT_FEATURE_TAG {
1787 DWRITE_FONT_FEATURE_TAG(make_open_type_tag(tag_name))
1788}
1789
1790#[inline]
1791fn get_name(string: IDWriteLocalizedStrings, locale: &str) -> Result<String> {
1792 let mut locale_name_index = 0u32;
1793 let mut exists = BOOL(0);
1794 unsafe {
1795 string.FindLocaleName(
1796 &HSTRING::from(locale),
1797 &mut locale_name_index,
1798 &mut exists as _,
1799 )?
1800 };
1801 if !exists.as_bool() {
1802 unsafe {
1803 string.FindLocaleName(
1804 DEFAULT_LOCALE_NAME,
1805 &mut locale_name_index as _,
1806 &mut exists as _,
1807 )?
1808 };
1809 anyhow::ensure!(exists.as_bool(), "No localised string for {locale}");
1810 }
1811
1812 let name_length = unsafe { string.GetStringLength(locale_name_index) }? as usize;
1813 let mut name_vec = vec![0u16; name_length + 1];
1814 unsafe {
1815 string.GetString(locale_name_index, &mut name_vec)?;
1816 }
1817
1818 Ok(String::from_utf16_lossy(&name_vec[..name_length]))
1819}
1820
1821fn get_system_ui_font_name() -> SharedString {
1822 unsafe {
1823 let mut info: LOGFONTW = std::mem::zeroed();
1824 let font_family = if SystemParametersInfoW(
1825 SPI_GETICONTITLELOGFONT,
1826 std::mem::size_of::<LOGFONTW>() as u32,
1827 Some(&mut info as *mut _ as _),
1828 SYSTEM_PARAMETERS_INFO_UPDATE_FLAGS(0),
1829 )
1830 .log_err()
1831 .is_none()
1832 {
1833 // https://learn.microsoft.com/en-us/windows/win32/uxguide/vis-fonts
1834 // Segoe UI is the Windows font intended for user interface text strings.
1835 "Segoe UI".into()
1836 } else {
1837 let font_name = String::from_utf16_lossy(&info.lfFaceName);
1838 font_name.trim_matches(char::from(0)).to_owned().into()
1839 };
1840 log::info!("Use {} as UI font.", font_family);
1841 font_family
1842 }
1843}
1844
1845// One would think that with newer DirectWrite method: IDWriteFontFace4::GetGlyphImageFormats
1846// but that doesn't seem to work for some glyphs, say ❤
1847fn is_color_glyph(
1848 font_face: &IDWriteFontFace3,
1849 glyph_id: GlyphId,
1850 factory: &IDWriteFactory5,
1851) -> bool {
1852 let glyph_run = DWRITE_GLYPH_RUN {
1853 fontFace: unsafe { std::mem::transmute_copy(font_face) },
1854 fontEmSize: 14.0,
1855 glyphCount: 1,
1856 glyphIndices: &(glyph_id.0 as u16),
1857 glyphAdvances: &0.0,
1858 glyphOffsets: &DWRITE_GLYPH_OFFSET {
1859 advanceOffset: 0.0,
1860 ascenderOffset: 0.0,
1861 },
1862 isSideways: BOOL(0),
1863 bidiLevel: 0,
1864 };
1865 unsafe {
1866 factory.TranslateColorGlyphRun(
1867 Vector2::default(),
1868 &glyph_run as _,
1869 None,
1870 DWRITE_GLYPH_IMAGE_FORMATS_COLR
1871 | DWRITE_GLYPH_IMAGE_FORMATS_SVG
1872 | DWRITE_GLYPH_IMAGE_FORMATS_PNG
1873 | DWRITE_GLYPH_IMAGE_FORMATS_JPEG
1874 | DWRITE_GLYPH_IMAGE_FORMATS_PREMULTIPLIED_B8G8R8A8,
1875 DWRITE_MEASURING_MODE_NATURAL,
1876 None,
1877 0,
1878 )
1879 }
1880 .is_ok()
1881}
1882
1883const DEFAULT_LOCALE_NAME: PCWSTR = windows::core::w!("en-US");
1884
1885#[cfg(test)]
1886mod tests {
1887 use crate::platform::windows::direct_write::ClusterAnalyzer;
1888
1889 #[test]
1890 fn test_cluster_map() {
1891 let cluster_map = [0];
1892 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 1);
1893 let next = analyzer.next();
1894 assert_eq!(next, Some((1, 1)));
1895 let next = analyzer.next();
1896 assert_eq!(next, None);
1897
1898 let cluster_map = [0, 1, 2];
1899 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 3);
1900 let next = analyzer.next();
1901 assert_eq!(next, Some((1, 1)));
1902 let next = analyzer.next();
1903 assert_eq!(next, Some((1, 1)));
1904 let next = analyzer.next();
1905 assert_eq!(next, Some((1, 1)));
1906 let next = analyzer.next();
1907 assert_eq!(next, None);
1908 // 👨👩👧👦👩💻
1909 let cluster_map = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 4, 4, 4];
1910 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 5);
1911 let next = analyzer.next();
1912 assert_eq!(next, Some((11, 4)));
1913 let next = analyzer.next();
1914 assert_eq!(next, Some((5, 1)));
1915 let next = analyzer.next();
1916 assert_eq!(next, None);
1917 // 👩💻
1918 let cluster_map = [0, 0, 0, 0, 0];
1919 let mut analyzer = ClusterAnalyzer::new(&cluster_map, 1);
1920 let next = analyzer.next();
1921 assert_eq!(next, Some((5, 1)));
1922 let next = analyzer.next();
1923 assert_eq!(next, None);
1924 }
1925}