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