1use collections::FxHashMap;
2use etagere::BucketedAtlasAllocator;
3use parking_lot::Mutex;
4use windows::Win32::Graphics::{
5 Direct3D11::{
6 D3D11_BIND_SHADER_RESOURCE, D3D11_BOX, D3D11_TEXTURE2D_DESC, D3D11_USAGE_DEFAULT,
7 ID3D11Device, ID3D11DeviceContext, ID3D11ShaderResourceView, ID3D11Texture2D,
8 },
9 Dxgi::Common::*,
10};
11
12use gpui::{
13 AtlasKey, AtlasTextureId, AtlasTextureKind, AtlasTextureList, AtlasTile, Bounds, DevicePixels,
14 PlatformAtlas, Point, Size,
15};
16
17pub(crate) struct DirectXAtlas(Mutex<DirectXAtlasState>);
18
19struct DirectXAtlasState {
20 device: ID3D11Device,
21 device_context: ID3D11DeviceContext,
22 monochrome_textures: AtlasTextureList<DirectXAtlasTexture>,
23 polychrome_textures: AtlasTextureList<DirectXAtlasTexture>,
24 subpixel_textures: AtlasTextureList<DirectXAtlasTexture>,
25 tiles_by_key: FxHashMap<AtlasKey, AtlasTile>,
26}
27
28struct DirectXAtlasTexture {
29 id: AtlasTextureId,
30 bytes_per_pixel: u32,
31 allocator: BucketedAtlasAllocator,
32 texture: ID3D11Texture2D,
33 view: [Option<ID3D11ShaderResourceView>; 1],
34 live_atlas_keys: u32,
35}
36
37impl DirectXAtlas {
38 pub(crate) fn new(device: &ID3D11Device, device_context: &ID3D11DeviceContext) -> Self {
39 DirectXAtlas(Mutex::new(DirectXAtlasState {
40 device: device.clone(),
41 device_context: device_context.clone(),
42 monochrome_textures: Default::default(),
43 polychrome_textures: Default::default(),
44 subpixel_textures: Default::default(),
45 tiles_by_key: Default::default(),
46 }))
47 }
48
49 pub(crate) fn get_texture_view(
50 &self,
51 id: AtlasTextureId,
52 ) -> [Option<ID3D11ShaderResourceView>; 1] {
53 let lock = self.0.lock();
54 let tex = lock.texture(id);
55 tex.view.clone()
56 }
57
58 pub(crate) fn handle_device_lost(
59 &self,
60 device: &ID3D11Device,
61 device_context: &ID3D11DeviceContext,
62 ) {
63 let mut lock = self.0.lock();
64 lock.device = device.clone();
65 lock.device_context = device_context.clone();
66 lock.monochrome_textures = AtlasTextureList::default();
67 lock.polychrome_textures = AtlasTextureList::default();
68 lock.subpixel_textures = AtlasTextureList::default();
69 lock.tiles_by_key.clear();
70 }
71}
72
73impl PlatformAtlas for DirectXAtlas {
74 fn get_or_insert_with<'a>(
75 &self,
76 key: &AtlasKey,
77 build: &mut dyn FnMut() -> anyhow::Result<
78 Option<(Size<DevicePixels>, std::borrow::Cow<'a, [u8]>)>,
79 >,
80 ) -> anyhow::Result<Option<AtlasTile>> {
81 let mut lock = self.0.lock();
82 if let Some(tile) = lock.tiles_by_key.get(key) {
83 Ok(Some(tile.clone()))
84 } else {
85 let Some((size, bytes)) = build()? else {
86 return Ok(None);
87 };
88 let tile = lock
89 .allocate(size, key.texture_kind())
90 .ok_or_else(|| anyhow::anyhow!("failed to allocate"))?;
91 let texture = lock.texture(tile.texture_id);
92 texture.upload(&lock.device_context, tile.bounds, &bytes);
93 lock.tiles_by_key.insert(key.clone(), tile.clone());
94 Ok(Some(tile))
95 }
96 }
97
98 fn remove(&self, key: &AtlasKey) {
99 let mut lock = self.0.lock();
100
101 let Some(id) = lock.tiles_by_key.remove(key).map(|tile| tile.texture_id) else {
102 return;
103 };
104
105 let textures = match id.kind {
106 AtlasTextureKind::Monochrome => &mut lock.monochrome_textures,
107 AtlasTextureKind::Polychrome => &mut lock.polychrome_textures,
108 AtlasTextureKind::Subpixel => &mut lock.subpixel_textures,
109 };
110
111 let Some(texture_slot) = textures.textures.get_mut(id.index as usize) else {
112 return;
113 };
114
115 if let Some(mut texture) = texture_slot.take() {
116 texture.decrement_ref_count();
117 if texture.is_unreferenced() {
118 textures.free_list.push(texture.id.index as usize);
119 } else {
120 *texture_slot = Some(texture);
121 }
122 }
123 }
124}
125
126impl DirectXAtlasState {
127 fn allocate(
128 &mut self,
129 size: Size<DevicePixels>,
130 texture_kind: AtlasTextureKind,
131 ) -> Option<AtlasTile> {
132 {
133 let textures = match texture_kind {
134 AtlasTextureKind::Monochrome => &mut self.monochrome_textures,
135 AtlasTextureKind::Polychrome => &mut self.polychrome_textures,
136 AtlasTextureKind::Subpixel => &mut self.subpixel_textures,
137 };
138
139 if let Some(tile) = textures
140 .iter_mut()
141 .rev()
142 .find_map(|texture| texture.allocate(size))
143 {
144 return Some(tile);
145 }
146 }
147
148 let texture = self.push_texture(size, texture_kind)?;
149 texture.allocate(size)
150 }
151
152 fn push_texture(
153 &mut self,
154 min_size: Size<DevicePixels>,
155 kind: AtlasTextureKind,
156 ) -> Option<&mut DirectXAtlasTexture> {
157 const DEFAULT_ATLAS_SIZE: Size<DevicePixels> = Size {
158 width: DevicePixels(1024),
159 height: DevicePixels(1024),
160 };
161 // Max texture size for DirectX. See:
162 // https://learn.microsoft.com/en-us/windows/win32/direct3d11/overviews-direct3d-11-resources-limits
163 const MAX_ATLAS_SIZE: Size<DevicePixels> = Size {
164 width: DevicePixels(16384),
165 height: DevicePixels(16384),
166 };
167 let size = min_size.min(&MAX_ATLAS_SIZE).max(&DEFAULT_ATLAS_SIZE);
168 let pixel_format;
169 let bind_flag;
170 let bytes_per_pixel;
171 match kind {
172 AtlasTextureKind::Monochrome => {
173 pixel_format = DXGI_FORMAT_R8_UNORM;
174 bind_flag = D3D11_BIND_SHADER_RESOURCE;
175 bytes_per_pixel = 1;
176 }
177 AtlasTextureKind::Polychrome => {
178 pixel_format = DXGI_FORMAT_B8G8R8A8_UNORM;
179 bind_flag = D3D11_BIND_SHADER_RESOURCE;
180 bytes_per_pixel = 4;
181 }
182 AtlasTextureKind::Subpixel => {
183 pixel_format = DXGI_FORMAT_R8G8B8A8_UNORM;
184 bind_flag = D3D11_BIND_SHADER_RESOURCE;
185 bytes_per_pixel = 4;
186 }
187 }
188 let texture_desc = D3D11_TEXTURE2D_DESC {
189 Width: size.width.0 as u32,
190 Height: size.height.0 as u32,
191 MipLevels: 1,
192 ArraySize: 1,
193 Format: pixel_format,
194 SampleDesc: DXGI_SAMPLE_DESC {
195 Count: 1,
196 Quality: 0,
197 },
198 Usage: D3D11_USAGE_DEFAULT,
199 BindFlags: bind_flag.0 as u32,
200 CPUAccessFlags: 0,
201 MiscFlags: 0,
202 };
203 let mut texture: Option<ID3D11Texture2D> = None;
204 unsafe {
205 // This only returns None if the device is lost, which we will recreate later.
206 // So it's ok to return None here.
207 self.device
208 .CreateTexture2D(&texture_desc, None, Some(&mut texture))
209 .ok()?;
210 }
211 let texture = texture.unwrap();
212
213 let texture_list = match kind {
214 AtlasTextureKind::Monochrome => &mut self.monochrome_textures,
215 AtlasTextureKind::Polychrome => &mut self.polychrome_textures,
216 AtlasTextureKind::Subpixel => &mut self.subpixel_textures,
217 };
218 let index = texture_list.free_list.pop();
219 let view = unsafe {
220 let mut view = None;
221 self.device
222 .CreateShaderResourceView(&texture, None, Some(&mut view))
223 .ok()?;
224 [view]
225 };
226 let atlas_texture = DirectXAtlasTexture {
227 id: AtlasTextureId {
228 index: index.unwrap_or(texture_list.textures.len()) as u32,
229 kind,
230 },
231 bytes_per_pixel,
232 allocator: etagere::BucketedAtlasAllocator::new(device_size_to_etagere(size)),
233 texture,
234 view,
235 live_atlas_keys: 0,
236 };
237 if let Some(ix) = index {
238 texture_list.textures[ix] = Some(atlas_texture);
239 texture_list.textures.get_mut(ix).unwrap().as_mut()
240 } else {
241 texture_list.textures.push(Some(atlas_texture));
242 texture_list.textures.last_mut().unwrap().as_mut()
243 }
244 }
245
246 fn texture(&self, id: AtlasTextureId) -> &DirectXAtlasTexture {
247 match id.kind {
248 AtlasTextureKind::Monochrome => &self.monochrome_textures[id.index as usize]
249 .as_ref()
250 .unwrap(),
251 AtlasTextureKind::Polychrome => &self.polychrome_textures[id.index as usize]
252 .as_ref()
253 .unwrap(),
254 AtlasTextureKind::Subpixel => {
255 &self.subpixel_textures[id.index as usize].as_ref().unwrap()
256 }
257 }
258 }
259}
260
261impl DirectXAtlasTexture {
262 fn allocate(&mut self, size: Size<DevicePixels>) -> Option<AtlasTile> {
263 let allocation = self.allocator.allocate(device_size_to_etagere(size))?;
264 let tile = AtlasTile {
265 texture_id: self.id,
266 tile_id: allocation.id.into(),
267 bounds: Bounds {
268 origin: etagere_point_to_device(allocation.rectangle.min),
269 size,
270 },
271 padding: 0,
272 };
273 self.live_atlas_keys += 1;
274 Some(tile)
275 }
276
277 fn upload(
278 &self,
279 device_context: &ID3D11DeviceContext,
280 bounds: Bounds<DevicePixels>,
281 bytes: &[u8],
282 ) {
283 unsafe {
284 device_context.UpdateSubresource(
285 &self.texture,
286 0,
287 Some(&D3D11_BOX {
288 left: bounds.left().0 as u32,
289 top: bounds.top().0 as u32,
290 front: 0,
291 right: bounds.right().0 as u32,
292 bottom: bounds.bottom().0 as u32,
293 back: 1,
294 }),
295 bytes.as_ptr() as _,
296 bounds.size.width.to_bytes(self.bytes_per_pixel as u8),
297 0,
298 );
299 }
300 }
301
302 fn decrement_ref_count(&mut self) {
303 self.live_atlas_keys -= 1;
304 }
305
306 fn is_unreferenced(&mut self) -> bool {
307 self.live_atlas_keys == 0
308 }
309}
310
311fn device_size_to_etagere(size: Size<DevicePixels>) -> etagere::Size {
312 etagere::Size::new(size.width.into(), size.height.into())
313}
314
315fn etagere_point_to_device(value: etagere::Point) -> Point<DevicePixels> {
316 Point {
317 x: DevicePixels::from(value.x),
318 y: DevicePixels::from(value.y),
319 }
320}