1use crate::{
2 AtlasKey, AtlasTextureId, AtlasTextureKind, AtlasTile, Bounds, DevicePixels, PlatformAtlas,
3 Point, Size,
4};
5use anyhow::{anyhow, Result};
6use collections::FxHashMap;
7use derive_more::{Deref, DerefMut};
8use etagere::BucketedAtlasAllocator;
9use metal::Device;
10use parking_lot::Mutex;
11use std::borrow::Cow;
12
13pub(crate) struct MetalAtlas(Mutex<MetalAtlasState>);
14
15impl MetalAtlas {
16 pub(crate) fn new(device: Device) -> Self {
17 MetalAtlas(Mutex::new(MetalAtlasState {
18 device: AssertSend(device),
19 monochrome_textures: Default::default(),
20 polychrome_textures: Default::default(),
21 path_textures: Default::default(),
22 tiles_by_key: Default::default(),
23 }))
24 }
25
26 pub(crate) fn metal_texture(&self, id: AtlasTextureId) -> metal::Texture {
27 self.0.lock().texture(id).metal_texture.clone()
28 }
29
30 pub(crate) fn allocate(
31 &self,
32 size: Size<DevicePixels>,
33 texture_kind: AtlasTextureKind,
34 ) -> Option<AtlasTile> {
35 self.0.lock().allocate(size, texture_kind)
36 }
37
38 pub(crate) fn clear_textures(&self, texture_kind: AtlasTextureKind) {
39 let mut lock = self.0.lock();
40 let textures = match texture_kind {
41 AtlasTextureKind::Monochrome => &mut lock.monochrome_textures,
42 AtlasTextureKind::Polychrome => &mut lock.polychrome_textures,
43 AtlasTextureKind::Path => &mut lock.path_textures,
44 };
45 for texture in textures {
46 texture.clear();
47 }
48 }
49}
50
51struct MetalAtlasState {
52 device: AssertSend<Device>,
53 monochrome_textures: Vec<MetalAtlasTexture>,
54 polychrome_textures: Vec<MetalAtlasTexture>,
55 path_textures: Vec<MetalAtlasTexture>,
56 tiles_by_key: FxHashMap<AtlasKey, AtlasTile>,
57}
58
59impl PlatformAtlas for MetalAtlas {
60 fn get_or_insert_with<'a>(
61 &self,
62 key: &AtlasKey,
63 build: &mut dyn FnMut() -> Result<Option<(Size<DevicePixels>, Cow<'a, [u8]>)>>,
64 ) -> Result<Option<AtlasTile>> {
65 let mut lock = self.0.lock();
66 if let Some(tile) = lock.tiles_by_key.get(key) {
67 Ok(Some(tile.clone()))
68 } else {
69 let Some((size, bytes)) = build()? else {
70 return Ok(None);
71 };
72 let tile = lock
73 .allocate(size, key.texture_kind())
74 .ok_or_else(|| anyhow!("failed to allocate"))?;
75 let texture = lock.texture(tile.texture_id);
76 texture.upload(tile.bounds, &bytes);
77 lock.tiles_by_key.insert(key.clone(), tile.clone());
78 Ok(Some(tile))
79 }
80 }
81}
82
83impl MetalAtlasState {
84 fn allocate(
85 &mut self,
86 size: Size<DevicePixels>,
87 texture_kind: AtlasTextureKind,
88 ) -> Option<AtlasTile> {
89 let textures = match texture_kind {
90 AtlasTextureKind::Monochrome => &mut self.monochrome_textures,
91 AtlasTextureKind::Polychrome => &mut self.polychrome_textures,
92 AtlasTextureKind::Path => &mut self.path_textures,
93 };
94
95 textures
96 .iter_mut()
97 .rev()
98 .find_map(|texture| texture.allocate(size))
99 .or_else(|| {
100 let texture = self.push_texture(size, texture_kind);
101 texture.allocate(size)
102 })
103 }
104
105 fn push_texture(
106 &mut self,
107 min_size: Size<DevicePixels>,
108 kind: AtlasTextureKind,
109 ) -> &mut MetalAtlasTexture {
110 const DEFAULT_ATLAS_SIZE: Size<DevicePixels> = Size {
111 width: DevicePixels(1024),
112 height: DevicePixels(1024),
113 };
114 // Max texture size on all modern Apple GPUs. Anything bigger than that crashes in validateWithDevice.
115 const MAX_ATLAS_SIZE: Size<DevicePixels> = Size {
116 width: DevicePixels(16384),
117 height: DevicePixels(16384),
118 };
119 let size = min_size.min(&MAX_ATLAS_SIZE).max(&DEFAULT_ATLAS_SIZE);
120 let texture_descriptor = metal::TextureDescriptor::new();
121 texture_descriptor.set_width(size.width.into());
122 texture_descriptor.set_height(size.height.into());
123 let pixel_format;
124 let usage;
125 match kind {
126 AtlasTextureKind::Monochrome => {
127 pixel_format = metal::MTLPixelFormat::A8Unorm;
128 usage = metal::MTLTextureUsage::ShaderRead;
129 }
130 AtlasTextureKind::Polychrome => {
131 pixel_format = metal::MTLPixelFormat::BGRA8Unorm;
132 usage = metal::MTLTextureUsage::ShaderRead;
133 }
134 AtlasTextureKind::Path => {
135 pixel_format = metal::MTLPixelFormat::R16Float;
136 usage = metal::MTLTextureUsage::RenderTarget | metal::MTLTextureUsage::ShaderRead;
137 }
138 }
139 texture_descriptor.set_pixel_format(pixel_format);
140 texture_descriptor.set_usage(usage);
141 let metal_texture = self.device.new_texture(&texture_descriptor);
142
143 let textures = match kind {
144 AtlasTextureKind::Monochrome => &mut self.monochrome_textures,
145 AtlasTextureKind::Polychrome => &mut self.polychrome_textures,
146 AtlasTextureKind::Path => &mut self.path_textures,
147 };
148 let atlas_texture = MetalAtlasTexture {
149 id: AtlasTextureId {
150 index: textures.len() as u32,
151 kind,
152 },
153 allocator: etagere::BucketedAtlasAllocator::new(size.into()),
154 metal_texture: AssertSend(metal_texture),
155 };
156 textures.push(atlas_texture);
157 textures.last_mut().unwrap()
158 }
159
160 fn texture(&self, id: AtlasTextureId) -> &MetalAtlasTexture {
161 let textures = match id.kind {
162 crate::AtlasTextureKind::Monochrome => &self.monochrome_textures,
163 crate::AtlasTextureKind::Polychrome => &self.polychrome_textures,
164 crate::AtlasTextureKind::Path => &self.path_textures,
165 };
166 &textures[id.index as usize]
167 }
168}
169
170struct MetalAtlasTexture {
171 id: AtlasTextureId,
172 allocator: BucketedAtlasAllocator,
173 metal_texture: AssertSend<metal::Texture>,
174}
175
176impl MetalAtlasTexture {
177 fn clear(&mut self) {
178 self.allocator.clear();
179 }
180
181 fn allocate(&mut self, size: Size<DevicePixels>) -> Option<AtlasTile> {
182 let allocation = self.allocator.allocate(size.into())?;
183 let tile = AtlasTile {
184 texture_id: self.id,
185 tile_id: allocation.id.into(),
186 bounds: Bounds {
187 origin: allocation.rectangle.min.into(),
188 size,
189 },
190 padding: 0,
191 };
192 Some(tile)
193 }
194
195 fn upload(&self, bounds: Bounds<DevicePixels>, bytes: &[u8]) {
196 let region = metal::MTLRegion::new_2d(
197 bounds.origin.x.into(),
198 bounds.origin.y.into(),
199 bounds.size.width.into(),
200 bounds.size.height.into(),
201 );
202 self.metal_texture.replace_region(
203 region,
204 0,
205 bytes.as_ptr() as *const _,
206 bounds.size.width.to_bytes(self.bytes_per_pixel()) as u64,
207 );
208 }
209
210 fn bytes_per_pixel(&self) -> u8 {
211 use metal::MTLPixelFormat::*;
212 match self.metal_texture.pixel_format() {
213 A8Unorm | R8Unorm => 1,
214 RGBA8Unorm | BGRA8Unorm => 4,
215 _ => unimplemented!(),
216 }
217 }
218}
219
220impl From<Size<DevicePixels>> for etagere::Size {
221 fn from(size: Size<DevicePixels>) -> Self {
222 etagere::Size::new(size.width.into(), size.height.into())
223 }
224}
225
226impl From<etagere::Point> for Point<DevicePixels> {
227 fn from(value: etagere::Point) -> Self {
228 Point {
229 x: DevicePixels::from(value.x),
230 y: DevicePixels::from(value.y),
231 }
232 }
233}
234
235impl From<etagere::Size> for Size<DevicePixels> {
236 fn from(size: etagere::Size) -> Self {
237 Size {
238 width: DevicePixels::from(size.width),
239 height: DevicePixels::from(size.height),
240 }
241 }
242}
243
244impl From<etagere::Rectangle> for Bounds<DevicePixels> {
245 fn from(rectangle: etagere::Rectangle) -> Self {
246 Bounds {
247 origin: rectangle.min.into(),
248 size: rectangle.size().into(),
249 }
250 }
251}
252
253#[derive(Deref, DerefMut)]
254struct AssertSend<T>(T);
255
256unsafe impl<T> Send for AssertSend<T> {}