1use crate::{
2 AtlasKey, AtlasTextureId, AtlasTextureKind, AtlasTile, Bounds, DevicePixels, PlatformAtlas,
3 Point, Size,
4};
5use 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 ) -> 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<(Size<DevicePixels>, Cow<'a, [u8]>)>,
64 ) -> Result<AtlasTile> {
65 let mut lock = self.0.lock();
66 if let Some(tile) = lock.tiles_by_key.get(key) {
67 Ok(tile.clone())
68 } else {
69 let (size, bytes) = build()?;
70 let tile = lock.allocate(size, key.texture_kind());
71 let texture = lock.texture(tile.texture_id);
72 texture.upload(tile.bounds, &bytes);
73 lock.tiles_by_key.insert(key.clone(), tile.clone());
74 Ok(tile)
75 }
76 }
77}
78
79impl MetalAtlasState {
80 fn allocate(&mut self, size: Size<DevicePixels>, texture_kind: AtlasTextureKind) -> AtlasTile {
81 let textures = match texture_kind {
82 AtlasTextureKind::Monochrome => &mut self.monochrome_textures,
83 AtlasTextureKind::Polychrome => &mut self.polychrome_textures,
84 AtlasTextureKind::Path => &mut self.path_textures,
85 };
86
87 textures
88 .iter_mut()
89 .rev()
90 .find_map(|texture| texture.allocate(size))
91 .unwrap_or_else(|| {
92 let texture = self.push_texture(size, texture_kind);
93 texture.allocate(size).unwrap()
94 })
95 }
96
97 fn push_texture(
98 &mut self,
99 min_size: Size<DevicePixels>,
100 kind: AtlasTextureKind,
101 ) -> &mut MetalAtlasTexture {
102 const DEFAULT_ATLAS_SIZE: Size<DevicePixels> = Size {
103 width: DevicePixels(1024),
104 height: DevicePixels(1024),
105 };
106 // Max texture size on all modern Apple GPUs. Anything bigger than that crashes in validateWithDevice.
107 const MAX_ATLAS_SIZE: Size<DevicePixels> = Size {
108 width: DevicePixels(16384),
109 height: DevicePixels(16384),
110 };
111 let size = min_size.min(&MAX_ATLAS_SIZE).max(&DEFAULT_ATLAS_SIZE);
112 let texture_descriptor = metal::TextureDescriptor::new();
113 texture_descriptor.set_width(size.width.into());
114 texture_descriptor.set_height(size.height.into());
115 let pixel_format;
116 let usage;
117 match kind {
118 AtlasTextureKind::Monochrome => {
119 pixel_format = metal::MTLPixelFormat::A8Unorm;
120 usage = metal::MTLTextureUsage::ShaderRead;
121 }
122 AtlasTextureKind::Polychrome => {
123 pixel_format = metal::MTLPixelFormat::BGRA8Unorm;
124 usage = metal::MTLTextureUsage::ShaderRead;
125 }
126 AtlasTextureKind::Path => {
127 pixel_format = metal::MTLPixelFormat::R16Float;
128 usage = metal::MTLTextureUsage::RenderTarget | metal::MTLTextureUsage::ShaderRead;
129 }
130 }
131 texture_descriptor.set_pixel_format(pixel_format);
132 texture_descriptor.set_usage(usage);
133 let metal_texture = self.device.new_texture(&texture_descriptor);
134
135 let textures = match kind {
136 AtlasTextureKind::Monochrome => &mut self.monochrome_textures,
137 AtlasTextureKind::Polychrome => &mut self.polychrome_textures,
138 AtlasTextureKind::Path => &mut self.path_textures,
139 };
140 let atlas_texture = MetalAtlasTexture {
141 id: AtlasTextureId {
142 index: textures.len() as u32,
143 kind,
144 },
145 allocator: etagere::BucketedAtlasAllocator::new(size.into()),
146 metal_texture: AssertSend(metal_texture),
147 };
148 textures.push(atlas_texture);
149 textures.last_mut().unwrap()
150 }
151
152 fn texture(&self, id: AtlasTextureId) -> &MetalAtlasTexture {
153 let textures = match id.kind {
154 crate::AtlasTextureKind::Monochrome => &self.monochrome_textures,
155 crate::AtlasTextureKind::Polychrome => &self.polychrome_textures,
156 crate::AtlasTextureKind::Path => &self.path_textures,
157 };
158 &textures[id.index as usize]
159 }
160}
161
162struct MetalAtlasTexture {
163 id: AtlasTextureId,
164 allocator: BucketedAtlasAllocator,
165 metal_texture: AssertSend<metal::Texture>,
166}
167
168impl MetalAtlasTexture {
169 fn clear(&mut self) {
170 self.allocator.clear();
171 }
172
173 fn allocate(&mut self, size: Size<DevicePixels>) -> Option<AtlasTile> {
174 let allocation = self.allocator.allocate(size.into())?;
175 let tile = AtlasTile {
176 texture_id: self.id,
177 tile_id: allocation.id.into(),
178 bounds: Bounds {
179 origin: allocation.rectangle.min.into(),
180 size,
181 },
182 padding: 0,
183 };
184 Some(tile)
185 }
186
187 fn upload(&self, bounds: Bounds<DevicePixels>, bytes: &[u8]) {
188 let region = metal::MTLRegion::new_2d(
189 bounds.origin.x.into(),
190 bounds.origin.y.into(),
191 bounds.size.width.into(),
192 bounds.size.height.into(),
193 );
194 self.metal_texture.replace_region(
195 region,
196 0,
197 bytes.as_ptr() as *const _,
198 bounds.size.width.to_bytes(self.bytes_per_pixel()) as u64,
199 );
200 }
201
202 fn bytes_per_pixel(&self) -> u8 {
203 use metal::MTLPixelFormat::*;
204 match self.metal_texture.pixel_format() {
205 A8Unorm | R8Unorm => 1,
206 RGBA8Unorm | BGRA8Unorm => 4,
207 _ => unimplemented!(),
208 }
209 }
210}
211
212impl From<Size<DevicePixels>> for etagere::Size {
213 fn from(size: Size<DevicePixels>) -> Self {
214 etagere::Size::new(size.width.into(), size.height.into())
215 }
216}
217
218impl From<etagere::Point> for Point<DevicePixels> {
219 fn from(value: etagere::Point) -> Self {
220 Point {
221 x: DevicePixels::from(value.x),
222 y: DevicePixels::from(value.y),
223 }
224 }
225}
226
227impl From<etagere::Size> for Size<DevicePixels> {
228 fn from(size: etagere::Size) -> Self {
229 Size {
230 width: DevicePixels::from(size.width),
231 height: DevicePixels::from(size.height),
232 }
233 }
234}
235
236impl From<etagere::Rectangle> for Bounds<DevicePixels> {
237 fn from(rectangle: etagere::Rectangle) -> Self {
238 Bounds {
239 origin: rectangle.min.into(),
240 size: rectangle.size().into(),
241 }
242 }
243}
244
245#[derive(Deref, DerefMut)]
246struct AssertSend<T>(T);
247
248unsafe impl<T> Send for AssertSend<T> {}