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 textures
87 .iter_mut()
88 .rev()
89 .find_map(|texture| texture.allocate(size))
90 .unwrap_or_else(|| {
91 let texture = self.push_texture(size, texture_kind);
92 texture.allocate(size).unwrap()
93 })
94 }
95
96 fn push_texture(
97 &mut self,
98 min_size: Size<DevicePixels>,
99 kind: AtlasTextureKind,
100 ) -> &mut MetalAtlasTexture {
101 const DEFAULT_ATLAS_SIZE: Size<DevicePixels> = Size {
102 width: DevicePixels(1024),
103 height: DevicePixels(1024),
104 };
105
106 let size = min_size.max(&DEFAULT_ATLAS_SIZE);
107 let texture_descriptor = metal::TextureDescriptor::new();
108 texture_descriptor.set_width(size.width.into());
109 texture_descriptor.set_height(size.height.into());
110 let pixel_format;
111 let usage;
112 match kind {
113 AtlasTextureKind::Monochrome => {
114 pixel_format = metal::MTLPixelFormat::A8Unorm;
115 usage = metal::MTLTextureUsage::ShaderRead;
116 }
117 AtlasTextureKind::Polychrome => {
118 pixel_format = metal::MTLPixelFormat::BGRA8Unorm;
119 usage = metal::MTLTextureUsage::ShaderRead;
120 }
121 AtlasTextureKind::Path => {
122 pixel_format = metal::MTLPixelFormat::R16Float;
123 usage = metal::MTLTextureUsage::RenderTarget | metal::MTLTextureUsage::ShaderRead;
124 }
125 }
126 texture_descriptor.set_pixel_format(pixel_format);
127 texture_descriptor.set_usage(usage);
128 let metal_texture = self.device.new_texture(&texture_descriptor);
129
130 let textures = match kind {
131 AtlasTextureKind::Monochrome => &mut self.monochrome_textures,
132 AtlasTextureKind::Polychrome => &mut self.polychrome_textures,
133 AtlasTextureKind::Path => &mut self.path_textures,
134 };
135 let atlas_texture = MetalAtlasTexture {
136 id: AtlasTextureId {
137 index: textures.len() as u32,
138 kind,
139 },
140 allocator: etagere::BucketedAtlasAllocator::new(size.into()),
141 metal_texture: AssertSend(metal_texture),
142 };
143 textures.push(atlas_texture);
144 textures.last_mut().unwrap()
145 }
146
147 fn texture(&self, id: AtlasTextureId) -> &MetalAtlasTexture {
148 let textures = match id.kind {
149 crate::AtlasTextureKind::Monochrome => &self.monochrome_textures,
150 crate::AtlasTextureKind::Polychrome => &self.polychrome_textures,
151 crate::AtlasTextureKind::Path => &self.path_textures,
152 };
153 &textures[id.index as usize]
154 }
155}
156
157struct MetalAtlasTexture {
158 id: AtlasTextureId,
159 allocator: BucketedAtlasAllocator,
160 metal_texture: AssertSend<metal::Texture>,
161}
162
163impl MetalAtlasTexture {
164 fn clear(&mut self) {
165 self.allocator.clear();
166 }
167
168 fn allocate(&mut self, size: Size<DevicePixels>) -> Option<AtlasTile> {
169 let allocation = self.allocator.allocate(size.into())?;
170 let tile = AtlasTile {
171 texture_id: self.id,
172 tile_id: allocation.id.into(),
173 bounds: Bounds {
174 origin: allocation.rectangle.min.into(),
175 size,
176 },
177 };
178 Some(tile)
179 }
180
181 fn upload(&self, bounds: Bounds<DevicePixels>, bytes: &[u8]) {
182 let region = metal::MTLRegion::new_2d(
183 bounds.origin.x.into(),
184 bounds.origin.y.into(),
185 bounds.size.width.into(),
186 bounds.size.height.into(),
187 );
188 self.metal_texture.replace_region(
189 region,
190 0,
191 bytes.as_ptr() as *const _,
192 bounds.size.width.to_bytes(self.bytes_per_pixel()) as u64,
193 );
194 }
195
196 fn bytes_per_pixel(&self) -> u8 {
197 use metal::MTLPixelFormat::*;
198 match self.metal_texture.pixel_format() {
199 A8Unorm | R8Unorm => 1,
200 RGBA8Unorm | BGRA8Unorm => 4,
201 _ => unimplemented!(),
202 }
203 }
204}
205
206impl From<Size<DevicePixels>> for etagere::Size {
207 fn from(size: Size<DevicePixels>) -> Self {
208 etagere::Size::new(size.width.into(), size.height.into())
209 }
210}
211
212impl From<etagere::Point> for Point<DevicePixels> {
213 fn from(value: etagere::Point) -> Self {
214 Point {
215 x: DevicePixels::from(value.x),
216 y: DevicePixels::from(value.y),
217 }
218 }
219}
220
221impl From<etagere::Size> for Size<DevicePixels> {
222 fn from(size: etagere::Size) -> Self {
223 Size {
224 width: DevicePixels::from(size.width),
225 height: DevicePixels::from(size.height),
226 }
227 }
228}
229
230impl From<etagere::Rectangle> for Bounds<DevicePixels> {
231 fn from(rectangle: etagere::Rectangle) -> Self {
232 Bounds {
233 origin: rectangle.min.into(),
234 size: rectangle.size().into(),
235 }
236 }
237}
238
239#[derive(Deref, DerefMut)]
240struct AssertSend<T>(T);
241
242unsafe impl<T> Send for AssertSend<T> {}