Move all crates to a top-level crates folder

Co-Authored-By: Max Brunsfeld <maxbrunsfeld@gmail.com>

crates/gpui/src/platform/mac/image_cache.rs

@@ -0,0 +1,49 @@
+use metal::{MTLPixelFormat, TextureDescriptor, TextureRef};
+
+use super::atlas::{AllocId, AtlasAllocator};
+use crate::{
+    geometry::{rect::RectI, vector::Vector2I},
+    ImageData,
+};
+use std::{collections::HashMap, mem};
+
+pub struct ImageCache {
+    prev_frame: HashMap<usize, (AllocId, RectI)>,
+    curr_frame: HashMap<usize, (AllocId, RectI)>,
+    atlases: AtlasAllocator,
+}
+
+impl ImageCache {
+    pub fn new(device: metal::Device, size: Vector2I) -> Self {
+        let descriptor = TextureDescriptor::new();
+        descriptor.set_pixel_format(MTLPixelFormat::BGRA8Unorm);
+        descriptor.set_width(size.x() as u64);
+        descriptor.set_height(size.y() as u64);
+        Self {
+            prev_frame: Default::default(),
+            curr_frame: Default::default(),
+            atlases: AtlasAllocator::new(device, descriptor),
+        }
+    }
+
+    pub fn render(&mut self, image: &ImageData) -> (AllocId, RectI) {
+        let (alloc_id, atlas_bounds) = self
+            .prev_frame
+            .remove(&image.id)
+            .or_else(|| self.curr_frame.get(&image.id).copied())
+            .unwrap_or_else(|| self.atlases.upload(image.size(), image.as_bytes()));
+        self.curr_frame.insert(image.id, (alloc_id, atlas_bounds));
+        (alloc_id, atlas_bounds)
+    }
+
+    pub fn finish_frame(&mut self) {
+        mem::swap(&mut self.prev_frame, &mut self.curr_frame);
+        for (_, (id, _)) in self.curr_frame.drain() {
+            self.atlases.deallocate(id);
+        }
+    }
+
+    pub fn atlas_texture(&self, atlas_id: usize) -> Option<&TextureRef> {
+        self.atlases.texture(atlas_id)
+    }
+}