WIP: Start on rendering glyphs

Co-Authored-By: Nathan Sobo <nathan@zed.dev>

gpui/src/platform/mac/sprite_cache.rs

@@ -0,0 +1,19 @@
+use crate::geometry::vector::Vector2I;
+use etagere::BucketedAtlasAllocator;
+
+struct SpriteCache {
+    atlasses: Vec<etagere::BucketedAtlasAllocator>,
+}
+
+impl SpriteCache {
+    fn new(size: Vector2I) -> Self {
+        let size = etagere::Size::new(size.x(), size.y());
+        Self {
+            atlasses: vec![BucketedAtlasAllocator::new(size)],
+        }
+    }
+
+    fn render_glyph(&mut self) {
+        self.atlasses.last().unwrap()
+    }
+}