diff --git a/crates/packer/src/atlasset.rs b/crates/packer/src/atlasset.rs
index 8481fa7..16d048b 100644
--- a/crates/packer/src/atlasset.rs
+++ b/crates/packer/src/atlasset.rs
@@ -205,16 +205,19 @@ impl AtlasSet {
 			)
 		})?;
 
-		self.index.index.insert(
-			p.to_path_buf(),
-			SpriteAtlasImage {
-				atlas: atlas_idx as u32,
-				x: (x + self.image_margin) as f32 / self.texture_width as f32,
-				y: (y + self.image_margin) as f32 / self.texture_height as f32,
-				w: image_dim.0 as f32 / self.texture_width as f32,
-				h: image_dim.1 as f32 / self.texture_height as f32,
-			},
-		);
+		self.index
+			.path_map
+			.insert(p.to_path_buf(), self.index.index.len() as u32);
+
+		self.index.index.push(SpriteAtlasImage {
+			true_size: image_dim,
+			idx: self.index.index.len() as u32,
+			atlas: atlas_idx as u32,
+			x: (x + self.image_margin) as f32 / self.texture_width as f32,
+			y: (y + self.image_margin) as f32 / self.texture_height as f32,
+			w: image_dim.0 as f32 / self.texture_width as f32,
+			h: image_dim.1 as f32 / self.texture_height as f32,
+		});
 
 		return Ok(atlas_idx);
 	}
diff --git a/crates/packer/src/lib.rs b/crates/packer/src/lib.rs
index d385233..204ad7b 100644
--- a/crates/packer/src/lib.rs
+++ b/crates/packer/src/lib.rs
@@ -13,6 +13,12 @@ pub struct SpriteAtlasImage {
 	/// This is an index in SpriteAtlas.atlas_list
 	pub atlas: u32,
 
+	/// A globally unique, consecutively numbered index for this sprite
+	pub idx: u32,
+
+	/// The size of this image, in pixels
+	pub true_size: (u32, u32),
+
 	/// x-position of this image
 	/// (between 0 and 1, using wgpu texture coordinates)
 	pub x: f32,
@@ -35,7 +41,10 @@ pub struct SpriteAtlasImage {
 #[derive(Debug, Serialize, Deserialize, Clone)]
 pub struct SpriteAtlas {
 	/// The images in this atlas
-	pub index: HashMap<PathBuf, SpriteAtlasImage>,
+	pub index: Vec<SpriteAtlasImage>,
+
+	/// Map paths to image indices
+	pub path_map: HashMap<PathBuf, u32>,
 
 	/// The file names of the atlas textures we've generated
 	pub atlas_list: Vec<String>,
@@ -45,7 +54,8 @@ impl SpriteAtlas {
 	/// Make an empty [`SpriteAtlasIndex`]
 	pub fn new() -> Self {
 		Self {
-			index: HashMap::new(),
+			path_map: HashMap::new(),
+			index: Vec::new(),
 			atlas_list: Vec::new(),
 		}
 	}