From eebe29e73a3569376b69ca5923839d96f665f275 Mon Sep 17 00:00:00 2001
From: Melody Madeline Lyons <lily@nowaffles.com>
Date: Tue, 2 Jul 2024 09:06:32 -0700
Subject: [PATCH] Store textures in a Weak

When a texture is no longer referenced anymore, it'll be deallocated. We still get the optimization of not needing to load the same texture multiple times, however when loading a texture that's not used anywhere else it'll immediately be deallocated. This is useful for graphic pickers, which shouldn't keep textures loaded
---
 crates/graphics/src/loaders/atlas.rs   | 72 +++++++++++++++++++++-----
 crates/graphics/src/loaders/texture.rs | 13 +++--
 2 files changed, 68 insertions(+), 17 deletions(-)

diff --git a/crates/graphics/src/loaders/atlas.rs b/crates/graphics/src/loaders/atlas.rs
index 7507b1b6..2f9741db 100644
--- a/crates/graphics/src/loaders/atlas.rs
+++ b/crates/graphics/src/loaders/atlas.rs
@@ -14,11 +14,39 @@
 //
 // You should have received a copy of the GNU General Public License
 // along with Luminol.  If not, see <http://www.gnu.org/licenses/>.
-use crate::{Atlas, GraphicsState};
+use crate::{primitives::tiles::AUTOTILE_AMOUNT, Atlas, GraphicsState, Texture};
+use std::sync::{Arc, Weak};
 
 #[derive(Default)]
 pub struct Loader {
-    atlases: dashmap::DashMap<usize, Atlas>,
+    atlases: dashmap::DashMap<usize, WeakAtlas>,
+}
+
+struct WeakAtlas {
+    atlas_texture: Weak<Texture>,
+    autotile_width: u32,
+    tileset_height: u32,
+    autotile_frames: [u32; AUTOTILE_AMOUNT as usize],
+}
+
+impl WeakAtlas {
+    fn upgrade(&self) -> Option<Atlas> {
+        self.atlas_texture.upgrade().map(|atlas_texture| Atlas {
+            atlas_texture,
+            autotile_width: self.autotile_width,
+            tileset_height: self.tileset_height,
+            autotile_frames: self.autotile_frames,
+        })
+    }
+
+    fn from_atlas(atlas: &Atlas) -> Self {
+        WeakAtlas {
+            atlas_texture: Arc::downgrade(&atlas.atlas_texture),
+            autotile_width: atlas.autotile_width,
+            tileset_height: atlas.tileset_height,
+            autotile_frames: atlas.autotile_frames,
+        }
+    }
 }
 
 impl Loader {
@@ -28,11 +56,17 @@ impl Loader {
         filesystem: &impl luminol_filesystem::FileSystem,
         tileset: &luminol_data::rpg::Tileset,
     ) -> color_eyre::Result<Atlas> {
-        Ok(self
-            .atlases
-            .entry(tileset.id)
-            .or_insert_with(|| Atlas::new(graphics_state, filesystem, tileset))
-            .clone())
+        self.atlases
+            .get(&tileset.id)
+            .as_deref()
+            .and_then(WeakAtlas::upgrade)
+            .map(Ok)
+            .unwrap_or_else(|| {
+                let atlas = Atlas::new(graphics_state, filesystem, tileset);
+                let weak_atlas = WeakAtlas::from_atlas(&atlas);
+                self.atlases.insert(tileset.id, weak_atlas);
+                Ok(atlas)
+            })
     }
 
     pub fn reload_atlas(
@@ -41,11 +75,25 @@ impl Loader {
         filesystem: &impl luminol_filesystem::FileSystem,
         tileset: &luminol_data::rpg::Tileset,
     ) -> color_eyre::Result<Atlas> {
-        Ok(self
-            .atlases
-            .entry(tileset.id)
-            .insert(Atlas::new(graphics_state, filesystem, tileset))
-            .clone())
+        let atlas = Atlas::new(graphics_state, filesystem, tileset);
+        let weak_atlas = WeakAtlas::from_atlas(&atlas);
+        self.atlases.insert(tileset.id, weak_atlas);
+        Ok(atlas)
+    }
+
+    pub fn get_atlas(&self, id: usize) -> Option<Atlas> {
+        self.atlases
+            .get(&id)
+            .as_deref()
+            .and_then(WeakAtlas::upgrade)
+    }
+
+    pub fn get_expect(&self, id: usize) -> Atlas {
+        self.atlases
+            .get(&id)
+            .as_deref()
+            .and_then(WeakAtlas::upgrade)
+            .expect("Atlas not loaded!")
     }
 
     pub fn clear(&self) {
diff --git a/crates/graphics/src/loaders/texture.rs b/crates/graphics/src/loaders/texture.rs
index e330f4db..2652cfb0 100644
--- a/crates/graphics/src/loaders/texture.rs
+++ b/crates/graphics/src/loaders/texture.rs
@@ -24,12 +24,12 @@
 
 use dashmap::DashMap;
 
-use std::sync::Arc;
+use std::sync::{Arc, Weak};
 
 use wgpu::util::DeviceExt;
 
 pub struct Loader {
-    loaded_textures: DashMap<camino::Utf8PathBuf, Arc<Texture>>,
+    loaded_textures: DashMap<camino::Utf8PathBuf, Weak<Texture>>,
 
     placeholder_texture: Arc<Texture>,
     blank_autotile_texture: Arc<Texture>,
@@ -231,18 +231,21 @@ impl Loader {
 
         let texture =
             register_native_texture(self.render_state.clone(), texture, Some(path.as_str()));
-        self.loaded_textures.insert(path, texture.clone());
+        self.loaded_textures.insert(path, Arc::downgrade(&texture));
         texture
     }
 
     pub fn get(&self, path: impl AsRef<camino::Utf8Path>) -> Option<Arc<Texture>> {
-        self.loaded_textures.get(path.as_ref()).as_deref().cloned()
+        self.loaded_textures
+            .get(path.as_ref())
+            .as_deref()
+            .and_then(Weak::upgrade)
     }
 
     pub fn remove(&self, path: impl AsRef<camino::Utf8Path>) -> Option<Arc<Texture>> {
         self.loaded_textures
             .remove(path.as_ref())
-            .map(|(_, value)| value)
+            .and_then(|(_, value)| value.upgrade())
     }
 
     pub fn clear(&self) {