switch to using rust Rc

agb/src/display/object.rs

@@ -1,4 +1,5 @@
 #![deny(missing_docs)]
+use alloc::rc::{Rc, Weak};
 use alloc::vec::Vec;
 use core::alloc::Layout;
 
@@ -398,6 +399,10 @@ impl Size {
         (self as u8 >> 2, self as u8 & 0b11)
     }
 
+    fn layout(self) -> Layout {
+        Layout::from_size_align(self.number_of_tiles() * BYTES_PER_TILE_4BPP, 8).unwrap()
+    }
+
     #[must_use]
     /// Creates a size from width and height in pixels, panics if the width and
     /// height is not representable by GBA sprites.
@@ -443,38 +448,9 @@ impl Size {
 /// counted and can be cloned to keep it in vram or otherwise manipulated. If
 /// objects no longer refer to this sprite, then it's vram slot is freed for the
 /// next sprite. This is obtained from the [ObjectController].
-pub struct SpriteBorrow<'a> {
+#[derive(Clone)]
-    id: SpriteId,
+pub struct SpriteBorrow {
-    sprite_location: u16,
+    sprite: SpriteVram,
-    palette_location: u16,
-    controller: ObjectControllerReference<'a>,
-}
-
-#[derive(Clone, Copy)]
-struct Storage {
-    location: u16,
-    count: u16,
-}
-
-impl Storage {
-    fn from_sprite_ptr(d: NonNull<u8>) -> Self {
-        Self {
-            location: (((d.as_ptr() as usize) - TILE_SPRITE) / BYTES_PER_TILE_4BPP) as u16,
-            count: 1,
-        }
-    }
-    fn from_palette_ptr(d: NonNull<u8>) -> Self {
-        Self {
-            location: ((d.as_ptr() as usize - PALETTE_SPRITE) / Palette16::layout().size()) as u16,
-            count: 1,
-        }
-    }
-    fn as_palette_ptr(self) -> *mut u8 {
-        (self.location as usize * Palette16::layout().size() + PALETTE_SPRITE) as *mut u8
-    }
-    fn as_sprite_ptr(self) -> *mut u8 {
-        (self.location as usize * BYTES_PER_TILE_4BPP + TILE_SPRITE) as *mut u8
-    }
 }
 
 #[derive(PartialEq, Eq)]
@@ -527,9 +503,56 @@ pub struct Object<'a> {
     loan: Loan<'a>,
 }
 
+#[derive(Clone, Copy)]
+struct Location(usize);
+
+impl Location {
+    fn from_sprite_ptr(d: NonNull<u8>) -> Self {
+        Self(((d.as_ptr() as usize) - TILE_SPRITE) / BYTES_PER_TILE_4BPP)
+    }
+    fn from_palette_ptr(d: NonNull<u8>) -> Self {
+        Self((d.as_ptr() as usize - PALETTE_SPRITE) / Palette16::layout().size())
+    }
+    fn as_palette_ptr(self) -> *mut u8 {
+        (self.0 as usize * Palette16::layout().size() + PALETTE_SPRITE) as *mut u8
+    }
+    fn as_sprite_ptr(self) -> *mut u8 {
+        (self.0 as usize * BYTES_PER_TILE_4BPP + TILE_SPRITE) as *mut u8
+    }
+}
+
+#[derive(Clone)]
+struct PaletteVram(Rc<PaletteData>);
+
+#[derive(Clone)]
+struct SpriteVram(Rc<SpriteArena>);
+
+struct PaletteData {
+    location: Location,
+}
+
+impl Drop for PaletteData {
+    fn drop(&mut self) {
+        unsafe { PALETTE_ALLOCATOR.dealloc(self.location.as_palette_ptr(), Palette16::layout()) };
+    }
+}
+
+struct SpriteArena {
+    location: Location,
+    size: Size,
+    palette: PaletteVram,
+}
+
+impl Drop for SpriteArena {
+    fn drop(&mut self) {
+        unsafe { SPRITE_ALLOCATOR.dealloc(self.location.as_sprite_ptr(), self.size.layout()) }
+    }
+}
+
+#[derive(Default)]
 struct SpriteControllerInner {
-    palette: HashMap<PaletteId, Storage>,
+    static_palette_map: HashMap<PaletteId, Weak<PaletteData>>,
-    sprite: HashMap<SpriteId, Storage>,
+    static_sprite_map: HashMap<SpriteId, Weak<SpriteArena>>,
 }
 
 struct Loan<'a> {
@@ -552,8 +575,8 @@ impl Drop for Loan<'_> {
 
 struct ObjectInner {
     attrs: Attributes,
-    sprite: SpriteBorrow<'static>,
+    sprite: SpriteBorrow,
-    previous_sprite: SpriteBorrow<'static>,
+    previous_sprite: SpriteBorrow,
     destroy: bool,
     z: i32,
 }
@@ -620,15 +643,10 @@ impl ObjectController {
                             .write_volatile(HIDDEN_VALUE);
                     }
 
-                    let a = unsafe { s.shadow_oam[z as usize].take().unwrap_unchecked() };
+                    let _ = unsafe { s.shadow_oam[z as usize].take().unwrap_unchecked() };
-                    a.previous_sprite.drop(&mut s.sprite_controller);
-                    a.sprite.drop(&mut s.sprite_controller);
                 } else {
                     o.attrs.commit(i);
-
+                    o.previous_sprite = o.sprite.clone();
-                    let mut a = o.sprite.clone(&mut s.sprite_controller);
-                    core::mem::swap(&mut o.previous_sprite, &mut a);
-                    a.drop(&mut s.sprite_controller);
                 }
             } else {
                 unsafe {
@@ -731,7 +749,7 @@ impl ObjectController {
     /// # }
     /// ```
     #[must_use]
-    pub fn object<'a>(&'a self, sprite: SpriteBorrow<'a>) -> Object<'a> {
+    pub fn object(&self, sprite: SpriteBorrow) -> Object {
         self.try_get_object(sprite).expect("No object available")
     }
 
@@ -757,28 +775,28 @@ impl ObjectController {
     /// # }
     /// ```
     #[must_use]
-    pub fn try_get_object<'a>(&'a self, sprite: SpriteBorrow<'a>) -> Option<Object<'a>> {
+    pub fn try_get_object(&self, sprite: SpriteBorrow) -> Option<Object> {
         let mut s = unsafe { self.inner.borrow_mut() };
 
         let mut attrs = Attributes::new();
 
-        attrs.a2.set_tile_index(sprite.sprite_location);
+        attrs.a2.set_tile_index(sprite.sprite.0.location.0 as u16);
-        let shape_size = sprite.id.sprite().size.shape_size();
+        let shape_size = sprite.sprite.0.size.shape_size();
-        attrs.a2.set_palete_bank(sprite.palette_location as u8);
+        attrs
+            .a2
+            .set_palete_bank((sprite.sprite.0.palette.0.location.0) as u8);
         attrs.a0.set_shape(shape_size.0);
         attrs.a1a.set_size(shape_size.1);
         attrs.a1s.set_size(shape_size.1);
 
         let index = s.free_object.pop()?;
 
-        let new_sprite: SpriteBorrow<'static> = unsafe { core::mem::transmute(sprite) };
-
         s.shadow_oam[index as usize] = Some(ObjectInner {
             attrs,
             z: 0,
-            previous_sprite: new_sprite.clone(&mut s.sprite_controller),
+            previous_sprite: sprite.clone(),
             destroy: false,
-            sprite: new_sprite,
+            sprite,
         });
 
         let loan = Loan {
@@ -840,7 +858,7 @@ impl ObjectController {
     pub fn try_get_sprite(&self, sprite: &'static Sprite) -> Option<SpriteBorrow> {
         unsafe { self.inner.borrow_mut() }
             .sprite_controller
-            .try_get_sprite(sprite, self.inner)
+            .try_get_sprite(sprite)
     }
 }
 
@@ -863,52 +881,24 @@ impl<'a> Object<'a> {
         }
     }
 
-    unsafe fn inner_controller(
-        &self,
-    ) -> (
-        impl DerefMut<Target = SpriteControllerInner> + 'a,
-        impl DerefMut<Target = ObjectInner> + 'a,
-    ) {
-        #[cfg(debug_assertions)]
-        {
-            core::cell::RefMut::map_split(self.loan.controller.borrow_cell_ref(), |s| {
-                (
-                    &mut s.sprite_controller,
-                    s.shadow_oam[self.loan.index as usize]
-                        .as_mut()
-                        .unwrap_unchecked(),
-                )
-            })
-        }
-        #[cfg(not(debug_assertions))]
-        {
-            let s = self.loan.controller.borrow_direct();
-            (
-                &mut s.sprite_controller,
-                s.shadow_oam[self.loan.index as usize]
-                    .as_mut()
-                    .unwrap_unchecked(),
-            )
-        }
-    }
-
     /// Swaps out the current sprite. This handles changing of size, palette,
     /// etc. No change will be seen until [ObjectController::commit] is called.
-    pub fn set_sprite(&'_ mut self, sprite: SpriteBorrow<'a>) {
+    pub fn set_sprite(&'_ mut self, sprite: SpriteBorrow) {
-        let (mut sprite_controller, mut object_inner) = unsafe { self.inner_controller() };
+        let mut object_inner = unsafe { self.object_inner() };
-        object_inner.attrs.a2.set_tile_index(sprite.sprite_location);
-        let shape_size = sprite.id.sprite().size.shape_size();
         object_inner
             .attrs
             .a2
-            .set_palete_bank(sprite.palette_location as u8);
+            .set_tile_index(sprite.sprite.0.location.0 as u16);
+        let shape_size = sprite.sprite.0.size.shape_size();
+        object_inner
+            .attrs
+            .a2
+            .set_palete_bank(sprite.sprite.0.palette.0.location.0 as u8);
         object_inner.attrs.a0.set_shape(shape_size.0);
         object_inner.attrs.a1a.set_size(shape_size.1);
         object_inner.attrs.a1s.set_size(shape_size.1);
 
-        let mut sprite = unsafe { core::mem::transmute(sprite) };
+        object_inner.sprite = sprite;
-        core::mem::swap(&mut object_inner.sprite, &mut sprite);
-        sprite.drop(&mut sprite_controller);
     }
 
     /// Shows the sprite. No change will be seen until
@@ -1027,15 +1017,6 @@ impl<'a> Object<'a> {
 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
 struct SpriteId(usize);
 
-impl SpriteId {
-    fn sprite(self) -> &'static Sprite {
-        // # Safety
-        // This must be constructed using the id() of a sprite, so
-        // they are always valid and always static
-        unsafe { (self.0 as *const Sprite).as_ref().unwrap_unchecked() }
-    }
-}
-
 /// The palette id is a thin wrapper around the pointer to the palette in rom
 /// and is therefore a unique reference to a palette
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
@@ -1076,23 +1057,16 @@ impl Sprite {
 }
 
 impl SpriteControllerInner {
-    fn try_get_sprite<'a>(
+    fn try_get_sprite<'a>(&mut self, sprite: &'static Sprite) -> Option<SpriteBorrow> {
-        &mut self,
-        sprite: &'static Sprite,
-        controller_reference: ObjectControllerReference<'a>,
-    ) -> Option<SpriteBorrow<'a>> {
         let id = sprite.id();
-        if let Some(storage) = self.sprite.get_mut(&id) {
+        if let Some(storage) = self.static_sprite_map.get_mut(&id) {
-            storage.count += 1;
+            if let Some(strong) = storage.upgrade() {
-            let location = storage.location;
+                return Some(SpriteBorrow {
-            let palette_location = self.palette(sprite.palette).unwrap();
+                    sprite: SpriteVram(strong),
-            Some(SpriteBorrow {
+                });
-                id,
+            }
-                palette_location,
+        }
-                sprite_location: location,
+
-                controller: controller_reference,
-            })
-        } else {
         // layout is non zero sized, so this is safe to call
 
         let dest = unsafe { SPRITE_ALLOCATOR.alloc(sprite.layout())? };
@@ -1114,32 +1088,28 @@ impl SpriteControllerInner {
             );
         }
 
-            let storage = Storage::from_sprite_ptr(dest);
+        let sprite = SpriteVram(Rc::new(SpriteArena {
-            self.sprite.insert(id, storage);
+            location: Location::from_sprite_ptr(dest),
+            size: sprite.size(),
+            palette: palette_location,
+        }));
 
-            Some(SpriteBorrow {
+        self.static_sprite_map.insert(id, Rc::downgrade(&sprite.0));
-                id,
+
-                palette_location,
+        Some(SpriteBorrow { sprite })
-                sprite_location: storage.location,
-                controller: controller_reference,
-            })
-        }
-    }
     }
 
-impl SpriteControllerInner {
     fn new() -> Self {
-        Self {
+        Default::default()
-            palette: HashMap::default(),
-            sprite: HashMap::default(),
     }
-    }
+    fn palette(&mut self, palette: &'static Palette16) -> Option<PaletteVram> {
-    fn palette(&mut self, palette: &'static Palette16) -> Option<u16> {
         let id = palette.id();
-        if let Some(storage) = self.palette.get_mut(&id) {
+        if let Some(storage) = self.static_palette_map.get(&id) {
-            storage.count += 1;
+            if let Some(up) = storage.upgrade() {
-            Some(storage.location)
+                return Some(PaletteVram(up));
-        } else {
+            }
+        }
+
         let dest = unsafe { PALETTE_ALLOCATOR.alloc(Palette16::layout())? };
 
         unsafe {
@@ -1150,71 +1120,13 @@ impl SpriteControllerInner {
             );
         }
 
-            let storage = Storage::from_palette_ptr(dest);
+        let storage = PaletteVram(Rc::new(PaletteData {
-            self.palette.insert(id, storage);
+            location: Location::from_palette_ptr(dest),
+        }));
+        self.static_palette_map
+            .insert(id, Rc::downgrade(&storage.0));
 
-            Some(storage.location)
+        Some(storage)
-        }
-    }
-
-    fn return_sprite(&mut self, sprite: &'static Sprite) {
-        let storage = self.sprite.get_mut(&sprite.id());
-
-        if let Some(storage) = storage {
-            storage.count -= 1;
-
-            if storage.count == 0 {
-                unsafe { SPRITE_ALLOCATOR.dealloc(storage.as_sprite_ptr(), sprite.layout()) };
-                self.sprite.remove(&sprite.id());
-            }
-        }
-
-        self.return_palette(sprite.palette);
-    }
-
-    fn return_palette(&mut self, palette: &'static Palette16) {
-        let id = palette.id();
-
-        if let Some(storage) = self.palette.get_mut(&id) {
-            storage.count -= 1;
-
-            if storage.count == 0 {
-                unsafe { PALETTE_ALLOCATOR.dealloc(storage.as_palette_ptr(), Palette16::layout()) };
-                self.palette.remove(&id);
-            }
-        }
-    }
-}
-
-impl<'a> Drop for SpriteBorrow<'a> {
-    fn drop(&mut self) {
-        let mut s = unsafe { self.controller.borrow_mut() };
-        s.sprite_controller.return_sprite(self.id.sprite());
-    }
-}
-
-impl<'a> SpriteBorrow<'a> {
-    fn drop(self, s: &mut SpriteControllerInner) {
-        s.return_sprite(self.id.sprite());
-        core::mem::forget(self);
-    }
-
-    fn clone(&self, s: &mut SpriteControllerInner) -> Self {
-        s.sprite.entry(self.id).and_modify(|a| a.count += 1);
-        let _ = s.palette(self.id.sprite().palette).unwrap();
-        Self {
-            id: self.id,
-            sprite_location: self.sprite_location,
-            palette_location: self.palette_location,
-            controller: self.controller,
-        }
-    }
-}
-
-impl<'a> Clone for SpriteBorrow<'a> {
-    fn clone(&self) -> Self {
-        let mut s = unsafe { self.controller.borrow_mut() };
-        self.clone(&mut s.sprite_controller)
     }
 }