Remove tile set ref in agb

agb/examples/animated_background.rs

@@ -17,7 +17,6 @@ fn main(mut gba: agb::Gba) -> ! {
     let vblank = agb::interrupt::VBlank::get();
 
     let tileset = TileSet::new(water_tiles::water_tiles.tiles, TileFormat::FourBpp);
-    let tileset_ref = vram.add_tileset(tileset);
 
     vram.set_background_palettes(water_tiles::water_tiles.palettes);
 
@@ -28,7 +27,7 @@ fn main(mut gba: agb::Gba) -> ! {
             bg.set_tile(
                 &mut vram,
                 (x, y).into(),
-                tileset_ref,
+                &tileset,
                 TileSetting::new(0, false, false, 0),
             );
         }
@@ -41,7 +40,7 @@ fn main(mut gba: agb::Gba) -> ! {
     loop {
         i = (i + 1) % 8;
 
-        vram.replace_tile(tileset_ref, 0, tileset_ref, i);
+        vram.replace_tile(&tileset, 0, &tileset, i);
 
         vblank.wait_for_vblank();
     }

agb/examples/chicken.rs

@@ -53,7 +53,6 @@ fn main(mut gba: agb::Gba) -> ! {
 
     vram.set_background_palette_raw(&MAP_PALETTE);
     let tileset = TileSet::new(&MAP_TILES, TileFormat::FourBpp);
-    let tileset_ref = vram.add_tileset(tileset);
 
     let mut background = gfx.background(agb::display::Priority::P0);
 
@@ -62,7 +61,7 @@ fn main(mut gba: agb::Gba) -> ! {
         background.set_tile(
             &mut vram,
             (i % 32, i / 32).into(),
-            tileset_ref,
+            &tileset,
             TileSetting::from_raw(tile),
         );
     }

agb/src/display/example_logo.rs

@@ -6,7 +6,6 @@ pub fn display_logo(map: &mut RegularMap, vram: &mut VRamManager) {
     vram.set_background_palettes(agb_logo::test_logo.palettes);
 
     let background_tilemap = TileSet::new(agb_logo::test_logo.tiles, TileFormat::FourBpp);
-    let background_tilemap_reference = vram.add_tileset(background_tilemap);
 
     for y in 0..20 {
         for x in 0..30 {
@@ -15,12 +14,7 @@ pub fn display_logo(map: &mut RegularMap, vram: &mut VRamManager) {
             let palette_entry = agb_logo::test_logo.palette_assignments[tile_id as usize];
             let tile_setting = TileSetting::new(tile_id, false, false, palette_entry);
 
-            map.set_tile(
-                vram,
-                (x, y).into(),
-                background_tilemap_reference,
-                tile_setting,
-            );
+            map.set_tile(vram, (x, y).into(), &background_tilemap, tile_setting);
         }
     }
 

agb/src/display/tiled/infinite_scrolled_map.rs

@@ -1,6 +1,6 @@
 use alloc::boxed::Box;
 
-use super::{MapLoan, RegularMap, TileSetReference, TileSetting, VRamManager};
+use super::{MapLoan, RegularMap, TileSet, TileSetting, VRamManager};
 
 use crate::{
     display,
@@ -9,7 +9,7 @@ use crate::{
 
 pub struct InfiniteScrolledMap<'a> {
     map: MapLoan<'a, RegularMap>,
-    tile: Box<dyn Fn(Vector2D<i32>) -> (TileSetReference, TileSetting)>,
+    tile: Box<dyn Fn(Vector2D<i32>) -> (&'a TileSet<'a>, TileSetting)>,
 
     current_pos: Vector2D<i32>,
     offset: Vector2D<i32>,
@@ -26,7 +26,7 @@ pub enum PartialUpdateStatus {
 impl<'a> InfiniteScrolledMap<'a> {
     pub fn new(
         map: MapLoan<'a, RegularMap>,
-        tile: Box<dyn Fn(Vector2D<i32>) -> (TileSetReference, TileSetting)>,
+        tile: Box<dyn Fn(Vector2D<i32>) -> (&'a TileSet<'a>, TileSetting)>,
     ) -> Self {
         Self {
             map,
@@ -79,12 +79,12 @@ impl<'a> InfiniteScrolledMap<'a> {
         {
             for (x_idx, x) in (x_start..x_end).enumerate() {
                 let pos = (x, y).into();
-                let (tile_set_ref, tile_setting) = (self.tile)(pos);
+                let (tileset, tile_setting) = (self.tile)(pos);
 
                 self.map.set_tile(
                     vram,
                     (x_idx as u16, (y_idx + copy_from as usize) as u16).into(),
-                    tile_set_ref,
+                    tileset,
                     tile_setting,
                 );
             }
@@ -172,7 +172,7 @@ impl<'a> InfiniteScrolledMap<'a> {
             .iter()
             .chain(horizontal_rect_to_update.iter())
         {
-            let (tile_set_ref, tile_setting) = (self.tile)((tile_x, tile_y).into());
+            let (tileset, tile_setting) = (self.tile)((tile_x, tile_y).into());
 
             self.map.set_tile(
                 vram,
@@ -181,7 +181,7 @@ impl<'a> InfiniteScrolledMap<'a> {
                     (tile_y - self.offset.y).rem_euclid(32) as u16,
                 )
                     .into(),
-                tile_set_ref,
+                tileset,
                 tile_setting,
             );
         }

agb/src/display/tiled/map.rs

@@ -7,7 +7,7 @@ use crate::dma::dma_copy16;
 use crate::fixnum::Vector2D;
 use crate::memory_mapped::MemoryMapped;
 
-use super::{Tile, TileSetReference, TileSetting, VRamManager};
+use super::{Tile, TileSet, TileSetting, VRamManager};
 
 pub struct RegularMap {
     background_id: u8,
@@ -42,7 +42,7 @@ impl RegularMap {
         &mut self,
         vram: &mut VRamManager,
         pos: Vector2D<u16>,
-        tileset_ref: TileSetReference,
+        tileset: &TileSet<'_>,
         tile_setting: TileSetting,
     ) {
         let pos = (pos.x + pos.y * 32) as usize;
@@ -55,7 +55,7 @@ impl RegularMap {
         let tile_index = tile_setting.index();
 
         let new_tile = if tile_index != TRANSPARENT_TILE_INDEX {
-            let new_tile_idx = vram.add_tile(tileset_ref, tile_index);
+            let new_tile_idx = vram.add_tile(tileset, tile_index);
             Tile::new(new_tile_idx, tile_setting)
         } else {
             Tile::default()

agb/src/display/tiled/mod.rs

@@ -6,7 +6,7 @@ mod vram_manager;
 pub use infinite_scrolled_map::{InfiniteScrolledMap, PartialUpdateStatus};
 pub use map::{MapLoan, RegularMap};
 pub use tiled0::Tiled0;
-pub use vram_manager::{TileFormat, TileIndex, TileSet, TileSetReference, VRamManager};
+pub use vram_manager::{TileFormat, TileIndex, TileSet, VRamManager};
 
 #[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
 #[repr(transparent)]

agb/src/display/tiled/vram_manager.rs

@@ -24,18 +24,6 @@ static TILE_ALLOCATOR: BlockAllocator = unsafe {
 
 const TILE_LAYOUT: Layout = unsafe { Layout::from_size_align_unchecked(8 * 8 / 2, 8 * 8 / 2) };
 
-#[cfg(debug_assertions)]
-unsafe fn debug_unreachable_unchecked(message: &'static str) -> ! {
-    unreachable!("{}", message);
-}
-
-#[cfg(not(debug_assertions))]
-const unsafe fn debug_unreachable_unchecked(_message: &'static str) -> ! {
-    use core::hint::unreachable_unchecked;
-
-    unreachable_unchecked();
-}
-
 #[derive(Clone, Copy, Debug)]
 pub enum TileFormat {
     FourBpp,
@@ -59,17 +47,9 @@ impl<'a> TileSet<'a> {
     pub fn new(tiles: &'a [u8], format: TileFormat) -> Self {
         Self { tiles, format }
     }
-}
 
-#[derive(Clone, Copy, PartialEq, Eq)]
-pub struct TileSetReference {
-    id: u16,
-    generation: u16,
-}
-
-impl TileSetReference {
-    fn new(id: u16, generation: u16) -> Self {
-        Self { id, generation }
+    fn reference(&self) -> NonNull<[u8]> {
+        self.tiles.into()
     }
 }
 
@@ -89,84 +69,22 @@ impl TileIndex {
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 struct TileReference(NonNull<u32>);
 
-enum ArenaStorageItem<T> {
-    EndOfFreeList,
-    NextFree(usize),
-    Data(T, u16),
+pub struct VRamManager {
+    tile_set_to_vram: HashMap<(NonNull<[u8]>, u16), TileReference>,
+    reference_counts: Vec<(u16, Option<(NonNull<[u8]>, u16)>)>,
 }
 
-pub struct VRamManager<'a> {
-    tilesets: Vec<ArenaStorageItem<TileSet<'a>>>,
-    generation: u16,
-    free_pointer: Option<usize>,
-
-    tile_set_to_vram: HashMap<(u16, u16), TileReference>,
-    reference_counts: Vec<(u16, Option<(TileSetReference, u16)>)>,
-}
-
-impl<'a> VRamManager<'a> {
+impl VRamManager {
     pub(crate) fn new() -> Self {
-        let tile_set_to_vram: HashMap<(u16, u16), TileReference> = HashMap::with_capacity(256);
+        let tile_set_to_vram: HashMap<(NonNull<[u8]>, u16), TileReference> =
+            HashMap::with_capacity(256);
 
         Self {
-            tilesets: Vec::new(),
-            generation: 0,
-            free_pointer: None,
-
             tile_set_to_vram,
             reference_counts: Default::default(),
         }
     }
 
-    pub fn add_tileset(&mut self, tileset: TileSet<'a>) -> TileSetReference {
-        let generation = self.generation;
-        self.generation = self.generation.wrapping_add(1);
-
-        let tileset = ArenaStorageItem::Data(tileset, generation);
-
-        let index = if let Some(ptr) = self.free_pointer.take() {
-            match self.tilesets[ptr] {
-                ArenaStorageItem::EndOfFreeList => {
-                    self.tilesets[ptr] = tileset;
-                    ptr
-                }
-                ArenaStorageItem::NextFree(next_free) => {
-                    self.free_pointer = Some(next_free);
-                    self.tilesets[ptr] = tileset;
-                    ptr
-                }
-                _ => unsafe { debug_unreachable_unchecked("Free pointer cannot point to data") },
-            }
-        } else {
-            self.tilesets.push(tileset);
-            self.tilesets.len() - 1
-        };
-
-        TileSetReference::new(index as u16, generation)
-    }
-
-    pub fn remove_tileset(&mut self, tile_set_ref: TileSetReference) {
-        let tileset = &self.tilesets[tile_set_ref.id as usize];
-
-        match tileset {
-            ArenaStorageItem::Data(_, generation) => {
-                debug_assert_eq!(
-                    *generation, tile_set_ref.generation,
-                    "Tileset generation must be the same when removing"
-                );
-
-                self.tilesets[tile_set_ref.id as usize] = if let Some(ptr) = self.free_pointer {
-                    ArenaStorageItem::NextFree(ptr)
-                } else {
-                    ArenaStorageItem::EndOfFreeList
-                };
-
-                self.free_pointer = Some(tile_set_ref.id as usize);
-            }
-            _ => panic!("Must remove valid tileset"),
-        }
-    }
-
     fn index_from_reference(reference: TileReference) -> usize {
         let difference = reference.0.as_ptr() as usize - TILE_RAM_START;
         difference / (8 * 8 / 2)
@@ -177,8 +95,8 @@ impl<'a> VRamManager<'a> {
         TileReference(NonNull::new(ptr as *mut _).unwrap())
     }
 
-    pub(crate) fn add_tile(&mut self, tile_set_ref: TileSetReference, tile: u16) -> TileIndex {
-        let reference = self.tile_set_to_vram.get(&(tile_set_ref.id, tile));
+    pub(crate) fn add_tile(&mut self, tile_set: &TileSet<'_>, tile: u16) -> TileIndex {
+        let reference = self.tile_set_to_vram.get(&(tile_set.reference(), tile));
 
         if let Some(reference) = reference {
             let index = Self::index_from_reference(*reference);
@@ -190,17 +108,17 @@ impl<'a> VRamManager<'a> {
             unsafe { TILE_ALLOCATOR.alloc(TILE_LAYOUT) }.unwrap().cast();
         let tile_reference = TileReference(new_reference);
 
-        self.copy_tile_to_location(tile_set_ref, tile, tile_reference);
+        self.copy_tile_to_location(tile_set, tile, tile_reference);
 
         let index = Self::index_from_reference(tile_reference);
 
         self.tile_set_to_vram
-            .insert((tile_set_ref.id, tile), tile_reference);
+            .insert((tile_set.reference(), tile), tile_reference);
 
         self.reference_counts
             .resize(self.reference_counts.len().max(index + 1), (0, None));
 
-        self.reference_counts[index] = (1, Some((tile_set_ref, tile)));
+        self.reference_counts[index] = (1, Some((tile_set.reference(), tile)));
 
         TileIndex::new(index)
     }
@@ -225,44 +143,34 @@ impl<'a> VRamManager<'a> {
         }
 
         let tile_ref = self.reference_counts[index].1.unwrap();
-        self.tile_set_to_vram.remove(&(tile_ref.0.id, tile_ref.1));
+        self.tile_set_to_vram.remove(&tile_ref);
         self.reference_counts[index].1 = None;
     }
 
     pub fn replace_tile(
         &mut self,
-        source_tile_set_ref: TileSetReference,
+        source_tile_set: &TileSet<'_>,
         source_tile: u16,
-        target_tile_set_ref: TileSetReference,
+        target_tile_set: &TileSet<'_>,
         target_tile: u16,
     ) {
         if let Some(&reference) = self
             .tile_set_to_vram
-            .get(&(source_tile_set_ref.id, source_tile))
+            .get(&(source_tile_set.reference(), source_tile))
         {
-            self.copy_tile_to_location(target_tile_set_ref, target_tile, reference);
+            self.copy_tile_to_location(target_tile_set, target_tile, reference);
         }
     }
 
     fn copy_tile_to_location(
         &self,
-        tile_set_ref: TileSetReference,
+        tile_set: &TileSet<'_>,
         tile_id: u16,
         tile_reference: TileReference,
     ) {
-        let tile_slice = if let ArenaStorageItem::Data(data, generation) =
-            &self.tilesets[tile_set_ref.id as usize]
-        {
-            debug_assert_eq!(
-                *generation, tile_set_ref.generation,
-                "Stale tile data requested"
-            );
-
-            let tile_offset = (tile_id as usize) * data.format.tile_size();
-            &data.tiles[tile_offset..(tile_offset + data.format.tile_size())]
-        } else {
-            panic!("Target tile set ref must point to an existing tile set reference")
-        };
+        let tile_size = tile_set.format.tile_size();
+        let tile_offset = (tile_id as usize) * tile_size;
+        let tile_slice = &tile_set.tiles[tile_offset..(tile_offset + tile_size)];
 
         let tile_size_in_half_words = tile_slice.len() / 2;
 

agb/src/display/video.rs

@@ -18,7 +18,7 @@ impl Video {
         unsafe { Bitmap4::new() }
     }
 
-    pub fn tiled0(&mut self) -> (Tiled0, VRamManager<'_>) {
+    pub fn tiled0(&mut self) -> (Tiled0, VRamManager) {
         (unsafe { Tiled0::new() }, VRamManager::new())
     }
 }