Struct TextureCache 

pub struct TextureCache {
    pub width: u32,
    pub height: u32,
    pub tile_size: u32,
    /* private fields */
}

2D tile-based LRU texture cache.

The simulated texture has width × height texels divided into tile_size × tile_size tiles. At most capacity tiles reside in the cache simultaneously.

Cache line model

Each cache “line” corresponds to one complete tile. On a miss the whole tile is loaded from simulated main memory. The tile’s data is a flat Vec<u8> with tile_size * tile_size bytes (one byte per texel).

Fields

width: u32

Width of the texture in texels.

height: u32

Height of the texture in texels.

tile_size: u32

Edge length (in texels) of each square tile / cache line.

Implementations

impl TextureCache

pub fn new( width: u32, height: u32, tile_size: u32, capacity: usize, texture_data: Vec<u8>, ) -> Result<Self, CacheError>

Create a new texture cache backed by a flat texture buffer.

texture_data must have exactly width * height bytes. If it is shorter it is padded with zeros; if longer, the excess is ignored.

Errors

Returns an error if width, height, tile_size, or capacity is 0.

pub fn fetch(&mut self, x: u32, y: u32) -> Result<u8, CacheError>

Fetch the texel value at (x, y).

If the tile containing (x, y) is not in the cache, it is loaded (a miss); otherwise the cached copy is used (a hit).

Errors

Returns CacheError::OutOfBounds if x >= width or y >= height.

pub fn prefetch(&mut self, x: u32, y: u32) -> Result<(), CacheError>

Prefetch the tile containing (x, y) into the cache.

If the tile is already cached, this is a no-op (the hit counter is not incremented). If it is not cached, it is loaded and the prefetch counter is incremented.

Errors

Returns CacheError::OutOfBounds if x >= width or y >= height.

pub fn flush(&mut self)

Invalidate (evict) all tiles from the cache.

Statistics are preserved; only the tile storage is cleared.

pub fn invalidate_tile(&mut self, key: TileKey) -> bool

Invalidate a specific tile if present.

Returns true if the tile was in the cache and was removed.

pub fn resident_count(&self) -> usize

Number of tiles currently resident in the cache.

pub fn is_resident(&self, key: TileKey) -> bool

Whether a specific tile is currently resident in the cache.

pub fn stats(&self) -> &TexCacheStats

A reference to the current aggregate statistics.

pub fn reset_stats(&mut self)

Reset all statistics counters to zero.

pub fn capacity(&self) -> usize

Maximum number of tiles the cache can hold.

pub fn grid_size(&self) -> (u32, u32)

Number of tiles in each dimension of the tile grid.