Struct UiImageAtlas 

pub struct UiImageAtlas { /* private fields */ }

Resource holding the UI image atlas (GPU texture) and an AssetUUID → AtlasRect cache mapping each uploaded UI image to its position inside the atlas.

Registered in [khora_core::Resources] at engine init; the UI agent allocates the GPU atlas lazily via UiImageAtlas::ensure_atlas and then borrows it for upload + render through UiImageAtlas::lock_atlas.

Implementations

impl UiImageAtlas

pub fn new() -> Self

Creates an empty resource. The GPU atlas itself is allocated lazily by ensure_atlas once a device is available.

pub fn ensure_atlas(&self, device: &dyn GraphicsDevice) -> bool

Allocates the GPU texture atlas if not yet present. Idempotent — safe to call every frame, the actual allocation happens once.

Returns true when the atlas is available after the call, false if allocation failed.

pub fn lock_atlas(&self) -> Option<MutexGuard<'_, Option<TextureAtlas>>>

Locks the GPU atlas for the duration of a frame’s upload + render.

Returns the locked MutexGuard<Option<TextureAtlas>>; callers dereference twice (guard.as_mut()) to reach the optional &mut TextureAtlas. The guard is held for the lifetime of the caller’s local — typically UiAgent::execute for one frame.

pub fn get_rect(&self, id: &AssetUUID) -> Option<AtlasRect>

Returns the AtlasRect previously stored for id, if any.

pub fn insert_rect(&self, id: AssetUUID, rect: AtlasRect)

Stores rect under id.

pub fn has_atlas(&self) -> bool

Reports whether the GPU atlas has been initialized.

pub fn cache_len(&self) -> usize

Returns the number of cache entries.

Trait Implementations

impl Default for UiImageAtlas

fn default() -> Self

Returns the “default value” for a type.