Struct TextureWindowAtlas 

pub struct TextureWindowAtlas<const PAGE_COUNT: usize> { /* private fields */ }

Tiny no-alloc atlas for PS1 texture-window-sized subtextures.

Each 256x256 texture page is tracked as a 32x32 bit grid where one bit represents an 8x8 texel block. Allocations are power-of-two rectangles that fit GP0(E2) texture-window constraints and are placed on their own width/height grid.

Implementations

impl<const PAGE_COUNT: usize> TextureWindowAtlas<PAGE_COUNT>

pub const fn new() -> Self

Build an empty atlas.

pub fn clear(&mut self)

Clear every occupied bit.

pub fn allocate( &mut self, width: u16, height: u16, ) -> Option<TextureWindowPlacement>

Allocate a power-of-two texture-window rectangle.

Dimensions are texels. They must be 8-texel aligned, power-of-two, and no larger than 128 texels, matching the hardware texture-window range.

pub fn reserve_empty_page(&mut self) -> Option<usize>

Reserve one completely empty texture page and return its page index.

This is for assets that use a whole page without GP0(E2) texture windows, such as large UI/background strips. It shares the atlas bookkeeping so later windowed material allocations cannot overlap the reserved page.

pub fn release(&mut self, placement: TextureWindowPlacement)

Release a placement previously returned by allocate, clearing its occupancy bits so the space can be reused. The width/height are the texel dimensions the placement was allocated with (the placement records them).

pub fn release_page(&mut self, page_index: usize)

Release a whole page previously taken by reserve_empty_page.

pub fn is_page_empty(&self, page_index: usize) -> bool

Whether a logical atlas page contains no live window or full-page reservation. Used by the physical allocator to return lazy backing at scene boundaries.

Trait Implementations

impl<const PAGE_COUNT: usize> Clone for TextureWindowAtlas<PAGE_COUNT>

fn clone(&self) -> TextureWindowAtlas<PAGE_COUNT>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<const PAGE_COUNT: usize> Debug for TextureWindowAtlas<PAGE_COUNT>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<const PAGE_COUNT: usize> Default for TextureWindowAtlas<PAGE_COUNT>

fn default() -> Self

Returns the “default value” for a type.

impl<const PAGE_COUNT: usize> PartialEq for TextureWindowAtlas<PAGE_COUNT>

fn eq(&self, other: &TextureWindowAtlas<PAGE_COUNT>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<const PAGE_COUNT: usize> Copy for TextureWindowAtlas<PAGE_COUNT>

impl<const PAGE_COUNT: usize> Eq for TextureWindowAtlas<PAGE_COUNT>

impl<const PAGE_COUNT: usize> StructuralPartialEq for TextureWindowAtlas<PAGE_COUNT>