Struct TextAtlas 

pub struct TextAtlas {
    texture: Texture,
    view: TextureView,
    sampler: Sampler,
    width: u32,
    height: u32,
    cpu_pixels: Vec<u8>,
    cursor_x: u32,
    cursor_y: u32,
    row_h: u32,
    glyphs: HashMap<GlyphKey, GlyphSlot>,
    fonts: Vec<FontArc>,
    dirty: bool,
}

GPU + CPU text atlas. Owned by TextPipeline.

Fields

texture: Texture

view: TextureView

sampler: Sampler

width: u32

height: u32

cpu_pixels: Vec<u8>

CPU-side shadow of the atlas pixels — keeps the atlas resident as a single Rgba8 buffer so partial updates don’t require GPU-side readback. Alpha lands in .r, other channels stay zero.

cursor_x: u32

Next free pixel inside the current row.

cursor_y: u32

Top of the current row.

row_h: u32

Height of the tallest glyph placed in the current row — used to advance cursor_y when the row fills up.

glyphs: HashMap<GlyphKey, GlyphSlot>

fonts: Vec<FontArc>

dirty: bool

Set when Self::ensure_glyph grew the CPU pixel buffer. Drives the queue.write_texture call on the next render.

Implementations

impl TextAtlas

pub fn new(device: &Device, queue: &Queue) -> Self

fn ensure_glyph( &mut self, font: u32, size_px: f32, glyph_id: u16, ch: char, ) -> Option<GlyphSlot>

Rasterise a glyph into the atlas if not already cached. Returns the cached slot — or None if rasterising failed (out-of-atlas or zero-extent glyph like a space).

fn flush(&mut self, queue: &Queue)

Push any pending atlas-pixel updates to the GPU. Cheap when dirty == false (no-op, common case after warm-up).

pub fn glyph_count(&self) -> usize

Number of glyphs currently cached. Test surface.