Struct StaticFontAtlas 

pub struct StaticFontAtlas { /* private fields */ }

A texture atlas containing font glyphs for efficient GL text rendering.

StaticFontAtlas manages a GL 2D texture array where each layer contains a single character glyph. This design enables efficient instanced rendering of text by allowing the GPU to select the appropriate character layer for each rendered cell.

Architecture

The atlas uses a GL 2D texture array where:

• Each layer contains one character glyph
• ASCII characters use their ASCII value as the layer index
• Non-ASCII characters are stored in a hash map for layer lookup
• All glyphs have uniform cell dimensions for consistent spacing

Implementations

impl StaticFontAtlas

pub fn load( gl: &Context, config: FontAtlasData, ) -> Result<StaticFontAtlas, Error>

Creates a TextureAtlas from a grid of equal-sized cells

Trait Implementations

impl Atlas for StaticFontAtlas

fn get_base_glyph_id(&self, key: &str) -> Option<u16>

Returns the base glyph identifier for the given key

fn underline(&self) -> LineDecoration

Returns the underline configuration

fn strikethrough(&self) -> LineDecoration

Returns the strikethrough configuration

fn get_symbol(&self, glyph_id: u16) -> Option<CompactString>

Returns the symbol for the given glyph ID, if it exists

fn recreate_texture(&mut self, gl: &Context) -> Result<(), Error>

Recreates the GPU texture after a context loss.

This method rebuilds the texture from the retained atlas data. All glyph mappings and other CPU-side state are preserved; only the GPU texture handle is recreated.

fn base_lookup_mask(&self) -> u32

Returns 0x1FFF to support the full glyph encoding from beamterm-atlas.

This 13-bit mask includes the emoji flag (bit 12) so that emoji base IDs can be extracted correctly for symbol lookup and texture coordinate calculation.

fn get_glyph_id(&self, key: &str, style_bits: u16) -> Option<u16>

Returns the glyph identifier for the given key and style bits

fn cell_size(&self) -> (i32, i32)

Returns the height of the atlas in pixels.

fn bind(&self, gl: &Context)

Binds the font atlas texture to the currently active texture unit.

fn get_ascii_char(&self, glyph_id: u16) -> Option<char>

Returns the ASCII character for the given glyph ID, if it represents an ASCII char.

fn glyph_tracker(&self) -> &GlyphTracker

Returns a reference to the glyph tracker for accessing missing glyphs.

fn glyph_count(&self) -> u32

Returns the number of glyphs currently in the atlas.

fn flush(&self, _gl: &Context) -> Result<(), Error>

Flushes any pending glyph data to the GPU texture.

fn for_each_symbol(&self, f: &mut dyn FnMut(u16, &str))

Iterates over all glyph ID to symbol mappings.

fn resolve_glyph_slot(&self, key: &str, style_bits: u16) -> Option<GlyphSlot>

Resolves a glyph to its texture slot.

fn delete(&self, gl: &Context)

Deletes the GPU texture resources associated with this atlas.

fn update_pixel_ratio( &mut self, _gl: &Context, pixel_ratio: f32, ) -> Result<f32, Error>

Updates the pixel ratio for HiDPI rendering.

fn cell_scale_for_dpr(&self, pixel_ratio: f32) -> f32

Returns the cell scale factor for layout calculations at the given DPR.

fn texture_cell_size(&self) -> (i32, i32)

Returns the texture cell size in physical pixels (for fragment shader calculations).

impl Debug for StaticFontAtlas

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

Formats the value using the given formatter.