Crate oxitext_sdf 

oxitext-sdf — Signed Distance Field glyph atlas generation for OxiText.

Provides a pure-Rust implementation of the Felzenszwalb-Huttenlocher EDT for computing signed distance fields from glyph coverage bitmaps, an atlas packer for producing GPU-ready SDF texture atlases, and a multi-channel SDF (MSDF) pipeline that generates 3-channel distance fields directly from glyph outlines for sharper rendering at large magnifications.

Quick start (single-channel SDF)

use oxitext_sdf::{compute_sdf, SdfAtlas, SdfTile};

// A solid 32×32 square (inside everywhere).
let coverage = vec![255u8; 32 * 32];
let sdf = compute_sdf(&coverage, 32, 32, 8.0, 0).expect("compute_sdf");
assert_eq!(sdf.len(), 32 * 32);

// Pack a single tile into an atlas.
let tile = SdfTile {
    glyph_id: 0,
    width: 32,
    height: 32,
    data: sdf,
    bearing_x: 0,
    bearing_y: 0,
    advance_x: 32.0,
};
let atlas = SdfAtlas::pack(&[tile]);
assert!(atlas.uv_map.contains_key(&0));

Re-exports

pub use analytic::glyph_to_sdf_tile_analytic;

pub use build_helper::generate_ascii_atlas;

pub use build_helper::generate_atlas_binary;

pub use msdf::color_edges;

pub use msdf::compute_msdf;

pub use msdf::compute_mtsdf;

pub use msdf::extract_glyph_shape;

pub use msdf::glyph_to_msdf_tile;

pub use msdf::glyph_to_mtsdf_tile;

pub use msdf::EdgeColor;

pub use msdf::GlyphShape;

pub use msdf::MsdfTile;

pub use msdf::MtsdfTile;

pub use psdf::glyph_to_psdf_tile;

pub use psdf::PsdfTile;

Modules

analytic

Direct bezier-to-SDF pipeline using analytic (Newton-Raphson refined) distance.

build_helper

Build-time SDF atlas generation helpers.

msdf

Multi-channel signed distance field (MSDF) generation.

psdf

Signed Pseudo-Distance Field (PSDF) generation.

Structs

AtlasGlyphMetrics

Per-glyph metrics stored alongside the atlas for rendering.

AtlasOptions

Options for atlas packing.

AtlasStats

Statistics returned from an atlas packing operation.

GpuAtlasDescriptor

A GPU-ready atlas descriptor: all the information needed to upload the atlas to a GPU texture (wgpu, Vulkan, Metal, OpenGL) without depending on any GPU crate.

MsdfAtlas

A packed atlas of MSDF glyph tiles, ready for GPU upload.

MultiPageAtlas

An atlas that spans multiple pages when a single texture is not large enough.

NormalizedUvRect

UV rectangle in normalized [0, 1] texture coordinates.

SdfAtlas

A packed atlas of SDF glyph tiles, ready for GPU upload.

SdfTile

A single SDF glyph tile produced by the SDF pipeline.

UvRect

A UV rectangle within the atlas texture (all values in [0, 1]).

Enums

GpuAtlasFormat

Pixel format for GPU atlas texture upload.

PackingAlgorithm

Packing algorithm selection.

SdfError

Error type for SDF computation failures.

Functions

bitmap_to_sdf_tile

Convert a greyscale coverage bitmap (from oxitext-raster) to a signed distance field tile.

compute_sdf

Compute a signed SDF from a grayscale coverage map.

glyph_to_sdf_tile

Generate a signed-distance-field tile for a single glyph.

pack_growing

Pack tiles into an atlas that grows automatically until all tiles fit or max_size is reached.