Crate fontmesh 

fontmesh

Convert font glyphs to 2D and 3D triangle meshes.

This crate provides a small, stateless API for tessellating glyph outlines into triangle meshes. Font parsing is handled by skrifa, so both TrueType (glyf) and CFF/PostScript (CFF/CFF2) outlines are supported, and the same parsed-font handle plugs straight into shaping libraries like cosmic-text.

Quick start

use fontmesh::{parse_font, glyph_id, glyph_to_mesh_3d};

let font = parse_font(font_data)?;
let gid = glyph_id(&font, 'A').expect("font has 'A'");
let mesh = glyph_to_mesh_3d(&font, gid, 0.1, 20)?;
assert!(!mesh.is_empty());

Coordinate system

All output coordinates are normalised to 1.0 em. (0, 0) is the glyph origin (typically the left side of the baseline), +X points right, and +Y points up. Extrusion depth is also in em units — depth = 0.1 is 10 % of the em square. Front faces sit at z = +depth/2, back faces at z = -depth/2.

Quality (subdivisions)

The subdivisions argument controls how finely Bézier curves are sampled before triangulation. 20 is a good default; higher values produce smoother curves at the cost of more vertices. 0 is rejected as FontMeshError::InvalidQuality.

API surface

• Parsing: parse_font returns a skrifa::FontRef. It’s also exposed directly as FontRef if you want to skip the wrapper.
• Glyph IDs: glyph_id resolves a char → GlyphId. If you’re driving fontmesh from a text shaper you already have these IDs and can skip the lookup.
• Meshes: glyph_to_mesh_2d / glyph_to_mesh_3d or the fluent GlyphMeshBuilder.
• Metrics: ascender, descender, line_gap, advance, glyph_advance — all normalised to 1.0 em.

Pipeline

1. Parse the font (FontRef::from_index)
2. Extract the glyph outline (skrifa OutlinePen)
3. Linearise curves (linearize_outline)
4. Triangulate (triangulate())
5. Optionally extrude to 3D (extrude())

Each stage is exposed publicly so advanced callers can plug their own glyph source in at step 3.

Re-exports

pub use error::FontMeshError;

pub use error::Result;

pub use extrude::compute_smooth_normals;

pub use extrude::extrude;

pub use font::advance;

pub use font::ascender;

pub use font::descender;

pub use font::glyph_advance;

pub use font::glyph_id;

pub use font::line_gap;

pub use font::parse_font;

pub use glyph::glyph_to_mesh_2d;

pub use glyph::glyph_to_mesh_3d;

pub use glyph::GlyphMeshBuilder;

pub use linearize::linearize_outline;

pub use triangulate::triangulate;

pub use types::Mesh2D;

pub use types::Mesh3D;

pub use types::Outline2D;

Modules

error

Error types returned by fontmesh operations.

extrude

3D extrusion — converts 2D meshes to 3D with depth.

font

Font parsing and em-normalised metrics.

glyph

Glyph outline extraction and tessellation.

linearize

Curve linearization — converts Bézier curves to line segments.

triangulate

2D triangulation using lyon_tessellation.

types

Mesh, outline, and contour types used throughout fontmesh.

Structs

FontRef

Reference to an in-memory font.

GlyphId

A 32-bit glyph identifier.

Traits

MetadataProvider

Interface for types that can provide font metadata.