Crate fontmesh 

fontmesh

A pure Rust library for converting TrueType font glyphs to 2D and 3D triangle meshes.

This library provides a simple API for loading TrueType fonts and generating triangle meshes from individual glyphs. It supports both 2D (flat) and 3D (extruded) meshes.

Features

• Pure Rust: No C dependencies, fully cross-platform including WASM
• 2D & 3D: Generate both flat 2D meshes and extruded 3D meshes
• Quality Control: Adjustable tessellation quality
• Efficient: Uses lyon_tessellation for robust triangulation
• Fluent API: Chain operations for ergonomic usage

Basic Usage

use fontmesh::Font;

// Load font
let font = Font::from_bytes(include_bytes!("path/to/font.ttf"))?;

// Generate a 2D mesh (uses default quality: 20 subdivisions)
let mesh_2d = font.glyph_to_mesh_2d('A')?;

// Generate a 3D mesh (uses default quality: 20 subdivisions)
let mesh_3d = font.glyph_to_mesh_3d('A', 5.0)?;

Fluent API

For more control, use the fluent API to chain operations:

use fontmesh::Font;

let font = Font::from_bytes(include_bytes!("font.ttf"))?;

// Fluent 2D mesh generation with default quality
let mesh_2d = font.glyph_by_char('A')?.to_mesh_2d()?;

// Fluent 3D mesh generation with custom quality (50 subdivisions)
let mesh_3d = font.glyph_by_char('A')?.with_subdivisions(50).to_mesh_3d(5.0)?;

// Access intermediate pipeline stages
let outline = font.glyph_by_char('A')?.linearize()?;
let mesh_2d = outline.triangulate()?;
let mesh_3d = mesh_2d.extrude(&outline, 5.0)?;

Advanced Usage

The mesh generation pipeline has discrete stages that you can access:

1. Outline Extraction: Glyph::outline() → Raw Bezier curves
2. Linearization: linearize_outline() → Straight line segments
3. Triangulation: triangulate() → 2D triangle mesh
4. Extrusion: extrude() → 3D mesh with depth

use fontmesh::{Font, linearize_outline, triangulate, extrude};

let font = Font::from_bytes(include_bytes!("font.ttf"))?;
let glyph = font.glyph_by_char('A')?;

// Get raw Bezier curves
let outline = glyph.outline()?;

// Convert curves to line segments (50 subdivisions per curve)
let linearized = linearize_outline(outline, 50)?;

// Triangulate into 2D mesh
let mesh_2d = triangulate(&linearized)?;

// Extrude to create multiple 3D variations
let shallow = extrude(&mesh_2d, &linearized, 1.0)?;
let deep = extrude(&mesh_2d, &linearized, 10.0)?;

Integration with Text Shaping

For integration with text shaping libraries like rustybuzz or cosmic-text, use glyph IDs directly:

use fontmesh::{Font, GlyphId};

let font = Font::from_bytes(include_bytes!("font.ttf"))?;

// From text shaping (e.g., rustybuzz)
let glyph_id = GlyphId(42);
let glyph = font.glyph_by_id(glyph_id, 'A');
let mesh = glyph.with_subdivisions(50).to_mesh_3d(5.0)?;

// Access glyph ID for caching
let id = glyph.glyph_id();

// Access ttf-parser for advanced features
let face = font.face();
let kerning = face.kerning_subtables();

Re-exports

pub use error::FontMeshError;

pub use error::Result;

pub use font::Font;

pub use glyph::Glyph;

pub use glyph::GlyphMeshBuilder;

pub use types::Mesh2D;

pub use types::Mesh3D;

pub use types::Outline2D;

pub use extrude::compute_smooth_normals;

pub use extrude::extrude;

pub use linearize::linearize_outline;

pub use triangulate::triangulate;

Modules

error

Error types for fontmesh

extrude

3D extrusion - converts 2D meshes to 3D with depth

font

Font loading and management

glyph

Glyph representation and outline extraction

linearize

Curve linearization - converts Bezier curves to line segments

triangulate

2D triangulation using lyon_tessellation

types

Core type definitions for fontmesh

Structs

GlyphId

A type-safe wrapper for glyph ID.