RustType is a pure Rust alternative to libraries like FreeType.
The current capabilities of RustType:
- Reading OpenType formatted fonts and font collections. This includes
*.ttf
as well as*.otf
font files. - Retrieving glyph shapes and commonly used properties for a font and its glyphs.
- Laying out glyphs horizontally using horizontal and vertical metrics, and glyph-pair-specific kerning.
- Rasterising glyphs with sub-pixel positioning using an accurate analytical algorithm (not based on sampling).
- Managing a font cache on the GPU with the
gpu_cache
module. This keeps recently used glyph renderings in a dynamic cache in GPU memory to minimise texture uploads per-frame. It also allows you keep the draw call count for text very low, as all glyphs are kept in one GPU texture.
Notable things that RustType does not support yet:
- Font hinting.
- Ligatures of any kind.
- Some less common TrueType sub-formats.
- Right-to-left and vertical text layout.
Heavier examples, tests & benchmarks are in the ./dev
directory. This avoids dev-dependency feature bleed.
Run all tests with cargo test --all --all-features
.
Run examples with cargo run --example <NAME> -p dev
To hit the ground running with RustType, look at dev/examples/ascii.rs
supplied with the crate. It demonstrates loading a font file, rasterising an
arbitrary string, and displaying the result as ASCII art. If you prefer to just
look at the documentation, the entry point for loading fonts is Font
,
from which you can access individual fonts, then their glyphs.
The initial motivation for the project was to provide easy-to-use font rendering for games. There are numerous avenues for improving RustType. Ideas:
- Support for some common forms of ligatures.
- And, eventually, support for embedded right-to-left Unicode text.
If you think you could help with achieving any of these goals, feel free to open a tracking issue for discussing them.
This crate is maintained with latest stable rust.
Licensed under either of
- Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.
- glyph_brush - can cache vertex generation & provides more complex layouts.