# Lyon
GPU-based 2D graphics rendering in rust.
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# Motivation
For now the goal is to provide efficient SVG-compliant path tessellation tools to help with rendering vector graphics on the GPU. For now think of this library as a way to turn complex paths into triangles for use in your own rendering engine.
The intent is for this library to be useful in projects like [Servo](https://servo.org/) and games.
## Example
```rust
// Build a Path.
let mut builder = SvgPathBuilder::new(Path::builder());
builder.move_to(point(0.0, 0.0));
builder.line_to(point(1.0, 0.0));
builder.quadratic_bezier_to(point(2.0, 0.0), point(2.0, 1.0));
builder.cubic_bezier_to(point(1.0, 1.0), point(0.0, 1.0), point(0.0, 0.0));
builder.close();
let path = builder.build();
// Will contain the result of the tessellation.
let mut geometry_cpu: VertexBuffers<Vec2> = VertexBuffers::new();
let mut tessellator = FillTessellator::new();
{
// The simple builder uses the tessellator's vertex type.
// You can implement the GeometryBuilder trait to create custom vertices.
let mut vertex_builder = simple_builder(&mut geometry_cpu);
// Compute the tessellation.
tessellator.tessellate_path(
path.path_iter().flattened(0.1),
&FillOptions::default(),
&mut vertex_builder
).unwrap();
}
// The tessellated geometry is ready to be uploaded to the GPU.
println!(" -- {} vertices {} indices",
geometry_cpu.vertices.len(),
geometry_cpu.indices.len()
);
```
## Structure
The project is split into small crates:
* [](https://docs.rs/lyon_tessellation) - [lyon_tessellation](https://crates.io/crates/lyon_tessellation) - Path tessellation routines.
* [](https://docs.rs/lyon_path_builder) - [lyon_path_builder](https://crates.io/crates/lyon_path_builder) - Tools to facilitate building paths.
* [](https://docs.rs/lyon_path_iterator) - [lyon_path_iterator](https://crates.io/crates/lyon_path_iterator) - Tools to facilitate iteratring over paths.
* [](https://docs.rs/lyon_path) - [lyon_path](https://crates.io/crates/lyon_path) - A simple optional path data structure, provided for convenience.
* [](https://docs.rs/lyon_bezier) - [lyon_bezier](https://crates.io/crates/lyon_bezier) - Cubic and Quadratic 2d bezier math.
* [](https://docs.rs/lyon_extra) - [lyon_extra](https://crates.io/crates/lyon_extra) - Additional testing and debugging tools.
* [](https://docs.rs/lyon_path_core) - [lyon_core](https://crates.io/crates/lyon_core) - Common types to most lyon crates.
There is also a toy [command-line tool](cli) to tessellate SVG path from your favorite terminal.
Have a look at the [gfx-rs example](examples/gfx_logo) to see how integrating the tessellators in a renderer can look like.
## TODO
There's a [rough list of things to do](https://github.com/nical/lyon/wiki/TODO) in the wiki. If you are interested in [contributing](https://github.com/nical/lyon/wiki/Contribute), please let me know on twitter ([@nicalsilva](https://twitter.com/nicalsilva)) or by e-mail.
## License
Licensed under either of
* Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
* MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
at your option.
### Contribution
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.