Rust-like syntax for GLSL

glassful translates a small subset of Rust to OpenGL Shading Language.

Besides one's personal preferences regarding Rust-like vs. C-like syntax, this has a few specific advantages for the Rust programmer:

• Syntax is checked at Rust compile time, with friendly rustc-style errors
• There's less cognitive overhead switching between CPU and GPU code
• Shaders can use Rust macros!
• Shaders embedded in a Rust program have syntax highlighting

The library is still in a very early stage! Many improvements are possible. See the issue tracker and don't hesitate to send pull requests :)

Usage

There are three ways to invoke the translator. The language syntax is exactly the same in all three cases.

As a macro

#![feature(plugin)]

#![plugin(glassful_macros)]

const VERTEX: &'static str = glassful! {
    #![version="110"]

    #[attribute] static position: vec2 = UNINIT;
    #[varying]   static color:    vec3 = UNINIT;

    fn main() {
        gl_Position = vec4(position, 0.0, 1.0);
        color = vec3(0.5*(position + vec2(1.0, 1.0)), 0.0);
    }
};

const FRAGMENT: &'static str = glassful! {
    #![version="110"]

    #[varying] static color: vec3 = UNINIT;

    fn main() {
        gl_FragColor = vec4(color, 1.0);
    }
};

let program = glium::Program::from_source(&display, VERTEX, FRAGMENT, None);

See examples/gradient/ for a full glium/glutin example.

As an external program

$ ./target/glassful < shader.glassful > shader.glsl

As an ordinary library

extern crate glassful;

pub fn main() {
    let prog = io::stdin().read_to_end().unwrap();
    let prog = String::from_utf8(prog).unwrap();
    print!("{}", glassful::translate(prog));
}