A Rust implementation of a small ray/pathtracer.

Inspired by Kevin Beason's educational 99-line raytracer/pathtracer.

Supports: - Ray-to-Sphere - Ray-to-Plane - Ray-to-Rectangle - Ray-to-Triangle (slow, no acceleration yet. Soon)

Usage

```toml

Cargo.toml

[dependencies] smallpt = "0.4.1" ```

Example

```rust extern crate smallpt; extern crate minifb;

use smallpt::*; use minifb::{Key, Window, WindowOptions};

fn main() { let num_samples = 128; let width = 512; let height = 512;

let mut backbuffer = vec![Vector3::new(0.0, 0.0, 0.0); width * height];

let mut scene = Scene::init();

// Spheres
// Mirror
scene.add(Box::new(Sphere::new(
    16.5,
    Vector3::new(27.0, 16.5, 47.0),
    Material::new(Vector3::new(0.0, 0.0, 0.0), Vector3::new(1.0, 1.0, 1.0), BSDF::Mirror),
)));

// Glass
scene.add(Box::new(Sphere::new(
    16.5,
    Vector3::new(73.0, 16.5, 78.0),
    Material::new(Vector3::new(0.0, 0.0, 0.0), Vector3::new(1.0, 1.0, 1.0), BSDF::Glass),
)));

// Planes
// Bottom
scene.add(Box::new(Plane::new(
    Vector3::new(0.0, 0.0, 0.0),
    Vector3::new(0.0, 1.0, 0.0),
    Material::new(Vector3::new(0.0, 0.0, 0.0), Vector3::new(0.75, 0.75, 0.75), BSDF::Diffuse),
)));

// Left
scene.add(Box::new(Plane::new(
    Vector3::new(1.0, 0.0, 0.0),
    Vector3::new(1.0, 0.0, 0.0),
    Material::new(Vector3::new(0.0, 0.0, 0.0), Vector3::new(0.75, 0.25, 0.25), BSDF::Diffuse),
)));

// Right
scene.add(Box::new(Plane::new(
    Vector3::new(99.0, 0.0, 0.0),
    Vector3::new(-1.0, 0.0, 0.0),
    Material::new(Vector3::new(0.0, 0.0, 0.0), Vector3::new(0.25, 0.25, 0.75), BSDF::Diffuse),
)));

// Front
scene.add(Box::new(Plane::new(
    Vector3::new(0.0, 0.0, 0.0),
    Vector3::new(0.0, 0.0, 1.0),
    Material::new(Vector3::new(0.0, 0.0, 0.0), Vector3::new(0.75, 0.75, 0.75), BSDF::Diffuse),
)));

// Back
scene.add(Box::new(Plane::new(
    Vector3::new(0.0, 0.0, 170.0),
    Vector3::new(0.0, 0.0, -1.0),
    Material::new(Vector3::new(0.0, 0.0, 0.0), Vector3::new(0.0, 0.0, 0.0), BSDF::Diffuse),
)));

// Top
scene.add(Box::new(Plane::new(
    Vector3::new(0.0, 81.6, 0.0),
    Vector3::new(0.0, -1.0, 0.0),
    Material::new(Vector3::new(0.0, 0.0, 0.0), Vector3::new(0.75, 0.75, 0.75), BSDF::Diffuse),
)));

// Light (emissive rectangle)
scene.add(Box::new(Rectangle::new(
    Vector3::new(50.0, 81.5, 50.0),
    Vector3::new(0.0, -1.0, 0.0),
    Vector3::new(1.0, 0.0, 0.0),
    Vector3::new(0.0, 0.0, 1.0),
    33.0,
    33.0,
    Material::new(Vector3::new(12.0, 12.0, 12.0), Vector3::new(0.0, 0.0, 0.0), BSDF::Diffuse),
)));

let camera = Camera {
    origin: Vector3::new(50.0, 50.0, 200.0),
    forward: Vector3::new(0.0, -0.05, -1.0).normalize(),
    right: Vector3::new(1.0, 0.0, 0.0).normalize(),
    up: Vector3::new(0.0, 1.0, 0.0).normalize(),
};

let mut buffer: Vec<u32> = vec![0; width * height];
let mut window = Window::new("smallpt in Rust", width, height, WindowOptions::default())
    .unwrap_or_else(|e| {
        panic!("{}", e);
    });

// Render
let mut num_rays = 0;
trace(&scene, &camera, width, height, num_samples, &mut backbuffer, &mut num_rays);

while window.is_open() && !window.is_key_down(Key::Escape) {
    for i in 0..width * height {
        let color = saturate(tonemap(backbuffer[i]));

        let r = (color.x * 255.0).round() as u32;
        let g = (color.y * 255.0).round() as u32;
        let b = (color.z * 255.0).round() as u32;

        buffer[i] = (r << 16) | (g << 8) | b;
    }

    window.update_with_buffer(&buffer, width, height).unwrap();
}

} ```

Architecture