1 files changed, 26 insertions, 11 deletions
diff --git a/src/render.rs b/src/render.rs
index 740c3eb..47c6698 100644
--- a/src/render.rs
+++ b/src/render.rs
@@ -1,6 +1,7 @@
 use cgmath::prelude::*;
 use cgmath::{Vector3, vec3};
 use rand::prelude::*;
+use rayon::prelude::*;
 use std::f64::INFINITY;
 use crate::camera::Camera;
 use crate::scene::Scene;
@@ -23,20 +24,34 @@ fn ray_colour(rng: &mut ThreadRng, ray: &Ray, scene: &Scene, depth: i32) -> Vect
     }
 }
 
-pub fn render(world: &Scene, camera: Camera, image_height: i32, image_width: i32,
-          samples: i32, max_depth: i32, rng: &mut ThreadRng) {
+pub fn thread_render(world: &Scene, camera: &Camera, rng: &mut ThreadRng, image_height: i32,
+                     image_width: i32, samples: i32, max_depth: i32, i: i32, j: i32) -> Vector3<f64> {
+    let mut colour = vec3(0.0, 0.0, 0.0);
+    for _ in 0 .. samples {
+        let ru: f64 = rng.gen();
+        let rv: f64 = rng.gen();
+        let u = (i as f64 + ru) / image_width as f64;
+        let v = ((image_height - 1 - j) as f64 + rv) / image_height as f64;
+        let ray = camera.get_ray(rng, u, v);
+        colour += ray_colour(rng, &ray, &world, max_depth);
+    }
+    colour
+}
+
+pub fn render(world: &Scene, camera: &Camera, image_height: i32, image_width: i32,
+              samples: i32, max_depth: i32, threads: i32) {
     for j in 0 .. image_height {
         eprint!("\rScanlines: {:3} / {:3}", j+1, image_height);
         for i in 0 .. image_width  {
-            let mut colour = vec3(0.0, 0.0, 0.0);
-            for _ in 0 .. samples {
-                let ru: f64 = rng.gen();
-                let rv: f64 = rng.gen();
-                let u = (i as f64 + ru) / image_width as f64;
-                let v = ((image_height - 1 - j) as f64 + rv) / image_height as f64;
-                let ray = camera.get_ray(rng, u, v);
-                colour += ray_colour(rng, &ray, &world, max_depth);
-            }
+            let colours = (0 .. threads)
+                .into_par_iter()
+                .map(|_| {
+                     let mut trng = thread_rng();
+                     thread_render(
+                         world, camera, &mut trng, image_height, image_width,
+                         samples / threads, max_depth, i, j)
+                });
+            let colour = colours.sum::<Vector3<f64>>();
             print_colour(&colour, samples);
         }
     }