sol.diff

diff --git a/rust/Cargo.toml b/rust/Cargo.toml
index b24d5cf..c715446 100644
--- a/rust/Cargo.toml
+++ b/rust/Cargo.toml
@@ -6,4 +6,6 @@ authors = [ "David Shoemaker <mrshoe@gmail.com>" ]
 
 [dependencies]
 image = "*"
+itertools = "*"
+rayon = "*"
 regex = "*"
diff --git a/rust/src/buffer.rs b/rust/src/buffer.rs
new file mode 100644
index 0000000..3bf0c78
--- /dev/null
+++ b/rust/src/buffer.rs
@@ -0,0 +1,33 @@
+use std::cell::UnsafeCell;
+
+pub struct ParallelPixelBuffer {
+    width: u32,
+    contents: UnsafeCell<Vec<u8>>,
+}
+
+unsafe impl Sync for ParallelPixelBuffer {}
+
+impl ParallelPixelBuffer {
+    pub fn new(width: u32, height: u32) -> ParallelPixelBuffer {
+        ParallelPixelBuffer {
+            width: width,
+            contents: UnsafeCell::new(vec![0u8; (width * height * 3) as usize]),
+        }
+    }
+
+    pub fn put_pixel(&self, l: u32, t: u32, x: u8, y: u8, z: u8) {
+        unsafe {
+            let contents = &mut *self.contents.get();
+            let base = (((t * self.width) + l) * 3) as usize;
+            *contents.get_unchecked_mut(base) = x;
+            *contents.get_unchecked_mut(base + 1) = y;
+            *contents.get_unchecked_mut(base + 2) = z;
+        }
+    }
+
+    pub fn into_inner(self) -> Vec<u8> {
+        unsafe {
+            self.contents.into_inner()
+        }
+    }
+}
diff --git a/rust/src/main.rs b/rust/src/main.rs
index 7c60dfc..0f32c14 100644
--- a/rust/src/main.rs
+++ b/rust/src/main.rs
@@ -1,4 +1,6 @@
 extern crate image;
+#[macro_use] extern crate itertools;
+extern crate rayon;
 extern crate regex;
 
 use std::fs::File;
@@ -7,6 +9,7 @@ use std::io::Read;
 use std::path::Path;
 use std::env;
 
+mod buffer;
 mod vector;
 mod ray;
 mod camera;
diff --git a/rust/src/scene.rs b/rust/src/scene.rs
index 3d21d15..30d89d9 100644
--- a/rust/src/scene.rs
+++ b/rust/src/scene.rs
@@ -1,3 +1,4 @@
+use buffer::ParallelPixelBuffer;
 use camera::Camera;
 use vector::Vector3;
 use ray::{ Ray, HitInfo };
@@ -6,6 +7,7 @@ use image::{ ImageBuffer, Rgb };
 use sceneobject::SceneObject;
 use light::Light;
 use material::Material;
+use rayon::prelude::*;
 
 #[derive(Debug)]
 pub struct Scene {
@@ -41,7 +43,13 @@ impl Scene {
     }
 
     pub fn raytrace(&self) -> ImageBuffer<Rgb<u8>, Vec<u8>> {
-        ImageBuffer::from_fn(self.width, self.height, |x, y| {
+        // TODO(jamwt) -- we don't have to actually collect this
+        // if we implement IntoParallelIterator on our pixel buffer.
+        let coords: Vec<_> = iproduct!(0..self.width, 0..self.height).collect();
+
+        // Now let's do the pixels in parallel.
+        let pixels = ParallelPixelBuffer::new(self.width, self.height);
+        coords.par_iter().for_each(|&(x, y)| {
             let eye_ray = self.camera.eye_ray(x, y);
             let color = if let Some(hit) = self.trace(&eye_ray, 0.001, f64::MAX) {
                 self.shade(&hit, &eye_ray, 0) * 255.0
@@ -49,8 +57,10 @@ impl Scene {
             else {
                 self.bgcolor * 255.0
             };
-            Rgb([color.x as u8, color.y as u8, color.z as u8])
-        })
+            pixels.put_pixel(x, y, color.x as u8, color.y as u8, color.z as u8);
+        });
+        ImageBuffer::from_raw(self.width, self.height, pixels.into_inner())
+            .expect("Buffer not big enough??")
     }
 
     fn trace(&self, ray: &Ray, min: f64, max: f64) -> Option<HitInfo> {
diff --git a/rust/src/sceneobject.rs b/rust/src/sceneobject.rs
index e6bd88d..432e1c5 100644
--- a/rust/src/sceneobject.rs
+++ b/rust/src/sceneobject.rs
@@ -1,6 +1,6 @@
 use ray::{ Ray, HitInfo };
 use std::fmt::Debug;
 
-pub trait SceneObject: Debug {
+pub trait SceneObject: Debug + Sync {
     fn intersect(&self, ray: &Ray, min: f64, max: f64) -> Option<HitInfo>;
 }