Add a sphere ray tracer

Cargo.lock

@@ -3334,12 +3334,15 @@ dependencies = [
 [[package]]
 name = "ray-tracer"
 version = "0.1.0"
+dependencies = [
+ "rayon",
+]
 
 [[package]]
 name = "rayon"
-version = "1.8.0"
+version = "1.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9c27db03db7734835b3f53954b534c91069375ce6ccaa2e065441e07d9b6cdb1"
+checksum = "b418a60154510ca1a002a752ca9714984e21e4241e804d32555251faf8b78ffa"
 dependencies = [
  "either",
  "rayon-core",
@@ -3347,9 +3350,9 @@ dependencies = [
 
 [[package]]
 name = "rayon-core"
-version = "1.12.0"
+version = "1.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5ce3fb6ad83f861aac485e76e1985cd109d9a3713802152be56c3b1f0e0658ed"
+checksum = "1465873a3dfdaa8ae7cb14b4383657caab0b3e8a0aa9ae8e04b044854c8dfce2"
 dependencies = [
  "crossbeam-deque",
  "crossbeam-utils",

ray-tracer/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+rayon = "1.10.0"
 
 [[bin]]
 name = "projectile"

ray-tracer/src/bin/sphere.rs

@@ -0,0 +1,40 @@
+use ray_tracer::{transforms::*, types::*, PPM};
+use rayon::prelude::*;
+use std::{fs::File, io::Write, sync::{Arc, RwLock}};
+
+const SIZE: usize = 1000;
+
+fn main() {
+    let canvas = Arc::new(RwLock::new(Canvas::new(SIZE, SIZE)));
+    let mut sphere = Sphere::default();
+    sphere.set_transformation(shearing(1., 0., 0., 0., 0., 0.));
+
+    let camera = Point::new(0., 1., -5.);
+    let wall_z = 10.;
+    let wall_size = 7.;
+    let half = wall_size / 2.;
+
+    let pixel_size = wall_size / SIZE as f64;
+
+    (0..SIZE).into_par_iter().for_each(|x| {
+        (0..SIZE).into_par_iter().for_each(|y| {
+            let wall_x = -half + pixel_size * x as f64;
+            let wall_y = half - pixel_size * y as f64;
+
+            let ray = Ray::new(
+                camera.clone(),
+                Vector::new(wall_x, wall_y, wall_z).normalize(),
+            );
+            let xs = ray.intersect(&sphere);
+            if xs.hit().is_some() {
+                *canvas.write().unwrap().pixel_mut(x, y) = Color::new(0., 0., 1.);
+            }
+        });
+    });
+
+    let canvas = canvas.read().unwrap();
+
+    let ppm = PPM::from(&*canvas);
+    let mut file = File::create("sphere.ppm").unwrap();
+    let _ = file.write(ppm.as_bytes());
+}

ray-tracer/src/ppm.rs

@@ -29,8 +29,8 @@ fn join_to_line_limit(data: impl IntoIterator<Item = String>) -> Vec<String> {
 #[derive(Debug)]
 pub struct PPM(String);
 
-impl From<Canvas> for PPM {
-    fn from(c: Canvas) -> Self {
+impl From<&Canvas> for PPM {
+    fn from(c: &Canvas) -> Self {
         // let v = vec![0.; c.width() * c.height() * 3];
         let header = format!("P3\n{} {}\n255\n", c.width(), c.height());
 
@@ -68,7 +68,7 @@ mod tests {
     #[test]
     fn construct_ppm_header() {
         let c = Canvas::new(5, 3);
-        let ppm = PPM::from(c);
+        let ppm = PPM::from(&c);
 
         assert!(ppm.starts_with(
             "P3\n\