tuple::new can take any type of number

.vscode/launch.json

@@ -0,0 +1,45 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "type": "lldb",
+            "request": "launch",
+            "name": "Debug executable 'ray-tracer'",
+            "cargo": {
+                "args": [
+                    "build",
+                    "--bin=ray-tracer",
+                    "--package=ray-tracer"
+                ],
+                "filter": {
+                    "name": "ray-tracer",
+                    "kind": "bin"
+                }
+            },
+            "args": [],
+            "cwd": "${workspaceFolder}"
+        },
+        {
+            "type": "lldb",
+            "request": "launch",
+            "name": "Debug unit tests in executable 'ray-tracer'",
+            "cargo": {
+                "args": [
+                    "test",
+                    "--no-run",
+                    "--bin=ray-tracer",
+                    "--package=ray-tracer"
+                ],
+                "filter": {
+                    "name": "ray-tracer",
+                    "kind": "bin"
+                }
+            },
+            "args": [],
+            "cwd": "${workspaceFolder}"
+        }
+    ]
+}

Cargo.lock

@@ -22,6 +22,7 @@ name = "features"
 version = "0.1.0"
 dependencies = [
  "approx",
+ "num-traits",
 ]
 
 [[package]]

features/Cargo.lock

@@ -22,6 +22,7 @@ name = "features"
 version = "0.1.0"
 dependencies = [
  "approx",
+ "num-traits",
 ]
 
 [[package]]

features/Cargo.toml

@@ -7,3 +7,4 @@ edition = "2018"
 
 [dependencies]
 approx = "0.5"
+num-traits = "0.2"

features/src/lib.rs

@@ -1,5 +1,6 @@
 #[macro_use]
 extern crate approx;
+extern crate num_traits;
 
 pub mod structs;
 pub mod color;

features/src/structs.rs

@@ -10,12 +10,12 @@ pub struct Tuple {
 }
 
 impl Tuple {
-    pub fn new(x: f32, y: f32, z: f32, w: f32) -> Tuple {
+    pub fn new<T: num_traits::NumCast>(x: T, y: T, z: T, w: T) -> Tuple {
         Tuple {
-            x,
-            y,
-            z,
-            w,
+            x: num_traits::cast(x).unwrap(),
+            y: num_traits::cast(y).unwrap(),
+            z: num_traits::cast(z).unwrap(),
+            w: num_traits::cast(w).unwrap(),
         }
     }
 
@@ -424,4 +424,12 @@ mod tests {
          let b_cross_a = Tuple::vector(1.0, -2.0, 1.0);
          assert_eq!(b_cross_a, b.cross(&a));
      }
+
+     #[test]
+     fn works_with_i32() {
+         let a = Tuple::new(1, 2, 3);
+         assert_eq!(1.0, a.x());
+         assert_eq!(2.0, a.y());
+         assert_eq!(3.0, a.z());
+     }
 }

src/main.rs

@@ -175,7 +175,7 @@ fn clock() {
     let mut canvas = Canvas::new(1024, 1024);
     let color = Color::new(1.0, 0.0, 0.0);
     let middle = 1024.0 / 2.0;
-    canvas.write_pixel(middle as usize, middle as usize, Color::new(0.0, 1.0, 0.0));
+
     let middle_point = &Tuple::point_zero() * &Matrix::translation(middle, middle, 0.0);
     draw_cross(&mut canvas, &middle_point, Color::new(0.0, 1.0, 0.0));