From 07651817dc2ec3fc6c4c92aa7f27659573e48473 Mon Sep 17 00:00:00 2001
From: Matthew Gordon <matthew@gordon.earth>
Date: Fri, 21 Mar 2025 20:51:50 -0300
Subject: [PATCH] Implement divide-by-scalar for Vec3

---
 src/math/vec3.rs | 34 +++++++++++++++++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/math/vec3.rs b/src/math/vec3.rs
index 3914f49..d5c8fb0 100644
--- a/src/math/vec3.rs
+++ b/src/math/vec3.rs
@@ -2,7 +2,7 @@ use super::Mat3;
 
 use itertools::izip;
 
-use std::ops::{Add, AddAssign, Index, IndexMut, Mul, MulAssign, Neg, Sub, SubAssign};
+use std::ops::{Add, AddAssign, Div, Index, IndexMut, Mul, MulAssign, Neg, Sub, SubAssign};
 
 #[derive(Copy, Clone, PartialEq, Debug, Default)]
 pub struct Vec3 {
@@ -316,6 +316,30 @@ impl Mul<&Vec3> for f64 {
     }
 }
 
+impl Div<f64> for &Vec3 {
+    type Output = Vec3;
+
+    fn div(self, rhs: f64) -> Vec3 {
+        let mut coords = [0.0; 3];
+        for (r, a) in coords.iter_mut().zip(self.coords.iter()) {
+            *r = a / rhs;
+        }
+        Vec3 { coords }
+    }
+}
+
+impl Div<f64> for Vec3 {
+    type Output = Vec3;
+
+    fn div(self, rhs: f64) -> Vec3 {
+        let mut coords = [0.0; 3];
+        for (r, a) in coords.iter_mut().zip(self.coords.iter()) {
+            *r = a / rhs;
+        }
+        Vec3 { coords }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -459,6 +483,14 @@ mod tests {
         assert!(a * b == c);
     }
 
+    #[test]
+    fn div_by_scalar_returns_correct_result() {
+        let a = Vec3::new(1.0, 2.0, 3.0);
+        let b = 2.0;
+        let c = Vec3::new(0.5, 1.0, 1.5);
+        assert!(dbg!(a / b) == dbg!(c));
+    }
+
     #[test]
     fn mul_assign_by_scalar_returns_correct_result() {
         let mut a = Vec3::new(1.0, 2.0, 3.0);