From d3eead53cf69abcfb8f45e135314823c25f0e6d2 Mon Sep 17 00:00:00 2001
From: tolelom <98kimsungmin@naver.com>
Date: Wed, 25 Mar 2026 10:45:06 +0900
Subject: [PATCH] feat(math): add Ray type with direction normalization

---
 crates/voltex_math/src/lib.rs |  2 ++
 crates/voltex_math/src/ray.rs | 46 +++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)
 create mode 100644 crates/voltex_math/src/ray.rs

diff --git a/crates/voltex_math/src/lib.rs b/crates/voltex_math/src/lib.rs
index a45c9ff..afda285 100644
--- a/crates/voltex_math/src/lib.rs
+++ b/crates/voltex_math/src/lib.rs
@@ -3,9 +3,11 @@ pub mod vec3;
 pub mod vec4;
 pub mod mat4;
 pub mod aabb;
+pub mod ray;
 
 pub use vec2::Vec2;
 pub use vec3::Vec3;
 pub use vec4::Vec4;
 pub use mat4::Mat4;
 pub use aabb::AABB;
+pub use ray::Ray;
diff --git a/crates/voltex_math/src/ray.rs b/crates/voltex_math/src/ray.rs
new file mode 100644
index 0000000..a6b1ee8
--- /dev/null
+++ b/crates/voltex_math/src/ray.rs
@@ -0,0 +1,46 @@
+use crate::Vec3;
+
+#[derive(Debug, Clone, Copy)]
+pub struct Ray {
+    pub origin: Vec3,
+    pub direction: Vec3,
+}
+
+impl Ray {
+    pub fn new(origin: Vec3, direction: Vec3) -> Self {
+        Self {
+            origin,
+            direction: direction.normalize(),
+        }
+    }
+
+    pub fn at(&self, t: f32) -> Vec3 {
+        self.origin + self.direction * t
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn approx(a: f32, b: f32) -> bool {
+        (a - b).abs() < 1e-5
+    }
+
+    fn approx_vec(a: Vec3, b: Vec3) -> bool {
+        approx(a.x, b.x) && approx(a.y, b.y) && approx(a.z, b.z)
+    }
+
+    #[test]
+    fn test_new_normalizes_direction() {
+        let r = Ray::new(Vec3::ZERO, Vec3::new(3.0, 0.0, 0.0));
+        assert!(approx_vec(r.direction, Vec3::X));
+    }
+
+    #[test]
+    fn test_at() {
+        let r = Ray::new(Vec3::new(1.0, 2.0, 3.0), Vec3::X);
+        let p = r.at(5.0);
+        assert!(approx_vec(p, Vec3::new(6.0, 2.0, 3.0)));
+    }
+}