diff --git a/rtchallenge/src/spheres.rs b/rtchallenge/src/spheres.rs
index 64bc3e3..ac85002 100644
--- a/rtchallenge/src/spheres.rs
+++ b/rtchallenge/src/spheres.rs
@@ -193,6 +193,10 @@ impl Sphere {
 /// assert_eq!(xs.len(), 0);
 /// ```
 pub fn intersect<'s>(sphere: &'s Sphere, ray: &Ray) -> Intersections<'s> {
+    intersect_rtc(sphere, ray)
+}
+
+fn intersect_rtc<'s>(sphere: &'s Sphere, ray: &Ray) -> Intersections<'s> {
     let ray = ray.transform(sphere.inverse_transform);
     let sphere_to_ray = ray.origin - Tuple::point(0., 0., 0.);
     let a = dot(ray.direction, ray.direction);
@@ -200,11 +204,25 @@ pub fn intersect<'s>(sphere: &'s Sphere, ray: &Ray) -> Intersections<'s> {
     let c = dot(sphere_to_ray, sphere_to_ray) - 1.;
     let discriminant = b * b - 4. * a * c;
     if discriminant < 0. {
-        Intersections::default()
-    } else {
-        Intersections::new(vec![
-            Intersection::new((-b - discriminant.sqrt()) / (2. * a), &sphere),
-            Intersection::new((-b + discriminant.sqrt()) / (2. * a), &sphere),
-        ])
+        return Intersections::default();
     }
+    Intersections::new(vec![
+        Intersection::new((-b - discriminant.sqrt()) / (2. * a), &sphere),
+        Intersection::new((-b + discriminant.sqrt()) / (2. * a), &sphere),
+    ])
+}
+fn intersect_rtiow<'s>(sphere: &'s Sphere, ray: &Ray) -> Intersections<'s> {
+    let ray = ray.transform(sphere.inverse_transform);
+    let oc = ray.origin - Tuple::point(0., 0., 0.);
+    let a = dot(ray.direction, ray.direction);
+    let b = dot(oc, ray.direction);
+    let c = dot(oc, oc) - 1.;
+    let discriminant = b * b - a * c;
+    if discriminant < 0. {
+        return Intersections::default();
+    }
+    Intersections::new(vec![
+        Intersection::new((-b - discriminant.sqrt()) / a, &sphere),
+        Intersection::new((-b + discriminant.sqrt()) / a, &sphere),
+    ])
 }