From b53ea71eb0a66a6afecdfff6b47d724bb22e6441 Mon Sep 17 00:00:00 2001
From: bijan2005 <bijan2005@users.noreply.github.com>
Date: Tue, 8 Dec 2020 11:25:26 -0500
Subject: [PATCH] Optimized bounding sphere intersection test

---
 src/object/bound.rs  | 9 +--------
 src/object/sphere.rs | 2 +-
 2 files changed, 2 insertions(+), 9 deletions(-)

diff --git a/src/object/bound.rs b/src/object/bound.rs
index b1a4832..7988305 100644
--- a/src/object/bound.rs
+++ b/src/object/bound.rs
@@ -18,17 +18,10 @@ pub struct Bound {
 
 impl Bound {
     pub fn is_intersected(&self, ray: Ray) -> bool {
-
         if self.bypass { return true; }
 
         let l = ray.origin - self.center;
-
-        let b_2 = ray.direction.dot(&l);
-        let c = l.norm_squared() - self.radius * self.radius;
-
-        let discr = b_2 * b_2 * c;
-
-        discr >= 0.0
+        l.norm_squared() >= self.radius * self.radius
     }
 
     pub fn contains(&self, point: &Point3<f32>) -> bool { distance(&self.center, point) < self.radius }
diff --git a/src/object/sphere.rs b/src/object/sphere.rs
index 7f4af73..9cf01f3 100644
--- a/src/object/sphere.rs
+++ b/src/object/sphere.rs
@@ -51,7 +51,7 @@ impl Surface for Sphere {
 
         let l = ray.origin - self.center;
         let b = 2.0 * ray.direction.dot(&l);
-        let c = l.normsquared() - self.radius * self.radius;
+        let c = l.norm_squared() - self.radius * self.radius;
 
         let (mut t0, mut t1) = solve_quadratic(b, c)?;