From e873ddac4036ce2fcc9d58b7b78bd992d90b74a3 Mon Sep 17 00:00:00 2001
From: Ishan Jain <contact@ishanjain.me>
Date: Tue, 2 Mar 2021 12:43:57 +0530
Subject: [PATCH] Fixed a bug in BVH implementation

---
 src/bvh.rs  | 7 ++++---
 src/demo.rs | 4 +---
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/bvh.rs b/src/bvh.rs
index a7bd00b..5db3983 100644
--- a/src/bvh.rs
+++ b/src/bvh.rs
@@ -20,8 +20,6 @@ impl<T: Hitable + Clone> BvhNode<T> {
         .choose(rng)
         .unwrap();
 
-        objects.sort_by(comparator);
-
         let (left, right) = match objects.len() {
             1 => (
                 HitNode::Direct(objects[0].clone()),
@@ -39,6 +37,7 @@ impl<T: Hitable + Clone> BvhNode<T> {
             },
 
             n => {
+                objects.sort_by(comparator);
                 let (l, r) = objects.split_at_mut(n / 2);
                 (
                     HitNode::Bvh(Box::new(BvhNode::new(rng, l, t0, t1))),
@@ -94,7 +93,9 @@ impl<T: Hitable + Clone> BvhNode<T> {
 
 impl<T: Hitable> Hitable for BvhNode<T> {
     fn hit(&self, ray: &Ray, t_min: f64, t_max: f64) -> Option<HitRecord> {
-        self.bounding_box(t_min, t_max)?;
+        if !self.bounding_box.hit(ray, t_min, t_max) {
+            return None;
+        }
 
         let hbox_left = self.left.hit(ray, t_min, t_max);
 
diff --git a/src/demo.rs b/src/demo.rs
index 6154d62..7e51370 100644
--- a/src/demo.rs
+++ b/src/demo.rs
@@ -1,12 +1,10 @@
-use crate::BvhNode;
-
 use {
     crate::{
         types::{
             material::{Dielectric, Lambertian, Metal},
             MovingSphere, Ray, Sphere, Vec3,
         },
-        Camera, Hitable, HORIZONTAL_PARTITION, VERTICAL_PARTITION,
+        BvhNode, Camera, Hitable, HORIZONTAL_PARTITION, VERTICAL_PARTITION,
     },
     rand::{rngs::SmallRng, Rng, SeedableRng},
     rayon::prelude::*,