Add BVH bounding boxes

src/hittable.rs

@@ -1,5 +1,8 @@
 use crate::{Point3, Ray, Vec3};
 use crate::material::{Material};
+use crate::aabb::Aabb;
+
+pub type HittableList = Vec<Box<dyn Hittable + Sync>>;
 
 #[derive(Debug, Clone, Copy)]
 pub struct HitRecord<'material> {
@@ -12,7 +15,10 @@ pub struct HitRecord<'material> {
 
 pub trait Hittable {
     fn hit(&self, ray: &Ray, t_min: f64, t_max: f64) -> Option<HitRecord>;
+    fn bounding_box(&self, time0: f64, time1: f64) -> Option<Aabb>;
 }
+
+#[derive(Clone)]
 pub struct Sphere {
     pub center: Point3,
     pub radius: f64,
@@ -32,7 +38,6 @@ impl Default for Sphere {
         }
     }
 }
-
 impl Hittable for Sphere {
     fn hit(&self, ray: &Ray, t_min: f64, t_max: f64) -> Option<HitRecord> {
         let oc = &ray.origin() - &self.center;
@@ -61,8 +66,16 @@ impl Hittable for Sphere {
             material: &self.material
         })
     }
+    fn bounding_box(&self, _time0: f64, _time1: f64) -> Option<Aabb> {
+        let s = Vec3::new(self.radius, self.radius, self.radius);
+        Some(Aabb {
+            minimum: self.center - s,
+            maximum: self.center + s,
+        })
+    }
 }
 
+#[derive(Clone)]
 pub struct MovableSphere {
     pub center0: Point3,
     pub center1: Point3,
@@ -126,4 +139,16 @@ impl Hittable for MovableSphere {
             material: &self.material
         })
     }
-}
+    fn bounding_box(&self, time0: f64, time1: f64) -> Option<Aabb> {
+        let s = Vec3::new(self.radius, self.radius, self.radius);
+        let center0 = self.center(time0);
+        let center1 = self.center(time1);
+        Some(Aabb {
+            minimum: center0 - s,
+            maximum: center0 + s,
+        }.surrounding(&Aabb {
+            minimum: center1 - s,
+            maximum: center1 + s
+        }))
+    }
+}