ft: 6.5: hitlist

src/objects/hit.rs

@@ -1,4 +1,4 @@
-use crate::vec3::Vec3;
+use crate::{objects::traits::Hittable, ray::Ray, vec3::Vec3};
 
 pub struct Hit {
     t: f32,
@@ -22,4 +22,17 @@ impl Hit {
     pub fn n(&self) -> &Vec3 {
         &self.n
     }
+
+    pub fn hit_list<T: Hittable>(hittables: &Vec<T>, r: &Ray) -> Option<Hit> {
+        let mut closest: Option<Hit> = None;
+        for hittable in hittables {
+            if let Some(hit) = hittable.hit(r) {
+                // hit happens in front of camera and is closer than closest
+                if *hit.t() > 0. && (closest.is_none() || closest.as_ref().unwrap().t() > hit.t()) {
+                    closest = Some(hit);
+                }
+            }
+        }
+        return closest;
+    }
 }

src/objects/sphere.rs

@@ -1,7 +1,7 @@
 use core::f32::math::sqrt;
 
 use crate::objects::hit::Hit;
-use crate::objects::traits::{Hittable, Normal};
+use crate::objects::traits::Hittable;
 use crate::Vec3;
 
 pub struct Sphere {
@@ -34,9 +34,7 @@ impl Hittable for Sphere {
             Some(Hit::new(t, p, self.normal_at(&p)))
         }
     }
-}
 
-impl Normal for Sphere {
     fn normal_at(&self, p: &Vec3) -> Vec3 {
         (*p - self.center).get_unit()
     }

src/objects/traits.rs

@@ -4,8 +4,5 @@ use crate::Vec3;
 
 pub trait Hittable {
     fn hit(&self, r: &Ray) -> Option<Hit>;
-}
-
-pub trait Normal {
     fn normal_at(&self, p: &Vec3) -> Vec3;
 }