ft: 6.5: hitlist

src/main.rs

@@ -9,26 +9,14 @@ use std::cmp::max;
 
 use crate::objects::hit::Hit;
 use crate::objects::sphere::Sphere;
-use crate::objects::traits::{Hittable, Normal};
+use crate::objects::traits::Hittable;
 use crate::ray::Ray;
 use crate::vec3::{Colour, Vec3};
 use log::info;
 use pretty_env_logger;
 
-fn ray_colour<T>(hittables: &Vec<T>, r: &Ray) -> Colour
+fn ray_colour<T: Hittable>(hittables: &Vec<T>, r: &Ray) -> Colour {
-where
+    let closest = Hit::hit_list(hittables, r);
-    T: Hittable + Normal,
-{
-    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);
-            }
-        }
-    }
-
     if let Some(hit) = closest {
         let n = hit.n();
         return 0.5 * Colour::new(n.x() + 1., n.y() + 1., n.z() + 1.);
@@ -42,12 +30,13 @@ where
 }
 
 fn main() {
-    // use structs so rust-analyzer can provide lsp
-    let s = Sphere::new(Vec3::new(0., 0., -1.), 0.5);
-    let objects = vec![s];
-
     pretty_env_logger::init();
 
+    // setup objects
+    let mut objects = vec![Sphere::new(Vec3::new(0., 0., -1.), 0.5)];
+    objects.push(Sphere::new(Vec3::new(0., 0., -0.1), 0.01));
+    objects.push(Sphere::new(Vec3::new(0., -100.5, -1.), 100.));
+
     let aspect_ratio = 16. / 9.;
     let image_width = 400;
     let image_height = max(1, (image_width as f32 / aspect_ratio) as u32);

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;
 }