Add initial files

1 files changed, 40 insertions, 0 deletions

diff --git a/src/sphere.rs b/src/sphere.rs
new file mode 100644
index 0000000..9ea9081
--- /dev/null
+++ b/src/sphere.rs
@@ -0,0 +1,40 @@
+use cgmath::prelude::*;
+use cgmath::{Vector3, dot};
+use core::borrow::Borrow;
+use crate::material::Material;
+use crate::hittable::{Hittable, Hit};
+use crate::ray::Ray;
+
+pub struct Sphere {
+    center: Vector3<f64>,
+    radius: f64,
+    material: Box<dyn Material>
+}
+
+impl Sphere {
+    pub fn new(center: Vector3<f64>, radius: f64, material: Box<dyn Material>) -> Sphere {
+        Sphere { center, radius, material }
+    }
+}
+
+impl Hittable for Sphere {
+    fn is_hit(&self, ray: &Ray, t_min: f64, t_max: f64) -> Option<Hit> {
+        let oc = ray.orig - self.center;
+        let a = ray.dir.magnitude2();
+        let b = dot(oc, ray.dir);
+        let c = oc.magnitude2() - self.radius * self.radius;
+        let discriminant = b*b - a*c;
+
+        if discriminant > 0.0 {
+            let soln = (-b - discriminant.sqrt()) / a;
+            if soln < t_max && soln > t_min {
+                return Some(Hit::new(ray, soln, (ray.at(soln) - self.center) / self.radius, self.material.borrow()))
+            }
+            let soln = (-b + discriminant.sqrt()) / a;
+            if soln < t_max && soln > t_min {
+                return Some(Hit::new(ray, soln, (ray.at(soln) - self.center) / self.radius, self.material.borrow()))
+            }
+        }
+        None
+    }
+}