🌍 Add Geometry

- Created a trait for all geometry that has to implement a hit
  function. Depending on if the ray hits or not it returns an option
  with the color.

- Add support for multiple samples per pixel

Current issues:
- Using cooperative multitasking which isn't that
  helpful in this situation since it's like running without async but
  without overhead. Should switch to rayon.

- All data gets copied once per job. Will decide later what to
  do (copy or put locks and share data between jobs).

1 files changed, 54 insertions, 0 deletions

diff --git a/racer-tracer/src/geometry.rs b/racer-tracer/src/geometry.rs
new file mode 100644
index 0000000..aa1c18c
--- /dev/null
+++ b/racer-tracer/src/geometry.rs
@@ -0,0 +1,54 @@
+pub mod sphere;
+
+use crate::ray::Ray;
+use crate::vec3::Vec3;
+
+pub struct HitRecord {
+    pub point: Vec3,
+    pub normal: Vec3,
+    pub t: f64,
+    pub front_face: bool,
+    pub color: Vec3,
+}
+
+impl HitRecord {
+    fn new(point: Vec3, t: f64, color: Vec3) -> Self {
+        Self {
+            point,
+            normal: Vec3::default(),
+            t,
+            front_face: true,
+            color,
+        }
+    }
+
+    fn set_face_normal(&mut self, ray: &Ray, outward_normal: Vec3) {
+        self.front_face = ray.direction().dot(&outward_normal) < 0.0;
+        self.normal = if self.front_face {
+            outward_normal
+        } else {
+            -outward_normal
+        };
+    }
+}
+
+impl Default for HitRecord {
+    fn default() -> Self {
+        HitRecord {
+            point: Vec3::default(),
+            normal: Vec3::default(),
+            t: 0.0,
+            front_face: true,
+            color: Vec3::default(),
+        }
+    }
+}
+
+pub trait Hittable {
+    //pub trait Hittable {
+    fn hit(&self, ray: &Ray, t_min: f64, t_max: f64) -> Option<HitRecord>;
+
+    // Manual ugly clone since forcing on Clone would make it a super trait.
+    // Clone requires Sized and super traits cannot be Sized.
+    fn clone_box(&self) -> Box<dyn Hittable>;
+}