2 files changed, 6 insertions, 0 deletions
diff --git a/src/core/ray.rs b/src/core/ray.rs
index 0517e50..19d3cf1 100644
--- a/src/core/ray.rs
+++ b/src/core/ray.rs
@@ -2,8 +2,12 @@
 use crate::core::Vector3f;
 use crate::Float;
 
+/// A ray that is sent into the world.
+/// This is the main type used for testing intersections.
 pub struct Ray {
+    /// Origin of the ray
     pub origin: Vector3f,
+    /// Direction is assumed to be a unit vector.
     pub direction: Vector3f,
 }
 
@@ -23,6 +27,7 @@ impl Ray {
         }
     }
 
+    /// Resolve a point on the ray at time t
     pub fn at(&self, t: Float) -> Vector3f {
         self.origin + self.direction * t
     }
diff --git a/src/core/spectrum.rs b/src/core/spectrum.rs
index bea056e..ed3505b 100644
--- a/src/core/spectrum.rs
+++ b/src/core/spectrum.rs
@@ -12,6 +12,7 @@ pub struct Spectrum {
 
 impl Spectrum {
     pub const ZERO: Self = Spectrum { c: [0.0; 3] };
+    pub const WHITE: Self = Spectrum { c: [1.0; 3] };
 
     pub fn new_rgb(r: Float, g: Float, b: Float) -> Spectrum {
         Spectrum { c: [r, g, b] }