1 files changed, 2 insertions, 0 deletions
diff --git a/ray.go b/ray.go
index c874e31..a3f78f8 100644
--- a/ray.go
+++ b/ray.go
@@ -1,9 +1,11 @@
 package main
 
+// Ray contains a ray data
 type Ray struct {
 	origin, direction Vec3D
 }
 
+// PointAt computes ray position at a time
 func (ray Ray) PointAt(time float64) Vec3D {
 	return AddVec3D(ray.origin, ScalarProduct(time, ray.direction))
 }