Add Vector3::normalized()

Makes a copy of the vector, normalizes it, and returns it.

src/basics.cc

@@ -220,8 +220,6 @@ Vector3::cross(const Vector3 &v)
 
 /*
  * Vector3::normalize --
- *
- * Normalize this vector in place. That is, make this vector's magnitude (length) 1.0.
  */
 Vector3 &
 Vector3::normalize()
@@ -231,6 +229,17 @@ Vector3::normalize()
 }
 
 
+/*
+ * Vector3::normalized --
+ */
+Vector3
+Vector3::normalized()
+    const
+{
+    return *this / length();
+}
+
+
 /*
  * operator* --
  *