From 1be5be38ea1b089893ca44f3a84a39c8230dd07f Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Wed, 15 Apr 2015 18:59:28 +1000
Subject: [PATCH] ray: add convenience point-point constructor

---
 ray.cpp | 13 +++++++++++++
 ray.hpp |  4 ++++
 2 files changed, 17 insertions(+)

diff --git a/ray.cpp b/ray.cpp
index 23218c35..7b269735 100644
--- a/ray.cpp
+++ b/ray.cpp
@@ -32,6 +32,19 @@ ray<S,T>::ray (util::point<S,T> _origin,
 }
 
 
+//-----------------------------------------------------------------------------
+template <size_t S, typename T>
+ray<S,T>
+ray<S,T>::make (util::point<S,T> origin,
+                util::point<S,T> target)
+{
+    return {
+        origin,
+        (target - origin).normalised ()
+    };
+}
+
+
 ///////////////////////////////////////////////////////////////////////////////
 /// returns the distance along the ray in a ray-plane intersection
 ///
diff --git a/ray.hpp b/ray.hpp
index ac95cabf..caca6810 100644
--- a/ray.hpp
+++ b/ray.hpp
@@ -32,6 +32,10 @@ namespace util {
         ray (point<S,T> origin,
              vector<S,T> direction);
 
+        static
+        ray<S,T> make (point<S,T> origin,
+                       point<S,T> target);
+
         // intersection tests
         T intersect (plane<S,T>) const;
         T intersect (AABB<S,T>) const;