From 999ec1c35c6634af0a79e4c1efb2a08f5f779f47 Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Wed, 18 Apr 2018 21:44:56 +1000
Subject: [PATCH] quaternion: add matrix multiply convenience method

---
 quaternion.hpp | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/quaternion.hpp b/quaternion.hpp
index 67ac4b5c..9fe6e068 100644
--- a/quaternion.hpp
+++ b/quaternion.hpp
@@ -152,6 +152,24 @@ namespace util {
     }
 
 
+    ///////////////////////////////////////////////////////////////////////////
+    template <typename T>
+    matrix<4,4,T>
+    operator* (quaternion<T> q, matrix<4,4,T> m)
+    {
+        return q.as_matrix () * m;
+    }
+
+
+    //-------------------------------------------------------------------------
+    template <typename T>
+    matrix<4,4,T>
+    operator* (matrix<4,4,T> m, quaternion<T> q)
+    {
+        return m * q.as_matrix ();
+    }
+
+
     ///////////////////////////////////////////////////////////////////////////
     template <typename T>
     constexpr