From e4eb234889255e65318e66a53372e34ed9768eac Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Fri, 24 Jul 2020 13:44:32 +1000
Subject: [PATCH] matrix: add `rotation_euler` conversion

---
 matrix.hpp | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/matrix.hpp b/matrix.hpp
index e5d8c02d..d6bf4502 100644
--- a/matrix.hpp
+++ b/matrix.hpp
@@ -245,6 +245,19 @@ namespace cruft {
     //template <typename T> matrix<4,4,T> scale       (T);
     template <typename T> matrix<4,4,T> rotation    (T angle, vector<3,T> about);
 
+
+    /// Returns a matrix representing the rotation vector specifying the
+    /// concatentation of: {yaw,pitch,roll}.
+    template <typename ValueT>
+    constexpr
+    matrix<4,4,ValueT>
+    rotation_euler (vector<3,ValueT> angles)
+    {
+        return rotation (angles[1], {0,1,0}) *
+               rotation (angles[0], {1,0,0}) *
+               rotation (angles[2], {0,0,1});
+    }
+
     //template <typename T> matrix<3,3,T> translation (vector<2,T>);
     //template <typename T> matrix<3,3,T> scale (vector<2,T>);