From 6f1278767ffb00507db4cc7d327aa650ab2b4361 Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Wed, 15 Apr 2015 13:48:51 +1000
Subject: [PATCH] vector: add is_normalised

---
 test/vector.cpp |  9 +++++++--
 vector.cpp      | 10 ++++++++++
 vector.hpp      |  5 ++++-
 3 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/test/vector.cpp b/test/vector.cpp
index 6e111eea..ad160bf5 100644
--- a/test/vector.cpp
+++ b/test/vector.cpp
@@ -64,8 +64,13 @@ test_polar (void)
 int
 main ()
 {
+    util::TAP::logger test;
+
+    test.skip ("convert to TAP");
     test_polar ();
 
-    util::TAP::logger test;
-    test.skip ("convert to TAP");
+    test.expect (!util::vector3f::ZERO.is_normalised (), "zero isn't normalised");
+    test.expect (!util::vector3f::UNIT.is_normalised (), "unit is normalised");
+
+    return test.status ();
 }
diff --git a/vector.cpp b/vector.cpp
index 57a82877..ef235f00 100644
--- a/vector.cpp
+++ b/vector.cpp
@@ -71,6 +71,16 @@ util::vector<S,T>::difference2 (const util::vector<S,T> &rhs) const
     return sum;
 }
 
+
+///////////////////////////////////////////////////////////////////////////////
+template <size_t S, typename T>
+bool
+vector<S,T>::is_normalised (void) const
+{
+    return almost_equal (magnitude (), 1.f);
+}
+
+
 //-----------------------------------------------------------------------------
 template <size_t S, typename T>
 util::vector<S,T>&
diff --git a/vector.hpp b/vector.hpp
index 20c405a3..4b5c96d3 100644
--- a/vector.hpp
+++ b/vector.hpp
@@ -30,15 +30,18 @@ namespace util {
     {
         using coord::base<S,T,util::vector,coord::xyzw,coord::stpq>::base;
 
+        // vector size
         bool is_zero (void) const;
 
-        // vector operators
         T magnitude  (void) const;
         T magnitude2 (void) const;
 
         T difference  (const vector<S,T>&) const;
         T difference2 (const vector<S,T>&) const;
 
+        // normalisation
+        bool is_normalised (void) const;
+
         vector<S,T>& normalise  (void);
         vector<S,T>  normalised [[gnu::warn_unused_result]] (void) const;