From 253be704cb270d31b7a97ee12b681456d7ab2f85 Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Mon, 15 Dec 2014 13:42:44 +1100
Subject: [PATCH] matrix: add transpose functions

---
 matrix.cpp | 26 ++++++++++++++++++++++++++
 matrix.hpp |  3 +++
 2 files changed, 29 insertions(+)

diff --git a/matrix.cpp b/matrix.cpp
index 97a8ee36..53054419 100644
--- a/matrix.cpp
+++ b/matrix.cpp
@@ -48,6 +48,32 @@ matrix<T>::translate (T x, T y, T z) {
 }
 
 
+//-----------------------------------------------------------------------------
+template <typename T>
+matrix<T>
+matrix<T>::transposed (void) const
+{
+    matrix<T> m;
+    for (size_t i = 0; i < 4; ++i)
+        for (size_t j = 0; j < 4; ++j)
+            m.values[i][j] = values[j][i];
+    return m;
+}
+
+
+//-----------------------------------------------------------------------------
+template <typename T>
+matrix<T>&
+matrix<T>::transpose (void)
+{
+    for (size_t i = 0; i < 4; ++i)
+        for (size_t j = i + 1; j < 4; ++j)
+            std::swap (values[i][j], values[j][i]);
+
+    return *this;
+}
+
+
 //-----------------------------------------------------------------------------
 template <typename T>
 matrix<T>
diff --git a/matrix.hpp b/matrix.hpp
index 702ce5f1..5751d0ff 100644
--- a/matrix.hpp
+++ b/matrix.hpp
@@ -35,6 +35,9 @@ namespace util {
         void scale     (T x, T y, T z);
         void translate (T x, T y, T z);
 
+        matrix& transpose  (void);
+        matrix  transposed (void) const;
+
         matrix<T>  inverse (void) const;
         matrix<T>& invert  (void);
         matrix<T>  inverse_affine (void) const;