matrix: add transpose functions

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>

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;