Math: added *Matrix::setRow().

Row equivalent for the mutable operator[]().

src/Magnum/Math/RectangularMatrix.h

@@ -191,10 +191,20 @@ template<std::size_t cols, std::size_t rows, class T> class RectangularMatrix {
          * Consider using @ref transposed() when accessing rows frequently, as
          * this is slower than accessing columns due to the way the matrix is
          * stored.
-         * @see @ref operator[]()
+         * @see @ref setRow(), @ref operator[]()
          */
         Vector<cols, T> row(std::size_t row) const;
 
+        /**
+         * @brief Set matrix row
+         *
+         * Consider using @ref transposed() when accessing rows frequently, as
+         * this is slower than accessing columns due to the way the matrix is
+         * stored.
+         * @see @ref row(), @ref operator()[]
+         */
+        void setRow(std::size_t row, const Vector<cols, T>& data);
+
         /** @brief Equality comparison */
         bool operator==(const RectangularMatrix<cols, rows, T>& other) const {
             for(std::size_t i = 0; i != cols; ++i)
@@ -662,6 +672,11 @@ template<std::size_t cols, std::size_t rows, class T> inline Vector<cols, T> Rec
     return out;
 }
 
+template<std::size_t cols, std::size_t rows, class T> inline void RectangularMatrix<cols, rows, T>::setRow(std::size_t row, const Vector<cols, T>& data) {
+    for(std::size_t i = 0; i != cols; ++i)
+        _data[i][row] = data[i];
+}
+
 template<std::size_t cols, std::size_t rows, class T> inline RectangularMatrix<cols, rows, T> RectangularMatrix<cols, rows, T>::operator-() const {
     RectangularMatrix<cols, rows, T> out;
 

src/Magnum/Math/Test/RectangularMatrixTest.cpp

@@ -300,11 +300,16 @@ void RectangularMatrixTest::data() {
 }
 
 void RectangularMatrixTest::row() {
-    const Matrix3x4 a(Vector4(1.0f,  2.0f,  3.0f,  4.0f),
-                      Vector4(5.0f,  6.0f,  7.0f,  8.0f),
-                      Vector4(9.0f, 10.0f, 11.0f, 12.0f));
+    Matrix3x4 a(Vector4(1.0f,  2.0f,  3.0f,  4.0f),
+                Vector4(5.0f,  6.0f,  7.0f,  8.0f),
+                Vector4(9.0f, 10.0f, 11.0f, 12.0f));
 
     CORRADE_COMPARE(a.row(1), Vector3(2.0f, 6.0f, 10.0f));
+
+    a.setRow(1, {-2.1f, -6.1f, -10.1f});
+    CORRADE_COMPARE(a, (Matrix3x4{Vector4{1.0f,  -2.1f,  3.0f,  4.0f},
+                                  Vector4{5.0f,  -6.1f,  7.0f,  8.0f},
+                                  Vector4{9.0f, -10.1f, 11.0f, 12.0f}}));
 }
 
 void RectangularMatrixTest::compare() {