Functions for getting translation part of the matrix.

src/Math/Matrix3.h

@@ -38,7 +38,8 @@ template<class T> class Matrix3: public Matrix<3, T> {
          * @brief 2D translation matrix
          * @param vec   Translation vector
          *
-         * @see Matrix4::translation(), Vector2::xAxis(), Vector2::yAxis()
+         * @see translation(), Matrix4::translation(const Vector3&),
+         *      Vector2::xAxis(), Vector2::yAxis()
          */
         inline constexpr static Matrix3<T> translation(const Vector2<T>& vec) {
             return Matrix3<T>( /* Column-major! */
@@ -122,6 +123,21 @@ template<class T> class Matrix3: public Matrix<3, T> {
                 (*this)[1].xy().normalized());
         }
 
+        /**
+         * @brief 2D translation part of the matrix
+         *
+         * First two elements of last column.
+         * @see translation(const Vector2&), Matrix4::translation()
+         */
+        inline Vector2<T>& translation() {
+            return (*this)[2].xy();
+        }
+
+        /** @overload */
+        inline constexpr Vector3<T> translation() const {
+            return (*this)[2].xy();
+        }
+
         MAGNUM_MATRIX_SUBCLASS_IMPLEMENTATION(Matrix3, Vector3, 3)
         MAGNUM_RECTANGULARMATRIX_SUBCLASS_OPERATOR_IMPLEMENTATION(3, 3, Matrix3<T>)
 };

src/Math/Matrix4.h

@@ -40,7 +40,8 @@ template<class T> class Matrix4: public Matrix<4, T> {
          * @brief 3D translation matrix
          * @param vec   Translation vector
          *
-         * @see Matrix3::translation(), Vector3::xAxis(), Vector3::yAxis(), Vector3::zAxis()
+         * @see translation(), Matrix3::translation(const Vector2&),
+         *      Vector3::xAxis(), Vector3::yAxis(), Vector3::zAxis()
          */
         inline constexpr static Matrix4<T> translation(const Vector3<T>& vec) {
             return Matrix4<T>( /* Column-major! */
@@ -161,6 +162,21 @@ template<class T> class Matrix4: public Matrix<4, T> {
                 (*this)[2].xyz().normalized());
         }
 
+        /**
+         * @brief 3D translation part of the matrix
+         *
+         * First three elements of last column.
+         * @see translation(const Vector3&), Matrix3::translation()
+         */
+        inline Vector3<T>& translation() {
+            return (*this)[3].xyz();
+        }
+
+        /** @overload */
+        inline constexpr Vector3<T> translation() const {
+            return (*this)[3].xyz();
+        }
+
         MAGNUM_MATRIX_SUBCLASS_IMPLEMENTATION(Matrix4, Vector4, 4)
         MAGNUM_RECTANGULARMATRIX_SUBCLASS_OPERATOR_IMPLEMENTATION(4, 4, Matrix4<T>)
 };

src/Math/Test/Matrix3Test.cpp

@@ -38,6 +38,7 @@ Matrix3Test::Matrix3Test() {
              &Matrix3Test::rotation,
              &Matrix3Test::rotationScalingPart,
              &Matrix3Test::rotationPart,
+             &Matrix3Test::translationPart,
              &Matrix3Test::debug,
              &Matrix3Test::configuration);
 }
@@ -122,6 +123,14 @@ void Matrix3Test::rotationPart() {
     CORRADE_COMPARE(rotationTransformed.rotation(), expectedRotationPart);
 }
 
+void Matrix3Test::translationPart() {
+    Matrix3 m(1.0f, 0.0f, 0.0f,
+              0.0f, 1.0f, 0.0f,
+              -5.0f, 12.0f, 1.0f);
+    Vector2 expected(-5.0f, 12.0f);
+    CORRADE_COMPARE(m.translation(), expected);
+}
+
 void Matrix3Test::debug() {
     Matrix3 m(
         3.0f, 5.0f, 8.0f,

src/Math/Test/Matrix3Test.h

@@ -30,6 +30,7 @@ class Matrix3Test: public Corrade::TestSuite::Tester<Matrix3Test> {
         void rotation();
         void rotationScalingPart();
         void rotationPart();
+        void translationPart();
 
         void debug();
         void configuration();

src/Math/Test/Matrix4Test.cpp

@@ -38,6 +38,7 @@ Matrix4Test::Matrix4Test() {
              &Matrix4Test::rotation,
              &Matrix4Test::rotationScalingPart,
              &Matrix4Test::rotationPart,
+             &Matrix4Test::translationPart,
              &Matrix4Test::debug,
              &Matrix4Test::configuration);
 }
@@ -135,6 +136,15 @@ void Matrix4Test::rotationPart() {
     CORRADE_COMPARE(rotationTransformed.rotation(), expectedRotationPart);
 }
 
+void Matrix4Test::translationPart() {
+    Matrix4 m(1.0f, 0.0f, 0.0f, 0.0f,
+              0.0f, 1.0f, 0.0f, 0.0f,
+              0.0f, 0.0f, 1.0f, 0.0f,
+              -5.0f, 12.0f, 0.5f, 1.0f);
+    Vector3 expected(-5.0f, 12.0f, 0.5f);
+    CORRADE_COMPARE(m.translation(), expected);
+}
+
 void Matrix4Test::debug() {
     Matrix4 m(
         3.0f, 5.0f, 8.0f, 4.0f,

src/Math/Test/Matrix4Test.h

@@ -30,6 +30,7 @@ class Matrix4Test: public Corrade::TestSuite::Tester<Matrix4Test> {
         void rotation();
         void rotationScalingPart();
         void rotationPart();
+        void translationPart();
 
         void debug();
         void configuration();