Implement GetRow, GetColumn, At methods for Mat2x2

src/J3ML/LinearAlgebra/Matrix2x2.cpp

@@ -2,4 +2,20 @@
 
 namespace LinearAlgebra {
 
+    Vector2 Matrix2x2::GetRow(int index) const {
+        float x = this->elems[index][0];
+        float y = this->elems[index][1];
+
+        return {x, y};
+    }
+
+    Vector2 Matrix2x2::GetColumn(int index) const {
+        float x = this->elems[0][index];
+        float y = this->elems[1][index];
+        return {x, y};
+    }
+
+    float Matrix2x2::At(int x, int y) const {
+        return this->elems[x][y];
+    }
 }