3. Subsequently click at the points where you want to place wall corners. Every click appends a linear segment to the wall you are drawing.
4. To append a curved segment, press the left mouse button at the point where the curved segment ends and then move the mouse with the button being
pressed. While moving you will see how the curving radius changes. To draw the circular segment, move the mouse exactly along the grid line. When done,
release the mouse button.