1°) Selection of the graphical entities owned by the contour.

To increase the ergonomics all entities can be selected before launching the commands mentioned above.

The selection must be done in sequence.

Closed and simple entities cannot be mixed. (example : circle + lines).

Pushing the spacebar ends the step, leaving the contour opened. Double click or simple click on an already stored entitie ends the contour.

2°) Junctions selection.

The entities of the contour can be disjoined or secant.
The result depend on mouse position, click when the wanted shape appears.