*/
public boolean addSegment(){
boolean ok = false;
if (elements.size() <= positions.size()-1){
Segment segment = new Segment(positions.get(indexElement), positions.get(indexElement+1));
segment.calculerLongueur();
this.elements.add(segment);
ok = true;
//System.out.println("Segment ajout� depuis : " + positions.get(indexElement).x + "/" + positions.get(indexElement).y);
indexElement++;
}