P p2 = new P(r.minx()+2*(layer+1), r.miny()+2*(layer+1));
R r2 = new R(r.minx()+2*(layer+1), r.miny()+2*(layer+1),
r.maxx()-2*(layer+1), r.maxy()-2*(layer+1));
P p2 = new P(r.minx()+2*(layer+1), r.miny()+2*(layer+1));
R r2 = new R(r.minx()+2*(layer+1), r.miny()+2*(layer+1),
r.maxx()-2*(layer+1), r.maxy()-2*(layer+1));