public ShapeTileSimplex(ArrayList<PlaLineInt> p_line_arr){
  lines_list=p_line_arr;
  Collections.sort(lines_list);
}

public ShapeTileSimplex ( ArrayList < PlaLineInt > p_line_arr ) { lines_list = p_line_arr ; Collections . sort ( lines_list ) ; }
constructs a simplex from the directed lines in p_line_arr . the simplex will not be normalized . to get a normalized simplex use tileshape . get_instance careful , the arraylist is not copyed
