case CONSTRAIN_ENDEND:
                                if ($c1[1] < $c2[1]) {
                                    $link = new Image\GanttLink($c1[2], $c1[3], $c2[2], $c2[1]);
                                } else {
                                    $link = new Image\GanttLink($c1[2], $c1[1], $c2[2], $c2[3]);