stepBefore method

List<Offset> stepBefore()

返回其 step图形样式(before)坐标点

Implementation

List<Offset> stepBefore() {
  if (_pointList.length <= 1) {
    return [..._pointList];
  }
  int n = _pointList.length - 1;
  List<Offset> list = [];
  for (int i = 0; i < n; i++) {
    Offset cur = _pointList[i];
    Offset next = _pointList[i + 1];
    list.add(cur);
    list.add(Offset(cur.dx, next.dy));
  }
  list.add(_pointList[n]);
  return list;
}