public void UpdateField(BitArray updated, int upPiece, int downPiece)
{
if (updated == null && Field != null)
Redraw = true;
else if (updated != null && Field == null)
Redraw = true;
else if (updated != null && (Up != upPiece || Down != downPiece || !updated.Compare(Field)))
Redraw = true;
Field = (updated != null) ? new BitArray(updated) : null;
Up = upPiece;
Down = downPiece;
Invalidate();
}