/// <summary>
/// 延长直线段
/// </summary>
/// <param name="type">延长类型：0都延长，1延长尾点，-1延长首点</param>
/// <param name="expandDis"></param>
/// <returns></returns>
public LineSegment Expand(int type, double expandDis)
{
switch (type)
{
case 0:
return(new LineSegment(BeginPoint.GetNextPoint(GetDirection() + Math.PI, expandDis),
EndPoint.GetNextPoint(GetDirection(), expandDis)));
case -1:
return(new LineSegment(BeginPoint.GetNextPoint(GetDirection() + Math.PI, expandDis), EndPoint));
case 1:
return(new LineSegment(BeginPoint, EndPoint.GetNextPoint(GetDirection(), expandDis)));
default:
break;
}
throw new ArgumentOutOfRangeException("扩展线段（LineSegment.Expand）时,出现了非法的延长类型");
}
/// <summary>
/// 根据指定方向和距离平移直线段
/// </summary>
/// <param name="radian"></param>
/// <param name="distance"></param>
public override void Move(double radian, double distance)
{
SetBeginPoint(BeginPoint.GetNextPoint(radian, distance));
SetEndPoint(EndPoint.GetNextPoint(radian, distance));
}