/// <summary>
/// 求父区间与若干子集并集的差集
/// </summary>
/// <param name="total">父集</param>
/// <param name="source">子集集合</param>
/// <returns>差集集合</returns>
public static List <RoadInterval> InverseInterval(RoadInterval total, List <RoadInterval> source)
{
List <RoadInterval> result = new List <RoadInterval>();
List <RoadInterval> sortedSource = source.OrderBy(x => x.start).ToList();
if (source.Count == 0)
{
result.Add(total);
return(result);
}
if (total.start < sortedSource.First().start)
{
result.Add(new RoadInterval {
start = total.start, end = sortedSource[0].start
});
}
for (int i = 0; i < sortedSource.Count - 1; i++)
{
if (sortedSource[i].end < sortedSource[i + 1].start)
{
result.Add(new RoadInterval {
start = sortedSource[i].end, end = sortedSource[i + 1].start
});
}
}
if (total.end > sortedSource.Last().end)
{
result.Add(new RoadInterval {
start = sortedSource.Last().end, end = total.end
});
}
return(result);
}
/// <summary>
/// 获取曲线子集
/// </summary>
/// <param name="curve">曲线</param>
/// <param name="interval">曲线子集的长度区间</param>
/// <returns>曲线子集</returns>
public static Curve GetSubCurve(Curve curve, RoadInterval interval)
{
double start = curve.GetParamAtDist(interval.start);
double end = curve.GetParamAtDist(interval.end);
DBObjectCollection splits = curve.GetSplitCurves(new DoubleCollection(new double[] { start, end }));
if (splits.Count == 1 || interval.start == 0)
{
return(splits[0] as Curve);
}
else
{
return(splits[1] as Curve);
}
}