/// <summary>
/// 用于合并传进来的多边形数组，返回合并后的多边形数组，
/// 如果生成了孤岛，则孤岛的tag标志递增
/// </summary>
/// <param name="polys"></param>
/// <returns></returns>
public static PolyResCode UnionAllPolygon(ref List <Polygon> polys)
{
int tag = 1;
for (int i = 0; i < polys.Count; i++)
{
polys[i].CW();
}
for (int i = 1; i < polys.Count; i++)
{
Polygon p1 = polys[i];
for (int j = 1; j < polys.Count; j++)
{
Polygon p2 = polys[j];
if (i != j && !p1.Equals(p2))
{
List <Polygon> polyResult = new List <Polygon>();
PolyResCode result = p1.Union(p2, ref polyResult);
if (result == PolyResCode.Success && polyResult.Count > 0)
{
polys.Remove(p1);
polys.Remove(p2);
for (int k = 0; k < polyResult.Count; k++)
{
Polygon poly = polyResult[k];
if (/*polyResult.Count > 1 &&*/ !poly.IsCW())
{
poly.SetTag(tag++);//如果逆时针说明这个多边形是孤岛
}
polys.Add(poly);
}
i = -1;
break;
}
}
}
}
return(PolyResCode.Success);
}