/// <summary>
/// 一个点是否在复杂多边形内部（点选是否选中了复杂多边形）
/// </summary>
/// <param name="point"></param>
/// <param name="multipolygon"></param>
/// <returns></returns>
static public bool IsPointInMultiPolygon(PointD point, MultiPolygon multipolygon)
{
if (!IsPointInRect(point, multipolygon.MBR))
{
return(false);
}
int spolygonCount = multipolygon.Count;
int sInterLineNum = 0;
//循环对每个polygon求交点并计算交点总数
for (int i = 0; i < spolygonCount; i++)
{
Polygon mpolygon = multipolygon.GetPolygon(i);
int sCount = mpolygon.Count;
PointD sP1 = new PointD();
PointD sP2 = new PointD();
for (int j = 0; j < sCount - 1; j++)
{
sP1 = mpolygon.GetPoint(j);
sP2 = mpolygon.GetPoint(j + 1);
if (IsRayInterLine(point, sP1, sP2))
{
sInterLineNum++;
}
}
if (IsRayInterLine(point, mpolygon.GetPoint(0), mpolygon.GetPoint(sCount - 1)))
{
sInterLineNum++;
}
}
return(sInterLineNum % 2 == 1);
}
/// <summary>
/// 判断复杂多边形是否位于矩形盒内(框选是否选中复杂多边形）
/// </summary>
/// <param name="multipolygon"></param>
/// <param name="rect"></param>
/// <returns></returns>
static public bool IsRectInterMultipolygon(MultiPolygon multipolygon, RectangleD rect)
{
//判断外包矩形与矩形框是否相交
if (IsMBRInterRect(multipolygon.MBR, rect) == false)
{
return(false);
}
//先判断是否有点在矩形框内
int spolygonCount = multipolygon.Count;
for (int i = 0; i < spolygonCount; i++)
{
Polygon spolygon = multipolygon.GetPolygon(i);
int sCount = spolygon.Count;
for (int j = 0; j < sCount; j++)
{
if (IsPointInRect(spolygon.GetPoint(j), rect))
{
return(true);
}
}
}
//判断矩形框点是否在复杂多边形内
if (IsPointInMultiPolygon(new PointD(rect.MaxX, rect.MaxY), multipolygon))
{
return(true);
}
if (IsPointInMultiPolygon(new PointD(rect.MaxX, rect.MinY), multipolygon))
{
return(true);
}
if (IsPointInMultiPolygon(new PointD(rect.MinX, rect.MaxY), multipolygon))
{
return(true);
}
if (IsPointInMultiPolygon(new PointD(rect.MinX, rect.MinY), multipolygon))
{
return(true);
}
//接着判断复杂多边形的边是否与矩形框相交
//循环对每个polygon的每条边做求交判断
for (int i = 0; i < spolygonCount; i++)
{
Polygon mpolygon = multipolygon.GetPolygon(i);
int sCount = mpolygon.Count;
for (int j = 0; j < sCount - 1; j++)
{
if (IsLineInterLine(mpolygon.GetPoint(j), mpolygon.GetPoint(j + 1), new PointD(rect.MaxX, rect.MaxY), new PointD(rect.MaxX, rect.MinY)))
{
return(true);
}
if (IsLineInterLine(mpolygon.GetPoint(j), mpolygon.GetPoint(j + 1), new PointD(rect.MaxX, rect.MaxY), new PointD(rect.MinX, rect.MaxY)))
{
return(true);
}
if (IsLineInterLine(mpolygon.GetPoint(j), mpolygon.GetPoint(j + 1), new PointD(rect.MinX, rect.MaxY), new PointD(rect.MinX, rect.MinY)))
{
return(true);
}
if (IsLineInterLine(mpolygon.GetPoint(j), mpolygon.GetPoint(j + 1), new PointD(rect.MinX, rect.MinY), new PointD(rect.MaxX, rect.MinY)))
{
return(true);
}
}
//判断最后一个顶点与起始点组成的边是否与矩形盒相交
if (IsLineInterLine(mpolygon.GetPoint(0), mpolygon.GetPoint(sCount - 1), new PointD(rect.MaxX, rect.MaxY), new PointD(rect.MaxX, rect.MinY)))
{
return(true);
}
if (IsLineInterLine(mpolygon.GetPoint(0), mpolygon.GetPoint(sCount - 1), new PointD(rect.MaxX, rect.MaxY), new PointD(rect.MinX, rect.MaxY)))
{
return(true);
}
if (IsLineInterLine(mpolygon.GetPoint(0), mpolygon.GetPoint(sCount - 1), new PointD(rect.MinX, rect.MaxY), new PointD(rect.MinX, rect.MinY)))
{
return(true);
}
if (IsLineInterLine(mpolygon.GetPoint(0), mpolygon.GetPoint(sCount - 1), new PointD(rect.MinX, rect.MinY), new PointD(rect.MaxX, rect.MinY)))
{
return(true);
}
}
//其他
return(false);
}