/// <summary>
/// ↑
/// | 0110 | 0010 | 1010
/// | 6 | 2 | 10
/// | -------|-------|--------
/// | 0100 | 0000 | 1000
/// | 4 | 0 | 8
/// | -------|-------|--------
/// | 0101 | 0001 | 1001
/// | 5 | 1 | 9
/// ---------------------------------→
/// </summary>
/// <param name="pt"></param>
/// <returns></returns>
int PointPosition(TysonGeoPoint pt)
{
var code1 = "00";
var code2 = "00";
if (pt.X <= Envelope[0])
{
code1 = "01";
}
else if (pt.X >= Envelope[2])
{
code1 = "10";
}
if (pt.Y <= Envelope[1])
{
code2 = "01";
}
else if (pt.Y >= Envelope[3])
{
code2 = "10";
}
return(Convert.ToInt32(code1 + code2, 2));
}
/// <summary>
/// 边界点类型，不检测角点
/// </summary>
/// <param name="pt"></param>
/// <param name="xieLv"></param>
/// <returns></returns>
EdgePointType CheckEdgePointType(TysonGeoPoint pt, double xieLv)
{
if (pt.EdgePointType != EdgePointType.NotCalc)
{
return(pt.EdgePointType);
}
EdgePointType type;
var pos = PointPosition(pt);
//内部
if (pos == 0)
{
type = EdgePointType.Inner;
}
//下部
else if (pos == 1)
{
type = EdgePointType.MinY;
}
//上部
else if (pos == 2)
{
type = EdgePointType.MaxY;
}
//左部
else if (pos == 4)
{
type = EdgePointType.MinX;
}
//右部
else if (pos == 8)
{
type = EdgePointType.MaxX;
}
else
{
if (pos == 5)
{
type = Pos5EdgePointType(pt, xieLv);
}
else if (pos == 6)
{
type = Pos6EdgePointType(pt, xieLv);
}
else if (pos == 9)
{
type = Pos9EdgePointType(pt, xieLv);
}
else //if (pos == 10)
{
type = Pos10EdgePointType(pt, xieLv);
}
}
pt.EdgePointType = type;
return(type);
}
EdgePointType Pos9EdgePointType(TysonGeoPoint pt, double oLineXieLv)
{
var xieLv = MathUtil.GetXieLv(pt, _rbPt);
if (xieLv > oLineXieLv)
{
return(EdgePointType.MinY);
}
else
{
return(EdgePointType.MaxX);
}
}
/// <summary>
/// 根据起点、重点和中间点构建多个线段
/// </summary>
/// <param name="innerPoints"></param>
/// <param name="start"></param>
/// <param name="end"></param>
/// <returns></returns>
List <GraphEdge> InsertPoint(IEnumerable <TysonGeoPoint> innerPoints,
TysonGeoPoint start, TysonGeoPoint end)
{
var lastPt = start;
var result = new List <GraphEdge>();
foreach (var innerPoint in innerPoints)
{
result.Add(new GraphEdge(lastPt, innerPoint));
lastPt = innerPoint;
}
result.Add(new GraphEdge(lastPt, end));
return(result);
}
/// <summary>
/// 边界点类型，检测角点
/// </summary>
/// <param name="pt"></param>
/// <returns></returns>
EdgePointType CheckEdgePointTypeWithCorner(TysonGeoPoint pt)
{
var xPos = PositionX(pt.X);
var yPos = PositionY(pt.Y);
if (xPos == -1)
{
if (yPos == -1)
{
return(EdgePointType.MinXMinY);
}
else if (yPos == 1)
{
return(EdgePointType.MinXMaxY);
}
return(EdgePointType.MinX);
}
else if (xPos == 1)
{
if (yPos == -1)
{
return(EdgePointType.MaxXMinY);
}
else if (yPos == 1)
{
return(EdgePointType.MaxXMaxY);
}
return(EdgePointType.MaxX);
}
else
{
if (yPos == -1)
{
return(EdgePointType.MinY);
}
else if (yPos == 1)
{
return(EdgePointType.MaxY);
}
else
{
return(EdgePointType.Inner);
}
}
}
public Dictionary <TysonGeoPoint, List <TysonGeoPoint> > Build(
List <TysonGeoPoint> points,
double[] envelope)
{
Envelope = envelope;
var ge = VoronoiBuilder.BuildLine(points, envelope);
//x→，y↑
_lbPt = new TysonGeoPoint(Envelope[0], Envelope[1]);
_ltPt = new TysonGeoPoint(Envelope[0], Envelope[3]);
_rbPt = new TysonGeoPoint(Envelope[2], Envelope[1]);
_rtPt = new TysonGeoPoint(Envelope[2], Envelope[3]);
var pointWithLines
= new Dictionary <int, List <GraphEdge> >();
var edgeLines = new List <GraphEdge>();
void SafeAddToDict(int pointIndex, GraphEdge edgeLine)
{
if (pointWithLines.ContainsKey(pointIndex))
{
pointWithLines[pointIndex].Add(edgeLine);
}
else
{
pointWithLines.Add(pointIndex,
new List <GraphEdge>()
{
edgeLine
}
);
}
}
foreach (var graphEdge in ge)
{
SafeAddToDict(graphEdge.Point1Index, graphEdge);
SafeAddToDict(graphEdge.Point2Index, graphEdge);
edgeLines.Add(graphEdge);
}
//处理边界点
EdgePointHandle(points, edgeLines, pointWithLines);
//遍历所有的EdgeLine，生成Polygon
var pointPolygonDict = new Dictionary <TysonGeoPoint, List <TysonGeoPoint> >();
foreach (var kv in pointWithLines)
{
var edges = kv.Value;
var linearRing = BuildLinearRingWithEdgeLine(edges); //BuildLinearRing(edges);
if (linearRing != null)
{
pointPolygonDict.Add(
points[kv.Key],
linearRing
);
}
}
return(pointPolygonDict);
}