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);
}
public FeatureSet Analysis(IFeatureSet featureSet, double[] envelope = null)
{
if (featureSet.FeatureType != FeatureType.Point)
{
return(null);
}
var geoPoints =
featureSet
.Features
.Select(e => (GeoPoint)(e
.Geometry
.BasicGeometry)
)
.ToList();
if (geoPoints.Count == 0)
{
return(null);
}
var firstPoint = geoPoints[0];
envelope ??= new double[4]
{
firstPoint.X, firstPoint.Y, firstPoint.X, firstPoint.Y
};
if (envelope.Length != 4)
{
throw new Exception(nameof(envelope) + "的长度必须为4");
}
foreach (var geoPoint in geoPoints)
{
if (geoPoint.X < envelope[0])
{
envelope[0] = geoPoint.X;
}
else if (geoPoint.X > envelope[2])
{
envelope[2] = geoPoint.X;
}
if (geoPoint.Y < envelope[1])
{
envelope[1] = geoPoint.Y;
}
else if (geoPoint.Y > envelope[3])
{
envelope[3] = geoPoint.Y;
}
}
envelope[0] -= EnvelopeEpsilon;
envelope[1] -= EnvelopeEpsilon;
envelope[2] += EnvelopeEpsilon;
envelope[3] += EnvelopeEpsilon;
var tysons = VoronoiBuilder
.BuildCellWithIndex(geoPoints, envelope);
var originTables = featureSet.AttrTable;
var originRows = originTables.Rows;
var polygonFeatureSet = new FeatureSet(FeatureType.Polygon);
var attrTable = originTables.Clone();
var attrTableRows = attrTable.Rows;
var cols = attrTable.Columns.Count;
foreach (var polygon in tysons)
{
IGeometry geometry = new Geometry(polygon.Value);
polygonFeatureSet.Features.Add(new CoreSpatial.Feature(geometry));
var newRow = attrTable.NewRow();
var oldRow = originRows[polygon.Key];
for (int i = 0; i < cols; i++)
{
newRow[i] = oldRow[i];
}
attrTableRows.Add(newRow);
}
polygonFeatureSet.AttrTable = attrTable;
return(polygonFeatureSet);
}