public void Buffer3()
{
var geometry = reader.Read(
@"LINESTRING(1250.7665 446.9385,1137.8786 170.4488,1136.3666106287267
166.74557327980631,1139.485009866369 125.36515638486206,1137.8786 121.7019)");
Assert.IsNotNull(geometry);
Assert.IsTrue(geometry.IsValid);
BufferParameters parameters = new BufferParameters()
{
EndCapStyle = EndCapStyle.Round
};
var curveBuilder = new OffsetCurveBuilder(
geometry.PrecisionModel, parameters);
var curveSetBuilder = new OffsetCurveSetBuilder(geometry, 5, curveBuilder);
var bufferSegStrList = curveSetBuilder.GetCurves();
Assert.AreEqual(1, bufferSegStrList.Count);
var segmentString = (NodedSegmentString)bufferSegStrList[0];
Assert.AreEqual(45, segmentString.Count);
for (var i = 0; i < segmentString.Coordinates.Length; i++)
{
var coord = segmentString.Coordinates[i];
Debug.WriteLine(String.Format("{1:R} {2:R}", i, coord.X, coord.Y));
}
}
public static IGeometry SingleSidedBufferCurve(IGeometry geom, double distance)
{
var bufParam = new BufferParameters();
bufParam.IsSingleSided = true;
var ocb = new OffsetCurveBuilder(
geom.Factory.PrecisionModel, bufParam
);
var pts = ocb.GetLineCurve(geom.Coordinates, distance);
var curve = geom.Factory.CreateLineString(pts);
return(curve);
}
private static IGeometry BuildCurveSet(IGeometry g, double dist, IBufferParameters bufParams)
{
// --- now construct curve
var ocb = new OffsetCurveBuilder(g.Factory.PrecisionModel, bufParams);
var ocsb = new OffsetCurveSetBuilder(g, dist, ocb);
var curves = ocsb.GetCurves();
var lines = new List <IGeometry>();
foreach (var ss in curves)
{
var pts = ss.Coordinates;
lines.Add(g.Factory.CreateLineString(pts));
}
IGeometry curve = g.Factory.BuildGeometry(lines);
return(curve);
}
/// <summary>
///
/// </summary>
/// <param name="inputGeom"></param>
/// <param name="distance"></param>
/// <param name="curveBuilder"></param>
public OffsetCurveSetBuilder(IGeometry inputGeom, double distance, OffsetCurveBuilder curveBuilder)
{
_inputGeom = inputGeom;
_distance = distance;
_curveBuilder = curveBuilder;
}
/// <summary>
///
/// </summary>
/// <param name="g"></param>
/// <param name="distance"></param>
/// <returns></returns>
public IGeometry Buffer(IGeometry g, double distance)
{
PrecisionModel precisionModel = workingPrecisionModel;
if (precisionModel == null)
precisionModel = new PrecisionModel(g.PrecisionModel);
// factory must be the same as the one used by the input
geomFact = g.Factory;
OffsetCurveBuilder curveBuilder = new OffsetCurveBuilder(precisionModel, quadrantSegments);
curveBuilder.EndCapStyle = endCapStyle;
OffsetCurveSetBuilder curveSetBuilder = new OffsetCurveSetBuilder(g, distance, curveBuilder);
IList bufferSegStrList = curveSetBuilder.GetCurves();
// short-circuit test
if (bufferSegStrList.Count <= 0)
{
IGeometry emptyGeom = geomFact.CreateGeometryCollection(new Geometry[0]);
return emptyGeom;
}
ComputeNodedEdges(bufferSegStrList, precisionModel);
graph = new PlanarGraph(new OverlayNodeFactory());
graph.AddEdges(edgeList.Edges);
IList subgraphList = CreateSubgraphs(graph);
PolygonBuilder polyBuilder = new PolygonBuilder(geomFact);
BuildSubgraphs(subgraphList, polyBuilder);
IList resultPolyList = polyBuilder.Polygons;
IGeometry resultGeom = geomFact.BuildGeometry(resultPolyList);
return resultGeom;
}
