public static IGeometry InsertCurvePoint(IGeometry geometry, ICoordinate coordinate, int index)
{
var vertices = new List<ICoordinate>(geometry.Coordinates);
vertices.Insert(index, coordinate);
var geometryFactory = new GeometryFactory();
if (geometry is ILineString)
{
return geometryFactory.CreateLineString(vertices.ToArray());
}
if (geometry is IPolygon)
{
return geometryFactory.CreatePolygon(geometryFactory.CreateLinearRing(vertices.ToArray()), null);
}
return geometry.Union(geometryFactory.CreatePoint(coordinate));
}
public static IGeometry RemoveCurvePoint(IGeometry geometry, int index, bool keepLineStringEndPoints=false)
{
var vertices = new List<ICoordinate>(geometry.Coordinates);
vertices.RemoveAt(index);
var geometryFactory = new GeometryFactory();
var lastIndex = geometry.Coordinates.Length - 1;
if (geometry is ILineString)
{
if (vertices.Count < 2)
{
return null;
}
if (keepLineStringEndPoints && (index == 0 || index == lastIndex))
{
return null;
}
return geometryFactory.CreateLineString(vertices.ToArray());
}
if (geometry is IPolygon)
{
// If first or last index is removed -> remove corresponding duplicate at the other end and close the ring.
if (index == lastIndex)
{
vertices[0] = vertices[lastIndex];
}
if (index == 0)
{
vertices[lastIndex - 1] = vertices[0];
}
if (vertices.Count < 4)
{
return null;
}
return geometryFactory.CreatePolygon(geometryFactory.CreateLinearRing(vertices.ToArray()), null);
}
if (index < geometry.Coordinates.Length)
{
var coordinate = geometry.Coordinates[index];
var point = geometryFactory.CreatePoint(coordinate);
return geometry.Difference(point);
}
return geometry;
}
internal static LineString ToNTSLineString(Geometries.LineString lineString,
GeometryFactory factory)
{
Coordinate[] coordinates = new Coordinate[lineString.NumPoints];
int index = 0;
foreach (Point point in lineString.Vertices)
coordinates[index++] = ToNTSCoordinate(point, factory);
return factory.CreateLineString(coordinates) as LineString;
}