ReverseOrientation Method (IGeometryEngine)

In This Topic

Reverse the orientation of the geometry.

Syntax

C#
Visual Basic (Declaration)

Multipart ReverseOrientation( 
   Multipart multipart
)

Function ReverseOrientation( _
   ByVal multipart As Multipart _
) As Multipart

Parameters

multipart: The polygon or polyline whose orientation will be reversed.

Return Value

A geometry whose directionality has been reversed.

Exceptions

Exception	Description
System.ArgumentNullException	Multipart is null or empty.

Remarks

Geometry must be either a Polygon or a Polyline. ReverseOrientation changes the direction of the curve without changing the spatial position of the curve. The From Point and To Point of each Segment are interchanged.
Caution should be taken in using ReverseOrientation on Polygons. Since ReverseOrientation changes the direction of each Ring within the Polygon, all Exterior Rings become Interior Rings and vice versa.

GeometryEngine Reverse Orientation

Example

Reverse the order of points in a Polygon

List<Coordinate2D> list2D = new List<Coordinate2D>();
list2D.Add(new Coordinate2D(1.0, 1.0));
list2D.Add(new Coordinate2D(1.0, 2.0));
list2D.Add(new Coordinate2D(2.0, 2.0));
list2D.Add(new Coordinate2D(2.0, 1.0));

Polygon polygon = PolygonBuilderEx.CreatePolygon(list2D);

Geometry g = GeometryEngine.Instance.ReverseOrientation(polygon);
Polygon gPolygon = g as Polygon;

// gPolygon.Points[0] = 1.0, 1.0
// gPolygon.Points[1] = 2.0, 1.0
// gPolygon.Points[2] = 2.0, 2.0
// gPolygon.Points[3] = 1.0, 2.0
// gPolygon.Points[4] = 1.0, 1.0
// gPolygon.Area = -1 * polygon.Area

Requirements

Target Platforms: Windows 11, Windows 10, Windows 8.1

Reference

IGeometryEngine Interface
IGeometryEngine Members

Send feedback