GeoFenceIsPointInPolygon Method

Determine if the coordinate is inside the polygon.

Definition

Namespace: CoordinateSharp
Assembly: CoordinateSharp (in CoordinateSharp.dll) Version: 3.2.1.1
XMLNS for XAML: Not mapped to an xmlns.
C#
public bool IsPointInPolygon(
	Coordinate point
)

Parameters

point  Coordinate
Point to test

Return Value

Boolean
bool

Remarks

This method utilizes 2D ray casting techniques and does not inherently account for the curvature of the Earth. To mitigate the impact of Earth shape distortion on polygons or polylines that span long distances, users should employ densification. Points sitting on the edge of a polygon may return true or false.

Example

The following example shows how to determine if a coordinate is inside of a specified polygon.
C#
List<GeoFence.Point> points = new List<GeoFence.Point>();

//Points specified manually to create a square in the USA.
//First and last points should be identical if creating a polygon boundary.
points.Add(new GeoFence.Point(31.65, -106.52));
points.Add(new GeoFence.Point(31.65, -84.02));
points.Add(new GeoFence.Point(42.03, -84.02));
points.Add(new GeoFence.Point(42.03, -106.52));
points.Add(new GeoFence.Point(31.65, -106.52));

GeoFence gf = new GeoFence(points);

Coordinate c = new Coordinate(36.67, -101.51);

//Determine if Coordinate is within polygon
Console.WriteLine(gf.IsPointInPolygon(c)); //True (coordinate is within the polygon)

See Also