Geodesic operations

View in Github

Description

This sample demonstrates how to use AGSGeometryEngine to calculate a geodesic path between two points and measure its distance.

How it works

Geodesic calculations take into account the curvature of the Earth, while planar calculations are based on a 2D Cartesian plane. Visualizing flight paths between cities is a common example of a geodesic operation.

Steps:

1. Click on the map to select destination of a path from the origin JFK Airport, NY.
2. A line graphic will display the geodesic path between origin and destination.
3. The geodesic distance of the path will display in map view's callout.

In code:

1. Create an instance of AGSPolyline using two points.
2. Densify the Polyline using the geodeticDensifyGeometry(_:maxSegmentLength:lengthUnit:curveType:) method on AGSGeometryEngine. This method will return a geodetically densified geometry.
3. Set this geometry to a Graphic to display the geodesic path between two points in a Graphics Overlay.
4. Get the geodetic distance of the path using the geodeticLength(of:lengthUnit:curveType:) method on AGSGeometryEngine.