Show geodesic path between two points

Calculate a geodesic path between two points and measure its distance.

Use case

A geodesic distance provides an accurate, real-world distance between two points. Visualizing flight paths between cities is a common example of a geodesic operation since the flight path between two airports takes into account the curvature of the earth, rather than following the planar path between those points, which appears as a straight line on a projected map.

How to use the sample

Click anywhere on the map. A line graphic will display the geodesic line between the two points. In addition, text that indicates the geodesic distance between the two points will be updated. Click elsewhere and a new line will be created.

How it works

1. Create a Point and display it as a Graphic when the MapView is tapped.
2. Obtain a new point when another tap occurs on the MapView and add this point as a graphic.
3. Create a Polyline from the two points.
4. Execute GeometryEngine.geodeticDensify(_:maxSegmentLength:lengthUnit:curveType:) by passing in the created polyline then create a graphic from the returned Geometry.
5. Execute GeometryEngine.geodeticDistance(from:to:distanceUnit:azimuthUnit:curveType:) by passing in the two points and display the returned length on the screen.

Relevant API

• GeometryEngine.geodeticDensify(_:maxSegmentLength:lengthUnit:curveType:)
• GeometryEngine.geodeticDistance(from:to:distanceUnit:azimuthUnit:curveType:)
• MapView.onSingleTapGesture(perform:)

About the data

The Imagery basemap provides the global context for the displayed geodesic line.

Tags

densify, distance, geodesic, geodetic