Gpx Class

The reader reads GPX 1.1 and GPX 1.0, and returns one feature per wpt, rte and trk element, in the order of the document. A waypoint is a GeoPoint, a route is a GeoLineString of its rtept, and a track is a GeoMultiLineString with one line per trkseg, even when it has a single segment, so the type of the geometry tells a track from a route. The ele of a point becomes its GeoPosition.Altitude, and its time its GeoPosition.Time (UTC when the text has no offset). The name of the metadata (or of the gpx element in GPX 1.0) becomes GeoFeatureCollection.Name.

The properties of a feature are the Gpx.TypePropertyName property, wpt, rte or trk, and the elements name, cmt, desc, src and type as a String, the sym of a waypoint as a String, the number of a route or a track as a Double, and the time of a waypoint as a DateTimeOffset, also kept as the time of its position. The other elements are ignored: link (url in GPX 1.0), extensions (such as the heart rate or the cadence of a Garmin device), the other data of a waypoint (magvar, fix, hdop…), the metadata other than its name, and every element of the points of the routes and tracks except ele and time. The features have no GeoFeature.Id.

The writer writes GPX 1.1. A GeoPoint is a wpt, a GeoMultiPoint is one wpt per point, a GeoLineString is a rte, and a GeoMultiLineString is a trk with one trkseg per line, as the reader returns them and as GDAL writes them. When the Gpx.TypePropertyName property is trk, a GeoLineString is a track of one segment; when it is rte, a GeoMultiLineString is one route per line. As GPX requires, the waypoints come first, then the routes, then the tracks. The altitude and the time of each position are its ele and time, the time in UTC. The writer writes the properties named after the elements the reader reads, as their text; the time property of a waypoint whose position has no time is written in UTC when it is a DateTimeOffset, a DateTime or a text that is a date, and the number when it is a non-negative integer. The measures are not written. The other properties and the identifiers are not written, as GPX has no element for them.