Arc
Arc feature attributes are attributes with a two-dimensional value-type (PointGroup) and at least two coordinates for each entry in the domain-unit.
Arc attributes are used as feature attribute for vector-data.
The points in the correct sequence define an arc, a line between a start point, zero or more intermediates and an end point. Arc attributes are often used for geographic coordinates of roads, railways, rivers etc.
To make the GeoDMS aware that a sequence of coordinates need to be interpreted as an arc, this is done by configuring the composition type to arc.
example
The following example shows the configuration of a domain-unit road, in which each road is represented by one arc. The data is read from an esri-shapefile with gdal.vect.
unit<uint32> road
: StorageName = "%SourceDataDir%/OSM/road.shp"
, StorageType = "gdal.vect"
{
attribute<point_rd> geometry (arc);
attribute<string> name;
}