Arc - ObjectVision/GeoDMS GitHub Wiki
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.
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;
}