Link
A Link is a topological LineString item that stores data regarding its topological relationship with other topological items.
A Link item is a sub-class of a LineString item that is created using Link (Topology > Build). A Link item has a Node item at each end.
Link items are also used to define the geometry of TopoLineString and TopoPolygon items, and can be created as a side-effect of creating TopoPolygon items.
Properties
- Automatic: _bAuto&
Was the Node item automatically created? Automatic Node items may be automatically deleted in future when associated Link items are edited or deleted. - Closed: _closed&
Does the geometry of the item form a closed loop? - Direction flags: _fDirection&
The restrictions on flow direction of a Link item. This affects the route finding algorithm. By default a Link item can be followed by the route finding algorithm in both directions.
0 (Both) = Two way, i.e. there are no direction restrictions.
1 (In) = One way, i.e. from start to end mode.
2 (Out) = Other way, i.e. reverse direction to "1 (In)" above.
3 (None) = Neither direction allowed, i.e. link cannot be routed along, it is closed. - End node: _id2&
The ID of the Node item at the end of the Link item. - Geometry class: _classGeom$
The C++ class used to store an item's geometry. This is handled automatically. You can see what precision an item's geometry is stored with by recognising the geometry classes. - Number of coverages: _nCoverage&
The number of "coverages" in which a Link is used. - Number of seeds: _nSeed&
The number of TopoPolygon or TopoLineString items of which this Link item forms part. - Number of vertices: _np&
The number of vertices in the item's geometry. - Seeds: _seeds$
The topological TopoLineString and TopoPolygon items which a Link item forms part of. - Start node: _id1&
The ID of the Node item at the start of the Link item.