A router point is a location on the network. Usually a router point is the result of snapping a location to the closest edge.
Image 1: A visualisation of the routerpoint concept.
In Itinero, the process of snapping a location to the closest edge is called resolving that location. You can resolve a location using the Router:
// snaps the given location to the nearest routable edge. var routerPoint = router.Resolve(profile, 51.26797020271655f, 4.801905155181885f);
Usually a routerpoint is resolved with a given Profile in mind, making sure the routerpoint is accessible and not snapping to another closer edge, think about a cylepath next to a road.
We introduced this concept to give applications using Itinero full control over this part of the routing process. There are two main motivations for this:
The routing algorithm can be so fast that the resolving process takes up a signficant part of the time when calculating a route. Routerpoints make it possible to cache the result, use a faster but less accurate resolving algorithm in one application, a slower but better one in another.
It's often not obvious where to start a route, just given the lat/lon. Just taking the closest street is sometimes not good enough, perhaps the snapping of a location to the network can depend on the streetname.
What to read next?
Learn more about the Router concept.