How to find the closest point on a street?

Open Source Routing Engine
1

Hi there!

How can I find the closest point (from another one) on a street? When you calculate a route using GraphHopper, it finds the closest point (from the start point of the route) such that it is on a street, so how can I do that?

Thanks in advance…

2

GraphHopper does that in the LocationIndex.

3

Yes, I know I can do this:

QueryResult rua = hopper.getLocationIndex().findClosest(latitude, longitude, EdgeFilter.ALL_EDGES);

but how can I use QueryResult to get the closest point? Thanks for the replay.

4

Have you looked into the QueryResult class? It contains many properties, like the closest edge, node, and also coordinates of the snapped position.

5

What exactly is that “closest edge”?
I tried:
EdgeIteratorState edge = qr.getClosestEdge();
PointList ghPoint3DS = edge.fetchWayGeometry(0);
for (int i = 0; i < ghPoint3DS.size(); i++) {
System.out.println("got point " + i + " along: " + ghPoint3DS.getLat(i) + ", " + ghPoint3DS.getLon(i));
}
But that does not give points along the closest road or way or similar. That gives points on a line a few Meters away on some way ca.50m away from the closest way.

6

And is there some Javadoc page?
I am missing the documentation of the classes and methods of Graphhopper.