[GraphHopper] Geoposition of an edge

[Philipp Kraus]

Am 01.05.2014 um 13:47 schrieb Peter K <peathal at yahoo.de>:

> I have really no idea - what is l_position.intValue() - is this the
> edgeId?

Yes

> Also probably use fetchWayGeometry(2) which will include the
> junction nodes of the edge.


I have used 1 in fetchWayGeometry, with 2 it works better, but at the moment I get "back jumps" in driving
my car.

The problem is, that the orientation of the edge is different than I expect. For example I get a route like
o the nodes and - the samples (the samples depends on the length. 

1    2            3               4
o---o---------o-----------o

I iterate over the route edges  and so in this case I iterate from 1 to 4 and the samples from [0,samples).
Depend on this structure my cells are numerated with
o---o---------o-----------o
o 0 1 2 o  0 1 2 3 4 5 6 7 8 o 0 1 2 3 4 5 6 7 8 9 10 o

but on some edges the numbering is inverse to the orientation e.g.

o 0 1 2 o  8 7 6 5 4 3 2 1 0 o 0 1 2 3 4 5 6 7 8 9 10 o

so this structure creates an "back jump" on simulation.
To create the sampling of an edge I run these lines of code:

    public CCellCarLinkage(int p_id, double p_length) {
        m_edgeid = p_id;
        m_edgelength = p_length;
        m_cells = new ICar[(int) Math.floor(m_edgelength / CConfiguration.getInstance().get().CellSampling)];

        // create geopositions of the cells
        m_cellgeoposition = new GeoPosition[m_cells.length];
        EdgeIteratorState l_state = CGraphHopper.getInstance().getEdgeIterator(m_edgeid);
        PointList l_points = l_state.fetchWayGeometry(2);

        double l_latitudesize   = (l_points.getLatitude(l_points.size()-1) - l_points.getLatitude(0)) / m_cellgeoposition.length;
        double l_longitutesize  = (l_points.getLongitude(l_points.size()-1) - l_points.getLongitude(0)) / m_cellgeoposition.length;

        for(int i=0; i < m_cellgeoposition.length; i++)
            m_cellgeoposition[i] = new GeoPosition(l_latitudesize*i + l_points.getLatitude(0), l_longitutesize*i + l_points.getLongitude(0));
    }

So I need to swap the PointList based on the driving orientation on the route. Did you have any idea to create a correct orientation?

Thx

Phil