[mkgmap-dev] Inter-tile routing now available in trunk

Thu Feb 19 12:18:37 GMT 2009

On Thu, Feb 19, 2009 at 12:19 PM, Robert Vollmert
<rvollmert-lists at gmx.net> wrote:
>
> If you shift this additional point towards the destination, is there a
> specific point where it starts going wrong?

It seems that as I approach or cross the boundary to the last tile,
the route starts to go wrong (the route crosses four tiles in total).

I will try to create a better test case, which can be more easily reproduced.

So far the behaviour seems to be as follows:

1. If the additional point is well inside the second-last tile, the
route is calculated correctly.

2. If the additional point is close to the tile boundaries of the last
and second-last tiles, the route is calculated as two straight lines.

3. If the additional point is well inside the last tile, the route is
a straight line from the start to the additional point, but the route
is calculated correctly from the additional point to the destination.

> One possibility is that the routes are just getting too long. I remember
> somebody saying there's a limit on the number of legs when routing using
> Garmin units.

I tested the same route on a map created with cGPSmapper which was
produced with similar, but older OSM data (available here:
http://emexes.powweb.com/osm/). In this case, the route was calculated
correctly. I am however not sure what can be deduced from this
observation.

Thanks again!