[mkgmap-dev] gpx track files do not work on routable maps

Thu Mar 8 14:00:50 GMT 2012

2012/3/8 Marko Mäkelä <marko.makela at iki.fi>:
...

Yes the Edge has an amazing GPS chip. Very sensitive and accurate.

Anyway, I have done further testing with the style file, and it has
indeed an influence on the way the Edge is able to do navigation over
GPX files. I created a theoretical style file with only a lines file
(I created the other style files but left them empty).
My lines file contains two sections: one for route names (as found in
the style cyclemap) and only one line for roads:

 # Roads
highway=*		[0x01 resolution 8]

This is of course an overkill and the Edge takes a while to draw all
the lines at low scale. But navigation on the
http://www.bikemap.net/route/392706 GPX track is almost perfectly
accurate. On the other hand, if I increase the resolution value, then
I start to see more and more breakages (pink lines of death). Thus
lines style is paramount for the navigation algorithm. I am curious
why this is happening? I always thought that navigation was relying on
NOD information, which should be (?) independent from the way the map
is displayed at various scales. Any idea?

Kind regards,
Eric