[mkgmap-dev] Wrong_route_calculation / strange straight routing lines on GPS

Thu Jan 29 10:46:52 GMT 2009

On Jan 28, 2009, at 23:10, Gert Münzel wrote:
> making my first steps with mkgmap that, although the routing works  
> fine in Mapsource, i get in trouble on my Gps unit Garmin gmap60csx.  
> Very often i got these strange straight magenta routing lines in  
> between normal routing.
> Meanwhile i figured out that it seems to be that t has something to  
> do with the length of a polyline. I don't know if it is the count of  
> points/nodes of the polyline or still the lenght or both.
> But comparing the same mp-file once compiled with mkgmap, once with  
> cgpsmapper i see, that cgpsmapper split these long lines during  
> mkgmap leave them like they are.

How did you compare the IMG files? Have you tried decompiling the  
broken IMG with test.display.*? Have you tried manually splitting the  
polylines in the .mp-file? Does it help?

My guess is that the problem lies with long polylines (in the .mp- 
file) that are split into several polylines (in the IMG) by mkgmap,  
which results in a road made up of several polylines.

But if I understand you correctly, maybe the problem is just with long  
polylines in the IMG file?

Cheers
Robert