[mkgmap-dev] Questions related to practical usage of MKGMAP

Wed Jul 1 13:59:04 BST 2009

Hi Garvan,

> Hi.
> 
> I have a few questions related to MKGMAP that I could not find answers 
> to in the archives. My data source is mostly OpenStreetmap, but I used 
> gpsmapedit for editing and adding my own traces, so I am using mp format 
> files with the compiler. I am open to other suggestions on managing 
> data, but I need strong editing capabilities.
> 
> Q1.
> 
> I have about sixty roads where I get the severe warning:
> 
> SEVERE (RouteArc): Way ~212 contains an arc whose length is too big to 
> be encoded so the road will not be routable
> 
> As the warning gives no line number, I am at a loss to find the problem. 
> Does anybody know how I might locate these 60 roads? I tried sorting the 
> roads by number of points, but did not seem to find a match. Perhaps if 
> I calculated the length of each road segment, and sorted by length?

The message does give the way's name (~212), does that not help?

Basically, you're looking for roads (or ferry routes) that have
long(ish) distances between routing nodes. If you were using OSM input
instead of MP input, it would not be a problem because mkgmap
introduces fake nodes to avoid the long segments.

> 
> Q2.
> 
> In encoding sea polygons, I must split the polygons up so that they have 
> less than 256 points (I did this in gpsmapedit). When zooming in and 
> out, sometimes polygons show white lines in between, where the shape has 
> been optimized. It there a way to avoid this, or a better way to split 
> up large polygons? Is there a utility to help with this problem? I would 
> only need to do it once, so it does not matter if it is a convoluted 
> route to what I want.
> 

Sorry, don't know anything about polygons.

> Q3.
> 
> I would like to use road numbers as labels. In gpsmapedit you use the a 
> code like this ~[0X06]117 in the label for the road, but this did not 
> work in MKGMAP. Is there some other way to display road numbers?

A while back (when this topic was last discussed), I suggested that we
supported that syntax but no one seemed keen. Also, if my memory is
correct, someone posted a patch that allowed you to specify that labels
are rendered in a chosen style.

Cheers,

Mark