[mkgmap-dev] [PATCH] Inter-Tile routing - alpha code for testing

Tue Feb 17 20:47:39 GMT 2009

On Feb 17, 2009, at 19:35, Mark Burton wrote:
>> To test the inter-tile routing I used Mapsource (this has generally
>> been a reliable indicator of routing success), and first created a
>> simple route on an Autobahn within a tile. This worked correctly. I
>> then added to the route another point on the same Autobahn, not far
>> away, but across a tile boundary. Mapsource took longer to calculate
>> the route, but then added a straight line between the last two  
>> points,
>> instead of routing along the Autobahn.
>
> Hmm, your test sounds good but the result wasn't.
>
> I don't know if the boundary node code has ever actually been used
> before. Perhaps Steve or Robert can confirm whether it is known to  
> work
> or not.

It's very barely tested: I created two small .mp-files with boundary  
node data, where some of the boundary nodes were actual junction nodes  
and some weren't. I loaded the combined gmapsupp.img on my GPS, and  
routing across tile boundaries worked partially; it seemed to work  
fine in the vicinity of non-junction boundary nodes. I didn't test  
this with MapSource.

A first thing to do to confirm the patch does what it should would be  
to run two such tiles through test.display.NodDisplay and see if the  
NOD3-entries are what you'd expect. There should be one per boundary  
node. (Furthermore, the corresponding entries in NOD1 should have a  
flag set.)

Cheers
Robert