[mkgmap-dev] [index] Automatic location completion

Wed Mar 2 17:35:30 GMT 2011

Am 02.03.2011 04:52, schrieb Scott Crosby:
>>> This boundary is open by the coast side, as many others (¿all?) in
>>> Spain. Something similar to the close-gaps in the sea generation could
>>> do the trick.
>>
>> That's not a nice job to do... We might continue the boundaries along
>> coastlines. This would be a job for a specialized BoundaryRelation class
>> that inherits from MultiPolygonRelation.
>>
>> I have finished my checks with Spain and the result is perplexing: The
>> splitted tiles do not contain any boundary tag. I have used splitter
>> r164. The .pbf file does contain them. So it seems to be a splitter bug
>> (or I have used it wrong).
>
> Ways that cross tile boundaries may be incomplete. When generating a
> tile, the splitter includes in each tile all of the nodes in the tile,
> all of the nodes within OVERLAP of the tile, and then any ways that
> use any of those nodes and finally any relations that use those ways
> or relations. If a way denoting a boundary has widely spaced nodes,
> where none occurs in the overlap region, the way will have a gap
> between the the last node in the region and the border. At present, it
> doesn't go back and 'fill in' missing nodes in those ways/relations,
> and it has never had that functionality. Doing that would require
> additional passes, but I think it could be added in a few days of
> work.
>
> Scott
>

I was too quick with my guess that the splitter removes all boundary 
tags. It was my wrong search statement. Sorry!

The real reason is, that multipolyong boundary definitions in Spain are 
tagged with type=boundary instead of type=multipolygon. Therefore the 
multipolygon algorithm does not handle them yet.

@list: Should mkgmap handle type=boundary in the same way 
type=multipolygon? I vote for that.

@Scott: I would be happy if there is a splitter option which ensures 
that all ways/relations are completely contained in a tile. That would 
improve the options we have to deal with the boundary information and 
would fix some multipolygon problems.

WanMil