[mkgmap-dev] tile takes very long time to generate

Mon Mar 15 12:08:28 GMT 2021

Hi Gerd

Some possible test cases:

Looking at the problems my code is detecting, the complicated cases are
when possible polygons share 2 or more end-points with other possibles;
for instance:

http://www.openstreetmap.org/relation/5329106

adjacent buildings, touching each other, are mapped as a complete set
of outers, using distinct ways.
In general there is no easy way to resolve this. In the simple case of
2 buildings together, after all the simple ways have been joined, there
are 4 ways between 2 points.

Another case is:

https://www.openstreetmap.org/relation/11093511

This is an outer area with an inner touching along part of the edge.
This can be resolved by looking at the roles except that the shared
edge uses the same way, which is repeated in the relation. Repeated
ways are removed when the MP relation is created.

Removing this de-dupe will probably causes other (invalid) relations
not to be resolvable.

The other class of problems I'm seeing is boundaries split across
tiles.

Ticker

On Mon, 2021-03-15 at 09:10 +0000, Gerd Petermann wrote:
> Hi Ticker,
> 
> OK, so I'll try to find a way to test this code. In the JOSM code
> there is a large collection of special cases which is used to test
> the validator. See
> https://josm.openstreetmap.de/browser/josm/trunk/nodist/data/multipol
> ygon.osm
> 
> I think about a similar file for mkgmap, I just have to find a good
> way to make the current code testable.
> 
> Gerd