[mkgmap-dev] [PATCH v1] Speedup for mp

Wed Jan 20 19:54:35 GMT 2010

Am 20.01.2010 10:42, schrieb Chris-Hein Lunkhusen:
> WanMil schrieb:
>
>> This is caused by the new mp code. The methods contains(JoinedWay,
>> JoinedWay) and createContainsMatrix(..) are not optimal for large and
>> lots of polygons (both apply to Norway).
>
> And what about the realy large boundary MPs used in Germany
> and Netherlands (other areas use type=boundary for boundaries).
>
> Maybe we should internaly convert them to type=boundary
> so that they don't stress the MP code ?
>
> Chris
>
> [1]<http://wiki.openstreetmap.org/wiki/Relations/Proposed/Boundaries>
> [2]<http://www.openstreetmap.org/browse/relation/62781>  (land_area MP)
> [3]<http://www.openstreetmap.org/browse/relation/51477>  (maritime)
>

As Felix reports the first patch for the mp speed problems seems to work 
pretty well. There are some other things that might be improved in the 
mp code. So I don't fear large boundaries.

And I don't think that Germany is a big problem. It does not have so 
much islands :-)

Norway is a real "acid test" for this. I counted over 3000 polygons 
which seem to be separate islands. The squared number of polygons 
multiplied with the number of single way segments give a rough estimate 
of the complexity. So at the moment the number of polygons is the 
important number for speed considerations.

WanMil