[mkgmap-dev] Incorrect multipolygon warnings?

Sun Mar 28 20:36:41 BST 2010

WanMil escribió:
> Am 28.03.2010 17:24, schrieb Carlos Dávila:
>   
>> WanMil escribió:
>>     
>>>> Hi,
>>>>
>>>> Whilst processing Italy, I've been getting a lot of mp warnings like:
>>>> 2010/03/27 13:57:27 WARNING (MultiPolygonRelation): 63242013.osm.gz:
>>>> Polygon 4611686018427439638 intersects itself. It is splitted into 2
>>>> polygons.
>>>> 2010/03/27 13:57:27 WARNING (MultiPolygonRelation): 63242013.osm.gz: The
>>>> polygon is composed of
>>>> 2010/03/27 13:57:27 WARNING (MultiPolygonRelation): 63242013.osm.gz: -
>>>> http://www.openstreetmap.org/browse/way/36433060
>>>>
>>>> I can't see anything wrong with this mp and the JOSM validator does not
>>>> pick up on anything.  Is this an error with mkgmap's MP code or am I
>>>> missing something?
>>>>
>>>>         
>>> Yes and no. While reading in the data from osm files mkgmap converts all
>>> coordinates to the garmin internal format. This reduces the resolution
>>> of the coordinates. So the multipolygon code works with other
>>> coordinates than OSM. Due to this a polygon might intersect itself
>>> although it does not in the original OSM data.
>>>
>>>
>>>       
>>>> Here's another:
>>>> 2010/03/27 13:57:27 WARNING (MultiPolygonRelation): 63242013.osm.gz:
>>>> Polygon 4611686018427439886 intersects itself. It is splitted into 2
>>>> polygons.
>>>> 2010/03/27 13:57:27 WARNING (MultiPolygonRelation): 63242013.osm.gz: The
>>>> polygon is composed of
>>>> 2010/03/27 13:57:27 WARNING (MultiPolygonRelation): 63242013.osm.gz: -
>>>> http://www.openstreetmap.org/browse/way/36434237
>>>>         
>> I also have a mp warning in which I can't see any error:
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> Cannot join the following ways to closed polygons. Multipolygon
>> http://www.openstreetmap.org/browse/relation/2909
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> - way: http://www.openstreetmap.org/browse/way/52489521
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> - way: http://www.openstreetmap.org/browse/way/4889739
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> - way: http://www.openstreetmap.org/browse/way/11276547
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> - way: http://www.openstreetmap.org/browse/way/11276563
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> - way: http://www.openstreetmap.org/browse/way/52288870
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> - way: http://www.openstreetmap.org/browse/way/52288868
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> - way: http://www.openstreetmap.org/browse/way/51442603
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> - way: http://www.openstreetmap.org/browse/way/11276562
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> - way: http://www.openstreetmap.org/browse/way/52489071
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> - way: http://www.openstreetmap.org/browse/way/52489520
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> - way: http://www.openstreetmap.org/browse/way/52489515
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> - way: http://www.openstreetmap.org/browse/way/4889860
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> - way: http://www.openstreetmap.org/browse/way/4889776
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> - way: http://www.openstreetmap.org/browse/way/4889848
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> - way: http://www.openstreetmap.org/browse/way/4889700
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> - way: http://www.openstreetmap.org/browse/way/51334155
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> - way: http://www.openstreetmap.org/browse/way/4889699
>> 2010/03/28 14:32:08 ADVERTENCIA (MultiPolygonRelation): 63240002.osm.gz:
>> Multipolygon http://www.openstreetmap.org/browse/relation/2909 does not
>> contain any way tagged with role=outer or empty role
>>
>> If I check relation 2909 in JOSM it does have lots of ways tagged with
>> role outer and they are connected in a closed polygon, apparently in the
>> right order. Do you have any clue? May it be a
>> clockwise/counterclockwise issue?
>>     
>
> Clockwise/Counterclockwise does not make any difference.
> Probably this is a tile splitter problem and therefore the multipolygon 
> is not completely cotainted in the tile.
Not a tile problem, but I've realized this mp is cut by geofabrik (it's 
in Spain/Portugal border). It is correctly processed when I compile full 
Iberian Peninsula map (from Europe excerpt), not just Spain or Portugal. 
Is there any workaround for these cases? (I have a lot more in 
Spain/France border).