WanMil escribió:

Am 12.02.2010 20:06, schrieb Carlos Dávila:

WanMil escribió:

Compiling Spain I get several warnings similar to the one below, that
point to data that are correct (or it seems to me).

|2010/02/12 09:26:39 ADVERTENCIA (MultiPolygonRelation):
63240004.osm.gz: Multipolygon
http://www.openstreetmap.org/browse/relation/319017 contains errors.
2010/02/12 09:26:39 ADVERTENCIA (MultiPolygonRelation): 63240004.osm.gz:
Polygon 4611686018427391078[5P : (44132028[5P]) carries role inner but
is not inside any outer polygon. Potentially it does not belong to this
multipolygon.

|Reported way (hole in the building) lacks in the resulting map.
Is it a know bug?
Another question, why are polygons so deformed in MapSource compared to
Mapnik?

Carlos,

the way http://www.openstreetmap.org/browse/way/44132028 overlaps the
outer way of multipolygon
http://www.openstreetmap.org/browse/relation/319017. If we look keenly
on the definition of the multipolygon relation
(http://wiki.openstreetmap.org/wiki/Relation:multipolygon) this is not
allowed. The current implementation of mkgmap does not support this.

Way 44132028 doesn't really overlap the outer polygon. They are
separated some 25 cm, but mkgmap seems to consider them overlapping.


~25cm is much below mkgmap resolution (I think so...)

I knew about ~4.7m garmin limit for routing, but didn't know such limit affected other things.

But it is widely used. There is a patch
(http://www.mkgmap.org.uk/pipermail/mkgmap-dev/2010q1/007086.html) which
is not yet committed and which fixes the problem. I think it will be
committed within the next days.

I'll test it and give feedback


Thanks! That will speed up the commit.

I'm not very fit with patches. I tried

patch -p 1 <
mp_linesoverlapping_v1.patch

within mkgmap root directory, but it didn't work

Hunk #1 FAILED at 38.

Hunk #2 FAILED at 397.

Hunk #3 FAILED at 407.

Hunk #4 FAILED at 494.

Hunk #5 FAILED at 509.

Hunk #6 FAILED at 648.

Hunk #7 FAILED at 671.

Hunk #8 FAILED at 698.

Hunk #9 FAILED at 843.

Hunk #10 FAILED at 945.

Hunk #11 FAILED at 1028.

Hunk #12 FAILED at 1071.

Hunk #13 FAILED at 1085.

Hunk #14 FAILED at 1119.

Hunk #15 FAILED at 1129.

Hunk #16 FAILED at 1171.

Hunk #17 FAILED at 1183.

Hunk #18 FAILED at 1227.

Hunk #19 FAILED at 1259.

Hunk #20 FAILED at 1442.

Hunk #21 FAILED at 1462.

21 out of 21 hunks FAILED

Can you give me some hint?

The deformations do not look good. I think the problem is that mkgmap
rounds the exact OSM coordinates to lower resolution garmin coordinates.

May it be also the origin of the overlapping problem in the above case?


Yes, propably.