[mkgmap-dev] Anti-island check confused; defined a monster multipolygon

Sat Feb 6 16:41:32 GMT 2010

Hi Mark,

> Hmm, I wonder if the test to see if an anti-island is contained within
> an island is failing if the anti-island reaches a tile edge.

That is a possibility.  It would not be the splitter tile edge, but the edge
of the Geofabrik extract.  The mapped coastline of lake Inari intersects with
the Finnish-Russian border (something that I was not aware of), and the
border polygons of Geofabrik can easily be a few km off.

> If you still have the same data, could you try modifying containsPointsOf()
> in Way.java so that it looks like this:
> 
> 	public boolean containsPointsOf(Way other) {
> 		Polygon thisPoly = new Polygon();
> 		for(Coord p : points)
> 			thisPoly.addPoint(p.getLongitude(), p.getLatitude());
> 		for(Coord p : other.points)
> 			if(thisPoly.contains(p.getLongitude(), p.getLatitude()))
> 				return true;
> 		return false;
> 	}
> 
> i.e. make it return true if any point is inside rather than all points
> are inside.

Done.  I get the very same warnings:

2010/02/06 18:37:01 WARNING (Osm5XmlHandler): 63240003.osm.gz: Converting anti-island starting at http://www.openstreetmap.org/?mlat=68.79379&mlon=27.95413&zoom=17 into an island as it is surrounded by water
2010/02/06 18:37:01 WARNING (Osm5XmlHandler): 63240003.osm.gz: Converting anti-island starting at http://www.openstreetmap.org/?mlat=69.41525&mlon=28.71751&zoom=17 into an island as it is surrounded by water
2010/02/06 18:37:02 WARNING (Osm5XmlHandler): 63240003.osm.gz: Converting anti-island starting at http://www.openstreetmap.org/?mlat=66.56882&mlon=27.78983&zoom=17 into an island as it is surrounded by water

Best regards,

	Marko