[OSM-dev] Coastline changes Antarctica

Christoph Hormann chris_hormann at gmx.de
Mon Mar 11 19:16:43 UTC 2013

On Monday 11 March 2013, Paul Norman wrote:
> OSM data is in WGS84 and the line going from -180 to +180 goes across
> the entire world in this projection. This is how osm2pgsql interprets
> it and I believe most other tools.

I know - but i was just musing about coastlines in an isolated manner.  
And since coastlines are not rendered from the database but from a 
separate shapefile this would not be an issue.  But of course coastline 
ways can have other tags or be part of relations and then will possibly 
be rendered from the database.  For this to work it would need to be 
ensured that the ways crossing the line are tagged natural=coastline 
only and are not part of a relation.  And rather than enforcing such a 
complex rule it would probably be much easier to simply introduce a new 
type of relation containing the two corresponding nodes on both sides 
or even simpler: have OSMCoastline determine the matching nodes on its 
own and make the connection itself (which is exactly what Jochen did - 
although at the moment only for the special case of the southmost 

Christoph Hormann

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