[OSM-dev] Coastline changes Antarctica

[Jochen Topf]

On Tue, Mar 12, 2013 at 09:12:39AM +0000, Tom Hughes wrote:
> On 12/03/13 09:07, Jochen Topf wrote:
> 
> >On Tue, Mar 12, 2013 at 08:41:36AM +0000, Tom Hughes wrote:
> >
> >>Andy and I were talking about this last week and were of the opinion
> >>that we should switch to using your data, and to using sea polygons
> >>with land as the default background rather than the current system,
> >>and I think Andy would happily take a patch against
> >>openstreetmap-carto which did that.
> >
> >I am not sure it is a good idea to switch to water polygons. Those polygons
> >are much more complicated because they contain lots of holes, so they are
> >slower to render. I'd only do that if really necessary (for instance when
> >you want to mask something below the water polygon.
> 
> Interesting - that change was Andy's idea and I think the thought
> was to reduce the damage done by any breakage and to ensure that
> we're not matching any massive polygons in the busy (land) areas.

OSMCoastline first generates the land polygons, them splits them, then
creates the water polygons as inverse from the lang polygons. If the
land polygons are broken, so are the water polygons. So I don't think
you can reduce the chance of breakage that way.

Jochen
-- 
Jochen Topf  jochen at remote.org  http://www.remote.org/jochen/  +49-721-388298