[OSM-talk] Cuba under the water

[Jon Burgess]

On Thu, 2008-04-24 at 18:45 +0100, Jon Burgess wrote:
> On Thu, 2008-04-24 at 15:01 +0300, Lauri Hahne wrote:
> > 
> > 
> > 2008/4/24 Juan Lucas Dominguez Rubio <jldominguez at prodevelop.es>:
> >         Hi,
> >          
> >         In Mapnik zooms 7, 8 and 9, most of the isle of Cuba is under
> >         the water. Is there anything I can do to fix this? Should I
> >         provide a hand-made shapefile or something? Thanks.
> >          
> >         Lucas
> >          
> >          
> > 
> > It looks ok at http://tile.openstreetmap.nl/coastlines.html so maybe
> > you should just wait till the mapnik shapefiles are updated. 
> > 
> It is not quite as simple as that. Zoom 7 - 9 use a shapefile derived
> from vmap0 that is not normally updated.
> 
> This weeks Mapnik tiles should finish rendering tomorrow. This weekend
> I'll try updating the style to use the OSM derived shapefiles for zoom 7
> + and re-render the 7 - 9 tiles.

> It may be too slow to render the tiles with these detailed shapefiles.
> If so, we may need to perform some simplification on the shapefile to
> optimise the rendering performance.

I generated a replacement shapefile for zoom 7-9[1] and rendered these
tiles again. I'm tempted to use this shapefile for z6 or even z5 soon.

	Jon


[1] Turns out this is quite easy to do with postgis:

$ shp2pgsql -s 900913 -I -g way processed_p shoreline_a | psql -q gis
...
$ pgsql2shp -f shoreline_300 gis "select simplify(way,300) as the_geom,
gid as id from shoreline_a where area(simplify(way,300)) > 0"