[Tagging] Using multipolygons to map bays in Alaska
osm at imagico.de
Sun Nov 18 12:22:30 UTC 2018
On Sunday 18 November 2018, Joseph Eisenberg wrote:
> Christoph, I was really looking forward to hearing how we can render
> good labels for bays and seas, based on a node and the coastline.
> Is there any possible solution the would work with Mapnik and
Well - as said the principal obstacle here is that the coastline way
data is not in the database. Changing that would be relatively easy to
do during a database reload. OSM-Carto missed doing any adjustments
with the last reload, the one that switched to Osmium for MP assembly,
so some looking ahead would be necessaray for that.
But as also said for this kind of analytic application the raw coastline
way data is not necessarily the most suitable or efficient solution.
So the approach of preprocessing the coastline data and then putting
that into the database is likely more suitable. Many map styles
already do that, in particular ones based on a vector tiles framework,
using osmcoastline processed data (which OSM-Carto gets from the
No matter what preprocessing you do and how you get the results into the
database you still have to think about how to efficiently query the
context of a bay/strait node to make the assessment you need. We
already had some discussion on this under one of the issues i linked to
back in the days. Of course this is related to preprocessing the data
as well because you will want to put it in the database in a form that
is efficient to query in the form you want to use.
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