[OSM-dev] Coastline changes Antarctica

Andy Allan gravitystorm at gmail.com
Tue Mar 12 10:38:36 UTC 2013


On 12 March 2013 09:12, Tom Hughes <tom at compton.nu> wrote:

>> 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.

So my line of thinking is as follows:

1) Jochen's proposed changes are going to break all coastcheck-created
shapefiles, so openstreetmap-carto should instead use ones from
OSMCoastline
2) Jochen does some form of QA for OSMCoastline so they are good to use directly
3) If you're not using hillshading, inverse vs normal makes no visual
difference. But as soon as you use hillshading, you want inverse. So
all else being equal, inverse should be the default
4) It's also confusing to have the map background as blue, when most
people editing stylesheets think the background colour would be the
land colour.
5) The vast majority of rendered tiles are all land. So it seems
strange to draw a blue background, to immediately colour it with a
land polygon, in almost every case.

I take the point about the complexity of water polygons vs land
polygons though, it's not something I'd thought of. I wonder if it
invalidates the performance advantages described in 5) ?

Cheers,
Andy



More information about the dev mailing list