[Tilesathome] Frustrated about oceantiles

[Andre Hinrichs]

Hi List,

I'm working on the oceantiles for three weeks now changing over 2200 tile 
definitions and am getting more and more frustrated. The decision about 
whether a tile is sea/land/mixed is sometimes very hard and often vague. I've 
seen cases where the coastline is about 0.5 meters away or within a tile. So 
the next time somebody is moving a single node there may harm the tile 
rendering.

I've also seen cases where the rendering of a tile depends on the state of a 
neighbor tile. Very strange!

And the situation at the pole areas is even more frustrating. I assume, that 
there are still thousands of tiles to be fixed especially in Canada and 
Russia. But also in Indonesia is still a lot of work to do.

I was thinking a lot about this and already dreamed of it... I cannot see the 
necessarity for a 'mixed' state. The oceantiles.dat should give the server 
the possibility to serve a colored image where no tile information is present 
and the renderer should only upload an empty tile if it really cannot decide 
whether there is land or sea. The renderer should only take the state of the 
tile as background color if there is no coastline or water or land in the 
rendered OSM data. Wherever the renderer is able to decide this on basis of 
the OSM data it should do so where the oceantiles.dat is not necessary for, 
is it? If there is a coastline or water or land, then the renderer should 
now, where there is land and where sea. That would make the definition of the 
oceantiles much more easy and flexible. The tile could be defined as 'sea' 
even if there is a node of the coastline whithin that tile. And the movement 
of a coastline by a few meters due to a storm or a tsunami would not force 
the oceantiles.dat to be changed.

The download of a bigger area by the renderer would also no longer be 
necessary, I think. Only probably slightly bigger for bezier curves where no 
node of that line is whithin the rendered tile. This would reduce the load of 
the OSM servers.

Furthermore, it would probably be useful if there are more states for the 
oceantiles.dat in case of big areas of wood (national park, rain forrests, 
etc.) and other areas I currently don't think of...


Opinions?


Regards,
Andre
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