On Friday 14 March 2008 00:05:49 Frederik Ramm wrote:
> for each way with area tagging
> if way is member of multipoly relation
> if role is "inner"
> ignore way
> else
> combine way and all "inner" members of relation
> generate drawing instruction for combined path
> end
> else
> generate drawing instruction for simple path
> end
> end
>
> The tags that determine how the way is drawn would always be those of
> the "outer" way. Those of the "inner" way(s) would be completely ignored,
> unless they, in turn, were "outer" ways in another relation (or unless
> a non-area rule would apply to them). Tags on the relation would be
> ignored as well.
If I understand this correctly, then for a forested island in a lake you'd
need to have the island twice in the osm data. Once for the hole in the lake
and once for the forest on the island.
How about:
for each way with area tagging
if way is member of multipoly relation
if role is "inner"
if tags "inner" not equal tags on "outer"
generate drawing instruction for simple path
else
ignore way
end
else
combine way and all "inner" members of relation
generate drawing instruction for combined path
end
else
generate drawing instruction for simple path
end
end
At least this is what I understood the discussion about multipolygons last
week tried to achieve.
--
m.v.g.,
Cartinus
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