[Tilesathome] RFC: Symbols rendering

[Henrik Niehaus]

Couldn't this be a test case for the validator plugin? I think checking
this case and maybe automatic fixing could be done with it.

Jiri Klement schrieb:
>>> Yes, it's workaround and if rendering rules stayed the same as now, it
>>> will be unnecessary. But I was thinking I will add support for more
>>> features applicable to both nodes and areas. For example big
>>> place_of_worship is usually tagged as both node and area. If I change
>>> rendering rules to add area symbol, I'll get thousands of churches
>>> with two icons.
>> Then the solution is again to fix the data, imho.
> 
> I don't really like the idea of changing so much data, but you're
> probably right. Fixing the data is the right way to go.
> 
>>>> Point-in-polygon is not all that simple, it's definitely not cheap
>>>> (pretty much no matter how you implement it).
>>> I think it's quite cheap. You get points in boundbox, it should be
>>> just one XPath query. Then you make horizontal line going through
>>> every point and count number of intersections with area edges. If the
>>> number is odd, then point is inside of polygon.
>> I think it's something like O(n^2) plus a bit with n being the number
>> of nodes in the polygon. That's not my idea of cheapness.
> 
> You can just say if there is more than 10 nodes in bounding box, then
> it's almost sure one of them is inside. Anyway as said above I will
> implement only label relation.
> 
> 
> What do you think about allowing more than one label/object in relation?
>