[Tilesathome] RFC: Symbols rendering

[Jiri Klement]

>> 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?