[OSM-talk] buildings

Martijn van Oosterhout kleptog at gmail.com
Mon Aug 13 20:06:55 BST 2007


On 8/13/07, Robert (Jamie) Munro <rjmunro at arjam.net> wrote:
> > In my original validator I made an exception for this: if a way is
> > looped (so that it is an area) then the the arrows don't have to face
> > the same way. They still need to be ordered, just the arrows don't
> > have all face the same way.
>
> That seems evil. Polygons must go clockwise(*) - the fill is on the
> right. All renderers should assume polygons go clockwise. Otherwise
> chaos will ensue.

Shrug. I don't see why. None of PS, GD or SVG have such a restriction.
The only reason you need it for coastlines is because you won't have
the whole object for rendering. But if you have the entire object you
can just use the even/odd rule.

I just proposed it as it's a very simple way of handling touching
areas that's next to trivial to support and easy to understand.

Have a nice day,
-- 
Martijn van Oosterhout <kleptog at gmail.com> http://svana.org/kleptog/




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