[OSM-dev] Consensus on areas?

[Etienne]

On 8/28/06, Nicola Ranaldo <ranaldo at unina.it> wrote:
>
>
> > Well; i would care. ANd my preference would really be to have areas
> being a
> > list of nodes.
> > This sounds to me like the apropriate datastructure for area data.
>
> A list of nodes is not sufficient. You  need an *ordered* list of nodes.
> As the community prefers not rigid formalized data structures, the only
> way to
> get an ordered list of nodes is via software sourcing from a list of
> segments.


A way *is* an ordered list of nodes (sort of).  A way is defined as an
ordered list of segments.  Each segment defines a from and to node.  The net
result is an ordered list of nodes.

The real problem is that segments have very little purpose in this model.
They do define the direction, but an ordered list of nodes would do the same
job.  You can also put tags on segments, but a hierarchical arrangement of
ways would make this redundant.

About areas i think *actually* their definitions is the same of the ways.


Yes, way=area.

If we plan to have a different definition we could separate them.
> For example area could be a recursive set of subareas you can add or
> subtract
> from the shape, to create holes, ring and other kind of complex objects.


 The SVG approach (see http://www.w3.org/TR/SVG/painting.html#FillProperties)
is quite elegant and seems to cover most possibilities.

        Niko
>
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>
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