[geos-devel] GEOS C API for Polygonal Coverage operations?

[Martin Davis]

On Wed, Sep 7, 2022 at 5:30 PM Daniel Baston <dbaston at gmail.com> wrote:

> But not sure how much extra overhead or difficulty that would cause for
>> other projects consuming such a new type.
>>
>
> It would be the same difficulty/overhead as creating a GeometryCollection
> instead of passing around an array of geometries or creating an Envelope
> instead of working with arrays of four doubles. In other words, negligible.
> We're just saying "this isn't a random array of polygons, it's a set that
> has some special properties."
>

If the Coverage type is just a list of polygons, then agreed, it has low
overhead.

If it is actually a full topological structure, then it has significant
overhead both in constructing the topology and allocating objects
representing the topology graph.  I think some of the ideas in this thread
might require this kind of structure to be efficient.  But it obviously has
significant extra complexity.  I'm not working in this direction (for now,
anyway).   I'm interested in seeing how many operations can be done
efficiently using the list-of-polygons representation.
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