[mapserver-dev] Vector Tile Production...

[Even Rouault]

Le lundi 14 septembre 2015 14:10:27, thomas bonfort a écrit :
> Hi all,
> 
> I have  a mostly functional and fully untested (on the client side)
> branch that implements vector tile rendering for mapserver:
> https://github.com/tbonfort/mapserver/tree/vector-tiles .

Thumbs up!

> It relies on
> mapserver's WFS implementation, so we'll need to also adapt mapcache
> to handle these WFS queries in order to present  x/y/z style URLS so
> it becomes actually usable.
> 
> Given that we're using WFS, we actually don't care about projections,
> you can request a vector tile for any extent/projection combo,
> although that isn't going to be supported by any client (yet?). I did
> have to fiddle around with handling scale computations as there's no
> concept of scale in traditional getfeature queries
> (https://github.com/tbonfort/mapserver/commit/50c3a44ddd3c182ca0e1a16a6e5a1
> c5c20675768) => Steve or Even could you have a glance?

That should be fine I think.

It raises a few interesting ideas for having a more generic scale-aware WFS 
mode. Perhaps we could have vendor WFS options WIDTH and HEIGHT that, if set, 
would trigger the msCalculateScale() call. So that could also potentially be 
used to have scale-aware shapezip output ("give me features in this AOI 
appropriate for a 1024x1024 rendering")
And the clipping to the BBOX could also potentially be a CLIPPED=YES vendor 
option (but you have to do it anyway for MVT output due to the way coordinates 
are encoded).

Even

-- 
Spatialys - Geospatial professional services
http://www.spatialys.com