[mapserver-users] Calculation of scale in mapserver

[Eichner, Andreas - SID]

This is part of section "7.2.4.6.9 Scale denominators" of the WMS spec:
...
For the purposes of this International Standard, the common pixel size is defined to be 0,28 mm × 0,28 mm.
Because arbitrary clients can request maps from a server, the true pixel size of the final rendering device is
unknown to the server.
...
But in your case you simply need to use the same BBOX for the WFS filter as for the current WMS view.

> -----Ursprüngliche Nachricht-----
> Von: mapserver-users-bounces at lists.osgeo.org [mailto:mapserver-users-
> bounces at lists.osgeo.org] Im Auftrag von Malm Paul
> Gesendet: Montag, 27. Oktober 2014 11:23
> An: 'mapserver-users at lists.osgeo.org'
> Betreff: [mapserver-users] Calculation of scale in mapserver
> 
> Hi,
> 
> I wounder how MapServer can know the current scale I'm using in my client,
> it must be calculated from the URL BBOX. But how does WMS know the
> physical size of this box on the clients screen?
> 
> 
> 
> The MIN/MAX-SCALEDENOM are used in WMS but not in WFS.
> 
> I would like to search for WFS objects from objects that are visible om my
> screen (WMS).
> 
> To do that I need to know what scale WMS is currently using, or how it's
> calculated. Otherwise I can't filter out the correct layers in my WFS
> query (layers that are not WMS-rendered).
> 
> 
> 
> Any ideas?
> 
> Kind regards,
> 
> Paul
> 
>