[Qgis-developer] Feedbacks about Qgis Server

[Marco Hugentobler]

Hi Michael

> > The issue with the different scales are really annoying, so why dont we
> > make the 96 dpi the default? Do you really think it is much slower?
> 
> Much slower, no, but I know for sure that decreasing tile sizes in one of
> the first optimisation you do when you deliver map on the web. But I am not
> sure decreasing DPI Tto 72 will make a big change though...

QGIS (desktop) reads the dpi from the system and uses this dpi for the WMS 
requests. The WMS server cannot know about the clients dpi, therefore relies 
on the DPI parameter from the request.

Is it possible to get the system DPI with javascript? If yes, we should use 
that value. If not, 96 seems better to me since most screens have a similar 
resolution (at least closer to 96 than 72).

Regards,
Marco

Am Dienstag, 15. November 2011, 10.21:53 schrieb kimaidou:
> Hi Andreas,
> 
> Thanks for your answer.
> 
> 
> 2011/11/14 Andreas Neumann <a.neumann at carto.net>
> 
> > Many of the issues you raise here were also identified before or at the
> > recent developer meeting. See also http://www.qgis.org/wiki/**
> > QGISWebClientIdeas <http://www.qgis.org/wiki/QGISWebClientIdeas>
> 
> I have read this page quite "live" during the hackfest (it was a rainy
> week-end down here in Montpellier). It has some very interesting things
> 
> > The issue with the different scales are really annoying, so why dont we
> > make the 96 dpi the default? Do you really think it is much slower?
> 
> Much slower, no, but I know for sure that decreasing tile sizes in one of
> the first optimisation you do when you deliver map on the web. But I am not
> sure decreasing DPI Tto 72 will make a big change though...
> 
> > BTW - we already get 96dpi images, only OL seems to calculate the scale
> > with 72dpi. We even try to detect the dpi when loading the client. Not
> > sure if this works properly ... Thanks anyway for the hint. I will test
> > it.
> 
> We spend half a day to understand why the layers did not have the correct
> behaviour regarding min and maxScale. After some deep thinking, it appeared
> it was relative to DPI . I can confirm for sure that using the OL option
> OpenLayers.DOTS_PER_INCH = 96 and asking tiles in 96 DPI works. No more
> problems (we tested it on a very complete and complex Qgis project)
> 
> > An improved GetLegendGraphics with user configurable sizes is already
> > requested and will be a paid development/improvement from Sourcepole.
> 
> Great news.
> 
> > GetCapabilities improvements: at the meeting we decided to use a web map
> > context (similar to GetCapabilities) but more configurable to transport
> > settings we want, e.g the initial layer visibility, etc.
> 
> I think it is a good idea :)
> 
> 
> Regards,
> Michael


-- 
Dr. Marco Hugentobler
Sourcepole -  Linux & Open Source Solutions
Churerstrasse 22, CH-8808 Pfäffikon SZ, Switzerland
marco.hugentobler at sourcepole.ch http://www.sourcepole.ch
Technical Advisor QGIS Project Steering Committee