[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 ___ mapserver-users mailing list mapserver-users@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/mapserver-users
Re: [mapserver-users] Calculation of scale in mapserver
WMS call has WIDTH and HEIGHT in pixels and combined with BBOX calculates the scale. http://localhost/wms/maps?LAYERS=parcelsTRANSPARENT=TRUESERVICE=WMSVERSION=1.1.1REQUEST=GetMapSTYLES=FORMAT=image%2FpngSRS=EPSG%3A2264BBOX=1843216.889,468292.,2517439.111,835847.7778WIDTH=1517HEIGHT=827 *Worth Lutz* -- On 10/27/2014 06:23 AM, Malm Paul wrote: 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 ___ mapserver-users mailing list mapserver-users@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/mapserver-users ___ mapserver-users mailing list mapserver-users@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/mapserver-users
Re: [mapserver-users] Calculation of scale in mapserver
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-boun...@lists.osgeo.org [mailto:mapserver-users- boun...@lists.osgeo.org] Im Auftrag von Malm Paul Gesendet: Montag, 27. Oktober 2014 11:23 An: 'mapserver-users@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 ___ mapserver-users mailing list mapserver-users@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/mapserver-users
