[OpenLayers-Users] map bounds or projection problem?

[Arnd Wippermann]

Hi Eoinyp,

if you want to see the whole USA, then your bounds are something like this:
var bounds = new OpenLayers.Bounds(-6906850,-2055250,3160850,3805350);
and 
maxResolution:10000

http://gis.ibbeck.de/ginfo/apps/OL27Client/OL27ClientGis.asp?WMC=./data/WMC/
EPSG_26986.wmc.xml


if you use google layer with sphericalMercator, then you have to set the
options for the map in the right way. You have taken the same as for
EPSG:26986. Your extent describes something in Togo, Benin.

try this:

var options = {
    projection: new OpenLayers.Projection("EPSG:900913"),
    displayProjection: new OpenLayers.Projection("EPSG:4326"),
    units: "m",
    numZoomLevels: 18,
    maxResolution: 156543.0339,
    maxExtent: new OpenLayers.Bounds(-20037508, -20037508,
                                     20037508, 20037508.34)
};
map = new OpenLayers.Map('map', options);

http://gis.ibbeck.de/ginfo/apps/OL27Client/OL27ClientGis.asp?WMC=./data/WMC/
EPSG_900913_Mass.wmc.xml 

Good luck
Arnd


-----Ursprüngliche Nachricht-----
Von: users-bounces at openlayers.org [mailto:users-bounces at openlayers.org] Im
Auftrag von eoinyp
Gesendet: Dienstag, 25. August 2009 18:27
An: users at openlayers.org
Betreff: Re: [OpenLayers-Users] map bounds or projection problem?


Thanks Arnd,
I made some progress, but Im not quite there yet.
Adding in the navigation control made a small difference. It works well when
I have 2 layers (no google)
see: http://www.eoinmaca.com/maps/OpenLayers/twolayers.htm
However the bounds of the area shown is still constrained. There is data
there for all US states so I think it is the line:
var bounds = new OpenLayers.Bounds(
19012.0201171875, 768402.5875,
345695.3353515625, 968859.1625);
that constrains the display of information. I just dont know how to figure
out what the correct bounds should be! 
Again, this problem is compounded with the addition of the third layer
see: http://www.eoinmaca.com/maps/OpenLayers/threelayers.htm
I cannot zoom in on the area where the layers are overlaid on the google
map, It always brings me to north Africa! :(

Thanks for the help on the epsg. When I have only 2 layers I used
EPSG:26986, the local projection, and when I add the google layer, I define
the map projection to be EPSG:900913, google spherical mercator.

Really puzzeled as to why it always zooms in on North africa and doesnt let
me pan to the Northeren USA.
Thanks again,

Eoinyp