[mapguide-users] Adding zoom levels to Google maps layer

[Zac Spitzer]

Sorry, have you even read the google TOS?

both redlining and stretching aren't permitted


On Sat, Jul 6, 2013 at 5:20 AM, cheesybiscuits <thomaschristian at gmail.com>wrote:

> I noticed that when adding a Google Maps basemap to my Fusion application
> the
> available zoom levels changed and I could not zoom further than 1:1128.5.
> Without the Google layer I could zoom in to something like 1:35.
>
> I eventually figured out where the resolutions were being set and overrode
> the OpenLayers.Layer.Google.prototype.initResolutions function to add an
> arbitrary number of resolutions and increase the numZoomLevels variable
> (code below).
>
> I found that this gave me additional zoom levels but beyond a certain point
> the Google Maps layer stopped zooming. My MapGuide layer continued zooming
> but the Google imagery remained the same and so the referencing got out of
> line. My solution was to hook into the zoomstart or zoomend event from
> OpenLayers and disable the Google layer before this happens, but I'd prefer
> to have the imagery 'blow up' as if it were still zooming. The reason for
> this is that my users are redlining over very small areas so must be very
> zoomed-in to the map for the work. They want the Google layer to remain
> visible and are happy with the potential inaccuracies in Google's data.
>
> I'd like to know if there's value in continuing to pursue this - is there a
> hard restriction somewhere in Fusion or OpenLayers that says I can never
> see
> the blown-up Google image once I zoom beyond the data limits? Is there
> something simple I can change to alter how OpenLayers handles the further
> reaches of this layer?
>
> Any thoughts much appreciated. I'm using Fusion with Autodesk
> Infrastructure
> Map Server 2013 on Windows 2008 R2 64-bit, Chrome 27
>
>
> function addZoomLevels(levelsToAdd, windowObj) {
>
>     windowObj.OpenLayers.Layer.Google.prototype.initResolutions = function
> (original, levelsToAdd) {
>         return function () {
>             original.apply(this);
>             this.numZoomLevels += levelsToAdd;
>
>             window.GoogleLayer.originalMaxResolution =
> this.resolutions[this.resolutions.length - 1];
>
>             for (i = 0; i < levelsToAdd; i++) {
>
> this.resolutions.push(this.resolutions[this.resolutions.length - 1] / 2);
>             }
>         };
>     }(windowObj.OpenLayers.Layer.Google.prototype.initResolutions,
> levelsToAdd);
> }
>
>
>
> --
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> http://osgeo-org.1560.x6.nabble.com/Adding-zoom-levels-to-Google-maps-layer-tp5064386.html
> Sent from the MapGuide Users mailing list archive at Nabble.com.
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>



-- 
Zac Spitzer
+61 405 847 168
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