[OpenLayers-Dev] Please,
help with vectors projection over google layer (really desperate)
Oscar Fonts
oscar.fonts.lists at gmail.com
Fri Jun 6 10:41:26 EDT 2008
Eric, you're faster. Catched them all while I tested...
Esteban, esta es la función init() resultante, por si la quieres aprovechar:
function init() {
var g = new OpenLayers.Projection("EPSG:4326");
var p = new OpenLayers.Projection("EPSG:900913");
var options = {
projection: p,
displayProjection: g,
units: "m",
maxResolution: 156543.0339,
maxExtent: new OpenLayers.Bounds(-20037508, -20037508,
20037508, 20037508.34)
};
map = new OpenLayers.Map('map', options);
var layergoogle = new OpenLayers.Layer.Google("Google Normal",
{type: G_NORMAL_MAP, 'sphericalMercator': true});
var vectores = new OpenLayers.Layer.Vector("Vector Features");
map.addLayers([layergoogle, vectores]);
//line near Barcelona, spain, for example
var p1 = new OpenLayers.Geometry.Point(2, 41);
var p2 = new OpenLayers.Geometry.Point(41, 2);
var lineString = new
OpenLayers.Geometry.LineString([p1,p2]).transform(g, p);
var lineFeature = new OpenLayers.Feature.Vector(lineString,
null, null);
vectores.addFeatures([lineFeature]);
var lonLat = new OpenLayers.LonLat(2, 41).transform(g, p);
map.setCenter(lonLat, 7);
}
2008/6/6 Eric Lemoine <eric.c2c at gmail.com>:
> 2008/6/6 Esteban olm <esteban.olm at gmail.com>:
> > Hello,
> >
> > I need help! I can not understand why I can not see a line in openlayers.
> > If I don't use projections, I can see it, but then the line is not
> properly
> > drawn in Firefox (but yes in Explorer).
> > I know that problem is a projection problem (I have read a lot in
> Internet),
> > I know Google use Mercator, but I don't know how to solve it.
> >
> > Please help !! There is something I can not find.
> > Here is the entire HTML page from what I think is the best approximation
> > (but it doesn't draw the line):
>
> See my comments in the code.
>
>
>
> >
> ----------------------------------------------------------------------------------------------------------------------
> > <html>
> > <head>
> > <title>prueba</title>
> >
> > <!-- this google key is fo HTTP://LOCALHOST, so it should go in your
> PC
> > -->
> > <script
> > src="
> http://maps.google.com/maps?file=api&v=2&key=ABQIAAAAAdktgbP3W_jzENycyyxYmhT2yXp_ZAY8_ufC3CFXhHIE1NvwkxQAmpwRv0-s77497-2GnWVaa_ulwA
> "
> > type="text/javascript"></script>
> > <script src="http://openlayers.org/dev/OpenLayers.js"></script>
> >
> > <script type="text/javascript">
> > var lat=42.508;
> > var lon=1.118;
> > var map; //complex object of type OpenLayers.Map
> >
> > function init() {
> >
> > //Initialise the 'map' object
> > map = new OpenLayers.Map ("map", {
> > controls:[
> > new OpenLayers.Control.Navigation(),
> > new OpenLayers.Control.PanZoomBar(),
> > new OpenLayers.Control.Attribution()],
> > maxExtent: new
> > OpenLayers.Bounds(-20037508.34,-20037508.34,20037508.34,20037508.34),
> > maxResolution: 156543.0399,
> > units: 'm',
> > projection: new OpenLayers.Projection("EPSG:900913")
> > } );
> > var layergoogle = new OpenLayers.Layer.Google("Google
> Normal",
> > { type: G_NORMAL_MAP },
> > {
> > 'sphericalMercator': true,
> > 'projection': new OpenLayers.Projection("EPSG:900913")
> > }
>
> Place the 'type' and 'sphericalMercator' properties in the same
> object. Remove the 'projection' property.
>
> {
> 'type': G_NORMAL_MAP,
> 'sphericalMercator': true
> }
>
> > );
> > var vectores = new OpenLayers.Layer.Vector ("Vector
> Features",
> > { 'projection': new OpenLayers.Projection("EPSG:4326"),
> > 'displayProjection': new
> > OpenLayers.Projection("EPSG:900913")
> > }
> > );
>
> You do not need any options for the vector layer:
>
> var vectores = new OpenLayers.Layer.Vector ("Vector Features");
>
>
> > map.addLayer(layergoogle);
> > map.addLayer(vectores);
> >
> > //line near Barcelona, spain, for example
> > var p1 = new OpenLayers.Geometry.Point(2, 41);
> > var p2 = new OpenLayers.Geometry.Point(41, 2);
> > var points = [p1,p2];
> > var lineString = new OpenLayers.Geometry.LineString(points);
>
> Reproject your line string before creating the feature with it:
>
> lineString.transform(
> new OpenLayers.Projection("EPSG:4326"),
> new OpenLayers.Projection("EPSG:900913")
> );
>
> > var lineFeature = new OpenLayers.Feature.Vector(lineString,
> > null, null);
> > features = [lineFeature];
> > vectores.addFeatures( [features] );
> >
> > var lonLat = new OpenLayers.LonLat(2, 41)
>
> Either pass mercator coordinates to the LonLat constructor or
> reproject it before passing to setCenter:
>
> lonLat.transform(
> new OpenLayers.Projection("EPSG:4326"),
> new OpenLayers.Projection("EPSG:900913")
> );
>
> > map.setCenter(lonLat, 7);
> > }
> > </script>
> > </head>
> > <body onload="init();">
> > <div style="width:500px; height:300px" id="map"></div>
> > </body>
> > </html>
>
> Hope this helps,
>
> Note that I haven't tested anything so there might still be errors lurking.
> --
> Eric
> _______________________________________________
> Dev mailing list
> Dev at openlayers.org
> http://openlayers.org/mailman/listinfo/dev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/openlayers-dev/attachments/20080606/d4597b24/attachment.html
More information about the Dev
mailing list