Example of two WMS layers using the projection EPSG:21781, which is unknown to the client.
As long as no coordinate transformations are required, OpenLayers 3 works fine with projections that are only configured with a code
and units
.
<!DOCTYPE html>
<html>
<head>
<title>WMS without client projection example</title>
<script src="https://code.jquery.com/jquery-1.11.2.min.js"></script>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="http://openlayers.org/en/v3.9.0/css/ol.css" type="text/css">
<script src="http://openlayers.org/en/v3.9.0/build/ol.js"></script>
</head>
<body>
<div class="container-fluid">
<div class="row-fluid">
<div class="span12">
<div id="map" class="map"></div>
</div>
</div>
</div>
<script>
var layers = [
new ol.layer.Tile({
source: new ol.source.TileWMS({
attributions: [new ol.Attribution({
html: '© ' +
'<a href="http://www.geo.admin.ch/internet/geoportal/' +
'en/home.html">' +
'Pixelmap 1:1000000 / geo.admin.ch</a>'
})],
crossOrigin: 'anonymous',
params: {
'LAYERS': 'ch.swisstopo.pixelkarte-farbe-pk1000.noscale',
'FORMAT': 'image/jpeg'
},
url: 'http://wms.geo.admin.ch/'
})
}),
new ol.layer.Image({
source: new ol.source.ImageWMS({
attributions: [new ol.Attribution({
html: '© ' +
'<a href="http://www.geo.admin.ch/internet/geoportal/' +
'en/home.html">' +
'National parks / geo.admin.ch</a>'
})],
crossOrigin: 'anonymous',
params: {'LAYERS': 'ch.bafu.schutzgebiete-paerke_nationaler_bedeutung'},
serverType: 'mapserver',
url: 'http://wms.geo.admin.ch/'
})
})
];
// A minimal projection object is configured with only the SRS code and the map
// units. No client-side coordinate transforms are possible with such a
// projection object. Requesting tiles only needs the code together with a
// tile grid of Cartesian coordinates; it does not matter how those
// coordinates relate to latitude or longitude.
var projection = new ol.proj.Projection({
code: 'EPSG:21781',
units: 'm'
});
var map = new ol.Map({
layers: layers,
target: 'map',
view: new ol.View({
center: [660000, 190000],
projection: projection,
zoom: 9
})
});
</script>
</body>
</html>