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Create ol.proj.Projection instances with additional properties

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This commit is contained in:
Andreas Hocevar
2015-03-26 10:50:52 +01:00
parent 338901774b
commit a920cd94d9
2 changed files with 26 additions and 17 deletions
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30
examples/wms-image-custom-proj.js
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@@ -5,21 +5,29 @@ goog.require('ol.control');
goog.require('ol.control.ScaleLine');
goog.require('ol.layer.Image');
goog.require('ol.proj');
goog.require('ol.proj.Projection');
goog.require('ol.source.ImageWMS');
// Transparent Proj4js support: ol.proj.get() creates and returns a projection
// known to Proj4js if it is unknown to OpenLayers, and registers functions to
// transform between all registered projections.
// Transparent Proj4js support:
//
// EPSG:21781 is known to Proj4js because its definition was loaded in the html.
// Note that we are getting the projection object here to set the extent. If
// you do not need this, you do not have to use ol.proj.get(); simply use the
// string code in the view projection below and the transforms will be
// registered transparently.
var projection = ol.proj.get('EPSG:21781');
// The extent is used to determine zoom level 0. Recommended values for a
// Now when we create an ol.proj.Projection instance with the 'EPSG:21781' code,
// OpenLayers will pick up parameters like units and transform functions from
// Proj4js.
//
// Note that we are setting the projection's extent here, which is used to
// determine the view resolution for zoom level 0. Recommended values for a
// projection's validity extent can be found at http://epsg.io/.
projection.setExtent([485869.5728, 76443.1884, 837076.5648, 299941.7864]);
//
// If you use Proj4js only to transform coordinates, you don't even need to
// create an ol.proj.Projection instance. ol.proj.get() will take care of it
// internally.
var projection = new ol.proj.Projection({
code: 'EPSG:21781',
extent: [485869.5728, 76443.1884, 837076.5648, 299941.7864]
});
var extent = [420000, 30000, 900000, 350000];
var layers = [
@@ -67,7 +75,7 @@ var map = new ol.Map({
target: 'map',
view: new ol.View({
projection: projection,
center: ol.proj.transform([8.23, 46.86], 'EPSG:4326', 'EPSG:21781'),
center: ol.proj.transform([8.23, 46.86], 'EPSG:4326', projection),
extent: extent,
zoom: 2
})