Let image resolution be calculated when the image loads

This commit is contained in:
Tim Schaub
2014-10-05 08:45:19 -06:00
parent ddc3dbaa87
commit ede37f26f7
2 changed files with 21 additions and 13 deletions

View File

@@ -34,8 +34,16 @@
<h4 id="title">Static image example</h4> <h4 id="title">Static image example</h4>
<p id="shortdesc">Example of a static image layer.</p> <p id="shortdesc">Example of a static image layer.</p>
<div id="docs"> <div id="docs">
<p>Source: <a href="http://xkcd.com/256/">xkcd.com/256/</a></p> <p>
<p>See the <a href="static-image.js" target="_blank">static-image.js source</a> to see how this is done.</p> This example uses a <a href="http://xkcd.com/256/">static image</a>
as a layer source. The map view is configured with a custom
projection that translates image coordinates directly into map
coordinates.
</p>
<p>
See the <a href="static-image.js" target="_blank">static-image.js source</a>
for details on how this is done.
</p>
</div> </div>
<div id="tags">static image, xkcd</div> <div id="tags">static image, xkcd</div>
</div> </div>

View File

@@ -7,13 +7,14 @@ goog.require('ol.proj.Projection');
goog.require('ol.source.ImageStatic'); goog.require('ol.source.ImageStatic');
// Maps always need a projection, but the static image is not geo-referenced, // Map views always need a projection. Here we just want to map image
// and are only measured in pixels. So, we create a fake projection that the // coordinates directly to map coordinates, so we create a projection that uses
// map can use to properly display the layer. // the image extent in pixels.
var pixelProjection = new ol.proj.Projection({ var extent = [0, 0, 1024, 968];
code: 'pixel', var projection = new ol.proj.Projection({
code: 'xkcd-image',
units: 'pixels', units: 'pixels',
extent: [0, 0, 1024, 968] extent: extent
}); });
var map = new ol.Map({ var map = new ol.Map({
@@ -26,16 +27,15 @@ var map = new ol.Map({
}) })
], ],
url: 'http://imgs.xkcd.com/comics/online_communities.png', url: 'http://imgs.xkcd.com/comics/online_communities.png',
imageSize: [1024, 968], projection: projection,
projection: pixelProjection, imageExtent: extent
imageExtent: pixelProjection.getExtent()
}) })
}) })
], ],
target: 'map', target: 'map',
view: new ol.View({ view: new ol.View({
projection: pixelProjection, projection: projection,
center: ol.extent.getCenter(pixelProjection.getExtent()), center: ol.extent.getCenter(extent),
zoom: 2 zoom: 2
}) })
}); });