Limited Layer Extent

Restricting layer rendering to a limited extent.

This example uses the layer.setExtent() method to modify the extent of the overlay layer. Use the controls below to limit rendering based on an extent.

<!DOCTYPE html>
<html>
  <head>
    <title>Limited Layer Extent</title>
    <link rel="stylesheet" href="http://openlayers.org/en/v3.16.0/css/ol.css" type="text/css">
    <script src="http://openlayers.org/en/v3.16.0/build/ol.js"></script>
  </head>
  <body>
    <div id="map" class="map"></div>
    <button type="button" class="btn btn-default" id="northwest">northwest</button>
    <button type="button" class="btn btn-default" id="northeast">northeast</button>
    <button type="button" class="btn btn-default" id="southeast">southeast</button>
    <button type="button" class="btn btn-default" id="southwest">southwest</button>
    <button type="button" class="btn btn-default" id="world">world</button>
    <script>
      function transform(extent) {
        return ol.proj.transformExtent(extent, 'EPSG:4326', 'EPSG:3857');
      }

      var extents = {
        northwest: transform([-180, 0, 0, 85]),
        northeast: transform([0, 0, 180, 85]),
        southeast: transform([0, -85, 180, 0]),
        southwest: transform([-180, -85, 0, 0]),
        world: transform([-180, -85, 180, 85])
      };

      var base = new ol.layer.Tile({
        source: new ol.source.TileJSON({
          url: 'http://api.tiles.mapbox.com/v3/' +
              'mapbox.world-black.json',
          crossOrigin: 'anonymous'
        })
      });

      var overlay = new ol.layer.Tile({
        extent: extents.northwest,
        source: new ol.source.TileJSON({
          url: 'http://api.tiles.mapbox.com/v3/' +
              'mapbox.world-glass.json',
          crossOrigin: 'anonymous'
        })
      });

      var map = new ol.Map({
        layers: [base, overlay],
        target: 'map',
        view: new ol.View({
          center: [0, 0],
          zoom: 1
        })
      });

      for (var key in extents) {
        document.getElementById(key).onclick = function(event) {
          overlay.setExtent(extents[event.target.id]);
        };
      }
    </script>
  </body>
</html>