High DPI WMTS

Example of a WMTS based HiDPI layer.

The WMTS source has a tilePixelRatio option. A HiDPI capable WMTS could provide tiles with 512x512 pixel tiles, but use them in a 256x256 pixel tile grid. In this case tilePixelRatio needs to be set to 2.

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import Map from 'ol/Map.js';
import View from 'ol/View.js';
import WMTSCapabilities from 'ol/format/WMTSCapabilities.js';
import {DEVICE_PIXEL_RATIO} from 'ol/has.js';
import TileLayer from 'ol/layer/Tile.js';
import WMTS, {optionsFromCapabilities} from 'ol/source/WMTS.js';

var capabilitiesUrl = 'https://www.basemap.at/wmts/1.0.0/WMTSCapabilities.xml';

// HiDPI support:
// * Use 'bmaphidpi' layer (pixel ratio 2) for device pixel ratio > 1
// * Use 'geolandbasemap' layer (pixel ratio 1) for device pixel ratio == 1
var hiDPI = DEVICE_PIXEL_RATIO > 1;
var layer = hiDPI ? 'bmaphidpi' : 'geolandbasemap';
var tilePixelRatio = hiDPI ? 2 : 1;

var map = new Map({
  target: 'map',
  view: new View({
    center: [1823849, 6143760],
    zoom: 11
  })
});

fetch(capabilitiesUrl).then(function(response) {
  return response.text();
}).then(function(text) {
  var result = new WMTSCapabilities().read(text);
  var options = optionsFromCapabilities(result, {
    layer: layer,
    matrixSet: 'google3857',
    style: 'normal'
  });
  options.tilePixelRatio = tilePixelRatio;
  map.addLayer(new TileLayer({
    source: new WMTS(/** @type {!module:ol/source/WMTS~Options} */ (options))
  }));
});

<!DOCTYPE html>
<html>
  <head>
    <title>High DPI WMTS</title>
    <link rel="stylesheet" href="https://openlayers.org/en/v5.3.0/css/ol.css" type="text/css">
    <!-- The line below is only needed for old environments like Internet Explorer and Android 4.x -->
    <script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList,URL"></script>

    <style>
      .map {
        background: white;
      }
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
    <script>
      import Map from 'ol/Map.js';
      import View from 'ol/View.js';
      import WMTSCapabilities from 'ol/format/WMTSCapabilities.js';
      import {DEVICE_PIXEL_RATIO} from 'ol/has.js';
      import TileLayer from 'ol/layer/Tile.js';
      import WMTS, {optionsFromCapabilities} from 'ol/source/WMTS.js';


      var capabilitiesUrl = 'https://www.basemap.at/wmts/1.0.0/WMTSCapabilities.xml';

      // HiDPI support:
      // * Use 'bmaphidpi' layer (pixel ratio 2) for device pixel ratio > 1
      // * Use 'geolandbasemap' layer (pixel ratio 1) for device pixel ratio == 1
      var hiDPI = DEVICE_PIXEL_RATIO > 1;
      var layer = hiDPI ? 'bmaphidpi' : 'geolandbasemap';
      var tilePixelRatio = hiDPI ? 2 : 1;

      var map = new Map({
        target: 'map',
        view: new View({
          center: [1823849, 6143760],
          zoom: 11
        })
      });

      fetch(capabilitiesUrl).then(function(response) {
        return response.text();
      }).then(function(text) {
        var result = new WMTSCapabilities().read(text);
        var options = optionsFromCapabilities(result, {
          layer: layer,
          matrixSet: 'google3857',
          style: 'normal'
        });
        options.tilePixelRatio = tilePixelRatio;
        map.addLayer(new TileLayer({
          source: new WMTS(/** @type {!module:ol/source/WMTS~Options} */ (options))
        }));
      });
    </script>
  </body>
</html>