Edit

High DPI WMTS

hidpi3 retina2 wmts7

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.

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

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(options),
      })
    );
  });
index.html
<!DOCTYPE html>
<html lang="en">
  <head>
    <title>High DPI WMTS</title>
    <!-- Pointer events polyfill for old browsers, see https://caniuse.com/#feat=pointer -->
    <script src="https://unpkg.com/elm-pep"></script>
    <style>
      .map {
        width: 100%;
        height:400px;
      }
      .map {
        background: white;
      }
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
    <script src="main.js"></script>
  </body>
</html>
package.json
{
  "name": "wmts-hidpi",
  "dependencies": {
    "ol": "6.4.3"
  },
  "devDependencies": {
    "parcel": "1.11.0"
  },
  "scripts": {
    "start": "parcel index.html",
    "build": "parcel build --experimental-scope-hoisting --public-url . index.html"
  }
}