Custom Tiled WMS

This example uses OpenLayers v4.0.1. The latest is v.

#### Custom Tiled WMS

Example of using custom coordinate transform functions.

With `ol.proj.addCoordinateTransforms()`, custom coordinate transform functions can be added to configured projections.

Related API documentation:

- ol.Map
,
- ol.View
,
- ol.control
,
- ol.control.ScaleLine
,
- ol.layer.Tile
,
- ol.proj
,
- ol.proj.Projection
,
- ol.source.TileWMS

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Custom Tiled WMS Example of using custom coordinate transform functions. // By default OpenLayers does not know about the EPSG:21781 (Swiss) projection. // So we create a projection instance for EPSG:21781 and pass it to // ol.proj.addProjection to make it available to the library for lookup by its // code. var projection = new ol.proj.Projection({ code: 'EPSG:21781', // The extent is used to determine zoom level 0. Recommended values for a // projection's validity extent can be found at https://epsg.io/. extent: [485869.5728, 76443.1884, 837076.5648, 299941.7864], units: 'm' }); ol.proj.addProjection(projection); // We also declare EPSG:21781/EPSG:4326 transform functions. These functions // are necessary for the ScaleLine control and when calling ol.proj.transform // for setting the view's initial center (see below). ol.proj.addCoordinateTransforms('EPSG:4326', projection, function(coordinate) { return [ WGStoCHy(coordinate[1], coordinate[0]), WGStoCHx(coordinate[1], coordinate[0]) ]; }, function(coordinate) { return [ CHtoWGSlng(coordinate[0], coordinate[1]), CHtoWGSlat(coordinate[0], coordinate[1]) ]; }); var extent = [420000, 30000, 900000, 350000]; var layers = [ new ol.layer.Tile({ extent: extent, source: new ol.source.TileWMS({ url: 'https://wms.geo.admin.ch/', crossOrigin: 'anonymous', attributions: '© <a href="http://www.geo.admin.ch/internet/geoportal/' + 'en/home.html">Pixelmap 1:1000000 / geo.admin.ch</a>', params: { 'LAYERS': 'ch.swisstopo.pixelkarte-farbe-pk1000.noscale', 'FORMAT': 'image/jpeg' }, serverType: 'mapserver' }) }), new ol.layer.Tile({ extent: extent, source: new ol.source.TileWMS({ url: 'https://wms.geo.admin.ch/', crossOrigin: 'anonymous', attributions: '© <a href="http://www.geo.admin.ch/internet/geoportal/' + 'en/home.html">National parks / geo.admin.ch</a>', params: {'LAYERS': 'ch.bafu.schutzgebiete-paerke_nationaler_bedeutung'}, serverType: 'mapserver' }) }) ]; var map = new ol.Map({ controls: ol.control.defaults().extend([ new ol.control.ScaleLine({ units: 'metric' }) ]), layers: layers, target: 'map', view: new ol.View({ projection: projection, center: ol.proj.transform([8.23, 46.86], 'EPSG:4326', 'EPSG:21781'), extent: extent, zoom: 2 }) }); /* * Swiss projection transform functions downloaded from * http://www.swisstopo.admin.ch/internet/swisstopo/en/home/products/software/products/skripts.html */ // Convert WGS lat/long (° dec) to CH y function WGStoCHy(lat, lng) { // Converts degrees dec to sex lat = DECtoSEX(lat); lng = DECtoSEX(lng); // Converts degrees to seconds (sex) lat = DEGtoSEC(lat); lng = DEGtoSEC(lng); // Axiliary values (% Bern) var lat_aux = (lat - 169028.66) / 10000; var lng_aux = (lng - 26782.5) / 10000; // Process Y var y = 600072.37 + 211455.93 * lng_aux - 10938.51 * lng_aux * lat_aux - 0.36 * lng_aux * Math.pow(lat_aux, 2) - 44.54 * Math.pow(lng_aux, 3); return y; } // Convert WGS lat/long (° dec) to CH x function WGStoCHx(lat, lng) { // Converts degrees dec to sex lat = DECtoSEX(lat); lng = DECtoSEX(lng); // Converts degrees to seconds (sex) lat = DEGtoSEC(lat); lng = DEGtoSEC(lng); // Axiliary values (% Bern) var lat_aux = (lat - 169028.66) / 10000; var lng_aux = (lng - 26782.5) / 10000; // Process X var x = 200147.07 + 308807.95 * lat_aux + 3745.25 * Math.pow(lng_aux, 2) + 76.63 * Math.pow(lat_aux, 2) - 194.56 * Math.pow(lng_aux, 2) * lat_aux + 119.79 * Math.pow(lat_aux, 3); return x; } // Convert CH y/x to WGS lat function CHtoWGSlat(y, x) { // Converts militar to civil and to unit = 1000km // Axiliary values (% Bern) var y_aux = (y - 600000) / 1000000; var x_aux = (x - 200000) / 1000000; // Process lat var lat = 16.9023892 + 3.238272 * x_aux - 0.270978 * Math.pow(y_aux, 2) - 0.002528 * Math.pow(x_aux, 2) - 0.0447 * Math.pow(y_aux, 2) * x_aux - 0.0140 * Math.pow(x_aux, 3); // Unit 10000" to 1 " and converts seconds to degrees (dec) lat = lat * 100 / 36; return lat; } // Convert CH y/x to WGS long function CHtoWGSlng(y, x) { // Converts militar to civil and to unit = 1000km // Axiliary values (% Bern) var y_aux = (y - 600000) / 1000000; var x_aux = (x - 200000) / 1000000; // Process long var lng = 2.6779094 + 4.728982 * y_aux + 0.791484 * y_aux * x_aux + 0.1306 * y_aux * Math.pow(x_aux, 2) - 0.0436 * Math.pow(y_aux, 3); // Unit 10000" to 1 " and converts seconds to degrees (dec) lng = lng * 100 / 36; return lng; } // Convert DEC angle to SEX DMS function DECtoSEX(angle) { // Extract DMS var deg = parseInt(angle, 10); var min = parseInt((angle - deg) * 60, 10); var sec = (((angle - deg) * 60) - min) * 60; // Result in degrees sex (dd.mmss) return deg + min / 100 + sec / 10000; } // Convert Degrees angle to seconds function DEGtoSEC(angle) { // Extract DMS var deg = parseInt(angle, 10); var min = parseInt((angle - deg) * 100, 10); var sec = (((angle - deg) * 100) - min) * 100; // Avoid rounding problems with seconds=0 var parts = String(angle).split('.'); if (parts.length == 2 && parts[1].length == 2) { min = Number(parts[1]); sec = 0; } // Result in degrees sex (dd.mmss) return sec + min * 60 + deg * 3600; } <div id="map" class="map"></div>

    <!DOCTYPE html>
    <html>
      <head>
        <title>Custom Tiled WMS</title>
        <link rel="stylesheet" href="https://openlayers.org/en/v4.0.1/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>
        <script src="https://openlayers.org/en/v4.0.1/build/ol.js"></script>
      </head>
      <body>
        <div id="map" class="map"></div>
        <script>
          // By default OpenLayers does not know about the EPSG:21781 (Swiss) projection.
          // So we create a projection instance for EPSG:21781 and pass it to
          // ol.proj.addProjection to make it available to the library for lookup by its
          // code.

          var projection = new ol.proj.Projection({
            code: 'EPSG:21781',
            // The extent is used to determine zoom level 0. Recommended values for a
            // projection's validity extent can be found at https://epsg.io/.
            extent: [485869.5728, 76443.1884, 837076.5648, 299941.7864],
            units: 'm'
          });
          ol.proj.addProjection(projection);

          // We also declare EPSG:21781/EPSG:4326 transform functions. These functions
          // are necessary for the ScaleLine control and when calling ol.proj.transform
          // for setting the view's initial center (see below).

          ol.proj.addCoordinateTransforms('EPSG:4326', projection,
              function(coordinate) {
                return [
                  WGStoCHy(coordinate[1], coordinate[0]),
                  WGStoCHx(coordinate[1], coordinate[0])
                ];
              },
              function(coordinate) {
                return [
                  CHtoWGSlng(coordinate[0], coordinate[1]),
                  CHtoWGSlat(coordinate[0], coordinate[1])
                ];
              });

          var extent = [420000, 30000, 900000, 350000];
          var layers = [
            new ol.layer.Tile({
              extent: extent,
              source: new ol.source.TileWMS({
                url: 'https://wms.geo.admin.ch/',
                crossOrigin: 'anonymous',
                attributions: '© <a href="http://www.geo.admin.ch/internet/geoportal/' +
                    'en/home.html">Pixelmap 1:1000000 / geo.admin.ch</a>',
                params: {
                  'LAYERS': 'ch.swisstopo.pixelkarte-farbe-pk1000.noscale',
                  'FORMAT': 'image/jpeg'
                },
                serverType: 'mapserver'
              })
            }),
            new ol.layer.Tile({
              extent: extent,
              source: new ol.source.TileWMS({
                url: 'https://wms.geo.admin.ch/',
                crossOrigin: 'anonymous',
                attributions: '© <a href="http://www.geo.admin.ch/internet/geoportal/' +
                    'en/home.html">National parks / geo.admin.ch</a>',
                params: {'LAYERS': 'ch.bafu.schutzgebiete-paerke_nationaler_bedeutung'},
                serverType: 'mapserver'
              })
            })
          ];

          var map = new ol.Map({
            controls: ol.control.defaults().extend([
              new ol.control.ScaleLine({
                units: 'metric'
              })
            ]),
            layers: layers,
            target: 'map',
            view: new ol.View({
              projection: projection,
              center: ol.proj.transform([8.23, 46.86], 'EPSG:4326', 'EPSG:21781'),
              extent: extent,
              zoom: 2
            })
          });

          /*
           * Swiss projection transform functions downloaded from
           * http://www.swisstopo.admin.ch/internet/swisstopo/en/home/products/software/products/skripts.html
           */

          // Convert WGS lat/long (° dec) to CH y
          function WGStoCHy(lat, lng) {

            // Converts degrees dec to sex
            lat = DECtoSEX(lat);
            lng = DECtoSEX(lng);

            // Converts degrees to seconds (sex)
            lat = DEGtoSEC(lat);
            lng = DEGtoSEC(lng);

            // Axiliary values (% Bern)
            var lat_aux = (lat - 169028.66) / 10000;
            var lng_aux = (lng - 26782.5) / 10000;

            // Process Y
            var y = 600072.37 +
                211455.93 * lng_aux -
                10938.51 * lng_aux * lat_aux -
                0.36 * lng_aux * Math.pow(lat_aux, 2) -
                44.54 * Math.pow(lng_aux, 3);

            return y;
          }

          // Convert WGS lat/long (° dec) to CH x
          function WGStoCHx(lat, lng) {

            // Converts degrees dec to sex
            lat = DECtoSEX(lat);
            lng = DECtoSEX(lng);

            // Converts degrees to seconds (sex)
            lat = DEGtoSEC(lat);
            lng = DEGtoSEC(lng);

            // Axiliary values (% Bern)
            var lat_aux = (lat - 169028.66) / 10000;
            var lng_aux = (lng - 26782.5) / 10000;

            // Process X
            var x = 200147.07 +
                308807.95 * lat_aux +
                3745.25 * Math.pow(lng_aux, 2) +
                76.63 * Math.pow(lat_aux, 2) -
                194.56 * Math.pow(lng_aux, 2) * lat_aux +
                119.79 * Math.pow(lat_aux, 3);

            return x;

          }

          // Convert CH y/x to WGS lat
          function CHtoWGSlat(y, x) {

            // Converts militar to civil and  to unit = 1000km
            // Axiliary values (% Bern)
            var y_aux = (y - 600000) / 1000000;
            var x_aux = (x - 200000) / 1000000;

            // Process lat
            var lat = 16.9023892 +
                3.238272 * x_aux -
                0.270978 * Math.pow(y_aux, 2) -
                0.002528 * Math.pow(x_aux, 2) -
                0.0447 * Math.pow(y_aux, 2) * x_aux -
                0.0140 * Math.pow(x_aux, 3);

            // Unit 10000" to 1 " and converts seconds to degrees (dec)
            lat = lat * 100 / 36;

            return lat;

          }

          // Convert CH y/x to WGS long
          function CHtoWGSlng(y, x) {

            // Converts militar to civil and  to unit = 1000km
            // Axiliary values (% Bern)
            var y_aux = (y - 600000) / 1000000;
            var x_aux = (x - 200000) / 1000000;

            // Process long
            var lng = 2.6779094 +
                4.728982 * y_aux +
                0.791484 * y_aux * x_aux +
                0.1306 * y_aux * Math.pow(x_aux, 2) -
                0.0436 * Math.pow(y_aux, 3);

            // Unit 10000" to 1 " and converts seconds to degrees (dec)
            lng = lng * 100 / 36;

            return lng;

          }

          // Convert DEC angle to SEX DMS
          function DECtoSEX(angle) {

            // Extract DMS
            var deg = parseInt(angle, 10);
            var min = parseInt((angle - deg) * 60, 10);
            var sec = (((angle - deg) * 60) - min) * 60;

            // Result in degrees sex (dd.mmss)
            return deg + min / 100 + sec / 10000;

          }

          // Convert Degrees angle to seconds
          function DEGtoSEC(angle) {

            // Extract DMS
            var deg = parseInt(angle, 10);
            var min = parseInt((angle - deg) * 100, 10);
            var sec = (((angle - deg) * 100) - min) * 100;

            // Avoid rounding problems with seconds=0
            var parts = String(angle).split('.');
            if (parts.length == 2 && parts[1].length == 2) {
              min = Number(parts[1]);
              sec = 0;
            }

            // Result in degrees sex (dd.mmss)
            return sec + min * 60 + deg * 3600;

          }
        </script>
      </body>
    </html>