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<!DOCTYPE html>
<html lang="en">
<title>Polygon masks - Azure Maps Web SDK Samples</title>
<meta charset="utf-8" />
<link rel="shortcut icon" href="/favicon.ico" />
<meta http-equiv="x-ua-compatible" content="IE=Edge" />
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no" />
<meta name="description" content="This sample shows how to create polygon masks for both regular Polygon and MultiPolygon geometries." />
<meta name="keywords" content="Microsoft maps, map, gis, API, SDK, multipolygon, polygon mask, restrict map view" />
<meta name="author" content="Microsoft Azure Maps" />
<!-- Add references to the Azure Maps Map control JavaScript and CSS files. -->
<link rel="stylesheet" href="" type="text/css" />
<script src=""></script>
<script type='text/javascript'>
var map, datasource, maskLayer;
//A polygon ring that covers the full globe.
var worldPolygonRing = [[-180, 90], [-180, -90], [0, -90], [180, -90], [180, 90], [0, 90], [-180, 90]];
//The polygon area to use to create a mask.
var polygonMaskArea = {
"type": "MultiPolygon",
"coordinates": [
function GetMap() {
//Point the Azure Maps domain to the US Azure Gov Cloud domain.
//Initialize a map instance.
map = new atlas.Map('myMap', {
center: [-43.3081, -17.56],
zoom: 4,
view: 'Auto',
//Add authentication details for connecting to Azure Maps.
authOptions: {
//Use Azure Active Directory authentication.
authType: 'anonymous',
clientId: 'c9f2f391-13f1-407b-a4a5-f0a241bacfbf', //Your Azure Active Directory client id for accessing your Azure Maps account.
getToken: function (resolve, reject, map) {
//URL to your authentication service that retrieves an Azure Active Directory Token.
var tokenServiceUrl = '';
fetch(tokenServiceUrl).then(r => r.text()).then(token => resolve(token));
//Alternatively, use an Azure Maps key. Get an Azure Maps key at NOTE: The primary key should be used as the key.
//authType: 'subscriptionKey',
//subscriptionKey: '<Your Azure Maps Key>'
//Wait until the map resources are ready.'ready', function () {
//Create a data source to add your data to.
datasource = new atlas.source.DataSource();
//Create and add the polygon mask to the data source.
//Create a layer to render the polygon mask with a solid color and add it to the map.
maskLayer = new atlas.layer.PolygonLayer(datasource, null, {
fillColor: 'black',
fillOpacity: 0.75
function createMask(geometry) {
if (geometry.type === 'Polygon') {
//Copy the polygon mask coordinates.
var coords = JSON.parse(JSON.stringify(geometry.coordinates));
//Add the world polygon ring as the first ring of the polygon mask area. This will cause rendering of the polygon to become inverted.
return new;
} else if (geometry.type === 'MultiPolygon') {
var mask = new[[worldPolygonRing]]);
//Loop through polygons in MultiPolygon
for (var i = 0, len = geometry.coordinates.length; i < len; i++) {
var p = geometry.coordinates[i];
//Loop through rings
for (var j = 0, cnt = p.length; j < cnt; j++) {
if (j === 0) {
//Subtract the first ring from each first polygon in the mask (rings 1+ in a polygon are holes).
} else {
//Create new polygons from the hole rings by wrapping them with an array.
return mask;
return null;
<body onload="GetMap()">
<div id="myMap" style="position:relative;width:100%;min-width:290px;height:600px;"></div>
<fieldset style="width:calc(100% - 30px);min-width:290px;margin-top:10px;">
<legend><h1 style="font-size:16px">Polygon masks</h1></legend>
This sample shows how to create polygon masks for both regular Polygon and MultiPolygon geometries.
Polygon masks limit the viewable area of the map to a polygon area, allowing the user to better focus on a specific area.