Samples/Spatial Math/Calculate a convex hull/Calculate a convex hull.html

﻿<!DOCTYPE html>
<html lang="en">
<head>
    <title>Calculate a convex hull - Azure Maps Web SDK Samples</title>

    <meta charset="utf-8" />
	<link rel="shortcut icon" href="/favicon.ico"/>
    
    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no" />
    <meta name="description" content="This sample shows how to calculate a convex hull from an array of shapes." />
    <meta name="keywords" content="Microsoft maps, map, gis, API, SDK, geospatial, spatial math, math, convex hull" />
    <meta name="author" content="Microsoft Azure Maps" /><meta name="version" content="1.0" />
    <meta name="screenshot" content="screenshot.jpg" />

    <!-- Add references to the Azure Maps Map control JavaScript and CSS files. -->
    <link href="https://atlas.microsoft.com/sdk/javascript/mapcontrol/3/atlas.min.css" rel="stylesheet" />
    <script src="https://atlas.microsoft.com/sdk/javascript/mapcontrol/3/atlas.min.js"></script>

    <script>
        var map, datasource;

        function getMap() {
            //Initialize a map instance.
            map = new atlas.Map('myMap', {
                center: [-90, 35],
                zoom: 3,
                view: 'Auto',

                //Add authentication details for connecting to Azure Maps.
                authOptions: {
                    //Use Microsoft Entra ID authentication.
                    authType: 'anonymous',
                    clientId: 'e6b6ab59-eb5d-4d25-aa57-581135b927f0', //Your Azure Maps client id for accessing your Azure Maps account.
                    getToken: function (resolve, reject, map) {
                        //URL to your authentication service that retrieves an Microsoft Entra ID Token.
                        var tokenServiceUrl = 'https://samples.azuremaps.com/api/GetAzureMapsToken';

                        fetch(tokenServiceUrl).then(r => r.text()).then(token => resolve(token));
                    }

                    //Alternatively, use an Azure Maps key. Get an Azure Maps key at https://azure.com/maps. NOTE: The primary key should be used as the key.
                    //authType: 'subscriptionKey',
                    //subscriptionKey: '[YOUR_AZURE_MAPS_KEY]'
                }
            });

            //Wait until the map resources are ready.
            map.events.add('ready', function () {
                //Create a data source and add it to the map.
                datasource = new atlas.source.DataSource();
                map.sources.add(datasource);

                updateCoordinates();

                //Create a layer to render the convex hull as a polygon and the point data as symbols.
                map.layers.add([
                    new atlas.layer.PolygonLayer(datasource),
                    
                    new atlas.layer.SymbolLayer(datasource, null, {
                        iconOptions: {
                            ignorePlacement: true,
                            allowOverlap: true
                        }
                    })
                ]);
            });
        }

        function updateCoordinates() {
            datasource.clear();

            //Generate some random coordinates over the USA.
            var shapes = [];
            for (var i = 0; i < 15; i++) {
                shapes.push(new atlas.data.Point([
                    Math.random() * 40 - 120,
                    Math.random() * 20 + 30
                ]));
            }

            var hull = atlas.math.getConvexHull(shapes);
            shapes.push(hull);
            datasource.setShapes(shapes);
        }
    </script>
</head>
<body onload="getMap()">
    <div id="myMap" style="position:relative;width:100%;min-width:290px;height:600px;"></div>

    <input type="button" value="Update Coordinates" onclick="updateCoordinates()" style="position:absolute;top:10px;left:10px;" />

    <fieldset style="width:calc(100% - 30px);min-width:290px;margin-top:10px;">
        <legend>Calculate a convex hull</legend>
        This sample shows how to calculate a convex hull from an array of shapes.
        A convex hull is a shape that represents that minimum convex geometry that encloses all shapes in the specified data set.
    </fieldset>
</body>
</html>