JSFiddle - React, Tailwind, and code Playground

by Dung Nguyen

HTML

<!DOCTYPE html>
<html>
  <head>
    <title>Data Layer: Polygon</title>
    <script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
    <!-- jsFiddle will insert css and js -->
  </head>
  <body>
    <div id="map"></div>

    <!-- Async script executes immediately and must be after any DOM elements used in callback. -->
    <script
      src="https://maps.googleapis.com/maps/api/js?key=AIzaSyB41DRUbKWJHPxaFjMAwdrzWzbVKartNGg&callback=initMap&v=weekly&channel=2"
      async
    ></script>
  </body>
</html>

CSS

/* Always set the map height explicitly to define the size of the div
       * element that contains the map. */
#map {
  height: 100%;
}

/* Optional: Makes the sample page fill the window. */
html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
}

JavaScript

// This example uses the Google Maps JavaScript API's Data layer
// to create a rectangular polygon with 2 holes in it.
const places = [
  {
    center: { "lat": 1.3512492664554796, "lng": 103.85072488875811 },
    radius: 2000
  },
  {
    center: { "lat": 1.3225896205754812, "lng": 103.86600275130694 },
    radius: 2000
  },
  {
    center:{ "lat": 1.3136655910729036, "lng": 103.88866205306475 },
    radius: 2000
  },
  {
    center: { "lat": 1.305427997082587, "lng": 103.83613367171709 },
    radius: 2000
  }
];

let map;

const mapDefault = {
    center: places[0].center,
    zoom: 10,
    minZoom: 1,
    maxZoom: 19,
    clickableIcons: false
};

function initMap() {
	map = new google.maps.Map(document.getElementById('map'), mapDefault);
  const bounds = new google.maps.LatLngBounds();
  
  let pathsCircle = [];
  
  places.forEach(place => {
    bounds.extend(place.center);
    pathsCircle.push(drawCircle(place.center, place.radius, 1));
  });

  map.fitBounds(bounds);
  
  const worldCoords = [
    new google.maps.LatLng(-85.1054596961173, -180),
    new google.maps.LatLng(85.1054596961173, -180),
    new google.maps.LatLng(85.1054596961173, 180),
    new google.maps.LatLng(-85.1054596961173, 180),
    new google.maps.LatLng(-85.1054596961173, 0)
  ];
  
  new google.maps.Polygon({
    paths: [worldCoords, ...pathsCircle],
    strokeColor: '#fff',
    strokeOpacity: 0,
    strokeWeight: 0,
    fillColor: '#000',
    fillOpacity: 0.3,
    map,
  });
}

function drawCircle(point, radius, dir) {
  let d2r = Math.PI / 180;   // degrees to radians 
  let r2d = 180 / Math.PI;   // radians to degrees 
  let earthsradius = 6378137; // 6378137 is the radius of the earth in metters
  let points = 128; // number of point to draw Circle

  // find the raidus in lat/lon 
  let rlat = (radius / earthsradius) * r2d;
  let rlng = rlat / Math.cos(point.lat * d2r);

  let extp = [];

  let start, end;
  if (dir == 1) {  // one extra here makes sure we connect the
    start...