Image Map Types

This example uses image tiles of the moon's surface to create a map.

function initMap() {
  var map = new google.maps.Map(document.getElementById('map'), {
    center: {lat: 0, lng: 0},
    zoom: 1,
    streetViewControl: false,
    mapTypeControlOptions: {
      mapTypeIds: ['moon']
    }
  });

  var moonMapType = new google.maps.ImageMapType({
    getTileUrl: function(coord, zoom) {
        var normalizedCoord = getNormalizedCoord(coord, zoom);
        if (!normalizedCoord) {
          return null;
        }
        var bound = Math.pow(2, zoom);
        return '//mw1.google.com/mw-planetary/lunar/lunarmaps_v1/clem_bw' +
            '/' + zoom + '/' + normalizedCoord.x + '/' +
            (bound - normalizedCoord.y - 1) + '.jpg';
    },
    tileSize: new google.maps.Size(256, 256),
    maxZoom: 9,
    minZoom: 0,
    radius: 1738000,
    name: 'Moon'
  });

  map.mapTypes.set('moon', moonMapType);
  map.setMapTypeId('moon');
}

// Normalizes the coords that tiles repeat across the x axis (horizontally)
// like the standard Google map tiles.
function getNormalizedCoord(coord, zoom) {
  var y = coord.y;
  var x = coord.x;

  // tile range in one direction range is dependent on zoom level
  // 0 = 1 tile, 1 = 2 tiles, 2 = 4 tiles, 3 = 8 tiles, etc
  var tileRange = 1 << zoom;

  // don't repeat across y-axis (vertically)
  if (y < 0 || y >= tileRange) {
    return null;
  }

  // repeat across x-axis
  if (x < 0 || x >= tileRange) {
    x = (x % tileRange + tileRange) % tileRange;
  }

  return {x: x, y: y};
}

<div id="map"></div>

/* 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;
}

<!-- Replace the value of the key parameter with your own API key. -->
<script async defer
src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk&callback=initMap">
</script>

Try it yourself

You can experiment with this code in JSFiddle by clicking the <> icon in the top-right corner of the code window.

<!DOCTYPE html>
<html>
  <head>
    <title>Image Map Types</title>
    <style>
      /* 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;
      }
    </style>
  </head>
  <body>
    <div id="map"></div>
    <script>

      function initMap() {
        var map = new google.maps.Map(document.getElementById('map'), {
          center: {lat: 0, lng: 0},
          zoom: 1,
          streetViewControl: false,
          mapTypeControlOptions: {
            mapTypeIds: ['moon']
          }
        });

        var moonMapType = new google.maps.ImageMapType({
          getTileUrl: function(coord, zoom) {
              var normalizedCoord = getNormalizedCoord(coord, zoom);
              if (!normalizedCoord) {
                return null;
              }
              var bound = Math.pow(2, zoom);
              return '//mw1.google.com/mw-planetary/lunar/lunarmaps_v1/clem_bw' +
                  '/' + zoom + '/' + normalizedCoord.x + '/' +
                  (bound - normalizedCoord.y - 1) + '.jpg';
          },
          tileSize: new google.maps.Size(256, 256),
          maxZoom: 9,
          minZoom: 0,
          radius: 1738000,
          name: 'Moon'
        });

        map.mapTypes.set('moon', moonMapType);
        map.setMapTypeId('moon');
      }

      // Normalizes the coords that tiles repeat across the x axis (horizontally)
      // like the standard Google map tiles.
      function getNormalizedCoord(coord, zoom) {
        var y = coord.y;
        var x = coord.x;

        // tile range in one direction range is dependent on zoom level
        // 0 = 1 tile, 1 = 2 tiles, 2 = 4 tiles, 3 = 8 tiles, etc
        var tileRange = 1 << zoom;

        // don't repeat across y-axis (vertically)
        if (y < 0 || y >= tileRange) {
          return null;
        }

        // repeat across x-axis
        if (x < 0 || x >= tileRange) {
          x = (x % tileRange + tileRange) % tileRange;
        }

        return {x: x, y: y};
      }
    </script>
    <script async defer
    src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap">
    </script>
  </body>
</html>