Make changes suggested during the review

examples/mapbox-vector-tiles.js

@@ -3,47 +3,19 @@ goog.require('ol.Map');
 goog.require('ol.View');
 goog.require('ol.format.MVT');
 goog.require('ol.layer.VectorTile');
-goog.require('ol.proj');
 goog.require('ol.source.VectorTile');
 goog.require('ol.style.Fill');
 goog.require('ol.style.Icon');
 goog.require('ol.style.Stroke');
 goog.require('ol.style.Style');
 goog.require('ol.style.Text');
-goog.require('ol.tilegrid.TileGrid');
 
 
 var key = 'pk.eyJ1IjoiYWhvY2V2YXIiLCJhIjoiRk1kMWZaSSJ9.E5BkluenyWQMsBLsuByrmg';
 
-// For how many zoom levels do we want to use the same vector tiles?
-// 1 means "use tiles from all zoom levels". 2 means "use the same tiles for 2
-// subsequent zoom levels".
-var reuseZoomLevels = 2;
-
-// Offset of loaded tiles from web mercator zoom level 0.
-// 0 means "At map zoom level 0, use tiles from zoom level 0". 1 means "At map
-// zoom level 0, use tiles from zoom level 1".
-var zoomOffset = 1;
-
-// Calculation of tile urls
-var resolutions = [];
-for (var z = zoomOffset / reuseZoomLevels; z <= 22 / reuseZoomLevels; ++z) {
-  resolutions.push(156543.03392804097 / Math.pow(2, z * reuseZoomLevels));
-}
-function tileUrlFunction(tileCoord) {
-  return ('http://{a-d}.tiles.mapbox.com/v4/mapbox.mapbox-streets-v6/' +
-      '{z}/{x}/{y}.vector.pbf?access_token=' + key)
-      .replace('{z}', String(tileCoord[0] * reuseZoomLevels + zoomOffset))
-      .replace('{x}', String(tileCoord[1]))
-      .replace('{y}', String(-tileCoord[2] - 1))
-      .replace('{a-d}', 'abcd'.substr(
-          ((tileCoord[1] << tileCoord[0]) + tileCoord[2]) % 4, 1));
-}
-
 var map = new ol.Map({
   layers: [
     new ol.layer.VectorTile({
-      preload: Infinity,
       source: new ol.source.VectorTile({
         attributions: [new ol.Attribution({
           html: '© <a href="https://www.mapbox.com/map-feedback/">Mapbox</a> ' +
@@ -51,12 +23,10 @@ var map = new ol.Map({
               'OpenStreetMap contributors</a>'
         })],
         format: new ol.format.MVT(),
-        tileGrid: new ol.tilegrid.TileGrid({
-          extent: ol.proj.get('EPSG:3857').getExtent(),
-          resolutions: resolutions
-        }),
+        tileGrid: ol.tilegrid.createXYZ({maxZoom: 22}),
         tilePixelRatio: 16,
-        tileUrlFunction: tileUrlFunction
+        url: 'http://{a-d}.tiles.mapbox.com/v4/mapbox.mapbox-streets-v6/' +
+            '{z}/{x}/{y}.vector.pbf?access_token=' + key
       }),
       style: createMapboxStreetsV6Style()
     })
@@ -64,7 +34,6 @@ var map = new ol.Map({
   target: 'map',
   view: new ol.View({
     center: [0, 0],
-    minZoom: 1,
     zoom: 2
   })
 });