Pass transformed tile coordinates to the tileUrlFunction

examples/xyz-esri-4326-512.html

@@ -3,7 +3,7 @@ template: example.html
 title: XYZ Esri EPSG:4326 tileSize 512 example
 shortdesc: Example of a XYZ source in EPSG:4326 using Esri 512x512 tiles.
 docs: >
-  ArcGIS REST tile services with custom tile sizes (here: 512x512 pixels) and projection (here: EPSG:4326) are supported by `ol.source.XYZ`. A custom tile grid and tile url function are required.
+  ArcGIS REST tile services with custom tile sizes (here: 512x512 pixels) and projection (here: EPSG:4326) are supported by `ol.source.XYZ`. A custom tile url function is used to handle zoom level offsets.
 tags: "xyz, esri, tilesize, custom projection"
 ---
 <div class="row-fluid">

examples/xyz-esri-4326-512.js

@@ -1,33 +1,19 @@
 goog.require('ol.Attribution');
 goog.require('ol.Map');
 goog.require('ol.View');
-goog.require('ol.extent');
 goog.require('ol.layer.Tile');
 goog.require('ol.proj');
-goog.require('ol.source.TileImage');
-goog.require('ol.tilegrid.TileGrid');
+goog.require('ol.source.XYZ');
 
 var attribution = new ol.Attribution({
   html: 'Copyright:© 2013 ESRI, i-cubed, GeoEye'
 });
 
 var projection = ol.proj.get('EPSG:4326');
-var projectionExtent = projection.getExtent();
 
 // The tile size supported by the ArcGIS tile service.
 var tileSize = 512;
 
-// Calculate the resolutions supported by the ArcGIS tile service.
-// There are 16 resolutions, with a factor of 2 between successive
-// resolutions. The max resolution is such that the world (360°)
-// fits into two (512x512 px) tiles.
-var maxResolution = ol.extent.getWidth(projectionExtent) / (tileSize * 2);
-var resolutions = new Array(16);
-var z;
-for (z = 0; z < 16; ++z) {
-  resolutions[z] = maxResolution / Math.pow(2, z);
-}
-
 var urlTemplate = 'http://services.arcgisonline.com/arcgis/rest/services/' +
     'ESRI_Imagery_World_2D/MapServer/tile/{z}/{y}/{x}';
 
@@ -35,31 +21,17 @@ var map = new ol.Map({
   target: 'map',
   layers: [
     new ol.layer.Tile({
-      /* ol.source.XYZ and ol.tilegrid.TileGrid have no resolutions config */
-      source: new ol.source.TileImage({
+      source: new ol.source.XYZ({
         attributions: [attribution],
-        tileUrlFunction: function(tileCoord, pixelRatio, projection) {
-          var z = tileCoord[0];
-          var x = tileCoord[1];
-          var y = -tileCoord[2] - 1;
-          // wrap the world on the X axis
-          var n = Math.pow(2, z + 1); // 2 tiles at z=0
-          x = x % n;
-          if (x * n < 0) {
-            // x and n differ in sign so add n to wrap the result
-            // to the correct sign
-            x = x + n;
-          }
-          return urlTemplate.replace('{z}', z.toString())
-              .replace('{y}', y.toString())
-              .replace('{x}', x.toString());
-        },
+        maxZoom: 16,
         projection: projection,
-        tileGrid: new ol.tilegrid.TileGrid({
-          origin: ol.extent.getTopLeft(projectionExtent),
-          resolutions: resolutions,
-          tileSize: 512
-        })
+        tileSize: 512,
+        tileUrlFunction: function(tileCoord) {
+          return urlTemplate.replace('{z}', (tileCoord[0] - 1).toString())
+                            .replace('{x}', tileCoord[1].toString())
+                            .replace('{y}', tileCoord[2].toString());
+        },
+        wrapX: true
       })
     })
   ],