Tidy up ol.source.Zoomify tile URL calculations

src/ol/source/zoomifysource.js

@@ -52,9 +52,13 @@ ol.source.Zoomify = function(opt_options) {
   }
   resolutions.reverse();
 
-  var createFromUrl = function(url) {
+  var tileGrid = new ol.tilegrid.Zoomify({
-    var template = url + '{tileIndex}/{z}-{x}-{y}.jpg';
+    resolutions: resolutions
-    return (
+  });
+
+  var url = options.url;
+  var tileUrlFunction = ol.TileUrlFunction.withTileCoordTransform(
+      tileGrid.createTileCoordTransform({extent: [0, 0, size[0], size[1]]}),
       /**
        * @this {ol.source.TileImage}
        * @param {ol.TileCoord} tileCoord Tile Coordinate.
@@ -66,24 +70,13 @@ ol.source.Zoomify = function(opt_options) {
           return undefined;
         } else {
           var tileIndex = tileCoord.x +
-                (tileCoord.y * tierSizeInTiles[tileCoord.z][0]) +
+              tileCoord.y * tierSizeInTiles[tileCoord.z][0] +
               tileCountUpToTier[tileCoord.z];
-            return template.replace('{tileIndex}', 'TileGroup' +
+          var tileGroup = (tileIndex / ol.DEFAULT_TILE_SIZE) | 0;
-                Math.floor((tileIndex) / ol.DEFAULT_TILE_SIZE))
+          return url + 'TileGroup' + tileGroup + '/' +
-                           .replace('{z}', '' + tileCoord.z)
+              tileCoord.z + '-' + tileCoord.x + '-' + tileCoord.y + '.jpg';
-                           .replace('{x}', '' + tileCoord.x)
-                           .replace('{y}', '' + tileCoord.y);
         }
-        }
-    );
-  };
-
-  var tileGrid = new ol.tilegrid.Zoomify({
-    resolutions: resolutions
       });
-  var tileUrlFunction = ol.TileUrlFunction.withTileCoordTransform(
-      tileGrid.createTileCoordTransform({extent: [0, 0, size[0], size[1]]}),
-      createFromUrl(options.url));
 
   goog.base(this, {
     attributions: options.attributions,