Add gutter support to TileUrlFunction

src/ol/source/tilewmssource.js

@@ -58,7 +58,7 @@ ol.source.TileWMS = function(options) {
     var tileUrlFunctions = goog.array.map(
         urls, function(url) {
           return ol.TileUrlFunction.createFromParamsFunction(
-              url, this.params_, ol.source.wms.getUrl);
+              url, this.params_, this.gutter_, ol.source.wms.getUrl);
         }, this);
     tileUrlFunction = ol.TileUrlFunction.createFromTileUrlFunctions(
         tileUrlFunctions);

src/ol/tileurlfunction.js

@@ -84,14 +84,16 @@ ol.TileUrlFunction.createFromTileUrlFunctions = function(tileUrlFunctions) {
 
 /**
  * @param {string} baseUrl Base URL (may have query data).
- * @param {Object.<string,*>} params to encode in the URL.
+ * @param {Object.<string,*>} params Params to encode in the URL.
+ * @param {number} gutter Gutter value.
  * @param {function(this: ol.source.TileImage, string, Object.<string,*>,
  *     ol.Extent, ol.Size, ol.proj.Projection)} paramsFunction params function.
  * @return {ol.TileUrlFunctionType} Tile URL function.
  */
 ol.TileUrlFunction.createFromParamsFunction =
-    function(baseUrl, params, paramsFunction) {
+    function(baseUrl, params, gutter, paramsFunction) {
   var tmpExtent = ol.extent.createEmpty();
+  var tmpSize = [0, 0];
   return (
       /**
        * @this {ol.source.TileImage}
@@ -107,10 +109,14 @@ ol.TileUrlFunction.createFromParamsFunction =
           if (goog.isNull(tileGrid)) {
             tileGrid = ol.tilegrid.getForProjection(projection);
           }
-          var size = tileGrid.getTileSize(tileCoord.z);
+          var tileResolution = tileGrid.getResolution(tileCoord.z);
+          var tileSize = tileGrid.getTileSize(tileCoord.z);
+          tmpSize[0] = tileSize[0] + (2 * gutter);
+          tmpSize[1] = tileSize[1] + (2 * gutter);
           var extent = tileGrid.getTileCoordExtent(tileCoord, tmpExtent);
+          ol.extent.buffer(extent, tileResolution * gutter);
           return paramsFunction.call(this, baseUrl, params,
-              extent, size, projection);
+              extent, tmpSize, projection);
         }
       });
 };

test/spec/ol/tileurlfunction.test.js

@@ -84,7 +84,7 @@ describe('ol.TileUrlFunction', function() {
     var fakeTileSource = {getTileGrid: function() {return null;}};
     var params = {foo: 'bar'};
     var tileUrlFunction = ol.TileUrlFunction.createFromParamsFunction(
-        'url', params, paramsFunction);
+        'url', params, 0, paramsFunction);
     it('calls the passed function with the correct arguments', function() {
       var args = tileUrlFunction.call(fakeTileSource,
           new ol.TileCoord(0, 0, 0), projection);