Support minZoom in ol.source.Stamen

src/ol/source/stamensource.js

@@ -70,7 +70,7 @@ ol.source.StamenProviderConfig = {
     maxZoom: 20
   },
   'watercolor': {
-    minZoom: 3,
+    minZoom: 1,
     maxZoom: 16
   }
 };
@@ -106,8 +106,7 @@ ol.source.Stamen = function(options) {
     cacheSize: options.cacheSize,
     crossOrigin: 'anonymous',
     maxZoom: providerConfig.maxZoom,
-    // FIXME uncomment the following when tilegrid supports minZoom
-    //minZoom: providerConfig.minZoom,
+    minZoom: providerConfig.minZoom,
     opaque: layerConfig.opaque,
     reprojectionErrorThreshold: options.reprojectionErrorThreshold,
     tileLoadFunction: options.tileLoadFunction,

src/ol/source/xyzsource.js

@@ -33,6 +33,7 @@ ol.source.XYZ = function(options) {
       ol.tilegrid.createXYZ({
         extent: ol.tilegrid.extentFromProjection(projection),
         maxZoom: options.maxZoom,
+        minZoom: options.minZoom,
         tileSize: options.tileSize
       });