Load features before rendering

src/ol/renderer/canvas/canvasvectorlayerrenderer.js

@@ -207,6 +207,7 @@ ol.renderer.canvas.VectorLayer.prototype.prepareFrame =
   var tolerance = frameStateResolution / (2 * pixelRatio);
   var replayGroup = new ol.render.canvas.ReplayGroup(tolerance, extent,
       frameStateResolution);
+  vectorSource.loadFeatures(extent, frameStateResolution);
   var renderFeature =
       /**
        * @param {ol.Feature} feature Feature.

src/ol/source/vectorsource.js

@@ -337,6 +337,13 @@ ol.source.Vector.prototype.isEmpty = function() {
 };
 
 
+/**
+ * @param {ol.Extent} extent Extent.
+ * @param {number} resolution Resolution.
+ */
+ol.source.Vector.prototype.loadFeatures = goog.nullFunction;
+
+
 /**
  * @param {ol.Feature} feature Feature.
  * @todo stability experimental