Merge pull request #7559 from ahocevar/unskip-image-features

Handle skipping and unskipping features with renderMode: 'image'

src/ol/renderer/canvas/imagelayer.js

@@ -4,6 +4,7 @@ goog.require('ol');
 goog.require('ol.ImageCanvas');
 goog.require('ol.LayerType');
 goog.require('ol.ViewHint');
+goog.require('ol.array');
 goog.require('ol.extent');
 goog.require('ol.layer.VectorRenderType');
 goog.require('ol.obj');
@@ -35,6 +36,11 @@ ol.renderer.canvas.ImageLayer = function(imageLayer) {
    */
   this.imageTransform_ = ol.transform.create();
 
+  /**
+   * @type {!Array.<string>}
+   */
+  this.skippedFeatures_ = [];
+
   /**
    * @private
    * @type {ol.renderer.canvas.VectorLayer}
@@ -139,11 +145,15 @@ ol.renderer.canvas.ImageLayer.prototype.prepareFrame = function(frameState, laye
           rotation: 0
         }))
       }));
-      if (vectorRenderer.prepareFrame(imageFrameState, layerState) && vectorRenderer.replayGroupChanged) {
+      var skippedFeatures = Object.keys(imageFrameState.skippedFeatureUids).sort();
+      if (vectorRenderer.prepareFrame(imageFrameState, layerState) &&
+          (vectorRenderer.replayGroupChanged ||
+          !ol.array.equals(skippedFeatures, this.skippedFeatures_))) {
         context.canvas.width = imageFrameState.size[0] * pixelRatio;
         context.canvas.height = imageFrameState.size[1] * pixelRatio;
         vectorRenderer.composeFrame(imageFrameState, layerState, context);
         this.image_ = new ol.ImageCanvas(renderedExtent, viewResolution, pixelRatio, context.canvas);
+        this.skippedFeatures_ = skippedFeatures;
       }
     } else {
       image = imageSource.getImage(