Merge pull request #7328 from ahocevar/declutter

Declutter text and images

src/ol/source/imagevector.js

@@ -4,6 +4,7 @@ goog.require('ol');
 goog.require('ol.dom');
 goog.require('ol.events');
 goog.require('ol.events.EventType');
+goog.require('ol.ext.rbush');
 goog.require('ol.extent');
 goog.require('ol.render.canvas.ReplayGroup');
 goog.require('ol.renderer.vector');
@@ -55,6 +56,12 @@ ol.source.ImageVector = function(options) {
    */
   this.canvasSize_ = [0, 0];
 
+  /**
+   * Declutter tree.
+   * @private
+   */
+  this.declutterTree_ = ol.ext.rbush(9);
+
   /**
    * @private
    * @type {number}
@@ -113,7 +120,7 @@ ol.source.ImageVector.prototype.canvasFunctionInternal_ = function(extent, resol
 
   var replayGroup = new ol.render.canvas.ReplayGroup(
       ol.renderer.vector.getTolerance(resolution, pixelRatio), extent,
-      resolution, pixelRatio, this.source_.getOverlaps(), this.renderBuffer_);
+      resolution, pixelRatio, this.source_.getOverlaps(), this.declutterTree_, this.renderBuffer_);
 
   this.source_.loadFeatures(extent, resolution, projection);
 
@@ -146,6 +153,7 @@ ol.source.ImageVector.prototype.canvasFunctionInternal_ = function(extent, resol
   replayGroup.replay(this.canvasContext_, transform, 0, {});
 
   this.replayGroup_ = replayGroup;
+  this.declutterTree_.clear();
 
   return this.canvasContext_.canvas;
 };
@@ -161,7 +169,7 @@ ol.source.ImageVector.prototype.forEachFeatureAtCoordinate = function(
   } else {
     /** @type {Object.<string, boolean>} */
     var features = {};
-    return this.replayGroup_.forEachFeatureAtCoordinate(
+    var result = this.replayGroup_.forEachFeatureAtCoordinate(
         coordinate, resolution, 0, hitTolerance, skippedFeatureUids,
         /**
          * @param {ol.Feature|ol.render.Feature} feature Feature.
@@ -173,7 +181,9 @@ ol.source.ImageVector.prototype.forEachFeatureAtCoordinate = function(
             features[key] = true;
             return callback(feature);
           }
-        });
+        }, null);
+    this.declutterTree_.clear();
+    return result;
   }
 };