Add updateVectorsWhileAnimating option

With this option, vector batches will be recreated with every frame.
For animations, this means that vector data won't be clipped to the
extent at which the animation started.

Author: ahocevar

externs/olx.js

@@ -178,6 +178,7 @@ olx.interaction.InteractionOptions.prototype.handleEvent;
  *     overlays: (ol.Collection.<ol.Overlay>|Array.<ol.Overlay>|undefined),
  *     renderer: (ol.RendererType|Array.<ol.RendererType|string>|string|undefined),
  *     target: (Element|string|undefined),
+ *     updateVectorsWhileAnimating: (boolean|undefined),
  *     view: (ol.View|undefined)}}
  * @api
  */
@@ -294,6 +295,16 @@ olx.MapOptions.prototype.renderer;
 olx.MapOptions.prototype.target;
 
 
+/**
+ * When set to true, vectors will be rendered immediately as they pan into view.
+ * This means that no vectors will be shown clipped, but the setting will have a
+ * performance impact for large amounts of vector data.
+ * Default is `false`.
+ * @type {boolean|undefined}
+ */
+olx.MapOptions.prototype.updateVectorsWhileAnimating;
+
+
 /**
  * The map's view.  No layer sources will be fetched unless this is specified at
  * construction time or through {@link ol.Map#setView}.

src/ol/map.js

@@ -187,6 +187,14 @@ ol.Map = function(options) {
   this.pixelRatio_ = goog.isDef(options.pixelRatio) ?
       options.pixelRatio : ol.has.DEVICE_PIXEL_RATIO;
 
+  /**
+   * @type {boolean}
+   * @private
+   */
+  this.updateVectorsWhileAnimating_ =
+      goog.isDef(options.updateVectorsWhileAnimating) ?
+          options.updateVectorsWhileAnimating : false;
+
   /**
    * @private
    * @type {Object}
@@ -1234,6 +1242,7 @@ ol.Map.prototype.renderFrame_ = function(time) {
       animate: false,
       attributions: {},
       coordinateToPixelMatrix: this.coordinateToPixelMatrix_,
+      updateVectorsWhileAnimating: this.updateVectorsWhileAnimating_,
       extent: null,
       focus: goog.isNull(this.focus_) ? viewState.center : this.focus_,
       index: this.frameIndex_++,

src/ol/renderer/canvas/canvasvectorlayerrenderer.js

@@ -169,7 +169,8 @@ ol.renderer.canvas.VectorLayer.prototype.prepareFrame =
       frameState.attributions, vectorSource.getAttributions());
   this.updateLogos(frameState, vectorSource);
 
-  if (!this.dirty_ && (frameState.viewHints[ol.ViewHint.ANIMATING] ||
+  if (!this.dirty_ && (!frameState.updateVectorsWhileAnimating &&
+      frameState.viewHints[ol.ViewHint.ANIMATING] ||
       frameState.viewHints[ol.ViewHint.INTERACTING])) {
     return true;
   }