Performance improvement: only create context when it is needed

2017-02-07 16:35:22 +01:00
parent 302087b4ec
commit 7db5eea56b
3 changed files with 37 additions and 22 deletions
@@ -24,7 +24,7 @@ ol.VectorTile = function(tileCoord, state, src, format, tileLoadFunction) {
   * @private
   * @type {CanvasRenderingContext2D}
   */
-  this.context_ = ol.dom.createCanvasContext2D();
+  this.context_ = null;

  /**
   * @private
@@ -83,6 +83,9 @@ ol.inherits(ol.VectorTile, ol.Tile);
 * @return {CanvasRenderingContext2D} The rendering context.
 */
 ol.VectorTile.prototype.getContext = function() {
+  if (!this.context_) {
+    this.context_ = ol.dom.createCanvasContext2D();
+  }
  return this.context_;
 };