Make icon size optional

src/ol/icon.js

@@ -5,12 +5,23 @@ goog.require('ol.style.Image');
 
 /**
  * @param {string} src Image source URI.
- * @param {ol.Size} size Image size.
+ * @param {ol.Size=} opt_size Image size.
  * @return {ol.style.Image} Image.
  */
-ol.icon.renderIcon = function(src, size) {
+ol.icon.renderIcon = function(src, opt_size) {
+
+  /**
+   * @type {ol.Size}
+   */
+  var size = goog.isDef(opt_size) ? opt_size : null;
+
+  /**
+   * @type {ol.Pixel}
+   */
+  var anchor = !goog.isNull(size) ? [size[0] / 2, size[1] / 2] : null;
+
   return new ol.style.Image({
-    anchor: [size[0] / 2, size[1] / 2],
+    anchor: anchor,
     size: size,
     src: src,
     rotation: 0,

src/ol/style/imagestyle.js

@@ -114,6 +114,12 @@ ol.style.Image.prototype.handleImageError_ = function() {
  */
 ol.style.Image.prototype.handleImageLoad_ = function() {
   this.imageState = ol.style.ImageState.LOADED;
+  if (goog.isNull(this.size)) {
+    this.size = [this.image.width, this.image.height];
+  }
+  if (goog.isNull(this.anchor)) {
+    this.anchor = [this.size[0] / 2, this.size[1] / 2];
+  }
   this.unlistenImage_();
   this.dispatchChangeEvent_();
 };