Implement setPolygons on ol.geom.MultiPolygon

src/ol/geom/multipolygon.js

@@ -1,5 +1,7 @@
 goog.provide('ol.geom.MultiPolygon');
 
+goog.require('goog.array');
+goog.require('goog.asserts');
 goog.require('ol.extent');
 goog.require('ol.geom.GeometryType');
 goog.require('ol.geom.Polygon');
@@ -258,3 +260,33 @@ ol.geom.MultiPolygon.prototype.setFlatCoordinates =
   this.endss_ = endss;
   this.dispatchChangeEvent();
 };
+
+
+/**
+ * @param {Array.<ol.geom.Polygon>} polygons Polygons.
+ * @todo stability experimental
+ */
+ol.geom.MultiPolygon.prototype.setPolygons = function(polygons) {
+  var layout = ol.geom.GeometryLayout.XY;
+  var flatCoordinates = [];
+  var endss = [];
+  var i, ii, ends;
+  for (i = 0, ii = polygons.length; i < ii; ++i) {
+    var polygon = polygons[i];
+    if (i === 0) {
+      layout = polygon.getLayout();
+    } else {
+      // FIXME better handle the case of non-matching layouts
+      goog.asserts.assert(polygon.getLayout() == layout);
+    }
+    var offset = flatCoordinates.length;
+    ends = polygon.getEnds();
+    var j, jj;
+    for (j = 0, jj = ends.length; j < jj; ++j) {
+      ends[j] += offset;
+    }
+    goog.array.extend(flatCoordinates, polygon.getFlatCoordinates());
+    endss.push(ends);
+  }
+  this.setFlatCoordinates(layout, flatCoordinates, endss);
+};