Merge pull request openlayers#2821 from elemoine/polygon-from-extent

Add ol.geom.Polygon.fromExtent
dasakigr · Oct 15, 2014 · 74fd55a · 74fd55a
2 parents 017703f + 1ce43e3
commit 74fd55a
Show file tree

Hide file tree

Showing 2 changed files with 33 additions and 0 deletions.
diff --git a/src/ol/geom/polygon.js b/src/ol/geom/polygon.js
@@ -374,3 +374,23 @@ ol.geom.Polygon.circular = function(sphere, center, radius, opt_n) {
       ol.geom.GeometryLayout.XY, flatCoordinates, [flatCoordinates.length]);
   return polygon;
 };
+
+
+/**
+ * Create a polygon from an extent. The layout used is `XY`.
+ * @param {ol.Extent} extent The extent.
+ * @return {ol.geom.Polygon} The polygon.
+ * @api
+ */
+ol.geom.Polygon.fromExtent = function(extent) {
+  var minX = extent[0];
+  var minY = extent[1];
+  var maxX = extent[2];
+  var maxY = extent[3];
+  var flatCoordinates =
+      [minX, minY, minX, maxY, maxX, maxY, maxX, minY, minX, minY];
+  var polygon = new ol.geom.Polygon(null);
+  polygon.setFlatCoordinates(
+      ol.geom.GeometryLayout.XY, flatCoordinates, [flatCoordinates.length]);
+  return polygon;
+};
diff --git a/test/spec/ol/geom/polygon.test.js b/test/spec/ol/geom/polygon.test.js
@@ -399,6 +399,19 @@ describe('ol.geom.Polygon', function() {
     });
   });
 
+  describe('ol.geom.Polygon.fromExtent', function() {
+    it('creates the correct polygon', function() {
+      var extent = [1, 2, 3, 5];
+      var polygon = ol.geom.Polygon.fromExtent(extent);
+      var flatCoordinates = polygon.getFlatCoordinates();
+      expect(flatCoordinates).to.eql(
+          [1, 2, 1, 5, 3, 5, 3, 2, 1, 2]);
+      var orientedFlatCoordinates = polygon.getOrientedFlatCoordinates();
+      expect(orientedFlatCoordinates).to.eql(
+          [1, 2, 1, 5, 3, 5, 3, 2, 1, 2]);
+    });
+  });
+
 });