Add ol.geom.{in,de}flateCoordinates

src/ol/geom/geometry.js

@@ -163,3 +163,46 @@ ol.geom.RawMultiLineString;
  * @typedef {Array.<ol.geom.RawPolygon>}
  */
 ol.geom.RawMultiPolygon;
+
+
+/**
+ * @param {Array.<number>} flatCoordinates Flat coordinates.
+ * @param {number} offset Offset.
+ * @param {Array.<ol.Coordinate>} coordinates Coordinates.
+ * @param {number} stride Stride.
+ * @return {number} offset Offset.
+ */
+ol.geom.deflateCoordinates =
+    function(flatCoordinates, offset, coordinates, stride) {
+  var i, ii;
+  for (i = 0, ii = coordinates.length; i < ii; ++i) {
+    var coordinate = coordinates[i];
+    goog.asserts.assert(coordinate.length == stride);
+    var j;
+    for (j = 0; j < stride; ++j) {
+      flatCoordinates[offset++] = coordinate[j];
+    }
+  }
+  return offset;
+};
+
+
+/**
+ * @param {Array.<number>} flatCoordinates Flat coordinates.
+ * @param {number} offset Offset.
+ * @param {number} end End.
+ * @param {number} stride Stride.
+ * @param {Array.<ol.Coordinate>=} opt_coordinates Coordinates.
+ * @return {Array.<ol.Coordinate>} Coordinates.
+ */
+ol.geom.inflateCoordinates =
+    function(flatCoordinates, offset, end, stride, opt_coordinates) {
+  var coordinates = goog.isDef(opt_coordinates) ? opt_coordinates : [];
+  var i = 0;
+  var j;
+  for (j = offset; j < end; j += stride) {
+    coordinates[i++] = flatCoordinates.slice(j, j + stride);
+  }
+  coordinates.length = i;
+  return coordinates;
+};

test/spec/ol/geom/geom.test.js

@@ -0,0 +1,31 @@
+goog.provide('ol.test.geom');
+
+
+describe('ol.geom', function() {
+
+  describe('ol.geom.deflateCoordinates', function() {
+
+    var flatCoordinates;
+    beforeEach(function() {
+      flatCoordinates = [];
+    });
+
+    it('flattens coordinates', function() {
+      var offset = ol.geom.deflateCoordinates(
+          flatCoordinates, 0, [[1, 2], [3, 4]], 2);
+      expect(offset).to.be(4);
+      expect(flatCoordinates).to.eql([1, 2, 3, 4]);
+    });
+
+  });
+
+  describe('ol.geom.inflateCoordinates', function() {
+
+    it('inflates coordinates', function() {
+      var coordinates = ol.geom.inflateCoordinates([1, 2, 3, 4], 0, 4, 2);
+      expect(coordinates).to.eql([[1, 2], [3, 4]]);
+    });
+
+  });
+
+});