polyline: Added encode/decodeUnsignedIntegers() functions

src/ol/parser/polyline.js

@@ -72,6 +72,52 @@ ol.parser.polyline.decodeFlatCoordinates = function(encoded, opt_dimension) {
 };
 
 
+/**
+ * Encode a list of unsigned integers and return an encoded string
+ *
+ * @param {Array.<number>} numbers A list of unsigned integers.
+ * @return {string} The encoded string.
+ */
+ol.parser.polyline.encodeUnsignedIntegers = function(numbers) {
+  var encoded = '';
+
+  var numbersLength = numbers.length;
+  for (var i = 0; i < numbersLength; ++i) {
+    encoded += ol.parser.polyline.encodeUnsignedInteger(numbers[i]);
+  }
+
+  return encoded;
+};
+
+
+/**
+ * Decode a list of unsigned integers from an encoded string
+ *
+ * @param {string} encoded An encoded string.
+ * @return {Array.<number>} A list of unsigned integers.
+ */
+ol.parser.polyline.decodeUnsignedIntegers = function(encoded) {
+  var numbers = new Array();
+
+  var encodedLength = encoded.length;
+  for (var i = 0; i < encodedLength;) {
+    var result = 0;
+    var shift = 0;
+
+    var b;
+    do {
+      b = encoded.charCodeAt(i++) - 63;
+      result |= (b & 0x1f) << shift;
+      shift += 5;
+    } while (b >= 0x20);
+
+    numbers.push(result);
+  }
+
+  return numbers;
+};
+
+
 /**
  * Encode one single floating point number and return an encoded string
  *

test/spec/ol/parser/polyline.test.js

@@ -26,6 +26,29 @@ describe('ol.parser.polyline', function() {
     });
   });
 
+
+  var unsignedIntegers = [0, 30, 1, 31, 32, 2, 174];
+  var encodedUnsignedIntegers = '?]@^_@AmD';
+
+  describe('encodeUnsignedIntegers', function() {
+    it('returns expected value', function() {
+      var encodeUnsignedIntegers = ol.parser.polyline.encodeUnsignedIntegers;
+
+      expect(encodeUnsignedIntegers(
+          unsignedIntegers)).toEqual(encodedUnsignedIntegers);
+    });
+  });
+
+  describe('decodeUnsignedIntegers', function() {
+    it('returns expected value', function() {
+      var decodeUnsignedIntegers = ol.parser.polyline.decodeUnsignedIntegers;
+
+      expect(decodeUnsignedIntegers(
+          encodedUnsignedIntegers)).toEqual(unsignedIntegers);
+    });
+  });
+
+
   describe('encodeFloat', function() {
     it('returns expected value', function() {
       var encodeFloat = ol.parser.polyline.encodeFloat;