Add ol.geom.flat.segments.forEach

src/ol/geom/flat/segmentsflatgeom.js

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+goog.provide('ol.geom.flat.segments');
+
+
+/**
+ * This function calls `callback` for each segment of the flat coordinates
+ * array. If the callback returns a truthy value the function returns that
+ * value immediately. Otherwise the function returns `false`.
+ * @param {Array.<number>} flatCoordinates Flat coordinates.
+ * @param {number} offset Offset.
+ * @param {number} end End.
+ * @param {number} stride Stride.
+ * @param {function(ol.Coordinate, ol.Coordinate): T} callback Function
+ *     called for each segment.
+ * @return {T|boolean} Value.
+ * @template T
+ */
+ol.geom.flat.segments.forEach =
+    function(flatCoordinates, offset, end, stride, callback) {
+  var point1 = [flatCoordinates[offset], flatCoordinates[offset + 1]];
+  var point2 = [];
+  var ret;
+  for (; (offset + stride) < end; offset += stride) {
+    point2[0] = flatCoordinates[offset + stride];
+    point2[1] = flatCoordinates[offset + stride + 1];
+    ret = callback(point1, point2);
+    if (ret) {
+      return ret;
+    }
+    point1[0] = point2[0];
+    point1[1] = point2[1];
+  }
+  return false;
+};

test/spec/ol/geom/flat/segmentsflatgeom.test.js

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+goog.provide('ol.test.geom.flat.segments');
+
+describe('ol.geom.flat.segments', function() {
+
+  describe('ol.geom.flat.segments.forEach', function() {
+    var flatCoordinates, offset, end, stride;
+    beforeEach(function() {
+      flatCoordinates = [0, 0, 1, 1, 2, 2, 3, 3];
+      offset = 0;
+      end = 8;
+      stride = 2;
+    });
+    describe('callback returns undefined', function() {
+      it('executes the callback for each segment', function() {
+        var args = [];
+        var spy = sinon.spy(function(point1, point2) {
+          args.push([point1[0], point1[1], point2[0], point2[1]]);
+        });
+        var ret = ol.geom.flat.segments.forEach(
+            flatCoordinates, offset, end, stride, spy);
+        expect(spy.callCount).to.be(3);
+        expect(args[0][0]).to.be(0);
+        expect(args[0][1]).to.be(0);
+        expect(args[0][2]).to.be(1);
+        expect(args[0][3]).to.be(1);
+        expect(args[1][0]).to.be(1);
+        expect(args[1][1]).to.be(1);
+        expect(args[1][2]).to.be(2);
+        expect(args[1][3]).to.be(2);
+        expect(args[2][0]).to.be(2);
+        expect(args[2][1]).to.be(2);
+        expect(args[2][2]).to.be(3);
+        expect(args[2][3]).to.be(3);
+        expect(ret).to.be(false);
+      });
+    });
+    describe('callback returns true', function() {
+      it('executes the callback for the first segment', function() {
+        var args = [];
+        var spy = sinon.spy(function(point1, point2) {
+          args.push([point1[0], point1[1], point2[0], point2[1]]);
+          return true;
+        });
+        var ret = ol.geom.flat.segments.forEach(
+            flatCoordinates, offset, end, stride, spy);
+        expect(spy.callCount).to.be(1);
+        expect(args[0][0]).to.be(0);
+        expect(args[0][1]).to.be(0);
+        expect(args[0][2]).to.be(1);
+        expect(args[0][3]).to.be(1);
+        expect(ret).to.be(true);
+      });
+    });
+  });
+});
+
+goog.require('ol.geom.flat.segments');