private static PathSegmentCollection SortPathSegmentCollection(PathSegmentCollection segments)
{
var n = segments.Count - 2;
Debug.Assert(n % 2 == 0);
var m = n / 2;
// TODO: use better variables for v1, v2 and v3
var v1 = Enumerable.Range(0, m).ToList();
var v2 = v1.Select(x => x * 2 + 1);
var v3 = v1.Select(x => x * 2 + 2);
var sortedSegments = new List<PathSegment> { segments.First() };
sortedSegments.AddRange(v2.Select(x => segments[x]));
sortedSegments.Add(segments.Last());
sortedSegments.AddRange(v3.Select(x => segments[x]).Reverse());
return new PathSegmentCollection(sortedSegments);
}