public List <Ring> AssignToRings(List <Way> ways)
{
var copyWays = new List <Way>(ways);
var joined = new Stack <Ring>();
int i = 0;
while (copyWays.Count != 0)
{
Action <List <Node> > how = null;
var what = new List <Node>();
var currentWay = copyWays.Pop();
var currentNodes = currentWay.Nodes.Select(n => currentWay.ResolvedNodes[n]).ToList();
var newRing = new Ring();
newRing.AddRange(currentNodes);
joined.Push(newRing);
while (copyWays.Count > 0 && currentNodes.First().Id != currentNodes.Last().Id)
{
currentNodes = newRing;
var firstNode = currentNodes.First();
var lastNode = currentNodes.Last();
for (i = 0; i < copyWays.Count; ++i)
{
what = copyWays[i].ResolvedNodes.Values.ToList();
if (lastNode.Equals(what.First()))
{
how = newRing.AddRange;
what = what.Skip(1).ToList();
break;
}
if (lastNode.Equals(what.Last()))
{
how = newRing.AddRange;
what = what.TakeAllButLast().Reverse().ToList();
break;
}
if (firstNode.Equals(what.Last()))
{
how = (nodes) => newRing.InsertRange(0, nodes);
what = what.TakeAllButLast().ToList();
break;
}
if (firstNode.Equals(what.First()))
{
how = (nodes) => newRing.InsertRange(0, nodes);
what = what.Skip(1).Reverse().ToList();
break;
}
else
{
what = null;
how = null;
}
}
if (what == null)
{
Debug.WriteLine("Multipolygon contains unclosed ring geometry");
break;
}
var wayToRemove = copyWays[i];
copyWays.Remove(wayToRemove);
how(what);
}
}
return(joined.ToList());
}