/// <summary>
/// Given an EdgeCollection with a bunch of edges:
/// 1. Grabs the outside perimeter formed by the available edges.
/// Edges not connected to this perimeter are left behind.
/// 2. Out of the left behind edges, grabs a cycle that contains no non-perimeter edges within it and orders them.
/// Again, edges not connected to this group are left behind.
/// 3. Repeat until all edges are ordered and split into their own connected groups.
/// Returns the split and ordered edges in a List.
/// </summary>
/// <param name="originalEdgeColl">Collection of all edges in a TileMap, regardless of whether they are connected or not</param>
/// <returns>A list of Edge Collections, all ordered, and all split into connected groups</returns>
private static List <EdgeCollection <TileEdge> > _SplitEdgeColl(EdgeCollection <TileEdge> originalEdgeColl)
{
var splitEdgeColl = new List <EdgeCollection <TileEdge> >();
EdgeCollection <TileEdge> cloneEdgeColl = originalEdgeColl.Clone();
EdgeCollection <TileEdge> outerEdgesColl = cloneEdgeColl.GetOuterClosedLoop(); //first pull the outer perim
splitEdgeColl.Add(outerEdgesColl);
cloneEdgeColl = cloneEdgeColl.GetExcludedCollection(outerEdgesColl);
while (cloneEdgeColl.Count > 0)
{
List <EdgeCollection <TileEdge> > smallClosedLoops = cloneEdgeColl.GetSmallClosedLoops();
foreach (EdgeCollection <TileEdge> smallClosedLoop in smallClosedLoops)
{
splitEdgeColl.Add(smallClosedLoop);
cloneEdgeColl = cloneEdgeColl.GetExcludedCollection(smallClosedLoop);
}
}
return(splitEdgeColl);
}