/// <summary>
/// Given some input EdgeCollection, iterates through its edges and adds 'valid' ones to a new
/// collection, which is then returned.
/// Validity is determined through the _IsLedgeValid function.
/// </summary>
/// <param name="ledgeColl"></param>
/// <param name="preTileMap"></param>
/// <param name="superTileMap"></param>
/// <returns></returns>
private static EdgeCollection <TileEdge> _BuildHoleGroupValidLedges(EdgeCollection <TileEdge> ledgeColl, TileMap preTileMap, TileMap superTileMap)
{
var validLedges = new EdgeCollection <TileEdge>();
foreach (TileEdge ledge in ledgeColl)
{
if (_IsLedgeValid(ledge, preTileMap, superTileMap))
{
TileEdge superimposedLedge = ledge.GetShiftedByN(SHIFT_DIST);
if (!validLedges.HasEdgePoints(superimposedLedge))
{
validLedges.Add(superimposedLedge);
}
}
}
return(validLedges);
}