/// <summary>
/// Finds removed switchpoints which now describe forlorn ends. Add these to ForlornStartNodes. Afterwards all unneeded SwitchPoints are removed.
/// </summary>
protected virtual void UpdateSwitchPoints()
{
var forlornStartNodes = (from switchPoint in SwitchPoints where switchPoint.Value.EndPoints.Count == 1 select switchPoint.Key).ToList();
foreach (var forlornStartNode in forlornStartNodes)
{
ForlornStartNodes.Add(forlornStartNode);
}
var listToRemove = (from switchPoint in SwitchPoints where switchPoint.Value.EndPoints.Count < 3 select switchPoint.Key).ToList();
foreach (var key in listToRemove)
{
SwitchPoints.Remove(key);
}
}
//Forlorn stuff
/// <summary>
/// Removes Forlorn out of the figure and converts them to LineObstacles.
/// </summary>
/// <param name="obstacles"></param>
protected virtual void GetForlorn(ObstacleCollection obstacles)
{
var forlornNodes = new Queue <Vector2>();
foreach (var forlornNodeStart in ForlornStartNodes)
{
forlornNodes.Enqueue(forlornNodeStart);
}
while (forlornNodes.Count > 0)
{
var currentItem = forlornNodes.Dequeue();
List <LineSegment> forlornLines;
Vector2 lastItemEndPoint; //this is needed for Switch Points below
var forlornRoot = GetforlornRoot(currentItem, out forlornLines, out lastItemEndPoint);
foreach (var line in forlornLines)
{
obstacles.Add(new LineObstacle(line.Start, line.End, Layer));
Lines.Remove(line);
}
if (SwitchPoints.Count == 0)
{
continue;
}
SwitchPoint switchPoint;
if (!SwitchPoints.TryGetValue(forlornRoot, out switchPoint))
{
continue;
}
if (switchPoint.EndPoints.Count > 0)
{
switchPoint.EndPoints.Remove(lastItemEndPoint);
}
if (switchPoint.EndPoints.Count == 1)
{
forlornNodes.Enqueue(forlornRoot);
SwitchPoints.Remove(forlornRoot);
}
}
ForlornStartNodes.Clear();
UpdateSwitchPoints();
}
protected List <LineSegment> WalkFigure(LineNodeDictionary nodes)
{
var lines = new List <LineSegment>();
var visitedItems = new List <Vector2>();
var nodesToVisit = new Stack <LineSegment>();
var origin = nodes.Keys.First();
var lineSegment = new LineSegment(origin, origin);
nodesToVisit.Push(lineSegment);
while (nodesToVisit.Count > 0)
{
var currentItem = nodesToVisit.Pop();
var connectedNodes = GetConnectedNodes(currentItem.End, nodes);
if (connectedNodes.Count == 1) //only the item I come from
{
ForlornStartNodes.Add(currentItem.End);
}
if (connectedNodes.Count > 2 && !SwitchPoints.ContainsKey(currentItem.End))
{
SwitchPoints.Add(currentItem.End, new SwitchPoint(new List <Vector2>(connectedNodes)));
}
connectedNodes.Remove(currentItem.Start);
foreach (var connectedNode in connectedNodes)
{
if (visitedItems.Contains(connectedNode))
{
continue;
}
lineSegment = AddLine(currentItem.End, connectedNode, lines);
nodesToVisit.Push(lineSegment);
}
visitedItems.Add(currentItem.End);
}
if (GetConnectedNodes(origin, nodes).Count <= 2)
{
SwitchPoints.Remove(origin); //remove start point, it's not really a switch point
}
return(lines);
}
