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;
}
protected void AddToNodes(Vector2 key, LineSegment line)
{
List<LineSegment> segments;
if (Nodes.TryGetValue(key, out segments))
{
segments.Add(line);
}
else
{
segments = new List<LineSegment> { line };
Nodes.Add(key, segments);
}
}
private void GetNeighborBlocks(LineSegment line, IEnumerable<Block> blocks, out Block blockX, out Block blockY, out Orientation orientation)
{
blockX = null;
blockY = null;
orientation = Orientation.Other;
foreach (var block in blocks)
{
var found = false;
var blockLines = Polygon.GetBlockLines(block, Layer).Where(item => item.IsSlope);
foreach (var lineObstacle in blockLines)
{
if (line.Start == lineObstacle.Start && line.End == lineObstacle.End)
found = true;
else if (line.End == lineObstacle.Start && line.Start == lineObstacle.End)
found = true;
if (found)
break;
}
if (!found)
continue;
if (blockX == null)
blockX = block;
else
{
blockY = block;
//ok, we have both blocks
var isVertical = line.Direction == Direction.Down || line.Direction == Direction.Up;
var isHorizontal = line.Direction == Direction.Left || line.Direction == Direction.Right;
if (isVertical)
{
orientation = Orientation.Vertical;
if (blockX.Position.X < blockY.Position.X)
return;
}
if (isHorizontal)
{
orientation = Orientation.Horizontal;
if (blockX.Position.Y < blockY.Position.Y)
return;
}
var blockTemp = blockX;
blockX = blockY;
blockY = blockTemp;
return;
}
}
}
private static void AddBlockLines(IDictionary<Block, List<LineSegment>> blockLines, Block block, LineSegment intersectionLine)
{
if (block == null)
return;
List<LineSegment> blockLineSegments;
if (blockLines.TryGetValue(block, out blockLineSegments))
{
blockLineSegments.Add(intersectionLine);
}
else
{
blockLineSegments = new List<LineSegment> {intersectionLine};
blockLines.Add(block, blockLineSegments);
}
}
//Line stuff
protected virtual LineSegment AddLine(Vector2 start, Vector2 end, ICollection<LineSegment> list)
{
var line = new LineSegment(start, end);
list.Add(line);
return line;
}
protected static int GetLinePriority(Direction baseDirection, LineSegment line)
{
var priority = _baseDirectionPriority[line.Direction];
if (baseDirection == Direction.None)
baseDirection = Direction.Down;
priority += 4 - _baseDirectionPriority[baseDirection];
if (priority < 0)
priority = 8 + priority;
if (priority > 8)
priority = priority - 8;
return priority;
}