private SquareCollection FindNeighBourSquares(int row, int column)
{
SquareCollection neighBourSquares = new SquareCollection();
// Check neighbourhood
try
{
if (IsSquareAvailable(this.innerBoard_[row, column - 1])) // left
{
neighBourSquares.Add(this.innerBoard_[row, column - 1]);
}
if (IsSquareAvailable(this.innerBoard_[row, column + 1])) // right
{
neighBourSquares.Add(this.innerBoard_[row, column + 1]);
}
if (IsSquareAvailable(this.innerBoard_[row - 1, column])) // up
{
neighBourSquares.Add(this.innerBoard_[row - 1, column]);
}
if (IsSquareAvailable(this.innerBoard_[row + 1, column])) // down
{
neighBourSquares.Add(this.innerBoard_[row + 1, column]);
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message + row.ToString() + column.ToString());
}
return(neighBourSquares);
}
private void FindSolution(int row, int column)
{
SquareCollection neighBours = new SquareCollection();
SelectSquare(new Square(row, column));
// increment the cost for this path manager
this.totalCost_++;
// look for the neighbour squares
neighBours = FindNeighBourSquares(row, column);
// determine what to do about the neighbours
if (!endManagePath_)
{
if (row == this.TargetSquare.X && column == this.TargetSquare.Y)
{
// first check if we have found the solution
EndManagePath(new Square(row, column), true);
}
else if (neighBours.Count == 0)
{
// no more solution
EndManagePath(new Square(row, column), true);
}
else if (neighBours.Count == 1)
{
// continue managing the path
FindSolution(neighBours[0].X, neighBours[0].Y);
}
else if (neighBours.Count > 1)
{
// more than one neighbours found, so end managing process with the current square
// then assing new pathmanagers for the rest of the neighbours
EndManagePath(new Square(row, column), false);
// assign new path managers
for (int i = 0; i < neighBours.Count; i++)
{
// assign this object as parent path for the sub path manager and indicate that sub manager is not root
PathManager subPathManager = new PathManager(this, i, new Square(neighBours[i].X, neighBours[i].Y),
this.SourceSquare, this.TargetSquare, this.innerBoard_, false);
PathManagerFetcher nFetcher = new PathManagerFetcher(this, subPathManager);
Thread workerThread = new Thread(new ThreadStart(nFetcher.Fetch));
workerThread.Name = "PathFinder" + this.Name;
workerThread.Start();
}
}
}
else
{
// this situation is not normal, not expected to happen; even if it happens assume no more solution
EndManagePath(new Square(row, column), true);
}
}
public PathManager(PathManager parentPathManager, int subIndex, Square startPoint, Square sourceSquare, Square targetSquare, SquareBoard board, bool isRoot)
{
// assign square board
this.innerBoard_ = board;
// which square this manager starts?
this.startPointSquare_ = startPoint;
// is this a root manager?
this.isRoot_ = isRoot;
// parent manager of this manager
this.parentPathManager_ = parentPathManager;
// total cost of this manager if we decide to take it
this.totalCost_ = 0;
this.innerThreadCount_ = 0;
this.totalSolutions_ = 0;
this.innerPathSquares_ = new SquareCollection();
// sub mangers collections
this.subPathManagers_ = new PathManagerCollection();
this.innerSolutions_ = new PathManagerCollection();
// which path are we looking for a solution?
this.sourceSquare_ = sourceSquare;
this.targetSquare_ = targetSquare;
this.endPointSquare_ = null;
this.pathStatus_ = SquarePathStatus.PATH;
// assign a unique name to the manager
if (isRoot)
{
this.managerName_ = "0";
}
else
{
this.managerName_ = parentPathManager.Name + subIndex.ToString();
}
}
