private string SearchForEligibleDirectionFromCell(
MazeCell inputCell,
Dictionary <string, MazeCell> mazeCellsVisited
)
{
List <string> shuffledDirections = Functions.ShuffleStringList(MazeCell.directions);
foreach (string direction in shuffledDirections)
{
var nCell = inputCell.GetNeighborMazeCell(direction);
if (nCell != null)
{
string nCellPos = this.GetFormattedPosition(nCell.position_X, nCell.position_Y);
var wall = inputCell.GetMazeWall(direction);
if (wall == null)
{
Debug.Log("wall not found..");
}
bool neighborCellIsEligible = (
!mazeCellsVisited.ContainsKey(nCellPos) &&
wall.isActive
);
if (neighborCellIsEligible)
{
return(direction);
}
}
}
return(null);
}
private Maze ApplyDepthFirstBacktrackingToMaze(Maze maze)
{
var backtrackMem = new Stack();
var mazeCellsVisited = new Dictionary <string, MazeCell>();
// select random cell to start and memorize
MazeCell currentMazeCell = this.SelectRandomMazeCell(maze);
MazeCell initialMazeCell = currentMazeCell;
do
{
// mark current maze cell as visited
string currPos = this.GetFormattedPosition(
currentMazeCell.position_X,
currentMazeCell.position_Y
);
if (!mazeCellsVisited.ContainsKey(currPos))
{
mazeCellsVisited.Add(currPos, currentMazeCell);
}
// check for eligible direction
string eligibleDirection = this.SearchForEligibleDirectionFromCell(
currentMazeCell,
mazeCellsVisited
);
if (eligibleDirection != null)
{
// per the direction, remove the wall, memorize current maze cell,
// and move to neighbor maze cell
var nCell = currentMazeCell.GetNeighborMazeCell(eligibleDirection);
var wall = currentMazeCell.GetMazeWall(eligibleDirection);
wall.isActive = false;
backtrackMem.Push(currentMazeCell);
currentMazeCell = nCell;
}
else
{
// backtrack one cell and try again in next loop
currentMazeCell = (MazeCell)backtrackMem.Pop();
}
} while(currentMazeCell != initialMazeCell);
return(maze);
}