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);
}
// IMPLEMENTATION METHODS
private Maze GenerateInitializedMaze(int width, int height)
{
var positionToMazeCell = new Dictionary <string, MazeCell>();
var positionToMazeCellWall = new Dictionary <string, MazeWall>();
// keep track of the last maze cell
MazeCell lastMazeCell = null;
// for each position instantiate maze cells and
// point to previous maze cell to create linked list
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
var mazeCell = new MazeCell(j, i);
if (lastMazeCell != null)
{
mazeCell.nextMazeCell = lastMazeCell;
}
lastMazeCell = mazeCell;
// add to position lookup dict
positionToMazeCell.Add(
GetFormattedPosition(mazeCell.position_X, mazeCell.position_Y),
mazeCell
);
}
}
// for every maze cell in the linked list set all the neighbor cells
MazeCell currentMazeCell = lastMazeCell;
MazeCell previousMazeCell = null;
while (currentMazeCell != null)
{
foreach (string direction in MazeCell.directions)
{
MazeCell nCell = this.GetMazeCellNeighborCellFromLookupDict(
positionToMazeCell,
currentMazeCell,
direction
);
MazeWall sharedWall = null;
if (nCell != null)
{
currentMazeCell.SetNeighborMazeCell(direction, nCell);
sharedWall = nCell.GetMazeWall(MazeCell.GetOppositeDirection(direction));
}
if (sharedWall != null)
{
currentMazeCell.SetWall(direction, sharedWall);
}
else
{
float xOffset = 0;
float yOffset = 0;
if (direction == MazeCell.NORTH)
{
yOffset = 0.5f;
}
else if (direction == MazeCell.SOUTH)
{
yOffset = -0.5f;
}
else if (direction == MazeCell.EAST)
{
xOffset = 0.5f;
}
else if (direction == MazeCell.WEST)
{
xOffset = -0.5f;
}
bool isOutwall = (
(direction == MazeCell.NORTH && currentMazeCell.position_Y == height - 1) ||
(direction == MazeCell.SOUTH && currentMazeCell.position_Y == 0) ||
(direction == MazeCell.EAST && currentMazeCell.position_X == 0) ||
(direction == MazeCell.WEST && currentMazeCell.position_X == width - 1)
);
bool isHorizontal = direction == MazeCell.NORTH || direction == MazeCell.SOUTH;
var mazeWall = new MazeWall(
currentMazeCell.position_X + xOffset,
currentMazeCell.position_Y + yOffset,
true,
isOutwall,
isHorizontal
);
currentMazeCell.SetWall(direction, mazeWall);
positionToMazeCellWall.Add(
this.GetFormattedPosition(
mazeWall.position_X,
mazeWall.position_Y
),
mazeWall
);
}
}
previousMazeCell = currentMazeCell;
currentMazeCell = currentMazeCell.nextMazeCell;
}
var maze = new Maze(
width,
height,
positionToMazeCell,
lastMazeCell,
positionToMazeCellWall
);
// this.TestValidateMaze(maze);
return(maze);
}