/// <summary>
/// Used to create a begin and end for a maze
/// </summary>
/// <param name="arr">The array of the maze</param>
private void makeMazeBeginEnd(Cell[,] arr)
{
Point temp = new Point();
temp.Y = this.random.Next(this.height);
arr[temp.Y, temp.X].LeftWall = false;
this.begin = arr[temp.Y, temp.X];
temp.Y = this.random.Next(this.height);
temp.X = this.width - 1;
arr[temp.Y, temp.X].RightWall = false;
this.end = arr[temp.Y, temp.X];
}
/// <summary>
/// Solves the maze with the right-hand role recursively -
/// DON'T USE! IT IS FOR DEMONSTRATING PURPOSES ONLY!
/// </summary>
/// <param name="start">The maze begin</param>
/// <param name="dir">the initial direction</param>
private void rightHandRuleSolve(Cell start, Directions dir)
{
/*بص على يمينك
فاضي؟ خش من غير كلام كثير
في حيطة؟ بص قدامك
في حيطة برضه؟ طب شوف شمالك كده
حيطة؟ ارجع بقى*/
// look at your right (with respect to your direction)
// No wall? go in it.
// Wall? look at your front (with respect to your direction)
// Wall too? look at your left (with respect to your direction)
// Wall too? go back (in the reverse of your direction)
// note that the right of the right is down, the left of down is right, ect
// has arrived, return
if (start.Position == this.end.Position)
{
return;
}
// mark it as visited for graphics
this.maze[start.Position.Y, start.Position.X].Visited = true;
// to view the current solving location
this.currentSolvePos = start.Position;
// to slow operation
Thread.SpinWait(this.Sleep * sleepPeriod);
bool flag;
switch (dir)
{
case Directions.Right:
flag = start.Position.Y + 1 < height;
if (!flag || this.maze[start.Position.Y + 1, start.Position.X].UpWall)
{
flag = start.Position.X + 1 < width;
if (!flag || maze[start.Position.Y, start.Position.X + 1].LeftWall)
{
flag = start.Position.Y - 1 >= 0;
if (!flag || maze[start.Position.Y - 1, start.Position.X].DownWall)
{
rightHandRuleSolve(this.maze[start.Position.Y, start.Position.X], Directions.Left);
}
else
{
rightHandRuleSolve(maze[start.Position.Y - 1, start.Position.X], Directions.Up);
}
}
else
{
rightHandRuleSolve(this.maze[start.Position.Y, start.Position.X + 1], Directions.Right);
}
}
else
{
rightHandRuleSolve(this.maze[start.Position.Y + 1, start.Position.X], Directions.Down);
}
break;
case Directions.Left:
flag = start.Position.Y - 1 >= 0;
if (!flag || maze[start.Position.Y - 1, start.Position.X].DownWall)
{
flag = start.Position.X - 1 >= 0;
if (!flag || maze[start.Position.Y, start.Position.X - 1].RightWall)
{
flag = start.Position.Y + 1 < this.height;
if (!flag || maze[start.Position.Y + 1, start.Position.X].UpWall)
{
rightHandRuleSolve(maze[start.Position.Y, start.Position.X], Directions.Right);
}
else
{
rightHandRuleSolve(maze[start.Position.Y + 1, start.Position.X], Directions.Down);
}
}
else
{
rightHandRuleSolve(maze[start.Position.Y, start.Position.X - 1], Directions.Left);
}
}
else
{
rightHandRuleSolve(maze[start.Position.Y - 1, start.Position.X], Directions.Up);
}
break;
case Directions.Up:
flag = start.Position.X + 1 < this.width;
if (!flag || maze[start.Position.Y, start.Position.X + 1].LeftWall)
{
flag = start.Position.Y - 1 >= 0;
if (!flag || maze[start.Position.Y - 1, start.Position.X].DownWall)
{
flag = start.Position.X - 1 >= 0;
if (!flag || maze[start.Position.Y, start.Position.X - 1].RightWall)
{
rightHandRuleSolve(maze[start.Position.Y, start.Position.X], Directions.Down);
}
else
{
rightHandRuleSolve(maze[start.Position.Y, start.Position.X - 1], Directions.Left);
}
}
else
{
rightHandRuleSolve(maze[start.Position.Y - 1, start.Position.X], Directions.Up);
}
}
else
{
rightHandRuleSolve(maze[start.Position.Y, start.Position.X + 1], Directions.Right);
}
break;
default:
flag = start.Position.X - 1 >= 0;
if (!flag || maze[start.Position.Y, start.Position.X - 1].RightWall)
{
flag = start.Position.Y + 1 < this.height;
if (!flag || maze[start.Position.Y + 1, start.Position.X].UpWall)
{
flag = start.Position.X + 1 < this.width;
if (!flag || maze[start.Position.Y, start.Position.X + 1].LeftWall)
{
rightHandRuleSolve(maze[start.Position.Y, start.Position.X], Directions.Up);
}
else
{
rightHandRuleSolve(maze[start.Position.Y, start.Position.X + 1], Directions.Right);
}
}
else
{
rightHandRuleSolve(maze[start.Position.Y + 1, start.Position.X], Directions.Down);
}
}
else
{
rightHandRuleSolve(maze[start.Position.Y, start.Position.X - 1], Directions.Left);
}
break;
}
}
/// <summary>
/// Solves the maze with the right-hand role iteratively
/// </summary>
/// <param name="start">The maze begin</param>
/// <param name="dir">the initial direction</param>
private void iterativeRightHandRuleSolve(Cell start, Directions dir)
{
// look at your right (with respect to your direction)
// No wall? go in it.
// Wall? look at your front (with respect to your direction)
// Wall too? look at your left (with respect to your direction)
// Wall too? go back (in the reverse of your direction)
// note that the right of the right is down, the left of down is right, ect
bool flag;
// repeat while you didn't reach the end
while (start.Position != this.end.Position)
{
// for graphics
this.maze[start.Position.Y, start.Position.X].Visited = true;
// for graphics
this.currentSolvePos = start.Position;
// to slow operation
Thread.SpinWait(this.Sleep * sleepPeriod);
switch (dir)
{
case Directions.Right:
// has up wall?
flag = start.Position.Y + 1 < height;
if (!flag || this.maze[start.Position.Y + 1, start.Position.X].UpWall)
{
// has left wall?
flag = start.Position.X + 1 < width;
if (!flag || maze[start.Position.Y, start.Position.X + 1].LeftWall)
{
// has down wall ?
flag = start.Position.Y - 1 >= 0;
if (!flag || maze[start.Position.Y - 1, start.Position.X].DownWall)
{
start = this.maze[start.Position.Y, start.Position.X];
dir = Directions.Left;
}
else
{
start = maze[start.Position.Y - 1, start.Position.X];
dir = Directions.Up;
}
}
else
{
start = this.maze[start.Position.Y, start.Position.X + 1];
dir = Directions.Right;
}
}
else
{
start = this.maze[start.Position.Y + 1, start.Position.X];
dir = Directions.Down;
}
break;
case Directions.Left:
flag = start.Position.Y - 1 >= 0;
if (!flag || maze[start.Position.Y - 1, start.Position.X].DownWall)
{
flag = start.Position.X - 1 >= 0;
if (!flag || maze[start.Position.Y, start.Position.X - 1].RightWall)
{
flag = start.Position.Y + 1 < this.height;
if (!flag || maze[start.Position.Y + 1, start.Position.X].UpWall)
{
start = maze[start.Position.Y, start.Position.X];
dir = Directions.Right;
}
else
{
start = maze[start.Position.Y + 1, start.Position.X];
dir = Directions.Down;
}
}
else
{
start = maze[start.Position.Y, start.Position.X - 1];
dir = Directions.Left;
}
}
else
{
start = maze[start.Position.Y - 1, start.Position.X];
dir = Directions.Up;
}
break;
case Directions.Up:
flag = start.Position.X + 1 < this.width;
if (!flag || maze[start.Position.Y, start.Position.X + 1].LeftWall)
{
flag = start.Position.Y - 1 >= 0;
if (!flag || maze[start.Position.Y - 1, start.Position.X].DownWall)
{
flag = start.Position.X - 1 >= 0;
if (!flag || maze[start.Position.Y, start.Position.X - 1].RightWall)
{
start = maze[start.Position.Y, start.Position.X];
dir = Directions.Down;
}
else
{
start = maze[start.Position.Y, start.Position.X - 1];
dir = Directions.Left;
}
}
else
{
start = maze[start.Position.Y - 1, start.Position.X];
dir = Directions.Up;
}
}
else
{
start = maze[start.Position.Y, start.Position.X + 1];
dir = Directions.Right;
}
break;
default:
flag = start.Position.X - 1 >= 0;
if (!flag || maze[start.Position.Y, start.Position.X - 1].RightWall)
{
flag = start.Position.Y + 1 < this.height;
if (!flag || maze[start.Position.Y + 1, start.Position.X].UpWall)
{
flag = start.Position.X + 1 < this.width;
if (!flag || maze[start.Position.Y, start.Position.X + 1].LeftWall)
{
start = maze[start.Position.Y, start.Position.X];
dir = Directions.Up;
}
else
{
start = maze[start.Position.Y, start.Position.X + 1];
dir = Directions.Right;
}
}
else
{
start = maze[start.Position.Y + 1, start.Position.X];
dir = Directions.Down;
}
}
else
{
start = maze[start.Position.Y, start.Position.X - 1];
dir = Directions.Left;
}
break;
}
}
this.maze[start.Position.Y, start.Position.X].Visited = true;
this.currentSolvePos = start.Position;
}
/// <summary>
/// Knocks wall between two neighbor cellls
/// </summary>
/// <param name="maze">The maze array</param>
/// <param name="current">the current cell</param>
/// <param name="next">the next neighbor cell</param>
private void knockWall(Cell[,] maze, ref Cell current, ref Cell next)
{
// The next is down
if (current.Position.X == next.Position.X && current.Position.Y > next.Position.Y)
{
maze[current.Position.Y, current.Position.X].UpWall = false;
maze[next.Position.Y, next.Position.X].DownWall = false;
}
// the next is up
else if (current.Position.X == next.Position.X)
{
maze[current.Position.Y, current.Position.X].DownWall = false;
maze[next.Position.Y, next.Position.X].UpWall = false;
}
// the next is right
else if (current.Position.X > next.Position.X)
{
maze[current.Position.Y, current.Position.X].LeftWall = false;
maze[next.Position.Y, next.Position.X].RightWall = false;
}
// the next is left
else
{
maze[current.Position.Y, current.Position.X].RightWall = false;
maze[next.Position.Y, next.Position.X].LeftWall = false;
}
}
/// <summary>
/// Resets a maze array
/// </summary>
/// <param name="arr">The maze array</param>
/// <param name="width">Number of squares in width</param>
/// <param name="height">Number of squares in height</param>
private void initailze(Cell[,] arr, int width, int height)
{
this.width = width;
this.height = height;
for (int i = 0; i < this.height; i++)
{
for (int j = 0; j < this.width; j++)
{
arr[i, j] = new Cell(new Point(j * this.unitX, i * this.unitY), new Point(j, i));
}
}
}
/// <summary>
/// Solves a maze with iterative backtracking DFS
/// </summary>
/// <param name="start">The start of the maze cell</param>
/// <param name="end">The end of the maze cell</param>
/// <returns>returrns true if the path is found</returns>
private unsafe bool iterativeDepthFirstSearchSolve(Cell start, Cell end)
{
// unsafe indicates that this method uses pointers
Stack<Cell> stack = new Stack<Cell>();
stack.Push(start);
while (stack.Count > 0)
{
Cell temp = stack.Pop();
// base condition
if (temp.Position == end.Position)
{
// add end point to foundPath
this.foundPath.Add(temp);
// dereference all pointers chain until you reach the begin
while (temp.Previous != null)
{
this.foundPath.Add(temp);
temp = *temp.Previous;
}
// add begin point to foundPath
this.foundPath.Add(temp);
// to view green square on it
this.maze[temp.Position.Y, temp.Position.X].Visited = true;
return true;
}
// for the graphics
this.currentSolvePos = temp.Position;
// mark as visited to prevent infinite loops
this.maze[temp.Position.Y, temp.Position.X].Visited = true;
// used to slow operation
Thread.SpinWait(this.Sleep * sleepPeriod);
// Check every neighbor cell
// If it exists (not outside the maze bounds)
// and if there is no wall between start and it
// set the next.Previous to the current cell
// push next into stack
// else complete
// Left
if (temp.Position.X - 1 >= 0
&& !this.maze[temp.Position.Y, temp.Position.X - 1].RightWall
&& !this.maze[temp.Position.Y, temp.Position.X - 1].Visited)
{
// fixed must be used to indicate that current memory-location won't be changed
fixed (Cell* cell = &this.maze[temp.Position.Y, temp.Position.X])
this.maze[temp.Position.Y, temp.Position.X - 1].Previous = cell;
stack.Push(this.maze[temp.Position.Y, temp.Position.X - 1]);
}
// Right
if (temp.Position.X + 1 < this.width
&& !this.maze[temp.Position.Y, temp.Position.X + 1].LeftWall
&& !this.maze[temp.Position.Y, temp.Position.X + 1].Visited)
{
fixed (Cell* cell = &this.maze[temp.Position.Y, temp.Position.X])
this.maze[temp.Position.Y, temp.Position.X + 1].Previous = cell;
stack.Push(this.maze[temp.Position.Y, temp.Position.X + 1]);
}
// Up
if (temp.Position.Y - 1 >= 0
&& !this.maze[temp.Position.Y - 1, temp.Position.X].DownWall
&& !this.maze[temp.Position.Y - 1, temp.Position.X].Visited)
{
fixed (Cell* cell = &this.maze[temp.Position.Y, temp.Position.X])
this.maze[temp.Position.Y - 1, temp.Position.X].Previous = cell;
stack.Push(this.maze[temp.Position.Y - 1, temp.Position.X]);
}
// Down
if (temp.Position.Y + 1 < this.height
&& !this.maze[temp.Position.Y + 1, temp.Position.X].UpWall
&& !this.maze[temp.Position.Y + 1, temp.Position.X].Visited)
{
fixed (Cell* cell = &this.maze[temp.Position.Y, temp.Position.X])
this.maze[temp.Position.Y + 1, temp.Position.X].Previous = cell;
stack.Push(this.maze[temp.Position.Y + 1, temp.Position.X]);
}
}
// no solution found
return false;
}
/// <summary>
/// Gets all neighbor cells to a specific cell,
/// where those neighbors exist and not visited already
/// </summary>
/// <param name="arr">The maze array</param>
/// <param name="cell">The current cell to get neighbors</param>
/// <param name="width">The width of the maze</param>
/// <param name="height">The height of the maze</param>
/// <returns></returns>
private List<Point> getNeighbours(Cell[,] arr, Cell cell, int width, int height)
{
Point temp = cell.Position;
List<Point> availablePlaces = new List<Point>();
// Left
temp.X = cell.Position.X - 1;
if (temp.X >= 0 && this.allWallsIntact(arr, arr[temp.Y, temp.X]))
{
availablePlaces.Add(temp);
}
// Right
temp.X = cell.Position.X + 1;
if (temp.X < width && this.allWallsIntact(arr, arr[temp.Y, temp.X]))
{
availablePlaces.Add(temp);
}
// Up
temp.X = cell.Position.X;
temp.Y = cell.Position.Y - 1;
if (temp.Y >= 0 && this.allWallsIntact(arr, arr[temp.Y, temp.X]))
{
availablePlaces.Add(temp);
}
// Down
temp.Y = cell.Position.Y + 1;
if (temp.Y < height && this.allWallsIntact(arr, arr[temp.Y, temp.X]))
{
availablePlaces.Add(temp);
}
return availablePlaces;
}
/// <summary>
/// Solves a maze with recursive backtracking DFS -
/// DON'T USE! IT IS FOR DEMONSTRATING PURPOSES ONLY!
/// </summary>
/// <param name="start">The start of the maze cell</param>
/// <param name="end">The end of the maze cell</param>
/// <returns>returrns true if the path is found</returns>
private unsafe bool depthFirstSearchSolve(Cell *st, ref Cell end)
{
// base condition
if (st->Position == end.Position)
{
// make it visited in order to be drawed with green
this.maze[st->Position.Y, st->Position.X].Visited = true;
// add end point to the foundPath
this.foundPath.Add(*st);
return true;
}
// has been visited alread, return
if (this.maze[st->Position.Y, st->Position.X].Visited)
return false;
// for the graphics
this.currentSolvePos = st->Position;
// used to slow the process
Thread.SpinWait(this.Sleep * sleepPeriod);
// mark as visited
this.maze[st->Position.Y, st->Position.X].Visited = true;
// Check every neighbor cell
// If it exists (not outside the maze bounds)
// and if there is no wall between start and it
// recursive call this method with it
// if it returns true, add the current start to foundPath and return true too
// else complete
// Left
if (st->Position.X - 1 >= 0 && !this.maze[st->Position.Y, st->Position.X - 1].RightWall)
{
this.maze[st->Position.Y, st->Position.X].Path = Cell.Paths.Left;
fixed (Cell *ptr = &this.maze[st->Position.Y, st->Position.X - 1])
{
if (this.depthFirstSearchSolve(ptr, ref end))
{
this.foundPath.Add(*st);
return true;
}
}
}
// for the graphics
this.currentSolvePos = st->Position;
// used to slow the process
Thread.SpinWait(this.Sleep * sleepPeriod);
// Right
if (st->Position.X + 1 < this.width && !this.maze[st->Position.Y, st->Position.X + 1].LeftWall)
{
this.maze[st->Position.Y, st->Position.X].Path = Cell.Paths.Right;
fixed (Cell* ptr = &this.maze[st->Position.Y, st->Position.X + 1])
{
if (this.depthFirstSearchSolve(ptr, ref end))
{
this.foundPath.Add(*st);
return true;
}
}
}
// for the graphics
this.currentSolvePos = st->Position;
// used to slow the process
Thread.SpinWait(this.Sleep * sleepPeriod);
// Up
if (st->Position.Y - 1 >= 0 && !this.maze[st->Position.Y - 1, st->Position.X].DownWall)
{
this.maze[st->Position.Y, st->Position.X].Path = Cell.Paths.Up;
fixed (Cell* ptr = &this.maze[st->Position.Y - 1, st->Position.X])
{
if (this.depthFirstSearchSolve(ptr, ref end))
{
this.foundPath.Add(*st);
return true;
}
}
}
// for the graphics
this.currentSolvePos = st->Position;
// used to slow the process
Thread.SpinWait(this.Sleep * sleepPeriod);
// Down
if (st->Position.Y + 1 < this.height && !this.maze[st->Position.Y + 1, st->Position.X].UpWall)
{
this.maze[st->Position.Y, st->Position.X].Path = Cell.Paths.Down;
fixed (Cell* ptr = &this.maze[st->Position.Y + 1, st->Position.X])
{
if (this.depthFirstSearchSolve(ptr, ref end))
{
this.foundPath.Add(*st);
return true;
}
}
}
this.maze[st->Position.Y, st->Position.X].Path = Cell.Paths.None;
return false;
}
/// <summary>
/// Generate a maze with the Depth-First Search approach
/// </summary>
/// <param name="arr">the array of cells</param>
/// <param name="width">A width for the maze</param>
/// <param name="height">A height for the maze</param>
private void depthFirstSearchMazeGeneration(Cell[,] arr, int width, int height)
{
Stack<Cell> stack = new Stack<Cell>();
Random random = new Random();
Cell location = arr[this.random.Next(height), this.random.Next(width)];
stack.Push(location);
while (stack.Count > 0)
{
List<Point> neighbours = this.getNeighbours(arr, location, width, height);
if (neighbours.Count > 0)
{
Point temp = neighbours[random.Next(neighbours.Count)];
this.currentGenerateLocation = temp;
this.knockWall(arr, ref location, ref arr[temp.Y, temp.X]);
stack.Push(location);
location = arr[temp.Y, temp.X];
}
else
{
location = stack.Pop();
}
Thread.SpinWait(this.Sleep * sleepPeriod);
}
this.makeMazeBeginEnd(this.maze);
}
/// <summary>
/// Determines whether a particular cell has all its walls intact
/// </summary>
/// <param name="arr">the maze array</param>
/// <param name="cell">The cell to check</param>
/// <returns></returns>
private bool allWallsIntact(Cell[,] arr, Cell cell)
{
for (int i = 0; i < 4; i++)
{
if (!arr[cell.Position.Y, cell.Position.X][i])
{
return false;
}
}
return true;
}
/// <summary>
/// Used to reset all cells
/// </summary>
/// <param name="arr">The maze array to reset elements</param>
private void unvisitAll(Cell[,] arr)
{
for (int i = 0; i < this.maze.GetLength(0); i++)
{
for (int j = 0; j < this.maze.GetLength(1); j++)
{
arr[i, j].Visited = false;
arr[i, j].Path = Cell.Paths.None;
}
}
}
