/// <summary>
/// Creates a maze by linking cells using Eller's algorithm
/// </summary>
/// <param name="service"></param>
public override void CreateMaze(MazeGenerationService service)
{
//create data structures necessary for algorithm to work
MazeCell[,] gridcells = service.Cells;
MazeCell[] cells = gridcells.Cast <MazeCell>().ToArray();
//assign maze cells their set numbers
AssignSetNumbers(gridcells, service.DebugMode);
for (int y = 0; y < gridcells.GetLength(1); y++)
{
for (int x = 0; x < gridcells.GetLength(0); x++)
{
//mark cell as visited
MazeCell cell = gridcells[x, y];
cell.MarkAsVisited();
List <MazeCell> neighbours = service.GetNeighboursNotPartOfSet(cell);
if (neighbours.Count > 0)
{
//pick a random neighbour not part of the cells set and create passage between cell and neighbour
MazeCell randomNeighbour = neighbours[Random.Range(0, neighbours.Count)];
randomNeighbour.CreatePassage(cell);
cell.CreatePassage(randomNeighbour);
//all the cells belonging to the set the random neighbour belongs to are overtaken by the cell's set
MazeCell[] set = cells.Where(c => c.NumberValue == randomNeighbour.NumberValue).ToArray();
foreach (MazeCell overtakableCell in set)
{
overtakableCell.SetNumberValue(cell.NumberValue);
}
}
}
}
}
/// <summary>
/// Returns an enumerator that creates a maze by linking cells using Kruskal's algorithm
/// </summary>
/// <param name="service"></param>
/// <returns></returns>
public override IEnumerator CreateMazeRoutine(MazeGenerationService service)
{
//assign each maze cell a number indicating which set it belongs to
AssignSetNumbers(service.Cells, service.DebugMode);
//create data structures necessary for algorithm to work
MazeCell[] cells = service.Cells.Cast <MazeCell>().ToArray();
List <MazeCell> bag = new List <MazeCell>(cells);
//loop while bag is not not empty
while (bag.Count != 0)
{
//pick a random cell and mark it as visited
MazeCell randomCell = bag[Random.Range(0, bag.Count)];
randomCell.MarkAsVisited();
//fetch the neigbours of this cell that are not part of the same set
List <MazeCell> neighbours = service.GetNeighboursNotPartOfSet(randomCell);
if (neighbours.Count > 0)
{
//pick a random neighbour and mark it as visited
MazeCell randomNeighbour = neighbours[Random.Range(0, neighbours.Count)];
randomNeighbour.MarkAsVisited();
//link the random neighbour with the random cell
randomNeighbour.CreatePassage(randomCell);
randomCell.CreatePassage(randomNeighbour);
//all the cells belonging to the set the random neighbour belongs to are overtaken by the random cell's set
MazeCell[] set = cells.Where(c => c.NumberValue == randomNeighbour.NumberValue).ToArray();
foreach (MazeCell overtakableCell in set)
{
overtakableCell.SetNumberValue(randomCell.NumberValue);
}
}
else
{
//if all neighbours of the cel are part of the same set, remove the cell from the bag
bag.Remove(randomCell);
}
yield return(null);
}
CompletedRoutine();
}
