PrimGenerator.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

/// <summary>
/// Prim's Algorithm. Inheritance from MazeGenerator.
/// </summary>
public sealed class PrimGenerator : MazeGenerator
{
    protected override void GenerateMaze() => StartCoroutine(GenerateMazeCoroutine(false));

    protected override IEnumerator GenerateMazeCoroutine(bool isSlowly = true)
    {
        // Initialize the visitedCells array and the cell stack
        VisitedCells = new bool[width, height];
        CellStack = new Stack<Vector3Int>();
        
        SetupMaze();

        // Choose a random starting cell and mark it as visited
        var startPosition = FindAndSetStartPosition();
        VisitedCells[startPosition.x, startPosition.y] = true;

        // Add the starting cell to the cell stack
        CellStack.Push(startPosition);

        // Loop until all cells have been visited
        while (!AllTilesVisited())
        {
            if (isSlowly)
            {
                yield return new WaitForSeconds(waitTime); // Pause execution and resume
                tileChangeSound.Play();
            }
            
            // Get the current cell from the top of the stack
            var currentCell = CellStack.Peek();

            // Get the unvisited neighbors of the current cell
            var unvisitedNeighbors = GetUnvisitedNeighbors(currentCell);

            if (unvisitedNeighbors.Count > 0)
            {
                var randomNeighbor = unvisitedNeighbors[Random.Range(0, unvisitedNeighbors.Count)];
                VisitedCells[randomNeighbor.x, randomNeighbor.y] = true;

                // Add the neighbor to the maze by updating the tile colors
                UpdateTileColor(currentCell, randomNeighbor);

                // Add the neighbor to the cell stack
                CellStack.Push(randomNeighbor);
            }
            else CellStack.Pop(); // If all neighbors have been visited, remove the current cell from the stack
        }

        CreateEntranceAndExit();
    }
}