Maze generator

maze.rb

EMPTY = 0x0
UP    = 0x1
RIGHT = 0x2
DOWN  = 0x4
LEFT  = 0x8

# Maze generator class.
class Generator

  def initialize(w, h)
    @w = w
    @h = h
    @maze = (0...@h).map { [EMPTY] * @w }
  end

  def out
    @maze.each do |row|
      row.each { |cell| print ' ║═╚║║╔╠═╝═╩╗╣╦╬'[cell] }
      puts
    end
  end

  def opposite(dir)
    return UP if dir == DOWN
    return DOWN if dir == UP
    return RIGHT if dir == LEFT
    return LEFT if dir == RIGHT
    EMPTY
  end

  def make
    queue = [[0, 0]]
    @maze[0][0] = UP

    until queue.empty?
      cell = queue.shift
      available_neighbors = get_available_neighbors cell
      had_one = false

      unless available_neighbors.empty?
        available_neighbors.map { |k, v| [k, v] }.shuffle.each do |k, v|
          break if had_one and rand(10) < 9

          @maze[cell[0]][cell[1]] |= k
          @maze[v[0]][v[1]] = opposite(k)
          queue << v
          had_one = true
        end
      end
    end
  end

  def get_available_neighbors(cell)
    available = {}
    { UP => [-1, 0], DOWN => [1, 0], LEFT => [0, -1], RIGHT => [0, 1] }.each do |dir, coord|
      y = cell[0] + coord[0]
      x = cell[1] + coord[1]
      available[dir] = [y, x] if y.between?(0, @h - 1) && x.between?(0, @w - 1) && @maze[y][x] == EMPTY
    end
    available
  end

end

# mg = Generator.new(96, 24)
# mg = Generator.new(356, 96)
mg = Generator.new(128, 46)
mg.make
mg.out