maze.py

import numpy as np
from numpy.random import random_integers as rnd
#import matplotlib.pyplot as plt
 
def maze(width=81, height=51, complexity=.9, density =0.9):
    # Only odd shapes
    shape = ((width // 2)*2+1, (height // 2)*2+1)
    # Adjust complexity and density relative to maze size
    complexity = int(complexity*(5*(shape[0]+shape[1])))
    density    = int(density*(shape[0]//2*shape[1]//2))
    # Build actual maze
    Z = np.zeros(shape, dtype=bool)
    # Fill borders
    Z[0,:] = Z[-1,:] = 1
    Z[:,0] = Z[:,-1] = 1
    # Make isles
    for i in range(density):
        if i % 10 == 0: print i/float(density) * 100, '%'
        x, y = rnd(0,shape[1]//2)*2, rnd(0,shape[0]//2)*2
        Z[y,x] = 1
        for j in range(complexity):
            neighbours = []
            if x > 1:           neighbours.append( (y,x-2) )
            if x < shape[1]-2:  neighbours.append( (y,x+2) )
            if y > 1:           neighbours.append( (y-2,x) )
            if y < shape[0]-2:  neighbours.append( (y+2,x) )
            if len(neighbours):
                y_,x_ = neighbours[rnd(0,len(neighbours)-1)]
                if Z[y_,x_] == 0:
                    Z[y_,x_] = 1
                    Z[y_+(y-y_)//2, x_+(x-x_)//2] = 1
                    x, y = x_, y_
    return Z