const WALL_SIZE = 5;

const DOOR_SIZE = 10;

​

const MIN_RAD = 20;

const MAX_RAD = 190;

​

const MIN_DIV_OUTER = 5;

const MAX_DIV_OUTER = 10;

​

const MIN_DIV_INNER = 1;

const MAX_DIV_INNER = 2;

​

function setup() {

  createCanvas(400, 400);

  noLoop();

}

​

function draw() {

  clear();

  drawMaze();

}

​

function drawMaze() {  

  push();

  translate(width/2, height/2);

  rectMode(CENTER);

​

  strokeCap(SQUARE);

  noFill();

  stroke(255);

  strokeWeight(WALL_SIZE);

​

  const divisions = [];

  for(let i = 0; i < RINGS; i ++) {

    const rad = map(i, 0, RINGS, MAX_RAD, MIN_RAD);

    circle(0, 0, rad * 2);

    // How many divisions in this ring

    const minDiv = map(i, 0, RINGS, MIN_DIV_OUTER, MIN_DIV_INNER);

    const maxDiv = map(i, 0, RINGS, MAX_DIV_OUTER, MAX_DIV_INNER);

    const divs = int(random(minDiv, maxDiv));

    divisions.push(divs);

    // Can't add divisions on outer most rings

    if(i == 0) {

      continue;

    }

    const prevRad = map(i - 1, 0, RINGS, MAX_RAD, MIN_RAD);

    // Add room divisions

    for(let d = 0; d < divs; d ++) {

      const ang = random(TAU);

      const x = cos(ang);

      const y = sin(ang);

      line(x * rad, y * rad, x * prevRad, y * prevRad);

    }    

  }

  // Add inter-ring connections

  blendMode(REMOVE);

  noStroke();

  fill(255, 0, 0);

  for(let i = 0; i < divisions.length; i ++) {

    const rad = map(i, 0, RINGS, MAX_RAD, MIN_RAD);

    const divs = divisions[i];

    for(let c = 0; c < divs; c ++) {

      const ang = random(TAU);

      push();

      rotate(ang);

      rect(rad, 0, WALL_SIZE + 2, DOOR_SIZE);

      pop();

    }

  }

  blendMode(BLEND);

  pop();

}