let grid;

​

​

function setup() {

  // createCanvas(800, 800);

  createCanvas(400, 400);

  background(0);

  stroke(255);

  noFill();

  let off = width * 0.25;

  rect(off, off, width-2*off, height-2*off);

  startpt = createVector(int(random(width-1)), int(random(height-1)));

  point(startpt);

  blank = color(0,0,0);

  wall = color(255,255,255);

  grid = [];

  loadPixels();

  for (let y = 0; y < height; y++) {

    grid[y] = []

    for (let x = 0; x < width; x++) {

      grid[y][x] = false;

    }

  }

  for (let y = off; y < height-off; y++) {

    for (let x = off; x < width-off; x++) {

      grid[y][x] = true;

    }

  }

  // console.log(grid)

}

​

let startpt;

function draw() {

  // floodFill(startpt.x, startpt.y);

  // background(220);

//   loadPixels();

//   updatePixels();

  startpt = bfsFloodFill(startpt.x, startpt.y);

  timer = 100;

}

​

let q = [];

let timer = 100;

function check(x, y) {

  if (x >= 0 && x <= width-1 && y >= 0 && y <= height-1) {

    if (grid[y][x]) return false;

    return true;

  }

  return false;

}

function bfsFloodFill(x, y) {

  q.push(createVector(x, y));

  while (q.length > 0 && timer > 0) {

    let pt = q.pop();

    point(pt.x, pt.y);

    grid[pt.y][pt.x] = true;

    if (check(pt.x+1, pt.y))

      q.push(createVector(pt.x+1,pt.y))

    if (check(pt.x-1, pt.y))

      q.push(createVector(pt.x-1,pt.y))

    if (check(pt.x, pt.y+1))

      q.push(createVector(pt.x,pt.y+1))

    if (check(pt.x, pt.y-1))

      q.push(createVector(pt.x,pt.y-1))

    timer--;

  }

  if (timer == 0) return q[0];

}

function floodFill(x, y)

{

  if (x > width-1 || x < 0 || y < 0 || y > height-1) return;

  let col = get(x, y);

  if (col == wall) return;

  point(x, y);

   floodFill(x + 1, y);  // then i can either go south

   floodFill(x - 1, y);  // or north

   floodFill(x, y + 1);  // or east

   floodFill(x, y - 1);  // or west

   return;

​

}