{ dx: 1, dy: 0 },

  { dx: -1, dy: 0 },

  { dx: 0, dy: 1 },

  { dx: 0, dy: -1 },

];

​

let x;

let y;

​

let size = 16;

let grid;

let spacing;

let cols, rows;

let direction = 0;

let margin = 10;

​

function make2DArray(cols, rows) {

  let arr = new Array(cols);

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

    arr[i] = new Array(rows);

  }

  return arr;

}

​

function setup() {

  createCanvas(600, 600);

  cols = size;

  rows = size;

  spacing = (width - margin * 2) / (size - 1);

  x = 0;

  y = 0;

  background(51);

  grid = make2DArray(cols, rows);

  for (let i = 0; i < cols; i++) {

    for (let j = 0; j < rows; j++) {

      grid[i][j] = false;

    }

  }

  grid[x][y] = true;

}

​

function isValid(i, j) {

  if (i < 0 || i >= cols || j < 0 || j >= rows) {

    return false;

  }

  return !grid[i][j];

}

​

function draw() {

  translate(margin, margin);

  noStroke();

  fill(0, 31, 255);

  circle(0, 0, 5);

  stroke(255);

  strokeWeight(spacing * 0.5);

  //point(x * spacing, y * spacing);

​

  let options = [];

  for (let option of allOptions) {

    let newX = x + option.dx;

    let newY = y + option.dy;

    if (isValid(newX, newY)) {

      options.push(option);

    }

  }

​

  if (options.length > 0) {

    let step = random(options);

    strokeWeight(1);

    stroke(255);

    noFill();

    beginShape();

    vertex(x * spacing, y * spacing);

    x += step.dx;

    y += step.dy;

    vertex(x * spacing, y * spacing);

    endShape();

    grid[x][y] = true;

    fill(0, 31, 255);

    noStroke();

    circle(x * spacing, y * spacing, 10);

    if (grid[cols - 1][rows - 1] == true) {

      noLoop();

    }

  } else {

    //console.log(`I'm stuck!`);

    background(51);

    options = [];

    x = 0;

    y = 0;

    for (let i = 0; i < cols; i++) {

      for (let j = 0; j < rows; j++) {

        grid[i][j] = false;

      }

    }

    grid[x][y] = true;

  }

}

​