let s = "";

  for (let i = 0; i < digits; i++) {

    s = str(num % 2) + s;

    num = int(num / 2);

  }

  return s;

}

​

function binary2(num) {

  let s = "";

  while (num > 0) {

    s = str(num % 2) + s;

    num = int(num / 2);

  }

  return s;

}

​

function sequence(n) {

  let seq = "";

  for (let i = 0; i < pow(2, n); i++) {

    seq += binary(i, n);

    // seq += binary2(i);

  }

  return seq;

}

​

function display() {

  let n = 19;

  let x = 0;

  let y = 0;

  let px = x;

  let py = y;

  let seq = sequence(n);

  let step = 0.05/4/4;

  noFill();

  stroke(0);

  strokeWeight(1);

  let a = [1001, 1001, -1, -1];

  let xs = [x];

  let ys = [y];

  let dir = [1, 0];

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

    px = x;

    py = y;

    x += dir[0] * step;

    y += dir[1] * step;

    xs.push(x);

    ys.push(y);

    a = [min(a[0], x), min(a[1], y), max(a[2], x), max(a[3], y)];

    if (seq[i] == '0') {

      if (dir[0] == 1 && dir[1] == 0) {

        dir = [0, 1];

      } else if (dir[0] == 0 && dir[1] == 1) {

        dir = [-1, 0];

      } else if (dir[0] == -1 && dir[1] == 0) {

        dir = [0, -1];

      } else {

        dir = [1, 0];

      }

    } else {

      if (dir[0] == 1 && dir[1] == 0) {

        dir = [0, -1];

      } else if (dir[0] == 0 && dir[1] == -1) {

        dir = [-1, 0];

      } else if (dir[0] == -1 && dir[1] == 0) {

        dir = [0, 1];

      } else {

        dir = [1, 0];

      }

    }

  }

  let midX = (a[0] + a[2]) / 2;

  let midY = height - (a[1] + a[3]) / 2;

  translate(width / 2 - midX, height / 2 - midY);

  colorMode(HSB, 100);

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

    stroke(i / seq.length * 100, 100, 75);

    line(xs[i], height - ys[i], xs[i+1], height - ys[i+1]);

  }

}

​

function setup() {

  createCanvas(1000, 1000);

}

​

function draw() {

  background(255);

  display();

  noLoop();

}