https://bernhardfritz.github.io/p8g/editor/7b6c7c25a1b6a0e9a48c75f89f5ac70b

sketch.js

import p8g, {
  background,
  createCanvas,
  height,
  line,
  noSmooth,
  random,
} from 'https://unpkg.com/p8g.js';

const iParent = (i) => Math.floor((i - 1) / 2);
const iLeftChild = (i) => 2 * i + 1;
const iRightChild = (i) => 2 * i + 2;

const siftDown = (a, start, end) => {
  let root = start;

  while (iLeftChild(root) <= end) {
    const child = iLeftChild(root);
    let swap = root;
    if (a[swap] < a[child]) {
      swap = child;
    }
    if (child + 1 <= end && a[swap] < a[child + 1]) {
      swap = child + 1;
    }
    if (swap === root) {
      return;
    } else {
      [a[root], a[swap]] = [a[swap], a[root]];
      root = swap;
    }
  }
}

const heapify = (a, count) => {
  let start = iParent(count - 1);

  while (start >= 0) {
    siftDown(a, start, count - 1);
    start = start - 1;
  }
}

const heapSort = (a, count = a.length) => {
  heapify(a, count);

  let end = count - 1;
  while (end > 0) {
    [a[end], a[0]] = [a[0], a[end]];
    end = end - 1;
    siftDown(a, 0, end);
  }

  return a;
}

const fisherYatesShuffle = (a) => {
  const n = a.length;
  for (let i = 0; i < n - 2; i++) {
    const j = Math.floor(random(i, n));
    [a[i], a[j]] = [a[j], a[i]];
  }
  return a;
};

function* makeIterator(fn, a) {
  const steps = [];
  const handler = {
    set(target, p, newValue) {
      steps.push([p, newValue]);
      target[p] = newValue;
      return true;
    },
  };
  const proxy = new Proxy([...a], handler);
  fn(proxy);
  for (const step of steps) {
    yield step;
  }
}

const n = 100;
const sorted = [...Array(n).keys()];
let it, a;
const init = () => {
  const unsorted = fisherYatesShuffle(sorted);
  it = makeIterator(heapSort, unsorted);
  a = [...unsorted];
};
init();

p8g.draw = () => {
  background(255);
  noSmooth();
  a.forEach((y, x) => {
    line(x, height, x, height - y);
  });
  const { value, done } = it.next();
  if (done) {
    init();
  } else {
    const [x, y] = value;
    a[x] = y;
  }
};

createCanvas(n, n);