const displacementFactor = 0.15

​

function setup() {

  createCanvas(w = 600, h = 600);

  bg = "#2e2e2e"

  frameRate(1)

}

​

function draw() {

  background(bg)

  rectMode(CENTER)

  noStroke()

  let stepSize = rectSize / 22

  for (let i = 0; i < 20; i++) {

    i % 2 ? fill(bg) : fill(0)

    if (frameCount % 4 == 1 || frameCount % 4 == 3) {

      rect(w / 2, h / 2, rectSize - i * stepSize)

      continue

    } else if (frameCount % 4 == 2) {

      let dx = random(rectSize * displacementFactor) * random([-1, 1]) % stepSize

      let dy = random(rectSize * displacementFactor) * random([-1, 1]) % stepSize

      rect(w / 2 + dx, h / 2 + dy, rectSize - i * stepSize)

      continue

    } else if (frameCount % 4 == 0) {

      let dx = floor(random(rectSize * displacementFactor) * random([-1, 1]) / stepSize) * stepSize

      let dy = floor(random(rectSize * displacementFactor) * random([-1, 1]) / stepSize) * stepSize

      rect(w / 2 + dx, h / 2 + dy, rectSize - i * stepSize)

    }

  }

}