Method #onIntersection

src/ts-default/Backgrounds/Ballpit/Ballpit.tsx:220–223

(entries: IntersectionObserverEntry[])

  }

  #onIntersection(entries: IntersectionObserverEntry[]) {
    this.#isAnimating = entries[0].isIntersecting;
    this.#isAnimating ? this.#startAnimation() : this.#stopAnimation();
  }

  #onVisibilityChange() {
    if (this.#isAnimating) {