Intersection Observer & Efficient Scroll Handling

What is the most efficient way to handle scroll-based animations using Intersection Observer?

const observer = new IntersectionObserver(entries => {
  entries.forEach(entry => {
    if (entry.isIntersecting) {
      entry.target.style.opacity = entry.intersectionRatio;
      entry.target.style.transform = `translateY(${(1 - entry.intersectionRatio) * 50}px)`;
    }
  });
}, {
  threshold: Array.from({ length: 100 }, (_, i) => i / 100)
});

Use setInterval for smooth animations
Combine with requestAnimationFrame
Use multiple thresholds for granular updates
Using multiple thresholds with Intersection Observer is the most efficient way to handle scroll-based animations because: 1) It provides granular control over animation steps without the overhead of scroll events, 2) The browser optimizes intersection calculations internally, 3) Animations can be tied directly to the intersection ratio for smooth transitions, 4) No manual calculations of scroll position or element visibility are needed. The example code creates 100 thresholds for very smooth animations while maintaining performance.
Add scroll event listeners

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