GSAP Cursor — Pointer-Driven Effects

Flow: gsap-setup → gsap-animate → gsap-cursor → gsap-optimise → gsap-test

Companion: For GSAP core tween API, invoke gsap-core. For performance methods, invoke gsap-performance. This skill covers cursor effect recipes only. Requires: greensock/gsap-skills

All patterns assume gsap.context() cleanup is in place (see gsap-animate skill).

1. Magnetic Buttons (quickTo)

gsap.quickTo pre-compiles a tween — 50-250% faster than gsap.to for frequent updates.

let xTo, yTo
ctx = gsap.context(() => {
  xTo = gsap.quickTo(btn, 'x', { duration: 0.4, ease: 'power3' })
  yTo = gsap.quickTo(btn, 'y', { duration: 0.4, ease: 'power3' })
}, scopeRef.value)

function onMagnetMove(e) {
  const rect = btn.getBoundingClientRect()
  xTo((e.clientX - rect.left - rect.width / 2) * 0.35)
  yTo((e.clientY - rect.top - rect.height / 2) * 0.35)
}
function onMagnetLeave() { xTo(0); yTo(0) }

See gsap-performance skill for quickTo vs quickSetter API comparison.

2. Flair Particle Trail

Distance-based particle spawning using gsap.ticker and pool recycling. Elements reappear at the cursor, animate out, then recycle via gsap.utils.wrap.

Core loop (runs every tick via gsap.ticker.add):

gsap.ticker.add(() => {
  const dist = Math.hypot(lastPos.x - mousePos.x, lastPos.y - mousePos.y)
  if (dist > gap) { spawnParticle(); lastPos = mousePos }
})

Spawn: gsap.set positions element at cursor, gsap.utils.wrap(0, pool.length) cycles the index, timeline scales + fades + drops the particle.

Full implementation with pool setup and animation timeline in references/cursor-patterns.md.

3. Spring Physics Elastic Followers

Multiple blobs chase the cursor with different duration values for a staggered, physics-like feel. Each blob uses elastic.out easing and overwrite: 'auto'.

self.add('moveBlobs', (mx, my) => {
  blobs.forEach((blob, i) => {
    gsap.to(blob.el, {
      x: mx, y: my,
      duration: blob.dur, ease: 'elastic.out(1.2, 0.3)',
      overwrite: 'auto', force3D: true,
    })
  })
})

Rest positions are percentage-based (containerWidth * pct / 100), recalculated on reset.

Full implementation with blob config, setup, and reset in references/cursor-patterns.md.

4. Spotlight Cursor (Clip-Path Circle)

Reveal a hidden layer by animating a clipPath circle to follow the cursor.

self.add('moveSpotlight', (x, y) => {
  gsap.to(spotlight, {
    clipPath: `circle(130px at ${x}px ${y}px)`,
    duration: 0.25, ease: 'power2.out', overwrite: 'auto',
  })
})

Initial state: gsap.set(spotlight, { clipPath: 'circle(0px at 50% 50%)' }) for clean revert.

Full implementation with hide animation in references/cursor-patterns.md.

5. Cursor-Tracking Image Preview

Images follow the cursor when hovering over list items. Uses gsap.quickTo with a two-arg snap on first enter to avoid interpolation lag.

const setX = gsap.quickTo(image, "x", { duration: 0.4, ease: "power3" })
// On first enter, snap: setX(e.clientX, e.clientX)
// On subsequent moves: setX(e.clientX)

Paused autoAlpha tween toggles visibility via play()/reverse() on mouseenter/mouseleave.

Full implementation in references/cursor-patterns.md.

6. Cursor-Driven Perspective Tilt

3D perspective tilt driven by pointer position. Parent gets perspective: 650, children rotate/translate via gsap.quickTo + gsap.utils.interpolate.

gsap.set("main", { perspective: 650 })
const outerRX = gsap.quickTo(".card", "rotationX", { ease: "power3" })
// pointermove: outerRX(gsap.utils.interpolate(15, -15, e.y / innerHeight))
// pointerleave: outerRX(0)

Outer element rotates (rotationX/Y), inner element translates (x/y) for parallax depth.

Full implementation in references/cursor-patterns.md.

7. Best Practices

// 1. overwrite: 'auto' on EVERY rapid-fire tween — prevents pile-up
gsap.to(el, { x: 100, overwrite: 'auto' })

// 2. ctx.add for cleanup — all event-handler tweens registered via ctx.add
self.add('onMove', (x, y) => { gsap.to(el, { x, y, overwrite: 'auto' }) })

// 3. will-change lifecycle — set on start, release onComplete
el.style.willChange = 'transform'
gsap.to(el, { x: 0, onComplete: () => { el.style.willChange = 'auto' } })

// 4. force3D: true on repeatedly animated elements
gsap.set(el, { force3D: true })

// 5. quickTo in onMounted, not in handlers — create once, call many

Cleanup checklist

1. Every cursor tween registered via ctx.add('name', fn)
2. ctx.revert() called in onUnmounted
3. quickTo instances created in onMounted, not in handlers
4. will-change released in onComplete, never permanent
5. gsap.ticker.remove(fn) in cleanup for ticker-based effects

References

• references/cursor-patterns.md — Flair particle trail, spring physics followers, spotlight cursor, circuit glow, cursor-tracking image preview, cursor-driven perspective tilt