∞ forever components

Particles & Physics

Spring Chain

A 16-node spring chain whips and follows the cursor in a lime-to-gold gradient; drifts in a figure-eight pattern when idle.

canvasmedium complexitymoderate motionpointer

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Live demo — the real component, running in a sandbox. One self-contained HTML file, zero dependencies. Open it on the canvas →
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When to use it

Cursor-follower effects, interactive hero backgrounds, playful physics demos where pointer engagement adds delight.

When not to

Contexts requiring legible overlaid text (constant motion competes). Touch-only devices where pointer events are limited to taps.

Working with an AI agent

Every component ships agent-ready metadata. An example instruction for this one:

Change node count from 16 to 24, set the hue base to 120 (green), and increase spring stiffness constant k from 0.32 to 0.45. Theme: dark tokens live in :root, the light variant in :root[data-theme="light"]; ?theme=light or a {type:'forever:theme'} postMessage switches at runtime.

Safe to edit

  • node count (N=16)
  • spring stiffness (k=0.32)
  • damping factor (damp=0.74)
  • hue start and step (90-i*3.5)
  • segment length (seg = min(W,H)*0.055)
  • idle figure-eight amplitude (W*0.3 / H*0.3)
  • theme tokens (:root dark defaults + [data-theme=light] overrides)

Keep intact

  • DPR-aware canvas sizing
  • visibilitychange pause/play guards
  • reduced-motion guard (single frame only)
  • IIFE-equivalent scoped vars
  • theme hook (?theme= bootstrap + forever:theme message listener + theme tokens)

Known limitations

  • Reduced-motion support is minimal — draws one static frame but the chain is still mid-motion; no true static fallback
  • Segment length computed at init with W/H at that moment — does not recompute on resize (reinits nodes but seg is const)
  • No IIFE wrapper — globals leak into page scope

springchainphysicspointercanvastailgradient

More Particles & Physics components

  • Gravity Dot RainMulticolored dots fall under gravity with motion trails, bounce off the floor, and scatter away from the cursor on a dark navy canvas.
  • Firework BurstColorful glowing sparks burst radially, fall under gravity, and fade against a dark sky. Auto-launches bursts; click anywhere to add more.
  • Confetti CannonColored rectangles fire from bottom corners in auto-cycling bursts, tumbling with gravity and flip animation. Click anywhere to trigger a cursor burst.
  • Bouncing Balls7–14 glossy pastel balls bounce off walls and collide with elastic physics; cursor repels balls within a 70px radius.
  • Cloth Wave GridAn 11x11 wireframe grid ripples like cloth via sine/cosine waves in cyan-to-violet hues; mesh nodes bulge away from the cursor on hover.
  • Metaball Fluid7 hot-pink blobs drift and merge via a high-contrast canvas threshold; cursor adds an attracting blob that pulls them toward the pointer.