∞ forever components

Particles & Physics

Double Pendulum Ghost

A double pendulum swings chaotically in emerald, tracing a slowly fading color-shifting ribbon ghost on canvas; pointer nudges velocity, click rekicks.

canvasheavy complexityintense motionpointer

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When to use it

Dark-mode hero backgrounds, screensavers, science/math-themed portfolios, ambient generative art displays.

When not to

Light backgrounds (hardcoded dark #16201A). Contexts requiring calm or subtle motion — the chaotic path is visually intense and unpredictable.

Working with an AI agent

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

Change the accent hue from emerald to teal by setting the strokeStyle hue base from 140 to 180 and the rod/bob color from #378651 to #80ffee, then slow substeps from 8 to 4 for a lazier swing. 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

  • accent hue base (140 in strokeStyle hsla)
  • substep count per frame (s<8)
  • trail fade speed (0.012 in fillStyle alpha)
  • bob size scale (L*0.04 / L*0.034)
  • damping coefficient (0.99992)
  • initial angle range (rekick values)
  • theme tokens (:root dark defaults + [data-theme=light] overrides)

Keep intact

  • RK4 integrator (step function)
  • offscreen trail canvas (tr/tctx) for ghost ribbon
  • visibilitychange pause/resume
  • reduced-motion static fallback
  • theme hook (?theme= bootstrap + forever:theme message listener + theme tokens)

Known limitations

  • Background color hardcoded in CSS and canvas fill — must edit both to change
  • No reduced-motion animation fallback beyond a single static frame
  • RK4 with 8 substeps per frame is CPU-intensive on low-end devices

double-pendulumphysicschaostrailcanvasglowgenerative

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