React Game Loop Hooks
Production-ready custom React hooks for game loops and animations using requestAnimationFrame.
Installation
Copy the hook file into your project:
# From your skill directory
cp <skill-dir>/assets/hooks/useGameLoop.ts src/hooks/
<skill-dir> resolves to your OpenClaw skill installation directory.
Dependencies
- React >= 16.8 (hooks support)
- TypeScript >= 4.0 (for type safety)
- react-dom >= 16.8 (for
requestAnimationFrame types in browser environment)
This is a browser-only hook — it requires requestAnimationFrame, which is not available in Node.js or SSR environments.
API Reference
useGameLoop(options)
import { useGameLoop } from './hooks/useGameLoop';
Parameters:
| Option | Type | Default | Description |
|---|
onFrame | (deltaTime: number, elapsedTime: number) => void | — | Called every frame with delta (ms) and elapsed time (ms). Required. |
maxDeltaTime | number | 100 | Maximum delta clamp in ms. Prevents huge jumps after tab-switch or lag. |
Returns:
| Field | Type | Description |
|---|
start | () => void | Start the game loop |
stop | () => void | Stop the game loop |
isRunning | boolean | Current loop state |
Patterns
Stale-closure safety
Use useRef for callbacks/state read inside async/closure contexts (e.g. requestAnimationFrame, setInterval, event listeners). Always sync ref in useEffect.
const cbRef = useRef(onFrame);
useEffect(() => { cbRef.current = onFrame; }, [onFrame]);
Cleanup on unmount
Always return cleanup from useEffect. For RAF/intervals, store handle in ref and cancel on unmount.
useEffect(() => {
const id = requestAnimationFrame(tick);
return () => cancelAnimationFrame(id);
}, []);
Error resilience
Wrap user callbacks in try/catch so errors don't break internal loop state.
try {
callbackRef.current(delta, elapsed);
} catch (err) {
console.error('hook callback error:', err);
}
Delta-time clamping
For game loops, clamp deltaTime to avoid huge jumps after tab-switch or lag spikes.
const delta = Math.min(rawDelta, maxDeltaTime);
Example
See assets/examples/GameTimer.tsx for a complete usage example showing elapsed time and FPS display.
Reference
assets/hooks/useGameLoop.ts — requestAnimationFrame-based game loop with start/stop/isRunning controls, deltaTime clamping, and error resilience
assets/examples/GameTimer.tsx — basic usage example