👷 Web Workers

If you have computation-heavy tasks in your app, you can offload them to a Web Worker (opens in a new tab). Workers are separate threads that runs in the background without blocking the UI, reducing jank in your canvas. You can for instance use Web Workers for pathfinding (opens in a new tab) or physics.

Web Workers rely on the postMessage and onmessage API to communicate with the main thread, which means you cannot wait for a particular message to be received and write code in a convenient async/await fashion. That's why some libraries have been created to help with the process:

Comlink 9k 196k/w
workerpool 2k 5M/w – Supports pools, Node.js
Supports pools, Node.js
threads.js 3k 116k/w 2y years – Supports pools, observables, Webpack, Node.js
Supports pools, observables, Webpack, Node.js
troika-worker-utils 106k/w
workerize-loader 2k 17k/w – Webpack loader
Workerize 4k 700/w 3y years
comlink-loader 600 7k/w 3y years – Webpack loader
Greenlet 5k 900/w 4y years

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`import.meta.url`

Note that you can use import.meta.url (opens in a new tab) to reference a Web Worker file from your filesystem:

const worker = new Worker(new URL('./worker.ts', import.meta.url))

🎱 Object Pooling 🙈 OffscreenCanvas