# framesync

> A frame-synced render loop for JavaScript

Latest version **6.1.2** (published 2022-08-15) · MIT license · 0 weekly downloads

## Install

```sh
npm install framesync
pnpm add framesync
yarn add framesync
bun add framesync
```

## Health

**Score 35/100 (D)** — status: abandoned.

Positive: has types; esm support; no vulnerabilities; high quality score; popular repo.

Warnings: low downloads.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 6.1.2 |
| Published | 2022-08-15 |
| First published | 2016-01-07 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | ESM + CommonJS |
| Dependencies | 1 |
| Unpacked size | 41.6 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 20155 |
| Author | Matt Perry |
| Maintainers | popmotion |
| Keywords | animation, raf |

## Links

- npm: https://www.npmjs.com/package/framesync
- Repository: https://github.com/Popmotion/popmotion
- Homepage: https://popmotion.io/
- Issues: https://github.com/Popmotion/popmotion/issues
- npm.io page: https://npm.io/package/framesync

## Dependencies (1)

- [tslib](https://npm.io/package/tslib.md) 2.4.0

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## Recent versions

- 6.1.2 (latest) — 2022-08-15
- 6.0.0-rc.1 (rc) — 2021-09-23
- 6.1.1 — 2022-08-10
- 6.1.0 — 2021-11-24
- 6.0.1 — 2021-10-22
- 6.0.0 — 2021-09-23
- 5.3.0 — 2021-03-30
- 5.2.3 — 2021-03-19
- 5.2.2 — 2021-03-19
- 5.2.1 — 2021-03-19
- 5.2.0 — 2021-03-01
- 5.1.0 — 2021-02-22
- 5.0.0 — 2020-12-18
- 4.1.0 — 2020-08-24
- 4.0.4 — 2019-07-04
- … 26 more at https://npm.io/package/framesync/versions

## README

# Framesync

A tiny frame scheduler for performantly batching reads, updates and renders.

Segregating actions that read and write to the DOM will avoid [layout thrashing](https://developers.google.com/web/fundamentals/performance/rendering/avoid-large-complex-layouts-and-layout-thrashing).

It's also a way of ensuring order of execution across a frame. For instance, [Framer Motion](https://github.com/framer/motion) batches animations on the `update` step, and renders on the `render` step, allowing independent animation of `transform` properties.

## Install

```bash
npm install framesync
```

## Usage

Framesync splits a frame into discrete `read`, `update`, `preRender`, `render` and `postRender` steps.

### Scheduling functions

Functions can be scheduled to different parts of the render loop with `sync`.

```javascript
import sync from 'framesync';
```

It provides four functions, one for scheduling a function to run on each part of the frame:

```javascript
sync.update(() => {});
```

### Frame data

Each function is provided data about the current frame:

```javascript
sync.update(({ delta, timestamp }) => {});
```

- `delta`: Time since last frame (in milliseconds)
- `timestamp`: Timestamp of the current frame.

This object is recycled across frames, so values should be destructured if intended to be used asynchronously.

### Keep alive

We can run a function as an ongoing process by passing `true` as the second parameter:

```javascript
let count = 0;

sync.update(() => count++, true);
```

This will keep the process running until it's actively cancelled.

### Run immediately

The third parameter, `immediate`, can be used to sync a function on the **current frame step**.

By default, Framesync will schedule functions to run the next time that frame step is fired:

```javascript
sync.update(({ timestamp }) => {
  // The following function will run on the subsequent frame:
  sync.update((frame) => frame.timestamp !== timestamp);
});
```

By setting `immediate` to `true`, we can add this at the end of the current step:

```javascript
sync.update(({ timestamp }) => {
  // The following function will run on the **current** frame:
  sync.update(
    (frame) => frame.timestamp === timestamp,
    false,
    true
  );
});
```

### Cancelling

Synced processes can be cancelled with the `cancelSync` function:

```javascript
import sync, { cancelSync } from 'framesync';

let count = 0;

const process = sync.render(() => {
  count++;
  if (count >= 10) cancelSync.render(process);
}, true);
```

---
_Source: https://npm.io/package/framesync · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._