Shifty is a tweening engine for JavaScript. It is a lightweight library meant to be encapsulated by higher level tools. At its core, Shifty provides:
- Interpolation of
Number
s over time (tweening) - Playback control of an individual tween
- Extensibility hooks for key points in the tweening process
This is useful because it is the least amount of functionality needed to build customizable animations. Shifty is optimized to run many times a second with minimal processing and memory overhead, which is necessary to achieve smooth animations.
Shifty officially supports Evergreen browsers.
npm install --save shifty
First, install the dependencies via npm like so:
npm install
Once those are installed, you can generate dist/shifty.js
with:
npm run build
To run the tests in CLI:
npm test
To generate the documentation (dist/doc
):
npm run doc
To generate, live-update, and view the documentation in your browser:
npm run doc:live
To start a development server:
npm start
Once that's running, you can run the tests at http://localhost:9009/test/.
Shifty exposes a UMD module, so you can load it however you like:
// ES6
import { tween } from 'shifty';
Or:
// AMD
define(['shifty'], function(shifty){
shifty.tween({ from: { x: 0 }, to: { x: 10 } });
});
Or even:
// CommonJS
const shifty = require('shifty');
shifty.tween({ from: { x: 0 }, to: { x: 10 } });
Take a peek at the Network page to see all of the Shifty contributors.
Special thanks goes to Thomas Fuchs: Shifty's easing formulas and Bezier curve code was adapted from his awesome Scripty2 project.
Shifty is distributed under the MIT license. You are encouraged to use and modify the code to suit your needs, as well as redistribute it.