The curve with a beginning, middle and end.
To try the following interactive visualisation of its simple numeric API see the homepage.
Install via NPM
$ npm install split-ease --save
import in your ES6 code
import SplitEase from 'split-ease';
require in your CommonJS code
const SplitEase = require('split-ease);
get in on unpkg
<script src="//unpkg.com/split-ease" charset="utf-8"></script>
or download and include a script link to the UMD version.
Most strictly-timed (i.e. not simulation-based) animation on the web makes use of interpolation (easing) functions originally popularized by Robert Penner in his 2002 book on programming Flash MX. This book proposed 10 curve-types (Sine, Quad, Cubic, Quart, Quint, Exp, Back, Circ, Elastic, Bounce) times 3 variations (easeIn, easeOut and easeInOut), to offer 30 different patterns of movement.
SplitEase takes the most common of these functions—the Sine and Power (Quad, Cubic, Quart, Quint) curves—and composes their underlying maths in a way that makes their ease-in/-out/-in-out proportions and their power curvature continuously independently variable.
Feedback or questions? Ping me.