...another easing equation library! Why!?
Most easing libraries export functions which take a bunch of arguments, capturing all sorts of wonderful details of an animation, such as start and end values, start and end times, plus the current time. This is a rather complicated way of representing what essentially boils down to a simple interpolation between the values of 0 and 1; anything extra is just noise that distracts from the essence of the calculation. For further information, take a look at Jari Komppa's article Interpolation Tricks where he explains matters much better than I am able.
easiness is a collection of 'pure' easing functions designed to work with domain and range
0..1 - single number in, single number out. Easy-peasy. If you find yourself in a situation where you need to interpolate between other values, each of
easiness's functions offers a
.mapped() method to derive another single argument function that can map any domain/range you desire.
npm install easiness
var easiness = require('easiness');
$easeFn with one of:
easiness.$easeFn.mapped(inStart, inEnd, outStart, outEnd)
Derives a new easing function based on $easeFn that expects an argument in the range
inStart..inEnd and interpolates it between
A 2-argument form of
mapped() is also available in which
inEnd are assumed to be 0 and 1, respectively. The resulting derived function will interpolate the values in the range