glsl-easings 
Robert Penner's easing functions in GLSL, available as a module for glslify.
Original package glslify/glsl-easings, forked from pending pull request.
Usage
Each easing function has its own file which can be required from glslify:
#pragma glslify: ease = require(@immersive-garden/glsl-easings/back-in-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/back-in)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/back-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/bounce-in-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/bounce-in)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/bounce-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/circular-in-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/circular-in)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/circular-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/cubic-in-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/cubic-in)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/cubic-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/elastic-in-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/elastic-in)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/elastic-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/exponential-in-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/exponential-in)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/exponential-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/linear)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/quadratic-in-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/quadratic-in)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/quadratic-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/quartic-in-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/quartic-in)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/quartic-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/quintic-in-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/quintic-in)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/quintic-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/sine-in-out)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/sine-in)
#pragma glslify: ease = require(@immersive-garden/glsl-easings/sine-out)And each function has the following signature:
float ease(float t)Where t is a value between 0 and 1, returning a new float between 0 and 1.
License
MIT. See LICENSE.md for details.