Robert Penners easing functions js (compatible with scroll-utility)

easing functions

/* ============================================================
 * jQuery Easing v1.3 - http://gsgd.co.uk/sandbox/jquery/easing/
 *
 * Open source under the BSD License.
 *
 * Copyright © 2008 George McGinley Smith
 * All rights reserved.
 * https://raw.github.com/danro/jquery-easing/master/LICENSE
 * ======================================================== */

const Easing = {
  // t: current time, b: begInnIng value, c: change In value, d: duration
  easeInQuad: function(t, b, c, d) {
    return c * (t /= d) * t + b
  },
  easeOutQuad: function(t, b, c, d) {
    return -c * (t /= d) * (t - 2) + b
  },
  easeInOutQuad: function(t, b, c, d) {
    if ((t /= d / 2) < 1) return (c / 2) * t * t + b
    return (-c / 2) * (--t * (t - 2) - 1) + b
  },
  easeInCubic: function(t, b, c, d) {
    return c * (t /= d) * t * t + b
  },
  easeOutCubic: function(t, b, c, d) {
    return c * ((t = t / d - 1) * t * t + 1) + b
  },
  easeInOutCubic: function(t, b, c, d) {
    if ((t /= d / 2) < 1) return (c / 2) * t * t * t + b
    return (c / 2) * ((t -= 2) * t * t + 2) + b
  },
  easeInQuart: function(t, b, c, d) {
    return c * (t /= d) * t * t * t + b
  },
  easeOutQuart: function(t, b, c, d) {
    return -c * ((t = t / d - 1) * t * t * t - 1) + b
  },
  easeInOutQuart: function(t, b, c, d) {
    if ((t /= d / 2) < 1) return (c / 2) * t * t * t * t + b
    return (-c / 2) * ((t -= 2) * t * t * t - 2) + b
  },
  easeInQuint: function(t, b, c, d) {
    return c * (t /= d) * t * t * t * t + b
  },
  easeOutQuint: function(t, b, c, d) {
    return c * ((t = t / d - 1) * t * t * t * t + 1) + b
  },
  easeInOutQuint: function(t, b, c, d) {
    if ((t /= d / 2) < 1) return (c / 2) * t * t * t * t * t + b
    return (c / 2) * ((t -= 2) * t * t * t * t + 2) + b
  },
  easeInSine: function(t, b, c, d) {
    return -c * Math.cos((t / d) * (Math.PI / 2)) + c + b
  },
  easeOutSine: function(t, b, c, d) {
    return c * Math.sin((t / d) * (Math.PI / 2)) + b
  },
  easeInOutSine: function(t, b, c, d) {
    return (-c / 2) * (Math.cos((Math.PI * t) / d) - 1) + b
  },
  easeInExpo: function(t, b, c, d) {
    return t == 0 ? b : c * Math.pow(2, 10 * (t / d - 1)) + b
  },
  easeOutExpo: function(t, b, c, d) {
    return t == d ? b + c : c * (-Math.pow(2, (-10 * t) / d) + 1) + b
  },
  easeInOutExpo: function(t, b, c, d) {
    if (t == 0) return b
    if (t == d) return b + c
    if ((t /= d / 2) < 1) return (c / 2) * Math.pow(2, 10 * (t - 1)) + b
    return (c / 2) * (-Math.pow(2, -10 * --t) + 2) + b
  },
  easeInCirc: function(t, b, c, d) {
    return -c * (Math.sqrt(1 - (t /= d) * t) - 1) + b
  },
  easeOutCirc: function(t, b, c, d) {
    return c * Math.sqrt(1 - (t = t / d - 1) * t) + b
  },
  easeInOutCirc: function(t, b, c, d) {
    if ((t /= d / 2) < 1) return (-c / 2) * (Math.sqrt(1 - t * t) - 1) + b
    return (c / 2) * (Math.sqrt(1 - (t -= 2) * t) + 1) + b
  },
  easeInElastic: function(t, b, c, d) {
    var s = 1.70158
    var p = 0
    var a = c
    if (t == 0) return b
    if ((t /= d) == 1) return b + c
    if (!p) p = d * 0.3
    if (a < Math.abs(c)) {
      a = c
      var s = p / 4
    } else var s = (p / (2 * Math.PI)) * Math.asin(c / a)
    return -(a * Math.pow(2, 10 * (t -= 1)) * Math.sin(((t * d - s) * (2 * Math.PI)) / p)) + b
  },
  easeOutElastic: function(t, b, c, d) {
    var s = 1.70158
    var p = 0
    var a = c
    if (t == 0) return b
    if ((t /= d) == 1) return b + c
    if (!p) p = d * 0.3
    if (a < Math.abs(c)) {
      a = c
      var s = p / 4
    } else var s = (p / (2 * Math.PI)) * Math.asin(c / a)
    return a * Math.pow(2, -10 * t) * Math.sin(((t * d - s) * (2 * Math.PI)) / p) + c + b
  },
  easeInOutElastic: function(t, b, c, d) {
    var s = 1.70158
    var p = 0
    var a = c
    if (t == 0) return b
    if ((t /= d / 2) == 2) return b + c
    if (!p) p = d * (0.3 * 1.5)
    if (a < Math.abs(c)) {
      a = c
      var s = p / 4
    } else var s = (p / (2 * Math.PI)) * Math.asin(c / a)
    if (t < 1)
      return (
        -0.5 * (a * Math.pow(2, 10 * (t -= 1)) * Math.sin(((t * d - s) * (2 * Math.PI)) / p)) + b
      )
    return (
      a * Math.pow(2, -10 * (t -= 1)) * Math.sin(((t * d - s) * (2 * Math.PI)) / p) * 0.5 + c + b
    )
  },
  easeInBack: function(t, b, c, d, s) {
    if (s == undefined) s = 1.70158
    return c * (t /= d) * t * ((s + 1) * t - s) + b
  },
  easeOutBack: function(t, b, c, d, s) {
    if (s == undefined) s = 1.70158
    return c * ((t = t / d - 1) * t * ((s + 1) * t + s) + 1) + b
  },
  easeInOutBack: function(t, b, c, d, s) {
    if (s == undefined) s = 1.70158
    if ((t /= d / 2) < 1) return (c / 2) * (t * t * (((s *= 1.525) + 1) * t - s)) + b
    return (c / 2) * ((t -= 2) * t * (((s *= 1.525) + 1) * t + s) + 2) + b
  },
  easeInBounce: function(t, b, c, d) {
    return c - Easing.easeOutBounce(d - t, 0, c, d) + b
  },
  easeOutBounce: function(t, b, c, d) {
    if ((t /= d) < 1 / 2.75) {
      return c * (7.5625 * t * t) + b
    } else if (t < 2 / 2.75) {
      return c * (7.5625 * (t -= 1.5 / 2.75) * t + 0.75) + b
    } else if (t < 2.5 / 2.75) {
      return c * (7.5625 * (t -= 2.25 / 2.75) * t + 0.9375) + b
    } else {
      return c * (7.5625 * (t -= 2.625 / 2.75) * t + 0.984375) + b
    }
  },
  easeInOutBounce: function(t, b, c, d) {
    if (t < d / 2) return Easing.easeInBounce(t * 2, 0, c, d) * 0.5 + b
    return Easing.easeOutBounce(t * 2 - d, 0, c, d) * 0.5 + c * 0.5 + b
  },
}

window.Easing = Easing

/*
 *
 * TERMS OF USE - EASING EQUATIONS
 *
 * Open source under the BSD License.
 *
 * Copyright © 2001 Robert Penner
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this list of
 * conditions and the following disclaimer.
 * Redistributions in binary form must reproduce the above copyright notice, this list
 * of conditions and the following disclaimer in the documentation and/or other materials
 * provided with the distribution.
 *
 * Neither the name of the author nor the names of contributors may be used to endorse
 * or promote products derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 *  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 *  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 *  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */