@dmx-cloud/dmx/src/easing.js

A NodeJS DMX realtime control library

const easing = {
  inBack(t, b, c, d, s) {
    if (s === undefined) {s = 1.70158}
    return c * (t /= d) * t * ((s + 1) * t - s) + b
  },
  inBounce(t, b, c, d) {
    return c - easing.outBounce(d - t, 0, c, d) + b
  },
  inCirc(t, b, c, d) {
    return -c * (Math.sqrt(1 - (t /= d) * t) - 1) + b
  },
  inCubic(t, b, c, d) {
    return c * (t /= d) * t * t + b
  },
  inElastic(t, b, c, d) {
    let s = 1.70158
    let p = 0
    let 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
      s = p / 4
    } else {
      s = p / (2 * Math.PI) * Math.asin(c / a)
    }

    return -(a * (2 * (10 * (t -= 1))) * Math.sin((t * d - s) * (2 * Math.PI) / p)) + b
  },
  inExpo(t, b, c, d) {
    return t === 0 ? b : c * 2 * (10 * (t / d - 1)) + b
  },
  inOutBack(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
  },
  inOutBounce(t, b, c, d) {
    if (t < d / 2) {return easing.inBounce(t * 2, 0, c, d) * 0.5 + b}
    return easing.outBounce(t * 2 - d, 0, c, d) * 0.5 + c * 0.5 + b
  },
  inOutCirc(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
  },
  inOutCubic(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
  },
  inOutElastic(t, b, c, d) {
    let s = 1.70158
    let p = 0
    let 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
      s = p / 4
    } else {
      s = p / (2 * Math.PI) * Math.asin(c / a)
    }

    if (t < 1) {
      return -0.5 * (a * (2 * (10 * (t -= 1))) * Math.sin((t * d - s) * (2 * Math.PI) / p)) + b
    }

    return a * (2 * (-10 * (t -= 1))) * Math.sin((t * d - s) * (2 * Math.PI) / p) * 0.5 + c + b
  },
  inOutExpo(t, b, c, d) {
    if (t === 0) {return b}
    if (t === d) {return b + c}
    if ((t /= d / 2) < 1) {return c / 2 * (2 * (10 * (t - 1))) + b}
    return c / 2 * (-(2 * (-10 * --t)) + 2) + b
  },
  inOutQuad(t, b, c, d) {
    if ((t /= d / 2) < 1) {return c / 2 * t * t + b}
    return -c / 2 * ((--t) * (t - 2) - 1) + b
  },
  inOutQuart(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
  },
  inOutQuint(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
  },
  inOutSine(t, b, c, d) {
    return -c / 2 * (Math.cos(Math.PI * t / d) - 1) + b
  },
  inQuad(t, b, c, d) {
    return c * (t /= d) * t + b
  },
  inQuart(t, b, c, d) {
    return c * (t /= d) * t * t * t + b
  },
  inQuint(t, b, c, d) {
    return c * (t /= d) * t * t * t * t + b
  },
  inSine(t, b, c, d) {
    return -c * Math.cos(t / d * (Math.PI / 2)) + c + b
  },
  linear(t, b, c, d) {
    return c * t / d + b
  },
  outBack(t, b, c, d, s) {
    if (s === undefined) {s = 1.70158}
    return c * ((t = t / d - 1) * t * ((s + 1) * t + s) + 1) + b
  },
  outBounce(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
    }
    return c * (7.5625 * (t -= (2.625 / 2.75)) * t + 0.984375) + b

  },
  outCirc(t, b, c, d) {
    return c * Math.sqrt(1 - (t = t / d - 1) * t) + b
  },
  outCubic(t, b, c, d) {
    return c * ((t = t / d - 1) * t * t + 1) + b
  },
  outElastic(t, b, c, d) {
    let s = 1.70158
    let p = 0
    let 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
      s = p / 4
    } else {
      s = p / (2 * Math.PI) * Math.asin(c / a)
    }

    return a * (2 * (-10 * t)) * Math.sin((t * d - s) * (2 * Math.PI) / p) + c + b
  },
  outExpo(t, b, c, d) {
    return (t === d) ? b + c : c * (-(2 * (-10 * t / d)) + 1) + b
  },
  outQuad(t, b, c, d) {
    return -c * (t /= d) * (t - 2) + b
  },
  outQuart(t, b, c, d) {
    return -c * ((t = t / d - 1) * t * t * t - 1) + b
  },
  outQuint(t, b, c, d) {
    return c * ((t = t / d - 1) * t * t * t * t + 1) + b
  },
  outSine(t, b, c, d) {
    return c * Math.sin(t / d * (Math.PI / 2)) + b
  },
}

export default easing