vui-design/src/utils/easings.js

A high quality UI Toolkit based on Vue.js

// Back
export function easeInBack(t, b, c, d, s) {
  if (s == undefined) {
    s = 1.70158;
  }

  return c * (t /= d) * t * ((s + 1) * t - s) + b;
};

export function easeOutBack(t, b, c, d, s) {
  if (s == undefined) {
    s = 1.70158;
  }

  return c * ((t = t / d - 1) * t * ((s + 1) * t + s) + 1) + b;
};

export function easeInOutBack(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;
};

// Bounce
export function easeInBounce(t, b, c, d) {
  return c - easeOutBounce(d - t, 0, c, d) + b;
};

export function easeOutBounce(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;
  }
};

export function easeInOutBounce(t, b, c, d) {
  if (t < d / 2) {
    return easeInBounce(t * 2, 0, c, d) * 0.5 + b;
  }
  else {
    return easeOutBounce(t * 2 - d, 0, c, d) * 0.5 + c * 0.5 + b;
  }
};

// Circ
export function easeInCirc(t, b, c, d) {
  return - c * (Math.sqrt(1 - (t /= d) * t) - 1) + b;
};

export function easeOutCirc(t, b, c, d) {
  return c * Math.sqrt(1 - (t = t / d - 1) * t) + b;
};

export function easeInOutCirc(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;
};

// Cubic
export function easeInCubic(t, b, c, d) {
  return c * (t /= d) * t * t + b;
};

export function easeOutCubic(t, b, c, d) {
  return c * ((t = t / d - 1) * t * t + 1) + b;
};

export function easeInOutCubic(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;
};

// Elastic
export function easeInElastic(t, b, c, d, a, p) {
  if (t == 0) {
    return b;
  }

  if ((t /= d) == 1) {
    return b + c;
  }

  if (!p) {
    p = d * 0.3;
  }

  let s;

  if (!a || a < Math.abs(c)) {
    a = c;
    s = p / 4;
  }
  else {
    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;
};

export function easeOutElastic(t, b, c, d, a, p) {
  if (t == 0) {
    return b;
  }

  if ((t /= d) == 1) {
    return b + c;
  }

  if (!p) {
    p = d * 0.3;
  }

  let s;

  if (!a || a < Math.abs(c)) {
    a = c;
    s = p / 4;
  }
  else {
    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);
};

export function easeInOutElastic(t, b, c, d, a, p) {
  if (t == 0) {
    return b;
  }

  if ((t /= d / 2) == 2) {
    return b + c;
  }

  if (!p) {
    p = d * (0.3 * 1.5);
  }

  let s;

  if (!a || 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 * 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;
};

// Expo
export function easeInExpo(t, b, c, d) {
  return (t == 0) ? b : c * Math.pow(2, 10 * (t / d - 1)) + b;
};

export function easeOutExpo(t, b, c, d) {
  return (t == d) ? b + c : c * ( - Math.pow(2, -10 * t / d) + 1) + b;
};

export function easeInOutExpo(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;
};

// Quad
export function easeInQuad(t, b, c, d) {
  return c * (t /= d) * t + b;
};

export function easeOutQuad(t, b, c, d) {
  return - c * (t /= d) * (t - 2) + b;
};

export function easeInOutQuad(t, b, c, d) {
  if ((t /= d / 2) < 1) {
    return c / 2 * t * t + b;
  }

  return - c / 2 * ((--t) * (t - 2) - 1) + b;
};

// Quart
export function easeInQuart(t, b, c, d) {
  return c * (t /= d) * t * t * t + b;
};

export function easeOutQuart(t, b, c, d) {
  return - c * ((t = t / d - 1) * t * t * t - 1) + b;
};

export function easeInOutQuart(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;
};

// Quint
export function easeInQuint(t, b, c, d) {
  return c * (t /= d) * t * t * t * t + b;
};

export function easeOutQuint(t, b, c, d) {
  return c * ((t = t / d - 1) * t * t * t * t + 1) + b;
};

export function easeInOutQuint(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;
};

// Sine
export function easeInSine(t, b, c, d) {
  return - c * Math.cos(t / d * (Math.PI / 2)) + c + b;
};

export function easeOutSine(t, b, c, d) {
  return c * Math.sin(t / d * (Math.PI / 2)) + b;
};

export function easeInOutSine(t, b, c, d) {
  return - c / 2 * (Math.cos(Math.PI * t / d) - 1) + b;
};

// Export all easings as default
export default {
  easeInBack,
  easeOutBack,
  easeInOutBack,
  easeInBounce,
  easeOutBounce,
  easeInOutBounce,
  easeInCirc,
  easeOutCirc,
  easeInOutCirc,
  easeInCubic,
  easeOutCubic,
  easeInOutCubic,
  easeInElastic,
  easeOutElastic,
  easeInOutElastic,
  easeInExpo,
  easeOutExpo,
  easeInOutExpo,
  easeInQuad,
  easeOutQuad,
  easeInOutQuad,
  easeInQuart,
  easeOutQuart,
  easeInOutQuart,
  easeInQuint,
  easeOutQuint,
  easeInOutQuint,
  easeInSine,
  easeOutSine,
  easeInOutSine
};