phaser/src/math/easing/bounce/In.js

A fast, free and fun HTML5 Game Framework for Desktop and Mobile web browsers from the team at Phaser Studio Inc.

/**
 * @author       Richard Davey <rich@phaser.io>
 * @copyright    2013-2025 Phaser Studio Inc.
 * @license      {@link https://opensource.org/licenses/MIT|MIT License}
 */

/**
 * Bounce ease-in.
 *
 * @function Phaser.Math.Easing.Bounce.In
 * @since 3.0.0
 *
 * @param {number} v - The value to be tweened.
 *
 * @return {number} The tweened value.
 */
var In = function (v)
{
    v = 1 - v;

    if (v < 1 / 2.75)
    {
        return 1 - (7.5625 * v * v);
    }
    else if (v < 2 / 2.75)
    {
        return 1 - (7.5625 * (v -= 1.5 / 2.75) * v + 0.75);
    }
    else if (v < 2.5 / 2.75)
    {
        return 1 - (7.5625 * (v -= 2.25 / 2.75) * v + 0.9375);
    }
    else
    {
        return 1 - (7.5625 * (v -= 2.625 / 2.75) * v + 0.984375);
    }
};

module.exports = In;