phaser/v3/src/math/easing/elastic/Out.js
2017-10-12 13:12:52 +01:00

43 lines
859 B
JavaScript

/**
* [description]
*
* @function Phaser.Math.Easing.Elastic.Out
* @since 3.0.0
*
* @param {number} v - [description]
* @param {float} [amplitude=0.1] - [description]
* @param {float} [period=0.1] - [description]
*
* @return {number} [description]
*/
var Out = function (v, amplitude, period)
{
if (amplitude === undefined) { amplitude = 0.1; }
if (period === undefined) { period = 0.1; }
if (v === 0)
{
return 0;
}
else if (v === 1)
{
return 1;
}
else
{
var s = period / 4;
if (amplitude < 1)
{
amplitude = 1;
}
else
{
s = period * Math.asin(1 / amplitude) / (2 * Math.PI);
}
return (amplitude * Math.pow(2, -10 * v) * Math.sin((v - s) * (2 * Math.PI) / period) + 1);
}
};
module.exports = Out;