phaser/src/math/Percent.js

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/**
* @author Richard Davey <rich@photonstorm.com>
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* @copyright 2019 Photon Storm Ltd.
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* @license {@link https://github.com/photonstorm/phaser/blob/master/license.txt|MIT License}
*/
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/**
* Work out what percentage `value` is of the range between `min` and `max`.
* If `max` isn't given then it will return the percentage of `value` to `min`.
*
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* You can optionally specify an `upperMax` value, which is a mid-way point in the range that represents 100%, after which the % starts to go down to zero again.
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*
* @function Phaser.Math.Percent
* @since 3.0.0
*
* @param {number} value - The value to determine the percentage of.
* @param {number} min - The minimum value.
* @param {number} [max] - The maximum value.
* @param {number} [upperMax] - The mid-way point in the range that represents 100%.
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*
* @return {number} A value between 0 and 1 representing the percentage.
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*/
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var Percent = function (value, min, max, upperMax)
{
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if (max === undefined) { max = min + 1; }
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var percentage = (value - min) / (max - min);
if (percentage > 1)
{
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if (upperMax !== undefined)
{
percentage = ((upperMax - value)) / (upperMax - max);
if (percentage < 0)
{
percentage = 0;
}
}
else
{
percentage = 1;
}
}
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else if (percentage < 0)
{
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percentage = 0;
}
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return percentage;
};
module.exports = Percent;