phaser/v3/src/math/Percent.js

var Percent = function (a, b, base)
{
    if (base === undefined) { base = 0; }

    if (a > b || base > b)
    {
        return 1;
    }
    else if (a < base || base > a)
    {
        return 0;
    }
    else
    {
        return (a - base) / b;
    }
};

module.exports = Percent;