_math-scale.js
702 Bytes
// https://rwaldron.github.io/proposal-math-extensions/
module.exports = Math.scale || function scale(x, inLow, inHigh, outLow, outHigh) {
if (
arguments.length === 0
// eslint-disable-next-line no-self-compare
|| x != x
// eslint-disable-next-line no-self-compare
|| inLow != inLow
// eslint-disable-next-line no-self-compare
|| inHigh != inHigh
// eslint-disable-next-line no-self-compare
|| outLow != outLow
// eslint-disable-next-line no-self-compare
|| outHigh != outHigh
) return NaN;
if (x === Infinity || x === -Infinity) return x;
return (x - inLow) * (outHigh - outLow) / (inHigh - inLow) + outLow;
};