lepu-test-platform-web/node_modules/es-abstract/2018/ToUint8Clamp.js

25 lines
607 B
JavaScript
Raw Normal View History

'use strict';
var GetIntrinsic = require('../GetIntrinsic');
var $Math = GetIntrinsic('%Math%');
var ToNumber = require('./ToNumber');
var $isNaN = require('../helpers/isNaN');
var $floor = $Math.floor;
// https://www.ecma-international.org/ecma-262/6.0/#sec-touint8clamp
module.exports = function ToUint8Clamp(argument) {
var number = ToNumber(argument);
if ($isNaN(number) || number <= 0) { return 0; }
if (number >= 0xFF) { return 0xFF; }
var f = $floor(argument);
if (f + 0.5 < number) { return f + 1; }
if (number < f + 0.5) { return f; }
if (f % 2 !== 0) { return f + 1; }
return f;
};