1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | 1× 1× 44× 1× 1× | var mathUtil = {}; mathUtil.isPowerOfTwo = function (value) { return (value & (value - 1)) === 0; }; mathUtil.nextPowerOfTwo = function (value) { value --; value |= value >> 1; value |= value >> 2; value |= value >> 4; value |= value >> 8; value |= value >> 16; value ++; return value; }; mathUtil.nearestPowerOfTwo = function (value) { return Math.pow( 2, Math.round( Math.log( value ) / Math.LN2 ) ); }; export default mathUtil; |