rounding functions

rounding functions .js

phh = phh || {};

phh.round = function (n) {
  return ~~((n >= 0 ? n : -n) + 0.5);
};

phh.ceil = function (n) {
  // faster than Math.ceil, but only behaves the same when testing positive numbers
  // http://jsperf.com/math-ceil/4

  return (n === ~~n) ? n : ~~n + 1;
};

phh.swingCeil = function (n) {
  // rounds to an integer
  // +ve numbers swing away from 0 (towards Ceiling)
  // -ve numbers swing away from 0
  //  5.2 -> 6
  // -5.2 -> -6
  return (n === ~~n) ? n : ~~n + ((n > 0) ? 1 : -1);
};