// Copyright 2016 Christian d'Heureuse, Inventec Informatik AG, Zurich, Switzerland
// www.source-code.biz, www.inventec.ch/chdh
//
// License: GPL, GNU General Public License, http://www.gnu.org/licenses/gpl.html
// Home page: http://www.source-code.biz/snippets/typescript

namespace Polyfills {

export const isInteger = Number.isInteger || function (value: any) {
   return typeof value === "number" && isFinite(value) && Math.floor(value) === value; };

export const sign = Math.sign || function (x: number) {
   return x > 0 ? 1 : -1; };

export const hypot = Math.hypot || function (...x: number[]) {
   let sum = 0;
   for (let i = 0; i < x.length; i++) {
      sum += x[i] * x[i]; }
   return Math.sqrt(sum); };

export const performanceNow = (window.performance && window.performance.now) ?
   function() {return window.performance.now(); } :
   Date.now;

export const windowRequestAnimationFrame = window.requestAnimationFrame || function (callback) {
   return window.setTimeout(callback, 0); };

export const windowCancelAnimationFrame = window.cancelAnimationFrame || function (handle) {
   return window.clearTimeout(handle); };

} // end namespace Polyfills

//------------------------------------------------------------------------------

// Declaration of ES6 functions.
interface NumberConstructor {
   isInteger (value: any): boolean; }
interface Math {
   sign(x: number): number;
   hypot(...x: number[]): number; }