Uplink/Numerics.class.php

   1 <?php
   2 /******************************* PHP-P10 v2 *****************************
   3  * Copyright (C) 2011-2012  Philipp Kreil (pk910)                       *
   4  *                                                                      *
   5  * This program is free software: you can redistribute it and/or modify *
   6  * it under the terms of the GNU General Public License as published by *
   7  * the Free Software Foundation, either version 3 of the License, or    *
   8  * (at your option) any later version.                                  *
   9  *                                                                      *
  10  * This program is distributed in the hope that it will be useful,      *
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of       *
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        *
  13  * GNU General Public License for more details.                         *
  14  *                                                                      *
  15  * You should have received a copy of the GNU General Public License    *
  16  * along with this program. If not, see <http://www.gnu.org/licenses/>. *
  17  *                                                                      *
  18  ************************************************************************
  19  *
  20  *  Uplink/Numerics.class.php
  21  *
  22  * P10 numeric functions
  23  *
  24  */
  25
  26 class Numerics {
  27         private static $base64chars = array(
  28           'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',
  29           'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',
  30           'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
  31           'w','x','y','z','0','1','2','3','4','5','6','7','8','9','[',']'
  32           );
  33           private static $base64charsLength = 64;
  34
  35           public static function intToNum($int, $length) {
  36                 $numeric = "";
  37                 for($pos = $length-1; $pos >= 0; $pos--) {
  38                         //current position represents floor($int / ($base64charsLength ^ $pos))
  39                         $base = 1;
  40                         for($i = 0; $i < $pos; $i++) {
  41                                 $base = $base * self::$base64charsLength;
  42                         }
  43                         $posValue = floor($int / $base);
  44                         $int -= $posValue * $base;
  45                         //get the char representing $posValue
  46                         $posChar = self::$base64chars[$posValue];
  47                         $numeric .= $posChar;
  48                 }
  49
  50                 return $numeric;
  51           }
  52
  53           public static function numToInt($numeric) {
  54                 $base = 1;
  55                 $int = 0;
  56                 for($pos = strlen($numeric)-1; $pos >= 0; $pos--) {
  57                         $posValue = array_search($numeric[$pos], self::$base64chars);
  58                         $int = ($posValue * $base);
  59                         $base = $base * self::$base64charsLength;
  60                 }
  61                 return $int;
  62           }
  63
  64 }
  65
  66 ?>