PocketMine-MP/src/utils/Random.php
2013-09-09 03:32:24 +02:00

75 lines
2.1 KiB
PHP

<?php
/**
*
* ____ _ _ __ __ _ __ __ ____
* | _ \ ___ ___| | _____| |_| \/ (_)_ __ ___ | \/ | _ \
* | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
* | __/ (_) | (__| < __/ |_| | | | | | | | __/_____| | | | __/
* |_| \___/ \___|_|\_\___|\__|_| |_|_|_| |_|\___| |_| |_|_|
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* @author PocketMine Team
* @link http://www.pocketmine.net/
*
*
*/
//Unsecure, not used for "Real Randomness"
class Random{
private $x, $y, $z, $w;
public function __construct($seed = false){
$this->setSeed($seed);
}
public function setSeed($seed = false){
$seed = $seed !== false ? Utils::writeInt((int) $seed):Utils::getRandomBytes(4, false);
$state = array();
for($i = 0; $i < 256; ++$i){
$state[] = $i;
}
for($i = $j = 0; $i < 256; ++$i){
$j = ($j + ord($seed{$i & 0x03}) + $state[$i]) & 0xFF;
$state[$i] ^= $state[$j];
$state[$j] ^= $state[$i];
$state[$i] ^= $state[$j];
}
$this->state = $state;
$this->i = $this->j = 0;
}
public function nextInt(){
return Utils::readInt($this->nextBytes(4)) & 0x7FFFFFFF;
}
public function nextFloat(){
return $this->nextInt() / 0x7FFFFFFF;
}
public function nextBytes($byteCount){
$bytes = "";
for($i = 0; $i < $byteCount; ++$i){
$this->i = ($this->i + 1) & 0xFF;
$this->j = ($this->j + $this->state[$this->i]) & 0xFF;
$this->state[$this->i] ^= $this->state[$this->j];
$this->state[$this->j] ^= $this->state[$this->i];
$this->state[$this->i] ^= $this->state[$this->j];
$bytes .= chr($this->state[($this->state[$this->i] + $this->state[$this->j]) & 0xFF]);
}
return $bytes;
}
public function nextBoolean(){
return ($this->nextBytes(1) & 0x01) == 0;
}
public function nextRange($start = 0, $end = PHP_INT_MAX){
return $start + ($this->nextInt() % ($end + 1 - $start));
}
}