Files
PocketMine-MP/src/pocketmine/utils/Random.php
2014-09-12 12:58:21 +02:00

116 lines
2.4 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/
*
*
*/
namespace pocketmine\utils;
/**
* Unsecure Random Number Generator, used for fast seeded values
* WARNING: This class is available on the PocketMine-MP Zephir project.
* If this class is modified, remember to modify the PHP C extension.
*/
class Random{
protected $seed;
/**
* @param int $seed Integer to be used as seed.
*/
public function __construct($seed = -1){
if($seed == -1){
$seed = time();
}
$this->setSeed($seed);
}
/**
* @param int $seed Integer to be used as seed.
*/
public function setSeed($seed){
$this->seed = crc32(pack("N", $seed));
}
/**
* Returns an 31-bit integer (not signed)
*
* @return int
*/
public function nextInt(){
return $this->nextSignedInt() & 0x7fffffff;
}
/**
* Returns a 32-bit integer (signed)
*
* @return int
*/
public function nextSignedInt(){
$t = crc32(pack("N", $this->seed));
$this->seed ^= $t;
if(PHP_INT_SIZE === 8){
return $t << 32 >> 32;
}else{
return $t;
}
}
/**
* Returns a float between 0.0 and 1.0 (inclusive)
*
* @return float
*/
public function nextFloat(){
return $this->nextInt() / 0x7fffffff;
}
/**
* Returns a float between -1.0 and 1.0 (inclusive)
*
* @return float
*/
public function nextSignedFloat(){
return $this->nextSignedInt() / 0x7fffffff;
}
/**
* Returns a random boolean
*
* @return bool
*/
public function nextBoolean(){
return ($this->nextSignedInt() & 0x01) === 0;
}
/**
* Returns a random integer between $start and $end
*
* @param int $start default 0
* @param int $end default 0x7fffffff
*
* @return int
*/
public function nextRange($start = 0, $end = 0x7fffffff){
return $start + ($this->nextInt() % ($end + 1 - $start));
}
}