random.cpp

   1 /*
   2 OOPoker
   3
   4 Copyright (c) 2010 Lode Vandevenne
   5 All rights reserved.
   6
   7 This file is part of OOPoker.
   8
   9 OOPoker is free software: you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation, either version 3 of the License, or
  12 (at your option) any later version.
  13
  14 OOPoker is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with OOPoker.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "random.h"
  24
  25 #if defined(_WIN32)
  26
  27 #include <windows.h>
  28 #include <iostream>
  29
  30 unsigned int getRandomUint()
  31 {
  32   unsigned int r;
  33
  34   HMODULE hLib=LoadLibrary("ADVAPI32.DLL");
  35   if (hLib) {
  36    BOOLEAN (APIENTRY *pfn)(void*, ULONG) =
  37         (BOOLEAN (APIENTRY *)(void*,ULONG))GetProcAddress(hLib,"SystemFunction036");
  38    if (pfn) {
  39     char buff[4];
  40     ULONG ulCbBuff = sizeof(buff);
  41     if(pfn(buff,ulCbBuff)) {
  42
  43      // use buff full of random goop
  44
  45      r = buff[0] + 256 * buff[1] + 256 * 256 * buff[2] + 256 * 256 * 256 * buff[3];
  46
  47     }
  48    }
  49
  50    FreeLibrary(hLib);
  51   }
  52
  53   return r;
  54 }
  55
  56 #elif defined(linux) || defined(__linux) || defined(__linux__) || defined(__GNU__) || defined(__GLIBC__)
  57
  58 #include <string>
  59 #include <fstream>
  60
  61 unsigned int getRandomUint()
  62 {
  63   unsigned int r;
  64   static std::string filename = "/dev/urandom";
  65   static std::ifstream file(filename.c_str(), std::ios::in|std::ios::binary|std::ios::ate);
  66   file.read((char*)(&r), sizeof(r));
  67   return r;
  68 }
  69
  70 #endif
  71
  72 double getRandom()
  73 {
  74   return getRandomUint() / 4294967296.0;
  75 }
  76
  77 int getRandom(int low, int high)
  78 {
  79   return getRandomUint() % (high - low + 1) + low;
  80 }
  81
  82
  83 static unsigned int m_w = 1;
  84 static unsigned int m_z = 2;
  85
  86 //"Multiply-With-Carry" generator of G. Marsaglia
  87 unsigned int getRandomUintFast()
  88 {
  89   m_z = 36969 * (m_z & 65535) + (m_z >> 16);
  90   m_w = 18000 * (m_w & 65535) + (m_w >> 16);
  91   return (m_z << 16) + m_w;  //32-bit result
  92 }
  93
  94 void seedRandomFast(unsigned int seed1, unsigned int seed2)
  95 {
  96   if(seed1 == 0) seed1 = 1;
  97   if(seed2 == 0) seed2 = 1;
  98   m_w = seed1;
  99   m_z = seed2;
 100 }
 101
 102 void seedRandomFastWithRandomSlow()
 103 {
 104   seedRandomFast(getRandomUint(), getRandomUint());
 105 }
 106
 107 double getRandomFast()
 108 {
 109   return getRandomUintFast() / 4294967296.0;
 110 }
 111
 112 int getRandomFast(int low, int high)
 113 {
 114   return getRandomUintFast() % (high - low + 1) + low;
 115 }