/* * random.h * * Mersenne Twister random number generator. * From Makoto Matsumoto and Takuji Nishimura. * * Portable Windows Library * * Copyright (c) 1993-2000 Equivalence Pty. Ltd. * * The contents of this file are subject to the Mozilla Public License * Version 1.0 (the "License"); you may not use this file except in * compliance with the License. You may obtain a copy of the License at * http://www.mozilla.org/MPL/ * * Software distributed under the License is distributed on an "AS IS" * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See * the License for the specific language governing rights and limitations * under the License. * * The Original Code is Portable Windows Library. * * The Initial Developer of the Original Code is Equivalence Pty. Ltd. * * Contributor(s): ______________________________________. * * $Log: random.h,v $ * Revision 1.1  2000/02/17 12:05:02  robertj * Added better random number generator after finding major flaws in MSVCRT version. * */#ifndef _PRANDOM#define _PRANDOM#ifdef __GNUC__#pragma interface#endif/**Mersenne Twister random number generator.   An application would create a static instance of this class, and then use   if to generate a sequence of psuedo-random numbers.   Usually an application would simply use PRandom::Number() but if   performance is an issue then it could also create a static local variable   such as:        {          static PRandom rand;          for (i = 0; i < 10000; i++)             array[i] = rand;        }    This method is not thread safe, so it is the applications responsibility    to assure that its calls are single threaded.  */class PRandom{  public:    /**Construct the random number generator.       This version will seed the random number generator with a value based       on the system time as returned by time() and clock().      */    PRandom();    /**Construct the random number generator.       This version allows the application to choose the seed, thus letting it       get the same sequence of values on each run. Useful for debugging.      */    PRandom(      DWORD seed    /// New seed value, must not be zero    );    /**Set the seed for the random number generator.      */    void SetSeed(      DWORD seed    /// New seed value, must not be zero    );    /**Get the next psuedo-random number in sequence.       This generates one pseudorandom unsigned integer (32bit) which is       uniformly distributed among 0 to 2^32-1 for each call.      */    unsigned Generate();    /**Get the next psuedo-random number in sequence.      */    inline operator unsigned() { return Generate(); }    /**Get the next psuedo-random number in sequence.       This utilises a single system wide thread safe PRandom variable. All       threads etc will share the same psuedo-random sequence.      */    static unsigned Number();  protected:    enum { N = 624 };     /* cycle size */    unsigned long mt[N];  /* the array for the state vector  */    int mti;};#endif  // _PRANDOM// End Of File ///////////////////////////////////////////////////////////////