41 lines
1.3 KiB
C++
41 lines
1.3 KiB
C++
#ifndef RNG_SFMT_H
|
|
#define RNG_SFMT_H
|
|
|
|
#include <climits>
|
|
#include <QMutex>
|
|
#include "sfmt/SFMT.h"
|
|
#include "rng_abstract.h"
|
|
|
|
/**
|
|
* This class encapsulates a state of the art PRNG and can be used
|
|
* to return uniformly distributed integer random numbers from a range [min, max].
|
|
* Though technically possible, min must be >= 0 and max should always be > 0.
|
|
* If max < 0 and min == 0 it is assumed that rand() % -max is wanted and the result will
|
|
* be -rand(0, -max).
|
|
* This is the only exception to the rule that !(min > max) and is actually unused in
|
|
* Cockatrice.
|
|
*
|
|
* Technical details:
|
|
* The RNG uses the SIMD-oriented Fast Mersenne Twister code v1.4.1 from
|
|
* http://www.math.sci.hiroshima-u.ac.jp/~%20m-mat/MT/SFMT/index.html
|
|
* The SFMT RNG creates unsigned int 64bit pseudo random numbers.
|
|
*
|
|
* These are mapped to values from the interval [min, max] without bias by using Knuth's
|
|
* "Algorithm S (Selection sampling technique)" from "The Art of Computer Programming 3rd
|
|
* Edition Volume 2 / Seminumerical Algorithms".
|
|
*/
|
|
|
|
class RNG_SFMT : public RNG_Abstract {
|
|
Q_OBJECT
|
|
private:
|
|
QMutex mutex;
|
|
sfmt_t sfmt;
|
|
// The discrete cumulative distribution function for the RNG
|
|
unsigned int cdf(unsigned int min, unsigned int max);
|
|
public:
|
|
RNG_SFMT(QObject *parent = 0);
|
|
unsigned int rand(int min, int max);
|
|
};
|
|
|
|
#endif
|
|
|