stellar

0 #ifndef STELLAR_RANDOM_H

1 #define STELLAR_RANDOM_H

2

3 #include "utils.hpp"

4

5 class Random {

6 public:

7 constexpr Random(void) = default;

8 constexpr Random(U64 seed) : state(seed) {}

9

10 constexpr U64 operator()(void) { return get_U64(); }

11

12 constexpr U32 get_U32(void) {

13 U32 number = state;

14

15 number ^= number << 13;

16 number ^= number >> 17;

17 number ^= number << 5;

18

19 return state = number;

20 }

21

22 constexpr U64 get_U64(void) {

23 U64 n1, n2, n3, n4;

24

25 n1 = (U64)(get_U32()) & C64(0xFFFF);

26 n2 = (U64)(get_U32()) & C64(0xFFFF);

27 n3 = (U64)(get_U32()) & C64(0xFFFF);

28 n4 = (U64)(get_U32()) & C64(0xFFFF);

29

30 return n1 | (n2 << 16) | (n3 << 32) | (n4 << 48);

31 }

32

33 private:

34 static const U32 default_seed = C32(1804289383);

35 U32 state = default_seed;

36 };

37

38 #endif