fast_irandom(): Implement
[pachi.git] / random.h
blobea08d28434b53173a4bb11bef600a578a200b02a
1 #ifndef ZZGO_RANDOM_H
2 #define ZZGO_RANDOM_H
4 #include <stdint.h>
6 void fast_srandom(unsigned long seed);
7 unsigned long fast_getseed(void);
9 /* Note that only 16bit numbers can be returned. */
10 uint16_t fast_random(unsigned int max);
11 /* Use this one if you want larger numbers. */
12 static uint32_t fast_irandom(unsigned int max);
14 /* Get random number in [0..1] range. */
15 float fast_frandom();
18 static inline uint32_t
19 fast_irandom(unsigned int max)
21 if (max <= 65536)
22 return fast_random(max);
23 return (fast_random(max / 65536 + 1) << 16) | fast_random(65536);
26 #endif