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/*Written by Timothy B. Terriberry (tterribe@xiph.org) 1999-2009 public domain.
Based on the public domain implementation by Robert J. Jenkins Jr.*/
#if !defined(_isaac_H)
#define _isaac_H (1)
typedef struct isaac_ctx isaac_ctx;
#define ISAAC_SZ_LOG (8)
#define ISAAC_SZ (1 << ISAAC_SZ_LOG)
#define ISAAC_SEED_SZ_MAX (ISAAC_SZ << 2)
/*ISAAC is the most advanced of a series of Pseudo-Random Number Generators
designed by Robert J. Jenkins Jr. in 1996.
http://www.burtleburtle.net/bob/rand/isaac.html
To quote:
No efficient method is known for deducing their internal states.
ISAAC requires an amortized 18.75 instructions to produce a 32-bit value.
There are no cycles in ISAAC shorter than 2**40 values.
The expected cycle length is 2**8295 values.*/
struct isaac_ctx {
unsigned n;
unsigned r[ISAAC_SZ];
unsigned m[ISAAC_SZ];
unsigned a;
unsigned b;
unsigned c;
};
void isaac_init(isaac_ctx *_ctx, const void *_seed, int _nseed);
unsigned isaac_next_uint32(isaac_ctx *_ctx);
unsigned isaac_next_uint(isaac_ctx *_ctx, unsigned _n);
#endif
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