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Diffstat (limited to 'zbar/qrcode/isaac.h')
| -rw-r--r-- | zbar/qrcode/isaac.h | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/zbar/qrcode/isaac.h b/zbar/qrcode/isaac.h new file mode 100644 index 0000000..e0b10e7 --- /dev/null +++ b/zbar/qrcode/isaac.h @@ -0,0 +1,34 @@ +/*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 |