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/*
------------------------------------------------------------------------------
rand.h: definitions for a random number generator
By Bob Jenkins, 1996, Public Domain
MODIFIED:
960327: Creation (addition of randinit, really)
970719: use context, not global variables, for internal state
980324: renamed seed to flag
980605: recommend RANDSIZL=4 for noncryptography.
010626: note this is public domain
------------------------------------------------------------------------------
*/
#ifndef STANDARD
#include "standard.h"
#endif
#ifndef RAND
#define RAND
#define RANDSIZL (8)
#define RANDSIZ (1<<RANDSIZL)
/* context of random number generator */
struct randctx
{
ub4 randcnt;
ub4 randrsl[RANDSIZ];
ub4 randmem[RANDSIZ];
ub4 randa;
ub4 randb;
ub4 randc;
};
typedef struct randctx randctx;
/*
------------------------------------------------------------------------------
If (flag==TRUE), then use the contents of randrsl[0..RANDSIZ-1] as the seed.
------------------------------------------------------------------------------
*/
void randinit(/*_ randctx *r, word flag _*/);
void isaac(/*_ randctx *r _*/);
/*
------------------------------------------------------------------------------
Call rand(/o_ randctx *r _o/) to retrieve a single 32-bit random value
------------------------------------------------------------------------------
*/
#define rand(r) \
(!(r)->randcnt-- ? \
(isaac(r), (r)->randcnt=RANDSIZ-1, (r)->randrsl[(r)->randcnt]) : \
(r)->randrsl[(r)->randcnt])
#endif /* RAND */
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