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authorLars-Dominik Braun <lars@6xq.net>2015-05-02 21:36:31 +0200
committerLars-Dominik Braun <lars@6xq.net>2015-05-02 21:36:31 +0200
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+/*
+------------------------------------------------------------------------------
+isaac.h: definitions for a random number generator
+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.
+ 991209: modified for inclusion with GNU Backgammon by Gary Wong
+ 070121: modified for inclusion with flam3 by Erik Reckase
+------------------------------------------------------------------------------
+*/
+
+#include "isaacs.h"
+
+#ifndef _ISAAC_H_
+#define _ISAAC_H_
+
+#define RANDSIZL (4) /* I recommend 8 for crypto, 4 for simulations */
+#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 irandinit( randctx *r, word flag );
+
+void isaac( randctx *r );
+
+
+/*
+------------------------------------------------------------------------------
+ Call irand(/o_ randctx *r _o/) to retrieve a single 32-bit random value
+------------------------------------------------------------------------------
+*/
+#define irand(r) \
+ (!(r)->randcnt-- ? \
+ (isaac(r), (r)->randcnt=RANDSIZ-1, (r)->randrsl[(r)->randcnt]) : \
+ (r)->randrsl[(r)->randcnt])
+
+#endif
+
+