1 files changed, 56 insertions, 0 deletions
diff --git a/isaac.h b/isaac.h
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index 0000000..6554569
--- /dev/null
+++ b/isaac.h
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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
+
+