*** empty log message ***

src/rnd.c

@@ -0,0 +1,145 @@
+/*	SCCS Id: @(#)rnd.c	3.3	96/02/07	*/
+/* NetHack may be freely redistributed.  See license for details. */
+
+#include "hack.h"
+
+/* "Rand()"s definition is determined by [OS]conf.h */
+#if defined(LINT) && defined(UNIX)	/* rand() is long... */
+extern int NDECL(rand);
+#define RND(x)	(rand() % x)
+#else /* LINT */
+# if defined(UNIX) || defined(RANDOM)
+#define RND(x)	(int)(Rand() % (long)(x))
+# else
+/* Good luck: the bottom order bits are cyclic. */
+#define RND(x)	(int)((Rand()>>3) % (x))
+# endif
+#endif /* LINT */
+
+#ifdef OVL0
+
+int
+rn2(x)		/* 0 <= rn2(x) < x */
+register int x;
+{
+#ifdef DEBUG
+	if (x <= 0) {
+		impossible("rn2(%d) attempted", x);
+		return(0);
+	}
+	x = RND(x);
+	return(x);
+#else
+	return(RND(x));
+#endif
+}
+
+#endif /* OVL0 */
+#ifdef OVLB
+
+int
+rnl(x)		/* 0 <= rnl(x) < x; sometimes subtracting Luck */
+register int x;	/* good luck approaches 0, bad luck approaches (x-1) */
+{
+	register int i;
+
+#ifdef DEBUG
+	if (x <= 0) {
+		impossible("rnl(%d) attempted", x);
+		return(0);
+	}
+#endif
+	i = RND(x);
+
+	if (Luck && rn2(50 - Luck)) {
+	    i -= (x <= 15 && Luck >= -5 ? Luck/3 : Luck);
+	    if (i < 0) i = 0;
+	    else if (i >= x) i = x-1;
+	}
+
+	return i;
+}
+
+#endif /* OVLB */
+#ifdef OVL0
+
+int
+rnd(x)		/* 1 <= rnd(x) <= x */
+register int x;
+{
+#ifdef DEBUG
+	if (x <= 0) {
+		impossible("rnd(%d) attempted", x);
+		return(1);
+	}
+	x = RND(x)+1;
+	return(x);
+#else
+	return(RND(x)+1);
+#endif
+}
+
+#endif /* OVL0 */
+#ifdef OVL1
+
+int
+d(n,x)		/* n <= d(n,x) <= (n*x) */
+register int n, x;
+{
+	register int tmp = n;
+
+#ifdef DEBUG
+	if (x < 0 || n < 0 || (x == 0 && n != 0)) {
+		impossible("d(%d,%d) attempted", n, x);
+		return(1);
+	}
+#endif
+	while(n--) tmp += RND(x);
+	return(tmp); /* Alea iacta est. -- J.C. */
+}
+
+#endif /* OVL1 */
+#ifdef OVLB
+
+int
+rne(x)
+register int x;
+{
+	register int tmp, utmp;
+
+	utmp = (u.ulevel < 15) ? 5 : u.ulevel/3;
+	tmp = 1;
+	while (tmp < utmp && !rn2(x))
+		tmp++;
+	return tmp;
+
+	/* was:
+	 *	tmp = 1;
+	 *	while(!rn2(x)) tmp++;
+	 *	return(min(tmp,(u.ulevel < 15) ? 5 : u.ulevel/3));
+	 * which is clearer but less efficient and stands a vanishingly
+	 * small chance of overflowing tmp
+	 */
+}
+
+int
+rnz(i)
+int i;
+{
+#ifdef LINT
+	int x = i;
+	int tmp = 1000;
+#else
+	register long x = i;
+	register long tmp = 1000;
+#endif
+	tmp += rn2(1000);
+	tmp *= rne(4);
+	if (rn2(2)) { x *= tmp; x /= 1000; }
+	else { x *= 1000; x /= tmp; }
+	return((int)x);
+}
+
+#endif /* OVLB */
+
+/*rnd.c*/