152 lines
3.1 KiB
C
152 lines
3.1 KiB
C
/* NetHack 3.6 rnd.c $NHDT-Date: 1432512767 2015/05/25 00:12:47 $ $NHDT-Branch: master $:$NHDT-Revision: 1.15 $ */
|
|
/* 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 */
|
|
|
|
int rn2(x) /* 0 <= rn2(x) < x */
|
|
register int x;
|
|
{
|
|
#ifdef BETA
|
|
if (x <= 0) {
|
|
debugpline1("rn2(%d) attempted", x);
|
|
return (0);
|
|
}
|
|
x = RND(x);
|
|
return (x);
|
|
#else
|
|
return (RND(x));
|
|
#endif
|
|
}
|
|
|
|
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, adjustment;
|
|
|
|
#ifdef BETA
|
|
if (x <= 0) {
|
|
debugpline1("rnl(%d) attempted", x);
|
|
return (0);
|
|
}
|
|
#endif
|
|
|
|
adjustment = Luck;
|
|
if (x <= 15) {
|
|
/* for small ranges, use Luck/3 (rounded away from 0);
|
|
also guard against architecture-specific differences
|
|
of integer division involving negative values */
|
|
adjustment = (abs(adjustment) + 1) / 3 * sgn(adjustment);
|
|
/*
|
|
* 11..13 -> 4
|
|
* 8..10 -> 3
|
|
* 5.. 7 -> 2
|
|
* 2.. 4 -> 1
|
|
* -1,0,1 -> 0 (no adjustment)
|
|
* -4..-2 -> -1
|
|
* -7..-5 -> -2
|
|
* -10..-8 -> -3
|
|
* -13..-11-> -4
|
|
*/
|
|
}
|
|
|
|
i = RND(x);
|
|
if (adjustment && rn2(37 + abs(adjustment))) {
|
|
i -= adjustment;
|
|
if (i < 0)
|
|
i = 0;
|
|
else if (i >= x)
|
|
i = x - 1;
|
|
}
|
|
return i;
|
|
}
|
|
|
|
int rnd(x) /* 1 <= rnd(x) <= x */
|
|
register int x;
|
|
{
|
|
#ifdef BETA
|
|
if (x <= 0) {
|
|
debugpline1("rnd(%d) attempted", x);
|
|
return (1);
|
|
}
|
|
x = RND(x) + 1;
|
|
return (x);
|
|
#else
|
|
return (RND(x) + 1);
|
|
#endif
|
|
}
|
|
|
|
int d(n, x) /* n <= d(n,x) <= (n*x) */
|
|
register int n, x;
|
|
{
|
|
register int tmp = n;
|
|
|
|
#ifdef BETA
|
|
if (x < 0 || n < 0 || (x == 0 && n != 0)) {
|
|
debugpline2("d(%d,%d) attempted", n, x);
|
|
return (1);
|
|
}
|
|
#endif
|
|
while (n--)
|
|
tmp += RND(x);
|
|
return (tmp); /* Alea iacta est. -- J.C. */
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
/*rnd.c*/
|