| 1 |
< |
/* Copyright (c) 1991 Regents of the University of California */ |
| 1 |
> |
/* Copyright (c) 1997 Silicon Graphics, Inc. */ |
| 2 |
|
|
| 3 |
|
#ifndef lint |
| 4 |
< |
static char SCCSid[] = "$SunId$ LBL"; |
| 4 |
> |
static char SCCSid[] = "$SunId$ SGI"; |
| 5 |
|
#endif |
| 6 |
|
|
| 7 |
|
/* |
| 8 |
< |
* Uncorrelated (anticorrelated) random function |
| 8 |
> |
* Anticorrelated random function due to Christophe Schlick |
| 9 |
|
*/ |
| 10 |
|
|
| 11 |
|
#include "random.h" |
| 14 |
|
|
| 15 |
|
extern char *malloc(); |
| 16 |
|
|
| 17 |
< |
short *urperm; /* urand() permutation */ |
| 17 |
> |
short *urperm = NULL; /* urand() permutation */ |
| 18 |
|
int urmask; /* bits used in permutation */ |
| 19 |
|
|
| 20 |
|
|
| 21 |
+ |
int |
| 22 |
|
initurand(size) /* initialize urand() for size entries */ |
| 23 |
|
int size; |
| 24 |
|
{ |
| 25 |
|
int order, n; |
| 26 |
|
register int i, offset; |
| 27 |
|
|
| 28 |
+ |
if (urperm != NULL) |
| 29 |
+ |
free((char *)urperm); |
| 30 |
|
size--; |
| 31 |
|
for (i = 1; size >>= 1; i++) |
| 32 |
|
; |
| 47 |
|
else |
| 48 |
|
urperm[i+offset]++; |
| 49 |
|
} |
| 50 |
+ |
return(1<<order); |
| 51 |
+ |
} |
| 52 |
+ |
|
| 53 |
+ |
|
| 54 |
+ |
int |
| 55 |
+ |
ilhash(d, n) /* hash a set of integer values */ |
| 56 |
+ |
register int *d; |
| 57 |
+ |
register int n; |
| 58 |
+ |
{ |
| 59 |
+ |
static int tab[8] = {13623,353,1637,5831,2314,3887,5832,8737}; |
| 60 |
+ |
register int hval; |
| 61 |
+ |
|
| 62 |
+ |
hval = 0; |
| 63 |
+ |
while (n-- > 0) |
| 64 |
+ |
hval += *d++ * tab[n&7]; |
| 65 |
+ |
return(hval); |
| 66 |
|
} |
