src/common/random.h

/* Copyright (c) 1999 Silicon Graphics, Inc. */

/* SCCSid "$SunId$ SGI" */

/*
 *  random.h - header file for random(3) and urand() function.
 *
 *     10/1/85
 */

#ifdef  MSDOS

#define random()        ((long)rand()<<16^(long)rand()<<6^(long)rand()>>4)
#define srandom(s)      srand((unsigned)(s))

#define frandom()       (rand()*(1./32768.))

#else
#ifdef  BSD

extern long  random();

#define  frandom()      (random()*(1./2147483648.))

#else

extern long  lrand48();
extern double  drand48();

#define  random()       lrand48()
#define  srandom(s)     srand48((long)(s))
#define  frandom()      drand48()

#endif
#endif

#ifdef  MC

#define  urand(i)       frandom()
#define  initurand(n)   (n)

#else

extern unsigned short   *urperm;
extern int      urmask, initurand();

#define  urand(i)       ((urperm[(i)&urmask]+frandom())/(urmask+1))

#endif
Revision:	2.7
Committed:	Sat Jan 9 09:15:48 1999 UTC (25 years, 3 months ago) by gwlarson
Content type:	text/plain
Branch:	MAIN
Changes since 2.6:	+3 -1 lines
Log Message:	added define for random seed function
#	User	Rev	Content
1	gwlarson	2.7	/* Copyright (c) 1999 Silicon Graphics, Inc. */
2	greg	1.1
3	gregl	2.5	/* SCCSid "$SunId$ SGI" */
4	greg	1.1
5			/*
6	greg	1.4	* random.h - header file for random(3) and urand() function.
7	greg	1.1	*
8			* 10/1/85
9			*/
10
11	greg	2.2	#ifdef MSDOS
12	greg	1.3
13	greg	2.3	#define random() ((long)rand()<<16^(long)rand()<<6^(long)rand()>>4)
14	gwlarson	2.7	#define srandom(s) srand((unsigned)(s))
15	greg	2.2
16			#define frandom() (rand()*(1./32768.))
17
18			#else
19			#ifdef BSD
20
21	greg	1.1	extern long random();
22
23	greg	2.2	#define frandom() (random()*(1./2147483648.))
24	greg	1.3
25			#else
26
27			extern long lrand48();
28			extern double drand48();
29
30	greg	2.2	#define random() lrand48()
31	gwlarson	2.7	#define srandom(s) srand48((long)(s))
32	greg	2.2	#define frandom() drand48()
33	greg	1.3
34			#endif
35	greg	2.2	#endif
36	greg	1.4
37	greg	2.4	#ifdef MC
38	gregl	2.5
39	greg	2.4	#define urand(i) frandom()
40	gregl	2.5	#define initurand(n) (n)
41
42	greg	2.4	#else
43	gregl	2.5
44	gregl	2.6	extern unsigned short *urperm;
45	gregl	2.5	extern int urmask, initurand();
46
47	greg	2.2	#define urand(i) ((urperm[(i)&urmask]+frandom())/(urmask+1))
48	gregl	2.5
49	greg	2.4	#endif