kscreensaver/xsavers/xs_yarandom.h

   1 /* xscreensaver, Copyright (c) 1997 by Jamie Zawinski <jwz@jwz.org>
   2  *
   3  * Permission to use, copy, modify, distribute, and sell this software and its
   4  * documentation for any purpose is hereby granted without fee, provided that
   5  * the above copyright notice appear in all copies and that both that
   6  * copyright notice and this permission notice appear in supporting
   7  * documentation.  No representations are made about the suitability of this
   8  * software for any purpose.  It is provided "as is" without express or
   9  * implied warranty.
  10  */
  11
  12 #ifndef __YARANDOM_H__
  13 #define __YARANDOM_H__
  14
  15 #undef random
  16 #undef rand
  17 #undef drand48
  18 #undef srandom
  19 #undef srand
  20 #undef srand48
  21 #undef frand
  22
  23 #ifdef VMS
  24 # include "vms-gtod.h"
  25 #endif
  26
  27 /* #define random()   ya_random()
  28  #define srandom(i) ya_rand_init(0) */
  29
  30 extern unsigned int ya_random (void);
  31 extern void ya_rand_init (unsigned int);
  32
  33
  34 #if defined (__GNUC__) && (__GNUC__ >= 2)
  35  /* Implement frand using GCC's statement-expression extension. */
  36
  37 # define frand(f)                                                       \
  38   ({ double tmp = (((double) random()) /                                \
  39                    (((double) ((unsigned int)~0)) / ((double) (f))));   \
  40      tmp < 0 ? (-tmp) : tmp; })
  41
  42 #else /* not GCC2 - implement frand using a global variable.*/
  43
  44 static double _frand_tmp_;
  45 # define frand(f)                                                       \
  46   (_frand_tmp_ = (((double) random()) /                                 \
  47                   (((double) ((unsigned int)~0)) / ((double) (f)))),    \
  48    _frand_tmp_ < 0 ? (-_frand_tmp_) : _frand_tmp_)
  49
  50 #endif /* not GCC2 */
  51
  52 #endif /* __YARANDOM_H__ */