http://svn.poeml.de/viewvc/ppc/src-unpacked/xscreensaver/xscreensaver-4.12.tar.bz2...

[xscreensaver] / utils / yarandom.h

diff --git a/utils/yarandom.h b/utils/yarandom.h
index 6563be7ed29ef2d41a090a9ed61caf0e5aa36edc..eb560a2fd04256a614d5cb30c0fde7cdffd6ff14 100644 (file)
--- a/utils/yarandom.h
+++ b/utils/yarandom.h
@@ -1,4 +1,4 @@
-/* xscreensaver, Copyright (c) 1997 by Jamie Zawinski <jwz@netscape.com>
+/* xscreensaver, Copyright (c) 1997, 1998, 2003 by Jamie Zawinski <jwz@jwz.org>
  *
  * Permission to use, copy, modify, distribute, and sell this software and its
  * documentation for any purpose is hereby granted without fee, provided that
@@ -19,32 +19,45 @@
 #undef srand
 #undef srand48
 #undef frand
+#undef RAND_MAX
 
 #ifdef VMS
 # include "vms-gtod.h"
 #endif
 
-#define random()   ya_random()
-#define srandom(i) ya_rand_init(0)
-
 extern unsigned int ya_random (void);
 extern void ya_rand_init (unsigned int);
 
+#define random()   ya_random()
+#define RAND_MAX   0xFFFFFFFF
+
+/*#define srandom(i) ya_rand_init(0)*/
+
+/* Define these away to keep people from using the wrong APIs in xscreensaver.
+ */
+#define rand          __ERROR_use_random_not_rand_in_xscreensaver__
+#define drand48       __ERROR_use_frand_not_drand48_in_xscreensaver__
+#define srandom       __ERROR_do_not_call_srandom_in_xscreensaver__
+#define srand         __ERROR_do_not_call_srand_in_xscreensaver__
+#define srand48       __ERROR_do_not_call_srand48_in_xscreensaver__
+#define ya_rand_init  __ERROR_do_not_call_ya_rand_init_in_xscreensaver__
+
 
 #if defined (__GNUC__) && (__GNUC__ >= 2)
  /* Implement frand using GCC's statement-expression extension. */
 
 # define frand(f)                                                      \
-  ({ double tmp = (((double) random()) /                               \
-                  (((double) ((unsigned int)~0)) / ((double) (f))));   \
+  __extension__                                                                \
+  ({ double tmp = ((((double) random()) * ((double) (f))) /            \
+                  ((double) ((unsigned int)~0)));                      \
      tmp < 0 ? (-tmp) : tmp; })
 
 #else /* not GCC2 - implement frand using a global variable.*/
 
 static double _frand_tmp_;
 # define frand(f)                                                      \
-  (_frand_tmp_ = (((double) random()) /                                \
-                 (((double) ((unsigned int)~0)) / ((double) (f)))),    \
+  (_frand_tmp_ = ((((double) random()) * ((double) (f))) /             \
+                 ((double) ((unsigned int)~0))),                       \
    _frand_tmp_ < 0 ? (-_frand_tmp_) : _frand_tmp_)
 
 #endif /* not GCC2 */