X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=utils%2Fyarandom.h;h=711aadd35a90ebaaa399edc11c9c3604b984fce9;hb=refs%2Fremotes%2Fgithub%2Fmaster2;hp=53b22fd88d0196d886da4cf270a7fcca65206bbb;hpb=ccbc9f87eb59497b23bd0424ee1ed20ad7c7db54;p=xscreensaver

diff --git a/utils/yarandom.h b/utils/yarandom.h
index 53b22fd8..711aadd3 100644
--- a/utils/yarandom.h
+++ b/utils/yarandom.h
@@ -1,19 +1,103 @@
+/* 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
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation.  No representations are made about the suitability of this
+ * software for any purpose.  It is provided "as is" without express or 
+ * implied warranty.
+ */
+
+#ifndef __YARANDOM_H__
+#define __YARANDOM_H__
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#ifdef HAVE_INTTYPES_H
+# include <inttypes.h>
+#endif
+
 #undef random
 #undef rand
 #undef drand48
 #undef srandom
 #undef srand
 #undef srand48
+#undef frand
+#undef RAND_MAX
+
+#ifdef VMS
+# include "vms-gtod.h"
+#endif
+
+extern unsigned int ya_random (void);
+extern void ya_rand_init (unsigned int);
 
 #define random()   ya_random()
-#define srandom(i) ya_rand_init(0)
+#define RAND_MAX   0xFFFFFFFF
+
+/*#define srandom(i) ya_rand_init(0)*/
 
-#undef P
-#if __STDC__
-# define P(x)x
+/* 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)							\
+  __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) (f))) /		\
+		  ((double) ((unsigned int)~0))),			\
+   _frand_tmp_ < 0 ? (-_frand_tmp_) : _frand_tmp_)
+
+#endif /* not GCC2 */
+
+/* Compatibility with the xlockmore RNG API
+   (note that the xlockmore hacks never expect negative numbers.)
+ */
+#define LRAND()         ((long) (random() & 0x7fffffff))
+
+/* The first NRAND(n) is much faster, when uint64_t is available to allow it.
+ * Especially on ARM and other processors without built-in division.
+ *
+ * n must be greater than zero.
+ *
+ * The division by RAND_MAX+1 should optimize down to a bit shift.
+ *
+ * Although the result here is never negative, this needs to return signed
+ * integers: A binary operator in C requires operands have the same type, and
+ * if one side is signed and the other is unsigned, but they're both the same
+ * size, then the signed operand is cast to unsigned, and the result is
+ * similarly unsigned. This can potentially cause problems when idioms like
+ * "NRAND(n) * RANDSIGN()" (where RANDSIGN() returns either -1 or 1) is used
+ * to get random numbers from the range (-n,n).
+ */
+#ifdef HAVE_INTTYPES_H
+# define NRAND(n)       ((int32_t) ((uint64_t) random() * (uint32_t) (n) / \
+                                    ((uint64_t) RAND_MAX + 1)))
 #else
-# define P(x)()
+# define NRAND(n)       ((int) (LRAND() % (n)))
 #endif
 
-extern unsigned int ya_random P((void));
-extern void ya_rand_init P((unsigned int));
+#define MAXRAND         (2147483648.0) /* unsigned 1<<31 as a float */
+#define SRAND(n)        /* already seeded by screenhack.c */
+
+#endif /* __YARANDOM_H__ */