--- ray/src/common/random.h	1989/02/02 10:34:21	1.1
+++ ray/src/common/random.h	1997/12/01 09:55:00	2.5
@@ -1,13 +1,47 @@
-/* Copyright (c) 1986 Regents of the University of California */
+/* Copyright (c) 1997 Silicon Graphics, Inc. */
 
-/* SCCSid "$SunId$ LBL" */
+/* SCCSid "$SunId$ SGI" */
 
 /*
- *  random.h - header file for random(3) function.
+ *  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 frandom()	(rand()*(1./32768.))
+
+#else
+#ifdef	BSD
+
 extern long  random();
 
-#define  frandom()	(random()/2147483648.0)
+#define	 frandom()	(random()*(1./2147483648.))
+
+#else
+
+extern long  lrand48();
+extern double  drand48();
+
+#define	 random()	lrand48()
+#define	 frandom()	drand48()
+
+#endif
+#endif
+
+#ifdef  MC
+
+#define  urand(i)	frandom()
+#define  initurand(n)	(n)
+
+#else
+
+extern short	*urperm;
+extern int	urmask, initurand();
+
+#define	 urand(i)	((urperm[(i)&urmask]+frandom())/(urmask+1))
+
+#endif