Initial revision

lbtt/src/Random.h

@@ -0,0 +1,96 @@
+/*
+ *  Copyright (C) 1999, 2000, 2001, 2002
+ *  Heikki Tauriainen <Heikki.Tauriainen@hut.fi>
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version 2
+ *  of the License, or (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifndef RANDOM_H
+#define RANDOM_H
+
+#include <config.h>
+#include <cstdlib>
+
+#ifdef HAVE_RAND48
+#define rand lrand48
+#define srand srand48
+static const double MAXRAND = static_cast<double>(1 << 30) * 2.0;
+#else
+static const double MAXRAND = RAND_MAX + 1.0;
+#endif /* HAVE_RAND48 */
+
+
+
+/******************************************************************************
+ *
+ * Functions for random number generation.  If HAVE_RAND48 is defined, the
+ * functions rely on the lrand48() function for generating a random integer
+ * between 0 and 2^31 and srand48() for setting the seed for the random
+ * number generator; otherwise, the rand() and srand() functions are used,
+ * respectively.
+ *
+ *****************************************************************************/
+
+/* ========================================================================= */
+inline void SRAND(unsigned int seed)
+/* ----------------------------------------------------------------------------
+ *
+ * Description:   Initializes the random number generator with a seed value.
+ *
+ * Argument:      seed  --  Seed for the random number generator.
+ *
+ * Returns:       Nothing.
+ *
+ * ------------------------------------------------------------------------- */
+{
+  srand (seed);
+}
+
+/* ========================================================================= */
+inline double DRAND()
+/* ----------------------------------------------------------------------------
+ *
+ * Description:   Generates a random double.
+ *
+ * Arguments:     None.
+ *
+ * Returns:       A random double in the half-open interval [0.0,1.0).
+ *
+ * ------------------------------------------------------------------------- */
+{
+  return rand () / MAXRAND;
+}
+
+/* ========================================================================= */
+inline long int LRAND(long int min, long int max)
+/* ----------------------------------------------------------------------------
+ *
+ * Description:   Generates a random long integer in a given interval.
+ *
+ * Arguments:     min, max  --  Bounds for the interval.
+ *
+ * Returns:       A random long integer in the half-open interval [min,max).
+ *
+ * ------------------------------------------------------------------------- */
+{
+  return min + static_cast<long int>(DRAND() * (max - min));
+}
+
+#ifdef HAVE_RAND48
+#undef rand
+#undef srand
+#endif /* HAVE_RAND48 */
+
+#endif /* !RANDOM_H */