// Written by Curtis Olson, started July 1997.
//
-// Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
+// Copyright (C) 1997 Curtis L. Olson - http://www.flightgear.org/~curt
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Library General Public License for more details.
//
-// You should have received a copy of the GNU Library General Public
-// License along with this library; if not, write to the
-// Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-// Boston, MA 02111-1307, USA.
+// 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// $Id$
#endif
+#define MT_N 624
+#define MT_M 397
+
+/**
+ * Structure to hold MT algorithm state to easily allow independant
+ * sets of random numbers with different seeds.
+ */
+typedef struct {unsigned int array[MT_N]; int index; } mt;
+
+/**
+ * Initialize a new MT state with a given seed.
+ */
+void mt_init(mt *mt, unsigned int seed);
+
+/**
+ * Generate a new 32-bit random number based on the given MT state.
+ */
+unsigned int mt_rand32( mt *mt);
+
+/**
+ * Generate a new random number between [0.0, 1.0) based
+ * on the given MT state.
+ */
+double mt_rand(mt *mt);
+
/**
* Seed the random number generater with time() so we don't see the
* same sequence every time.
*/
void sg_srandom_time();
+/**
+ * Seed the random number generater with time() in 10 minute intervals
+ * so we get the same sequence within 10 minutes interval.
+ * This is useful for synchronizing two display systems.
+ */
+void sg_srandom_time_10();
+
/**
* Seed the random number generater with your own seed so can set up
* repeatable randomization.
* @param seed random number generator seed
*/
-void sg_srandom( unsigned int seed );
+void sg_srandom(unsigned int seed );
/**
* Return a random number between [0.0, 1.0)