1 files changed, 145 insertions, 0 deletions
diff --git a/tdecore/krandomsequence.h b/tdecore/krandomsequence.h
new file mode 100644
index 000000000..383eee9ce
--- /dev/null
+++ b/tdecore/krandomsequence.h
@@ -0,0 +1,145 @@
+/* This file is part of the KDE libraries
+   Copyright (c) 1999 Sean Harmer <sh@astro.keele.ac.uk>
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public
+   License version 2 as published by the Free Software Foundation.
+
+   This library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public License
+   along with this library; see the file COPYING.LIB.  If not, write to
+   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02110-1301, USA.
+*/
+#ifndef K_RANDOM_SEQUENCE_H
+#define K_RANDOM_SEQUENCE_H
+
+#include "kdelibs_export.h"
+
+class KRandomSequencePrivate;
+class TQGList;
+/**
+ * A class to create a pseudo-random sequence
+ *
+ * Given a seed number, this class will produce a sequence of
+ * pseudo-random numbers. This would typically be used in
+ * applications like games.
+ *
+ * In general, you should instantiate a KRandomSequence object and
+ * pass along your seed number in the constructor. From then on,
+ * simply call getDouble() or getLong() to obtain the next
+ * number in the sequence.
+ *
+ * @author Sean Harmer <sh@astro.keele.ac.uk>
+ */
+class KDECORE_EXPORT KRandomSequence
+{
+public: 
+  /**
+   * Creates a pseudo-random sequence based on the seed lngSeed.
+   *
+   * A Pseudo-random sequence is different for each seed but can be 
+   * reproduced by starting the sequence with the same seed.
+   *
+   * If you need a single value which needs to be unpredictable, 
+   * you need to use kapp->random() instead.
+   * 
+   * @param lngSeed Seed to initialize the sequence with.
+   * If lngSeed is 0, the sequence is initialized with a value from
+   * KApplication::random().
+   */
+  KRandomSequence( long lngSeed = 0 );
+
+  /**
+   * Standard destructor
+   */
+  virtual ~KRandomSequence();
+
+  /**
+   * Copy constructor
+   */
+  KRandomSequence(const KRandomSequence &a);
+  
+  /**
+   * Assignment
+   */
+  KRandomSequence &operator=(const KRandomSequence &a);
+
+  /**
+   * Restart the sequence based on lngSeed.
+   * @param lngSeed Seed to initialize the sequence with.
+   * If lngSeed is 0, the sequence is initialized with a value from
+   * KApplication::random().
+   */
+  void setSeed( long lngSeed = 0 );
+
+  /**
+   * Get the next number from the pseudo-random sequence.
+   *
+   * @return a pseudo-random double value between [0,1[
+   */
+  double getDouble(); 
+  
+  /**
+   * Get the next number from the pseudo-random sequence.
+   *
+   * @return a pseudo-random integer value between [0, max[
+   * with 0 <= max < 1.000.000
+   */
+  unsigned long getLong(unsigned long max); 
+
+  /**
+   * Get a boolean from the pseudo-random sequence.
+   *
+   * @return a boolean which is either true or false
+   */
+  bool getBool(); 
+
+  /**
+   * Put a list in random order.
+   *
+   * @param list the list whose order will be modified
+   */
+  void randomize(TQGList *list);
+
+  /**
+   * Modulate the random sequence. 
+   *
+   * If S(i) is the sequence of numbers that will follow 
+   * given the current state after calling modulate(i), 
+   * then S(i) != S(j) for i != j and   
+   *      S(i) == S(j) for i == j.
+   *
+   * This can be useful in game situation where "undo" restores
+   * the state of the random sequence. If the game modulates the
+   * random sequence with the move chosen by the player, the 
+   * random sequence will be identical whenever the player "redo"-s 
+   * his or hers original move, but different when the player 
+   * chooses another move.
+   *
+   * With this scenario "undo" can no longer be used to repeat a 
+   * certain move over and over again until the computer reacts 
+   * with a favorable response or to predict the response for a 
+   * certain move based on the response to another move.
+   * @param i the sequence identified
+   */
+  void modulate(int i);
+	
+private:
+  void Draw(); // Generate the random number
+  long m_lngSeed1;
+  long m_lngSeed2;
+  long m_lngShufflePos;
+
+  static const int    m_nShuffleTableSize;
+  long *m_ShuffleArray;
+
+  KRandomSequencePrivate *d;
+};
+
+#endif
+