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Diffstat (limited to 'kdecore/krandomsequence.h')
-rw-r--r-- | kdecore/krandomsequence.h | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/kdecore/krandomsequence.h b/kdecore/krandomsequence.h new file mode 100644 index 000000000..7d18f732d --- /dev/null +++ b/kdecore/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 QGList; +/** + * 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(QGList *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 + |