Faith::RandomSequence Class Reference

#include <faith/randomsequence.h>

List of all members.

Public Member Functions

 RandomSequence (long lngSeed=0)
virtual ~RandomSequence ()
 RandomSequence (const RandomSequence &a)
RandomSequenceoperator= (const RandomSequence &a)
void setSeed (long lngSeed=1)
double getDouble ()
unsigned long getLong (unsigned long max)
bool getBool ()
void modulate (int i)

Static Public Member Functions

static int random ()


Detailed Description

A class to create a random sequence

Given a seed number, this class will produce a sequence of random numbers. This would typically be used in applications like games.

In general, you should instantiate a RandomSequence 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>


Constructor & Destructor Documentation

Faith::RandomSequence::RandomSequence ( long  lngSeed = 0  ) 

Creates a random sequence based on the seed lngSeed.

A 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 random() instead.

Parameters:
lngSeed Seed to initialize the sequence with. If lngSeed is 0, the sequence is initialized with a value from KApplication::random().

virtual Faith::RandomSequence::~RandomSequence (  )  [virtual]

Standard destructor

Faith::RandomSequence::RandomSequence ( const RandomSequence a  ) 

Copy constructor


Member Function Documentation

bool Faith::RandomSequence::getBool (  ) 

Get a boolean from the pseudo-random sequence.

Returns:
a boolean which is either true or false

double Faith::RandomSequence::getDouble (  ) 

Get the next number from the pseudo-random sequence.

Returns:
a pseudo-random double value between [0,1[

unsigned long Faith::RandomSequence::getLong ( unsigned long  max  ) 

Get the next number from the pseudo-random sequence.

Returns:
a pseudo-random integer value between [0, max[ with 0 <= max < 1.000.000

void Faith::RandomSequence::modulate ( int  i  ) 

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.

Parameters:
i the sequence identified

RandomSequence& Faith::RandomSequence::operator= ( const RandomSequence a  ) 

Assignment

static int Faith::RandomSequence::random (  )  [static]

void Faith::RandomSequence::setSeed ( long  lngSeed = 1  ) 

Restart the sequence based on lngSeed.

Parameters:
lngSeed Seed to initialize the sequence with. If lngSeed is 0, the sequence is initialized with a value from KApplication::random().


The documentation for this class was generated from the following file:
Generated on Fri Sep 1 00:23:09 2006 for Faith by  doxygen 1.4.7