JUCE  v5.1.1-3-g1a0b28c73
JUCE API
Random Class Reference

A random number generator. More...

#include <juce_Random.h>

Collaboration diagram for Random:

Public Member Functions

 Random (int64 seedValue) noexcept
 Creates a Random object based on a seed value. More...
 
 Random ()
 Creates a Random object using a random seed value. More...
 
 ~Random () noexcept
 Destructor. More...
 
void combineSeed (int64 seedValue) noexcept
 Merges this object's seed with another value. More...
 
void fillBitsRandomly (void *bufferToFill, size_t sizeInBytes)
 Fills a block of memory with random values. More...
 
void fillBitsRandomly (BigInteger &arrayToChange, int startBit, int numBits)
 Sets a range of bits in a BigInteger to random values. More...
 
int64 getSeed () const noexcept
 Returns the RNG's current seed. More...
 
bool nextBool () noexcept
 Returns the next random boolean value. More...
 
double nextDouble () noexcept
 Returns the next random floating-point number. More...
 
float nextFloat () noexcept
 Returns the next random floating-point number. More...
 
int nextInt () noexcept
 Returns the next random 32 bit integer. More...
 
int nextInt (int maxValue) noexcept
 Returns the next random number, limited to a given range. More...
 
int nextInt (Range< int > range) noexcept
 Returns the next random number, limited to a given range. More...
 
int64 nextInt64 () noexcept
 Returns the next 64-bit random number. More...
 
BigInteger nextLargeNumber (const BigInteger &maximumValue)
 Returns a BigInteger containing a random number. More...
 
void setSeed (int64 newSeed) noexcept
 Resets this Random object to a given seed value. More...
 
void setSeedRandomly ()
 Reseeds this generator using a value generated from various semi-random system properties like the current time, etc. More...
 

Static Public Member Functions

static RandomgetSystemRandom () noexcept
 The overhead of creating a new Random object is fairly small, but if you want to avoid it, you can call this method to get a global shared Random object. More...
 

Private Attributes

int64 seed
 

Detailed Description

A random number generator.

You can create a Random object and use it to generate a sequence of random numbers.

Constructor & Destructor Documentation

◆ Random() [1/2]

Random::Random ( int64  seedValue)
explicitnoexcept

Creates a Random object based on a seed value.

For a given seed value, the subsequent numbers generated by this object will be predictable, so a good idea is to set this value based on the time, e.g.

new Random (Time::currentTimeMillis())

◆ Random() [2/2]

Random::Random ( )

Creates a Random object using a random seed value.

Internally, this calls setSeedRandomly() to randomise the seed.

◆ ~Random()

Random::~Random ( )
noexcept

Destructor.

Member Function Documentation

◆ combineSeed()

void Random::combineSeed ( int64  seedValue)
noexcept

Merges this object's seed with another value.

This sets the seed to be a value created by combining the current seed and this new value.

◆ fillBitsRandomly() [1/2]

void Random::fillBitsRandomly ( void *  bufferToFill,
size_t  sizeInBytes 
)

Fills a block of memory with random values.

◆ fillBitsRandomly() [2/2]

void Random::fillBitsRandomly ( BigInteger arrayToChange,
int  startBit,
int  numBits 
)

Sets a range of bits in a BigInteger to random values.

◆ getSeed()

int64 Random::getSeed ( ) const
inlinenoexcept

Returns the RNG's current seed.

◆ getSystemRandom()

static Random& Random::getSystemRandom ( )
staticnoexcept

The overhead of creating a new Random object is fairly small, but if you want to avoid it, you can call this method to get a global shared Random object.

It's not thread-safe though, so threads should use their own Random object, otherwise you run the risk of your random numbers becoming.. erm.. randomly corrupted..

Referenced by JuceWindowIdentifier::getImprobableWindowNumber(), and File::getVolumeSerialNumber().

◆ nextBool()

bool Random::nextBool ( )
noexcept

Returns the next random boolean value.

◆ nextDouble()

double Random::nextDouble ( )
noexcept

Returns the next random floating-point number.

Returns
a random value in the range 0 (inclusive) to 1.0 (exclusive)

◆ nextFloat()

float Random::nextFloat ( )
noexcept

Returns the next random floating-point number.

Returns
a random value in the range 0 (inclusive) to 1.0 (exclusive)

◆ nextInt() [1/3]

int Random::nextInt ( )
noexcept

Returns the next random 32 bit integer.

Returns
a random integer from the full range 0x80000000 to 0x7fffffff

◆ nextInt() [2/3]

int Random::nextInt ( int  maxValue)
noexcept

Returns the next random number, limited to a given range.

The maxValue parameter may not be negative, or zero.

Returns
a random integer between 0 (inclusive) and maxValue (exclusive).

◆ nextInt() [3/3]

int Random::nextInt ( Range< int range)
noexcept

Returns the next random number, limited to a given range.

Returns
a random integer between the range start (inclusive) and its end (exclusive).

◆ nextInt64()

int64 Random::nextInt64 ( )
noexcept

Returns the next 64-bit random number.

Returns
a random integer from the full range 0x8000000000000000 to 0x7fffffffffffffff

Referenced by JuceWindowIdentifier::getImprobableWindowNumber().

◆ nextLargeNumber()

BigInteger Random::nextLargeNumber ( const BigInteger maximumValue)

Returns a BigInteger containing a random number.

Returns
a random value in the range 0 to (maximumValue - 1).

◆ setSeed()

void Random::setSeed ( int64  newSeed)
noexcept

Resets this Random object to a given seed value.

◆ setSeedRandomly()

void Random::setSeedRandomly ( )

Reseeds this generator using a value generated from various semi-random system properties like the current time, etc.

Because this function convolves the time with the last seed value, calling it repeatedly will increase the randomness of the final result.

Member Data Documentation

◆ seed

int64 Random::seed
private

The documentation for this class was generated from the following file: