gf::Random Class Reference

A random engine. More...

#include <gf/Random.h>

Public Member Functions
	Random ()
	Default constructor with complex initialization. More...
	Random (std::uint_fast32_t seed)
	Constructor with simple initialization. More...
template<typename T >
T	computeUniformInteger (T min, T max)
	Compute an integer with a uniform distribution. More...
template<typename T >
T	computeUniformFloat (T min, T max)
	Compute a float with a uniform distribution. More...
template<typename T >
T	computeNormalFloat (T mean, T stddev)
	Compute a float with a normal (Gaussian) distribution. More...
bool	computeBernoulli (double p)
	Compute a boolean with a Bernoulli distribution. More...
Vector2f	computePosition (const RectF &area)
	Compute a uniform position in a given area. More...
Vector2i	computePosition (const RectI &area)
	Compute a uniform position in a given area. More...
std::mt19937 &	getEngine ()
	Get the underlying engine. More...

Detailed Description

A random engine.

gf::Random is a wrapper around C++11 standard random features. It embeds a Mersenne Twister engine and provides several distributions above this engine.

Constructor & Destructor Documentation

Random() [1/2]

gf::Random::Random

(

)

Default constructor with complex initialization.

This constructor initializes the Mersenne Twister thanks to a random device and a seed sequence. This ensures that the state of the engine is different for each instanciation. Choose this constructor if you need good statistical randomness.

Random() [2/2]

gf::Random::Random ( std::uint_fast32_t  seed )

inline

Constructor with simple initialization.

This constructor initializes the Mersenne Twister with a single seed. This method is easy but not very good because it allows only \( 2^{32} \) possible states. Choose this constructor if you need reproducible randomness as a same seed will always provide the same sequence.

Parameters

seed	The seed for the engine

Member Function Documentation

computeBernoulli()

bool gf::Random::computeBernoulli ( double  p )

inline

Compute a boolean with a Bernoulli distribution.

Parameters

p	The probability of true

Returns

true with a probability of \( p \).

computeNormalFloat()

template<typename T >

T gf::Random::computeNormalFloat ( T  mean, T  stddev  )

inline

Compute a float with a normal (Gaussian) distribution.

Parameters

mean	The mean of the distribution
stddev	The standard deviation of the distribution

Returns

A value with a normal distribution

computePosition() [1/2]

Vector2f gf::Random::computePosition

(

const RectF &

area

)

Compute a uniform position in a given area.

Parameters

area

The area

Returns

A value in the area

computePosition() [2/2]

Vector2i gf::Random::computePosition

(

const RectI &

area

)

Compute a uniform position in a given area.

Parameters

area

The area

Returns

A value in the area

computeUniformFloat()

template<typename T >

T gf::Random::computeUniformFloat ( T  min, T  max  )

inline

Compute a float with a uniform distribution.

Parameters

min	The minimum value (inclusive)
max	The maximum value (exclusive)

Returns

A value between min and max

computeUniformInteger()

template<typename T >

T gf::Random::computeUniformInteger ( T  min, T  max  )

inline

Compute an integer with a uniform distribution.

Parameters

min	The minimum value (inclusive)
max	The maximum value (inclusive)

Returns

A value between min and max

getEngine()

std::mt19937& gf::Random::getEngine ( )

inline

Get the underlying engine.

Returns

A reference to the engine