Table of Contents

Class RandomNumberGenerator

Namespace
Godot
Assembly
GodotSharp.dll

RandomNumberGenerator is a class for generating pseudo-random numbers. It currently uses PCG32.

Note: The underlying algorithm is an implementation detail and should not be depended upon.

To generate a random float number (within a given range) based on a time-dependent seed:

var rng = RandomNumberGenerator.new()
  func _ready():
      var my_random_number = rng.randf_range(-10.0, 10.0)
public class RandomNumberGenerator : RefCounted, IDisposable
Inheritance
RandomNumberGenerator
Implements
Inherited Members

Constructors

RandomNumberGenerator() 

public RandomNumberGenerator()

Properties

Seed

Initializes the random number generator state based on the given seed value. A given seed will give a reproducible sequence of pseudo-random numbers.

Note: The RNG does not have an avalanche effect, and can output similar random streams given similar seeds. Consider using a hash function to improve your seed quality if they're sourced externally.

Note: Setting this property produces a side effect of changing the internal State, so make sure to initialize the seed before modifying the State:

Note: The default value of this property is pseudo-random, and changes when calling Randomize(). The 0 value documented here is a placeholder, and not the actual default seed.

var rng = RandomNumberGenerator.new()
  rng.seed = hash("Godot")
  rng.state = 100 # Restore to some previously saved state.
public ulong Seed { get; set; }

Property Value

ulong

State

The current state of the random number generator. Save and restore this property to restore the generator to a previous state:

var rng = RandomNumberGenerator.new()
  print(rng.randf())
  var saved_state = rng.state # Store current state.
  print(rng.randf()) # Advance internal state.
  rng.state = saved_state # Restore the state.
  print(rng.randf()) # Prints the same value as in previous.

Note: Do not set state to arbitrary values, since the random number generator requires the state to have certain qualities to behave properly. It should only be set to values that came from the state property itself. To initialize the random number generator with arbitrary input, use Seed instead.

Note: The default value of this property is pseudo-random, and changes when calling Randomize(). The 0 value documented here is a placeholder, and not the actual default seed.

public ulong State { get; set; }

Property Value

ulong

Methods

HasGodotClassMethod(in godot_string_name)

Check if the type contains a method with the given name. This method is used by Godot to check if a method exists before invoking it. Do not call or override this method.

protected override bool HasGodotClassMethod(in godot_string_name method)

Parameters

method godot_string_name

Name of the method to check for.

Returns

bool

HasGodotClassSignal(in godot_string_name)

Check if the type contains a signal with the given name. This method is used by Godot to check if a signal exists before raising it. Do not call or override this method.

protected override bool HasGodotClassSignal(in godot_string_name signal)

Parameters

signal godot_string_name

Name of the signal to check for.

Returns

bool

InvokeGodotClassMethod(in godot_string_name, NativeVariantPtrArgs, out godot_variant)

Invokes the method with the given name, using the given arguments. This method is used by Godot to invoke methods from the engine side. Do not call or override this method.

protected override bool InvokeGodotClassMethod(in godot_string_name method, NativeVariantPtrArgs args, out godot_variant ret)

Parameters

method godot_string_name

Name of the method to invoke.

args NativeVariantPtrArgs

Arguments to use with the invoked method.

ret godot_variant

Value returned by the invoked method.

Returns

bool

Randf()

Returns a pseudo-random float between 0.0 and 1.0 (inclusive).

public float Randf()

Returns

float

RandfRange(float, float)

Returns a pseudo-random float between from and to (inclusive).

public float RandfRange(float from, float to)

Parameters

from float
to float

Returns

float

Randfn(float, float)

Returns a normally-distributed pseudo-random number, using Box-Muller transform with the specified mean and a standard deviation. This is also called Gaussian distribution.

public float Randfn(float mean = 0, float deviation = 1)

Parameters

mean float
deviation float

Returns

float

Randi()

Returns a pseudo-random 32-bit unsigned integer between 0 and 4294967295 (inclusive).

public uint Randi()

Returns

uint

RandiRange(int, int)

Returns a pseudo-random 32-bit signed integer between from and to (inclusive).

public int RandiRange(int from, int to)

Parameters

from int
to int

Returns

int

Randomize()

Sets up a time-based seed for this RandomNumberGenerator instance. Unlike the @GlobalScope random number generation functions, different RandomNumberGenerator instances can use different seeds.

public void Randomize()
Edit this page