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godot-docs/classes/class_randomnumbergenerator.rst
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.. Generated automatically by doc/tools/makerst.py in Godot's source tree.
.. DO NOT EDIT THIS FILE, but the RandomNumberGenerator.xml source instead.
.. The source is found in doc/classes or modules/<name>/doc_classes.
.. _class_RandomNumberGenerator:
RandomNumberGenerator
=====================
**Inherits:** :ref:`Reference<class_Reference>` **<** :ref:`Object<class_Object>`
A class for generating pseudo-random numbers.
Description
-----------
RandomNumberGenerator is a class for generating pseudo-random numbers. It currently uses `PCG32 <http://www.pcg-random.org/>`_.
**Note:** The underlying algorithm is an implementation detail. As a result, it should not be depended upon for reproducible random streams across Godot versions.
To generate a random float number (within a given range) based on a time-dependant seed:
::
var rng = RandomNumberGenerator.new()
func _ready():
rng.randomize()
var my_random_number = rng.randf_range(-10.0, 10.0)
Properties
----------
+-----------------------+--------------------------------------------------------+--------------------------+
| :ref:`int<class_int>` | :ref:`seed<class_RandomNumberGenerator_property_seed>` | ``-6398989897141750821`` |
+-----------------------+--------------------------------------------------------+--------------------------+
Methods
-------
+---------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------+
| :ref:`float<class_float>` | :ref:`randf<class_RandomNumberGenerator_method_randf>` **(** **)** |
+---------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------+
| :ref:`float<class_float>` | :ref:`randf_range<class_RandomNumberGenerator_method_randf_range>` **(** :ref:`float<class_float>` from, :ref:`float<class_float>` to **)** |
+---------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------+
| :ref:`float<class_float>` | :ref:`randfn<class_RandomNumberGenerator_method_randfn>` **(** :ref:`float<class_float>` mean=0.0, :ref:`float<class_float>` deviation=1.0 **)** |
+---------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------+
| :ref:`int<class_int>` | :ref:`randi<class_RandomNumberGenerator_method_randi>` **(** **)** |
+---------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------+
| :ref:`int<class_int>` | :ref:`randi_range<class_RandomNumberGenerator_method_randi_range>` **(** :ref:`int<class_int>` from, :ref:`int<class_int>` to **)** |
+---------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------+
| void | :ref:`randomize<class_RandomNumberGenerator_method_randomize>` **(** **)** |
+---------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------+
Property Descriptions
---------------------
.. _class_RandomNumberGenerator_property_seed:
- :ref:`int<class_int>` **seed**
+-----------+--------------------------+
| *Default* | ``-6398989897141750821`` |
+-----------+--------------------------+
| *Setter* | set_seed(value) |
+-----------+--------------------------+
| *Getter* | get_seed() |
+-----------+--------------------------+
The seed used by the random number generator. 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.
Method Descriptions
-------------------
.. _class_RandomNumberGenerator_method_randf:
- :ref:`float<class_float>` **randf** **(** **)**
Generates a pseudo-random float between ``0.0`` and ``1.0`` (inclusive).
----
.. _class_RandomNumberGenerator_method_randf_range:
- :ref:`float<class_float>` **randf_range** **(** :ref:`float<class_float>` from, :ref:`float<class_float>` to **)**
Generates a pseudo-random float between ``from`` and ``to`` (inclusive).
----
.. _class_RandomNumberGenerator_method_randfn:
- :ref:`float<class_float>` **randfn** **(** :ref:`float<class_float>` mean=0.0, :ref:`float<class_float>` deviation=1.0 **)**
Generates a `normally-distributed <https://en.wikipedia.org/wiki/Normal_distribution>`_ pseudo-random number, using Box-Muller transform with the specified ``mean`` and a standard ``deviation``. This is also called Gaussian distribution.
----
.. _class_RandomNumberGenerator_method_randi:
- :ref:`int<class_int>` **randi** **(** **)**
Generates a pseudo-random 32-bit unsigned integer between ``0`` and ``4294967295`` (inclusive).
----
.. _class_RandomNumberGenerator_method_randi_range:
- :ref:`int<class_int>` **randi_range** **(** :ref:`int<class_int>` from, :ref:`int<class_int>` to **)**
Generates a pseudo-random 32-bit signed integer between ``from`` and ``to`` (inclusive).
----
.. _class_RandomNumberGenerator_method_randomize:
- void **randomize** **(** **)**
Setups a time-based seed to generator.