godot/doc/classes/RandomNumberGenerator.xml

<?xml version="1.0" encoding="UTF-8" ?>
<class name="RandomNumberGenerator" inherits="Reference" version="3.2">
	<brief_description>
		A class for generating pseudo-random numbers.
	</brief_description>
	<description>
		RandomNumberGenerator is a class for generating pseudo-random numbers. It currently uses [url=http://www.pcg-random.org/]PCG32[/url].
		[b]Note:[/b] 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:
		[codeblock]
		var rng = RandomNumberGenerator.new()
		func _ready():
		    rng.randomize()
		    var my_random_number = rng.randf_range(-10.0, 10.0)
		[/codeblock]
	</description>
	<tutorials>
		<link title="Random number generation">https://docs.godotengine.org/en/3.2/tutorials/math/random_number_generation.html</link>
	</tutorials>
	<methods>
		<method name="randf">
			<return type="float">
			</return>
			<description>
				Generates a pseudo-random float between [code]0.0[/code] and [code]1.0[/code] (inclusive).
			</description>
		</method>
		<method name="randf_range">
			<return type="float">
			</return>
			<argument index="0" name="from" type="float">
			</argument>
			<argument index="1" name="to" type="float">
			</argument>
			<description>
				Generates a pseudo-random float between [code]from[/code] and [code]to[/code] (inclusive).
			</description>
		</method>
		<method name="randfn">
			<return type="float">
			</return>
			<argument index="0" name="mean" type="float" default="0.0">
			</argument>
			<argument index="1" name="deviation" type="float" default="1.0">
			</argument>
			<description>
				Generates a [url=https://en.wikipedia.org/wiki/Normal_distribution]normally-distributed[/url] pseudo-random number, using Box-Muller transform with the specified [code]mean[/code] and a standard [code]deviation[/code]. This is also called Gaussian distribution.
			</description>
		</method>
		<method name="randi">
			<return type="int">
			</return>
			<description>
				Generates a pseudo-random 32-bit unsigned integer between [code]0[/code] and [code]4294967295[/code] (inclusive).
			</description>
		</method>
		<method name="randi_range">
			<return type="int">
			</return>
			<argument index="0" name="from" type="int">
			</argument>
			<argument index="1" name="to" type="int">
			</argument>
			<description>
				Generates a pseudo-random 32-bit signed integer between [code]from[/code] and [code]to[/code] (inclusive).
			</description>
		</method>
		<method name="randomize">
			<return type="void">
			</return>
			<description>
				Setups a time-based seed to generator.
			</description>
		</method>
	</methods>
	<members>
		<member name="seed" type="int" setter="set_seed" getter="get_seed" default="0">
			The seed used by the random number generator. A given seed will give a reproducible sequence of pseudo-random numbers.
			[b]Note:[/b] 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.
			[b]Note:[/b] The default value of this property is pseudo-random, and changes when calling [method randomize]. The [code]0[/code] value documented here is a placeholder, and not the actual default seed.
		</member>
	</members>
	<constants>
	</constants>
</class>