Commit 71753ede authored by Chaosus's avatar Chaosus Committed by Hein-Pieter van Braam-Stewart
Browse files

Added normally distributed generation function to RNG 


(cherry picked from commit 5f137925)
parent ff398759

core/math/random_number_generator.cpp

+1 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ void RandomNumberGenerator::_bind_methods() { 


	ClassDB::bind_method(D_METHOD("randi"), &RandomNumberGenerator::randi);

	ClassDB::bind_method(D_METHOD("randf"), &RandomNumberGenerator::randf);

	ClassDB::bind_method(D_METHOD("randfn", "mean", "deviation"), &RandomNumberGenerator::randfn, DEFVAL(0.0), DEFVAL(1.0));

	ClassDB::bind_method(D_METHOD("randf_range", "from", "to"), &RandomNumberGenerator::randf_range);

	ClassDB::bind_method(D_METHOD("randi_range", "from", "to"), &RandomNumberGenerator::randi_range);

	ClassDB::bind_method(D_METHOD("randomize"), &RandomNumberGenerator::randomize);

core/math/random_number_generator.h

+2 −0
Original line number Diff line number Diff line
@@ -55,6 +55,8 @@ public: 


	_FORCE_INLINE_ real_t randf_range(real_t from, real_t to) { return randbase.random(from, to); }



	_FORCE_INLINE_ real_t randfn(real_t mean = 0.0, real_t deviation = 1.0) { return randbase.randfn(mean, deviation); }



	_FORCE_INLINE_ int randi_range(int from, int to) {

		unsigned int ret = randbase.rand();

		return ret % (to - from + 1) + from;

core/math/random_pcg.h

+9 −0
Original line number Diff line number Diff line
@@ -31,6 +31,8 @@ 
#ifndef RANDOM_PCG_H

#define RANDOM_PCG_H



#include <math.h>



#include "core/math/math_defs.h"



#include "thirdparty/misc/pcg.h"
@@ -61,6 +63,13 @@ public: 
	_FORCE_INLINE_ double randd() { return (double)rand() / (double)RANDOM_MAX; }

	_FORCE_INLINE_ float randf() { return (float)rand() / (float)RANDOM_MAX; }



	_FORCE_INLINE_ double randfn(double p_mean, double p_deviation) {

		return p_mean + p_deviation * (cos(Math_TAU * randd()) * sqrt(-2.0 * log(randd()))); // Box-Muller transform

	}

	_FORCE_INLINE_ float randfn(float p_mean, float p_deviation) {

		return p_mean + p_deviation * (cos(Math_TAU * randf()) * sqrt(-2.0 * log(randf()))); // Box-Muller transform

	}



	double random(double p_from, double p_to);

	float random(float p_from, float p_to);

	real_t random(int p_from, int p_to) { return (real_t)random((real_t)p_from, (real_t)p_to); }

doc/classes/RandomNumberGenerator.xml

+11 −0
Original line number Diff line number Diff line
@@ -27,6 +27,17 @@ 
				Generates 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 normally(gaussian) distributed pseudo-random number, using Box-Muller transform with the specified [code]mean[/code] and a standard [code]deviation[/code].

			</description>

		</method>

		<method name="randi">

			<return type="int">

			</return>