From 5f137925dccd8a7facc34d05d2652af6d03285ba Mon Sep 17 00:00:00 2001 From: Chaosus Date: Thu, 14 Mar 2019 13:53:08 +0300 Subject: Added normally distributed generation function to RNG --- core/math/random_number_generator.cpp | 1 + core/math/random_number_generator.h | 2 ++ core/math/random_pcg.h | 9 +++++++++ 3 files changed, 12 insertions(+) (limited to 'core/math') diff --git a/core/math/random_number_generator.cpp b/core/math/random_number_generator.cpp index fccc0f72fe..6add00c1d8 100644 --- a/core/math/random_number_generator.cpp +++ b/core/math/random_number_generator.cpp @@ -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); diff --git a/core/math/random_number_generator.h b/core/math/random_number_generator.h index 66c77b8ccf..6b6bcdd2cd 100644 --- a/core/math/random_number_generator.h +++ b/core/math/random_number_generator.h @@ -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; diff --git a/core/math/random_pcg.h b/core/math/random_pcg.h index 230eb9a11b..f377ccfc86 100644 --- a/core/math/random_pcg.h +++ b/core/math/random_pcg.h @@ -31,6 +31,8 @@ #ifndef RANDOM_PCG_H #define RANDOM_PCG_H +#include + #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); } -- cgit v1.2.3