virtualx-engine/core/math/random_pcg.cpp

/*************************************************************************/
/*  random_pcg.cpp                                                       */
/*************************************************************************/
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/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2019 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2019 Godot Engine contributors (cf. AUTHORS.md)    */
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#include "random_pcg.h"

#include "core/os/os.h"

RandomPCG::RandomPCG(uint64_t p_seed, uint64_t p_inc) :
		pcg(),
		current_seed(DEFAULT_SEED) {
	pcg.inc = p_inc;
	seed(p_seed);
}

void RandomPCG::randomize() {
	seed(OS::get_singleton()->get_ticks_usec() * pcg.state + PCG_DEFAULT_INC_64);
}

double RandomPCG::random(double p_from, double p_to) {
	unsigned int r = rand();
	double ret = (double)r / (double)RANDOM_MAX;
	return (ret) * (p_to - p_from) + p_from;
}

float RandomPCG::random(float p_from, float p_to) {
	unsigned int r = rand();
	float ret = (float)r / (float)RANDOM_MAX;
	return (ret) * (p_to - p_from) + p_from;
}