80 lines
3.4 KiB
C++
80 lines
3.4 KiB
C++
/**************************************************************************/
|
|
/* random_pcg.cpp */
|
|
/**************************************************************************/
|
|
/* This file is part of: */
|
|
/* GODOT ENGINE */
|
|
/* https://godotengine.org */
|
|
/**************************************************************************/
|
|
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
|
|
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
|
|
/* */
|
|
/* Permission is hereby granted, free of charge, to any person obtaining */
|
|
/* a copy of this software and associated documentation files (the */
|
|
/* "Software"), to deal in the Software without restriction, including */
|
|
/* without limitation the rights to use, copy, modify, merge, publish, */
|
|
/* distribute, sublicense, and/or sell copies of the Software, and to */
|
|
/* permit persons to whom the Software is furnished to do so, subject to */
|
|
/* the following conditions: */
|
|
/* */
|
|
/* The above copyright notice and this permission notice shall be */
|
|
/* included in all copies or substantial portions of the Software. */
|
|
/* */
|
|
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
|
|
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
|
|
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
|
|
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
|
|
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
|
|
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
|
|
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
|
|
/**************************************************************************/
|
|
|
|
#include "random_pcg.h"
|
|
|
|
#include "core/os/os.h"
|
|
#include "core/templates/vector.h"
|
|
|
|
RandomPCG::RandomPCG(uint64_t p_seed, uint64_t p_inc) :
|
|
pcg(),
|
|
current_inc(p_inc) {
|
|
seed(p_seed);
|
|
}
|
|
|
|
void RandomPCG::randomize() {
|
|
seed(((uint64_t)OS::get_singleton()->get_unix_time() + OS::get_singleton()->get_ticks_usec()) * pcg.state + PCG_DEFAULT_INC_64);
|
|
}
|
|
|
|
int64_t RandomPCG::rand_weighted(const Vector<float> &p_weights) {
|
|
ERR_FAIL_COND_V_MSG(p_weights.is_empty(), -1, "Weights array is empty.");
|
|
int64_t weights_size = p_weights.size();
|
|
const float *weights = p_weights.ptr();
|
|
float weights_sum = 0.0;
|
|
for (int64_t i = 0; i < weights_size; ++i) {
|
|
weights_sum += weights[i];
|
|
}
|
|
|
|
float remaining_distance = Math::randf() * weights_sum;
|
|
for (int64_t i = 0; i < weights_size; ++i) {
|
|
remaining_distance -= weights[i];
|
|
if (remaining_distance < 0) {
|
|
return i;
|
|
}
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
double RandomPCG::random(double p_from, double p_to) {
|
|
return randd() * (p_to - p_from) + p_from;
|
|
}
|
|
|
|
float RandomPCG::random(float p_from, float p_to) {
|
|
return randf() * (p_to - p_from) + p_from;
|
|
}
|
|
|
|
int RandomPCG::random(int p_from, int p_to) {
|
|
if (p_from == p_to) {
|
|
return p_from;
|
|
}
|
|
return rand(abs(p_from - p_to) + 1) + MIN(p_from, p_to);
|
|
}
|