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/*************************************************************************/
/* math_funcs.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* http://www.godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2017 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 "math_funcs.h"
#include "core/os/os.h"
pcg32_random_t Math::default_pcg = { 1, PCG_DEFAULT_INC_64 };
#define PHI 0x9e3779b9
#if 0
static uint32_t Q[4096];
#endif
// TODO: we should eventually expose pcg.inc too
uint32_t Math::rand_from_seed(uint64_t *seed) {
pcg32_random_t pcg = { *seed, PCG_DEFAULT_INC_64 };
uint32_t r = pcg32_random_r(&pcg);
*seed = pcg.state;
return r;
}
void Math::seed(uint64_t x) {
default_pcg.state = x;
}
void Math::randomize() {
OS::Time time = OS::get_singleton()->get_time();
seed(OS::get_singleton()->get_ticks_usec() * (time.hour + 1) * (time.min + 1) * (time.sec + 1) * rand()); // TODO: can be simplified.
}
uint32_t Math::rand() {
return pcg32_random_r(&default_pcg);
}
int Math::step_decimals(double p_step) {
static const int maxn = 9;
static const double sd[maxn] = {
0.9999, // somehow compensate for floating point error
0.09999,
0.009999,
0.0009999,
0.00009999,
0.000009999,
0.0000009999,
0.00000009999,
0.000000009999
};
double as = Math::abs(p_step);
for (int i = 0; i < maxn; i++) {
if (as >= sd[i]) {
return i;
}
}
return maxn;
}
double Math::dectime(double p_value, double p_amount, double p_step) {
double sgn = p_value < 0 ? -1.0 : 1.0;
double val = Math::abs(p_value);
val -= p_amount * p_step;
if (val < 0.0)
val = 0.0;
return val * sgn;
}
double Math::ease(double p_x, double p_c) {
if (p_x < 0)
p_x = 0;
else if (p_x > 1.0)
p_x = 1.0;
if (p_c > 0) {
if (p_c < 1.0) {
return 1.0 - Math::pow(1.0 - p_x, 1.0 / p_c);
} else {
return Math::pow(p_x, p_c);
}
} else if (p_c < 0) {
//inout ease
if (p_x < 0.5) {
return Math::pow(p_x * 2.0, -p_c) * 0.5;
} else {
return (1.0 - Math::pow(1.0 - (p_x - 0.5) * 2.0, -p_c)) * 0.5 + 0.5;
}
} else
return 0; // no ease (raw)
}
double Math::stepify(double p_value, double p_step) {
if (p_step != 0) {
p_value = Math::floor(p_value / p_step + 0.5) * p_step;
}
return p_value;
}
uint32_t Math::larger_prime(uint32_t p_val) {
static const uint32_t primes[] = {
5,
13,
23,
47,
97,
193,
389,
769,
1543,
3079,
6151,
12289,
24593,
49157,
98317,
196613,
393241,
786433,
1572869,
3145739,
6291469,
12582917,
25165843,
50331653,
100663319,
201326611,
402653189,
805306457,
1610612741,
0,
};
int idx = 0;
while (true) {
ERR_FAIL_COND_V(primes[idx] == 0, 0);
if (primes[idx] > p_val)
return primes[idx];
idx++;
}
return 0;
}
double Math::random(double from, double to) {
unsigned int r = Math::rand();
double ret = (double)r / (double)RANDOM_MAX;
return (ret) * (to - from) + from;
}
float Math::random(float from, float to) {
unsigned int r = Math::rand();
float ret = (float)r / (float)RANDOM_MAX;
return (ret) * (to - from) + from;
}
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