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/*
* Copyright (C) Volition, Inc. 1999. All rights reserved.
*
* All source code herein is the property of Volition, Inc. You may not sell
* or otherwise commercially exploit the source or things you created based on the
* source.
*
*/
#include <cstdlib>
#include "io/timer.h"
#include "math/floating.h"
#include "math/staticrand.h"
#include "utils/Random.h"
/**
* @brief Rounds off a floating point number to a multiple of some number
* @param x Input floating point number
* @param multiple Multiple to round to
*/
float fl_roundoff(float x, int multiple)
{
float half = multiple / 2.0f;
if (x < 0)
half = -half;
x += half;
return i2fl((fl2i(x) / multiple) * multiple);
}
/**
* @brief Return random value in range 0.0..1.0- (1.0- means the closest number less than 1.0)
*/
float frand()
{
int i_rval;
do {
i_rval = Random::next();
} while (i_rval == Random::MAX_VALUE);
float rval = i2fl(i_rval) * Random::INV_F_MAX_VALUE;
return rval;
}
/**
* @brief Return a floating point number in the range min..max.
* @param min Minimum (inclusive)
* @param max Maxiumum (inclusive)
*/
float frand_range(float min, float max)
{
float rval;
rval = frand();
rval = rval * (max - min) + min;
return rval;
}
/**
* @brief Call this in the frame interval to get TRUE chance times per second.
* @details If you want it to return TRUE 3 times per second, call it in the frame interval like so: rand_chance(flFrametime, 3.0f);
* @param frametime
* @param chance
*/
int rand_chance(float frametime, float chance)
{
while (--chance > 0.0f)
if (frand() < frametime)
return 1;
return frand() < (frametime * (chance + 1.0f));
}
static float accum_golden_ratio_rand_seed = 0.0f;
// generates a quasirandom, low discrepancy number sequence
// acts very much like a random number generator, but has the property of being very well distributed
// use if you need quasirandom numbers, but don't want ugly 'runs' or 'clumps' of similar numbers
float golden_ratio_rand() {
accum_golden_ratio_rand_seed += GOLDEN_RATIO;
if (accum_golden_ratio_rand_seed >= 1.0f)
accum_golden_ratio_rand_seed -= 1.0f;
return accum_golden_ratio_rand_seed;
}
float acosf_safe(float x) {
CLAMP(x, -1.f, 1.f);
return acosf(x);
}
float asinf_safe(float x) {
CLAMP(x, -1.f, 1.f);
return asinf(x);
}
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