random8.h

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#pragma once
 
#ifndef __INC_LIB8TION_RANDOM_H
#define __INC_LIB8TION_RANDOM_H
 
#include "platforms/is_platform.h"
 
#if defined(FL_IS_AVR)
#include "platforms/avr/is_avr.h"  // ok platform headers  // IWYU pragma: keep
#endif
 
#include "fl/stl/stdint.h"
 
#include "fl/math/lib8static.h"
#include "fl/stl/noexcept.h"




#define FASTLED_RAND16_2053 ((fl::u16)(2053))
#define FASTLED_RAND16_13849 ((fl::u16)(13849))
 
#ifdef FL_IS_AVR_ATTINY
#define APPLY_FASTLED_RAND16_2053(x) (x << 11) + (x << 2) + x
#else
#define APPLY_FASTLED_RAND16_2053(x) (x * FASTLED_RAND16_2053)
#endif

extern fl::u16 rand16seed; // = RAND16_SEED;

LIB8STATIC fl::u8 random8() FL_NOEXCEPT {
    rand16seed = APPLY_FASTLED_RAND16_2053(rand16seed) + FASTLED_RAND16_13849;
    // return the sum of the high and low bytes, for better
    //  mixing and non-sequential correlation
    return (fl::u8)(((fl::u8)(rand16seed & 0xFF)) +
                     ((fl::u8)(rand16seed >> 8)));
}

LIB8STATIC fl::u16 random16() FL_NOEXCEPT {
    rand16seed = APPLY_FASTLED_RAND16_2053(rand16seed) + FASTLED_RAND16_13849;
    return rand16seed;
}

LIB8STATIC fl::u8 random8(fl::u8 lim) FL_NOEXCEPT {
    fl::u8 r = random8();
    r = (r * lim) >> 8;
    return r;
}

LIB8STATIC fl::u8 random8(fl::u8 min, fl::u8 lim) FL_NOEXCEPT {
    fl::u8 delta = lim - min;
    fl::u8 r = random8(delta) + min;
    return r;
}

LIB8STATIC fl::u16 random16(fl::u16 lim) FL_NOEXCEPT {
    fl::u16 r = random16();
    fl::u32 p = (fl::u32)lim * (fl::u32)r;
    r = p >> 16;
    return r;
}

LIB8STATIC fl::u16 random16(fl::u16 min, fl::u16 lim) FL_NOEXCEPT {
    fl::u16 delta = lim - min;
    fl::u16 r = random16(delta) + min;
    return r;
}

LIB8STATIC void random16_set_seed(fl::u16 seed) FL_NOEXCEPT { rand16seed = seed; }

LIB8STATIC fl::u16 random16_get_seed() FL_NOEXCEPT { return rand16seed; }

LIB8STATIC void random16_add_entropy(fl::u16 entropy) FL_NOEXCEPT {
    rand16seed += entropy;
}

 
#endif