galois_lfsr()

MAYAFLUX_API bool MayaFlux::Kinesis::Discrete::galois_lfsr ( double  input, std::span< double >  coefs  )

noexcept

Linear feedback shift register clocked by the rises of the input.

coefs: [threshold, latched, taps, register]. Each rise shifts the register right and, when a bit fell out, folds the taps in. The output is the low bit, a pseudo-random bit stream with a period set by the taps.

Definition at line 151 of file Boolean.cpp.

{
    if (coefs.size() < 4)
        return false;
 
    uint32_t reg = word_of(coefs[3]);
    if (rises(input > coefs[0], coefs[1])) {
        if (reg == 0)
            reg = 1;
        const bool fell_out = (reg & 1U) != 0U;
        reg >>= 1U;
        if (fell_out)
            reg ^= word_of(coefs[2]);
        coefs[3] = static_cast<double>(reg);
    }
    return (reg & 1U) != 0U;
}

References input.