Function compute_damp_decay_q15

src/fl/math/wave/wave_simulation_real.cpp.hpp:49–53

Precompute the Q15 damping decay factor for a power-of-two exponent. The damping update is `f_new = f * (1 - 1/2^damp)`, equivalent to the arithmetic-shift form `f -= f >> damp` (modulo 1-LSB rounding). Caching it as Q15 here lets the kernel use a single Q15 multiply per cell and opens the door to non-power-of-two damping if the public API ever needs it (today it's still int-only). damp <= 0 means

// opens the door to non-power-of-two damping if the public API ever
// needs it (today it's still int-only). damp <= 0 means no decay.
i16 compute_damp_decay_q15(int damp) FL_NOEXCEPT {
    if (damp <= 0) return INT16_POS;  // ~1.0 — no decay
    const float decay = 1.0f - 1.0f / static_cast<float>(1 << damp);
    return float_to_fixed(decay);
}
} // namespace wave_detail

WaveSimulation1D_Real::WaveSimulation1D_Real(u32 len, float courantSq,