diff options
Diffstat (limited to 'sos-iir-filter.h')
| -rw-r--r-- | sos-iir-filter.h | 39 |
1 files changed, 19 insertions, 20 deletions
diff --git a/sos-iir-filter.h b/sos-iir-filter.h index 4d345f1..c827ef9 100644 --- a/sos-iir-filter.h +++ b/sos-iir-filter.h @@ -32,34 +32,36 @@ extern "C" { float qfp_fpow(float b, float e) { - return qfp_fexp(e * qfp_fln(b)); + return qfp_fexp(qfp_fmul(e, qfp_fln(b))); } float qfp_flog10(float x) { - return qfp_fln(x) / qfp_fln(10); + static const auto ln10 = qfp_fln(10.f); + return qfp_fdiv(qfp_fln(x), ln10); } -struct sos_t +class sos_t { float v; +public: constexpr sos_t(float v_ = 0.f): v(v_) {} - sos_t operator+(const sos_t& o) const noexcept { - return qfp_fadd(v, o.v); + sos_t operator+(auto x) const noexcept { + return qfp_fadd(v, x); } sos_t operator-(const sos_t& o) const noexcept { return qfp_fsub(v, o.v); } - sos_t operator*(const sos_t& o) const noexcept { - return qfp_fmul(v, o.v); + sos_t operator*(auto x) const noexcept { + return qfp_fmul(v, x); } - sos_t operator/(const sos_t& o) const noexcept { - return qfp_fdiv(v, o.v); + sos_t operator/(auto x) const noexcept { + return qfp_fdiv(v, x); } sos_t& operator+=(const sos_t& o) noexcept { @@ -100,17 +102,14 @@ struct SOS_IIR_Filter { } void filter(auto samples, std::size_t n = N) { - for ([[maybe_unused]] auto _ : std::views::zip_transform( - [](auto samps, const auto& coeffs, auto& ww) { - // Assumes a0 and b0 coefficients are one (1.0) - for (auto& s : samps) { - auto f6 = s + coeffs.a1 * ww.w0 + coeffs.a2 * ww.w1; - s = f6 + coeffs.b1 * ww.w0 + coeffs.b2 * ww.w1; - ww.w1 = std::exchange(ww.w0, f6); - } - return 0; - }, - std::views::repeat(samples, n), sos, w)) {} + for (auto [coeffs, ww] : std::views::zip(sos, w) | std::views::take(n)) { + // Assumes a0 and b0 coefficients are one (1.0) + for (auto& s : samples) { + auto f6 = s + coeffs.a1 * ww.w0 + coeffs.a2 * ww.w1; + s = f6 + coeffs.b1 * ww.w0 + coeffs.b2 * ww.w1; + ww.w1 = std::exchange(ww.w0, f6); + } + } } sos_t filter_sum_sqr(auto samples) { |