diff options
| -rw-r--r-- | alc/alu.cpp | 67 |
1 files changed, 33 insertions, 34 deletions
diff --git a/alc/alu.cpp b/alc/alu.cpp index bfbc6ead..3ef9615b 100644 --- a/alc/alu.cpp +++ b/alc/alu.cpp @@ -559,49 +559,48 @@ inline float WrapRadians(float r) * precomputed since they're constant. The second-order coefficients are * followed by the third-order coefficients, etc. */ -struct RotatorCoeffs { - float u, v, w; +template<size_t L> +constexpr size_t CalcRotatorSize() +{ return (L*2 + 1)*(L*2 + 1) + CalcRotatorSize<L-1>(); } - template<size_t N0, size_t N1> - static std::array<RotatorCoeffs,N0+N1> ConcatArrays(const std::array<RotatorCoeffs,N0> &lhs, - const std::array<RotatorCoeffs,N1> &rhs) - { - std::array<RotatorCoeffs,N0+N1> ret; - auto iter = std::copy(lhs.cbegin(), lhs.cend(), ret.begin()); - std::copy(rhs.cbegin(), rhs.cend(), iter); - return ret; - } +template<> constexpr size_t CalcRotatorSize<0>() = delete; +template<> constexpr size_t CalcRotatorSize<1>() = delete; +template<> constexpr size_t CalcRotatorSize<2>() { return 5*5; } + +struct RotatorCoeffs { + struct CoeffValues { + float u, v, w; + }; + std::array<CoeffValues,CalcRotatorSize<MaxAmbiOrder>()> mCoeffs{}; - template<int l, int num_elems=l*2+1> - static std::array<RotatorCoeffs,num_elems*num_elems> GenCoeffs() + constexpr RotatorCoeffs() { - std::array<RotatorCoeffs,num_elems*num_elems> ret{}; - auto coeffs = ret.begin(); + auto coeffs = mCoeffs.begin(); - for(int m{-l};m <= l;++m) + for(int l=2;l <= MaxAmbiOrder;++l) { - for(int n{-l};n <= l;++n) + for(int m{-l};m <= l;++m) { - // compute u,v,w terms of Eq.8.1 (Table I) - const bool d{m == 0}; // the delta function d_m0 - const float denom{static_cast<float>((std::abs(n) == l) ? - (2*l) * (2*l - 1) : (l*l - n*n))}; - - const int abs_m{std::abs(m)}; - coeffs->u = std::sqrt(static_cast<float>(l*l - m*m)/denom); - coeffs->v = std::sqrt(static_cast<float>(l+abs_m-1) * static_cast<float>(l+abs_m) / - denom) * (1.0f+d) * (1.0f - 2.0f*d) * 0.5f; - coeffs->w = std::sqrt(static_cast<float>(l-abs_m-1) * static_cast<float>(l-abs_m) / - denom) * (1.0f-d) * -0.5f; - ++coeffs; + for(int n{-l};n <= l;++n) + { + // compute u,v,w terms of Eq.8.1 (Table I) + const bool d{m == 0}; // the delta function d_m0 + const float denom{static_cast<float>((std::abs(n) == l) ? + (2*l) * (2*l - 1) : (l*l - n*n))}; + + const int abs_m{std::abs(m)}; + coeffs->u = std::sqrt(static_cast<float>(l*l - m*m)/denom); + coeffs->v = std::sqrt(static_cast<float>(l+abs_m-1) * + static_cast<float>(l+abs_m) / denom) * (1.0f+d) * (1.0f - 2.0f*d) * 0.5f; + coeffs->w = std::sqrt(static_cast<float>(l-abs_m-1) * + static_cast<float>(l-abs_m) / denom) * (1.0f-d) * -0.5f; + ++coeffs; + } } } - - return ret; } }; -const auto RotatorCoeffArray = RotatorCoeffs::ConcatArrays(RotatorCoeffs::GenCoeffs<2>(), - RotatorCoeffs::GenCoeffs<3>()); +const RotatorCoeffs RotatorCoeffArray{}; /** * Given the matrix, pre-filled with the (zeroth- and) first-order rotation @@ -665,7 +664,7 @@ void AmbiRotator(AmbiRotateMatrix &matrix, const int order) }; // compute rotation matrix of each subsequent band recursively - auto coeffs = RotatorCoeffArray.cbegin(); + auto coeffs = RotatorCoeffArray.mCoeffs.cbegin(); size_t band_idx{4}, last_band{1}; for(int l{2};l <= order;++l) { |