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| author | Chris Robinson <chris.kcat@gmail.com> | 2021-04-25 11:36:37 -0700 |
|---|---|---|
| committer | Chris Robinson <chris.kcat@gmail.com> | 2021-04-25 11:36:37 -0700 |
| commit | 0fe38c053d8dd827e774fbe0aef121e7aa0a0f28 (patch) | |
| tree | aaa18481969ff730ff2c287016644aca03622506 /core/mixer.cpp | |
| parent | 9b65ca4556611c0b5b582a57d0c7714614badcc0 (diff) | |
Move some functions to core
And clean up more includes
Diffstat (limited to 'core/mixer.cpp')
| -rw-r--r-- | core/mixer.cpp | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/core/mixer.cpp b/core/mixer.cpp new file mode 100644 index 00000000..71e48fe3 --- /dev/null +++ b/core/mixer.cpp @@ -0,0 +1,126 @@ + +#include "config.h" + +#include "mixer.h" + +#include <cmath> + +#include "devformat.h" +#include "device.h" +#include "math_defs.h" +#include "mixer/defs.h" + +struct CTag; + + +MixerFunc MixSamples{Mix_<CTag>}; + + +std::array<float,MaxAmbiChannels> CalcAmbiCoeffs(const float y, const float z, const float x, + const float spread) +{ + std::array<float,MaxAmbiChannels> coeffs; + + /* Zeroth-order */ + coeffs[0] = 1.0f; /* ACN 0 = 1 */ + /* First-order */ + coeffs[1] = 1.732050808f * y; /* ACN 1 = sqrt(3) * Y */ + coeffs[2] = 1.732050808f * z; /* ACN 2 = sqrt(3) * Z */ + coeffs[3] = 1.732050808f * x; /* ACN 3 = sqrt(3) * X */ + /* Second-order */ + const float xx{x*x}, yy{y*y}, zz{z*z}, xy{x*y}, yz{y*z}, xz{x*z}; + coeffs[4] = 3.872983346f * xy; /* ACN 4 = sqrt(15) * X * Y */ + coeffs[5] = 3.872983346f * yz; /* ACN 5 = sqrt(15) * Y * Z */ + coeffs[6] = 1.118033989f * (3.0f*zz - 1.0f); /* ACN 6 = sqrt(5)/2 * (3*Z*Z - 1) */ + coeffs[7] = 3.872983346f * xz; /* ACN 7 = sqrt(15) * X * Z */ + coeffs[8] = 1.936491673f * (xx - yy); /* ACN 8 = sqrt(15)/2 * (X*X - Y*Y) */ + /* Third-order */ + coeffs[9] = 2.091650066f * (y*(3.0f*xx - yy)); /* ACN 9 = sqrt(35/8) * Y * (3*X*X - Y*Y) */ + coeffs[10] = 10.246950766f * (z*xy); /* ACN 10 = sqrt(105) * Z * X * Y */ + coeffs[11] = 1.620185175f * (y*(5.0f*zz - 1.0f)); /* ACN 11 = sqrt(21/8) * Y * (5*Z*Z - 1) */ + coeffs[12] = 1.322875656f * (z*(5.0f*zz - 3.0f)); /* ACN 12 = sqrt(7)/2 * Z * (5*Z*Z - 3) */ + coeffs[13] = 1.620185175f * (x*(5.0f*zz - 1.0f)); /* ACN 13 = sqrt(21/8) * X * (5*Z*Z - 1) */ + coeffs[14] = 5.123475383f * (z*(xx - yy)); /* ACN 14 = sqrt(105)/2 * Z * (X*X - Y*Y) */ + coeffs[15] = 2.091650066f * (x*(xx - 3.0f*yy)); /* ACN 15 = sqrt(35/8) * X * (X*X - 3*Y*Y) */ + /* Fourth-order */ + /* ACN 16 = sqrt(35)*3/2 * X * Y * (X*X - Y*Y) */ + /* ACN 17 = sqrt(35/2)*3/2 * (3*X*X - Y*Y) * Y * Z */ + /* ACN 18 = sqrt(5)*3/2 * X * Y * (7*Z*Z - 1) */ + /* ACN 19 = sqrt(5/2)*3/2 * Y * Z * (7*Z*Z - 3) */ + /* ACN 20 = 3/8 * (35*Z*Z*Z*Z - 30*Z*Z + 3) */ + /* ACN 21 = sqrt(5/2)*3/2 * X * Z * (7*Z*Z - 3) */ + /* ACN 22 = sqrt(5)*3/4 * (X*X - Y*Y) * (7*Z*Z - 1) */ + /* ACN 23 = sqrt(35/2)*3/2 * (X*X - 3*Y*Y) * X * Z */ + /* ACN 24 = sqrt(35)*3/8 * (X*X*X*X - 6*X*X*Y*Y + Y*Y*Y*Y) */ + + if(spread > 0.0f) + { + /* Implement the spread by using a spherical source that subtends the + * angle spread. See: + * http://www.ppsloan.org/publications/StupidSH36.pdf - Appendix A3 + * + * When adjusted for N3D normalization instead of SN3D, these + * calculations are: + * + * ZH0 = -sqrt(pi) * (-1+ca); + * ZH1 = 0.5*sqrt(pi) * sa*sa; + * ZH2 = -0.5*sqrt(pi) * ca*(-1+ca)*(ca+1); + * ZH3 = -0.125*sqrt(pi) * (-1+ca)*(ca+1)*(5*ca*ca - 1); + * ZH4 = -0.125*sqrt(pi) * ca*(-1+ca)*(ca+1)*(7*ca*ca - 3); + * ZH5 = -0.0625*sqrt(pi) * (-1+ca)*(ca+1)*(21*ca*ca*ca*ca - 14*ca*ca + 1); + * + * The gain of the source is compensated for size, so that the + * loudness doesn't depend on the spread. Thus: + * + * ZH0 = 1.0f; + * ZH1 = 0.5f * (ca+1.0f); + * ZH2 = 0.5f * (ca+1.0f)*ca; + * ZH3 = 0.125f * (ca+1.0f)*(5.0f*ca*ca - 1.0f); + * ZH4 = 0.125f * (ca+1.0f)*(7.0f*ca*ca - 3.0f)*ca; + * ZH5 = 0.0625f * (ca+1.0f)*(21.0f*ca*ca*ca*ca - 14.0f*ca*ca + 1.0f); + */ + const float ca{std::cos(spread * 0.5f)}; + /* Increase the source volume by up to +3dB for a full spread. */ + const float scale{std::sqrt(1.0f + spread/al::MathDefs<float>::Tau())}; + + const float ZH0_norm{scale}; + const float ZH1_norm{scale * 0.5f * (ca+1.f)}; + const float ZH2_norm{scale * 0.5f * (ca+1.f)*ca}; + const float ZH3_norm{scale * 0.125f * (ca+1.f)*(5.f*ca*ca-1.f)}; + + /* Zeroth-order */ + coeffs[0] *= ZH0_norm; + /* First-order */ + coeffs[1] *= ZH1_norm; + coeffs[2] *= ZH1_norm; + coeffs[3] *= ZH1_norm; + /* Second-order */ + coeffs[4] *= ZH2_norm; + coeffs[5] *= ZH2_norm; + coeffs[6] *= ZH2_norm; + coeffs[7] *= ZH2_norm; + coeffs[8] *= ZH2_norm; + /* Third-order */ + coeffs[9] *= ZH3_norm; + coeffs[10] *= ZH3_norm; + coeffs[11] *= ZH3_norm; + coeffs[12] *= ZH3_norm; + coeffs[13] *= ZH3_norm; + coeffs[14] *= ZH3_norm; + coeffs[15] *= ZH3_norm; + } + + return coeffs; +} + +void ComputePanGains(const MixParams *mix, const float*RESTRICT coeffs, const float ingain, + const al::span<float,MAX_OUTPUT_CHANNELS> gains) +{ + auto ambimap = mix->AmbiMap.cbegin(); + + auto iter = std::transform(ambimap, ambimap+mix->Buffer.size(), gains.begin(), + [coeffs,ingain](const BFChannelConfig &chanmap) noexcept -> float + { return chanmap.Scale * coeffs[chanmap.Index] * ingain; } + ); + std::fill(iter, gains.end(), 0.0f); +} |