diff options
Diffstat (limited to 'utils/makehrtf.cpp')
| -rw-r--r-- | utils/makehrtf.cpp | 108 |
1 files changed, 92 insertions, 16 deletions
diff --git a/utils/makehrtf.cpp b/utils/makehrtf.cpp index 6db97236..27b1d69d 100644 --- a/utils/makehrtf.cpp +++ b/utils/makehrtf.cpp @@ -2407,8 +2407,8 @@ static void CalcAzIndices(const HrirFdT &field, const uint ei, const double az, *af = f; } -/* Synthesize any missing onset timings at the bottom elevations of each - * field. This just mirrors the top elevation for the bottom, and blends the +/* Synthesize any missing onset timings at the bottom elevations of each field. + * This just mirrors some top elevations for the bottom, and blends the * remaining elevations (not an accurate model). */ static void SynthesizeOnsets(HrirDataT *hData) @@ -2417,36 +2417,112 @@ static void SynthesizeOnsets(HrirDataT *hData) auto proc_field = [channels](HrirFdT &field) -> void { - const uint oi{field.mEvStart}; - if(oi <= 0) return; + /* Get the starting elevation from the measurements, and use it as the + * upper elevation limit for what needs to be calculated. + */ + const uint upperElevReal{field.mEvStart}; + if(upperElevReal <= 0) return; - /* Get the -90 degree elevation delays by mirroring the +90 degree - * elevation delays. The responses are on a spherical grid centered - * between the ears, so these should align. + /* Get the lowest half of the missing elevations' delays by mirroring + * the top elevation delays. The responses are on a spherical grid + * centered between the ears, so these should align. */ + uint ei{}; if(channels > 1) { + /* Take the polar opposite position of the desired measurement and + * swap the ears. + */ field.mEvs[0].mAzs[0].mDelays[0] = field.mEvs[field.mEvCount-1].mAzs[0].mDelays[1]; field.mEvs[0].mAzs[0].mDelays[1] = field.mEvs[field.mEvCount-1].mAzs[0].mDelays[0]; + for(ei = 1u;ei < (upperElevReal+1)/2;++ei) + { + const uint topElev{field.mEvCount-ei-1}; + + for(uint ai{0u};ai < field.mEvs[ei].mAzCount;ai++) + { + uint a0, a1; + double af; + + /* Rotate this current azimuth by a half-circle, and lookup + * the mirrored elevation to find the indices for the polar + * opposite position (may need blending). + */ + const double az{field.mEvs[ei].mAzs[ai].mAzimuth + M_PI}; + CalcAzIndices(field, topElev, az, &a0, &a1, &af); + + /* Blend the delays, and again, swap the ears. */ + field.mEvs[ei].mAzs[ai].mDelays[0] = Lerp( + field.mEvs[topElev].mAzs[a0].mDelays[1], + field.mEvs[topElev].mAzs[a1].mDelays[1], af); + field.mEvs[ei].mAzs[ai].mDelays[1] = Lerp( + field.mEvs[topElev].mAzs[a0].mDelays[0], + field.mEvs[topElev].mAzs[a1].mDelays[0], af); + } + } } else + { field.mEvs[0].mAzs[0].mDelays[0] = field.mEvs[field.mEvCount-1].mAzs[0].mDelays[0]; + for(ei = 1u;ei < (upperElevReal+1)/2;++ei) + { + const uint topElev{field.mEvCount-ei-1}; - for(uint ei{1u};ei < field.mEvStart;ei++) + for(uint ai{0u};ai < field.mEvs[ei].mAzCount;ai++) + { + uint a0, a1; + double af; + + /* For mono data sets, mirror the azimuth front<->back + * since the other ear is a mirror of what we have (e.g. + * the left ear's back-left is simulated with the right + * ear's front-right, which uses the left ear's front-left + * measurement). + */ + double az{field.mEvs[ei].mAzs[ai].mAzimuth}; + if(az <= M_PI) az = M_PI - az; + else az = (M_PI*2.0)-az + M_PI; + CalcAzIndices(field, topElev, az, &a0, &a1, &af); + + field.mEvs[ei].mAzs[ai].mDelays[0] = Lerp( + field.mEvs[topElev].mAzs[a0].mDelays[0], + field.mEvs[topElev].mAzs[a1].mDelays[0], af); + } + } + } + /* Record the lowest elevation filled in with the mirrored top. */ + const uint lowerElevFake{ei-1u}; + + /* Fill in the remaining delays using bilinear interpolation. This + * helps smooth the transition back to the real delays. + */ + for(;ei < upperElevReal;++ei) { - const double of{static_cast<double>(ei) / field.mEvStart}; + const double ef{(field.mEvs[upperElevReal].mElevation - field.mEvs[ei].mElevation) / + (field.mEvs[upperElevReal].mElevation - field.mEvs[lowerElevFake].mElevation)}; + for(uint ai{0u};ai < field.mEvs[ei].mAzCount;ai++) { - uint a0, a1; - double af; + uint a0, a1, a2, a3; + double af0, af1; + + double az{field.mEvs[ei].mAzs[ai].mAzimuth}; + CalcAzIndices(field, upperElevReal, az, &a0, &a1, &af0); + CalcAzIndices(field, lowerElevFake, az, &a2, &a3, &af1); + double blend[4]{ + (1.0-ef) * (1.0-af0), + (1.0-ef) * ( af0), + ( ef) * (1.0-af1), + ( ef) * ( af1) + }; - CalcAzIndices(field, oi, field.mEvs[ei].mAzs[ai].mAzimuth, &a0, &a1, &af); for(uint ti{0u};ti < channels;ti++) { - double other{Lerp(field.mEvs[oi].mAzs[a0].mDelays[ti], - field.mEvs[oi].mAzs[a1].mDelays[ti], af)}; - field.mEvs[ei].mAzs[ai].mDelays[ti] = Lerp(field.mEvs[0].mAzs[0].mDelays[ti], - other, of); + field.mEvs[ei].mAzs[ai].mDelays[ti] = + field.mEvs[upperElevReal].mAzs[a0].mDelays[ti]*blend[0] + + field.mEvs[upperElevReal].mAzs[a1].mDelays[ti]*blend[1] + + field.mEvs[lowerElevFake].mAzs[a2].mDelays[ti]*blend[2] + + field.mEvs[lowerElevFake].mAzs[a3].mDelays[ti]*blend[3]; } } } |