diff options
| -rw-r--r-- | Alc/hrtf.c | 128 |
1 files changed, 72 insertions, 56 deletions
@@ -174,76 +174,92 @@ void GetLerpedHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azi ALuint BuildBFormatHrtf(const struct Hrtf *Hrtf, ALfloat (*coeffs)[HRIR_LENGTH][2], ALuint NumChannels) { - ALuint total_hrirs = 0; + static const struct { + ALfloat elevation; + ALfloat azimuth; + } CubePoints[8] = { + { DEG2RAD( 35.0f), DEG2RAD( -45.0f) }, + { DEG2RAD( 35.0f), DEG2RAD( 45.0f) }, + { DEG2RAD( 35.0f), DEG2RAD(-135.0f) }, + { DEG2RAD( 35.0f), DEG2RAD( 135.0f) }, + { DEG2RAD(-35.0f), DEG2RAD( -45.0f) }, + { DEG2RAD(-35.0f), DEG2RAD( 45.0f) }, + { DEG2RAD(-35.0f), DEG2RAD(-135.0f) }, + { DEG2RAD(-35.0f), DEG2RAD( 135.0f) }, + }; + static const ALfloat CubeMatrix[8][MAX_AMBI_COEFFS] = { + { 0.25f, 0.14425f, 0.14425f, 0.14425f }, + { 0.25f, -0.14425f, 0.14425f, 0.14425f }, + { 0.25f, 0.14425f, 0.14425f, -0.14425f }, + { 0.25f, -0.14425f, 0.14425f, -0.14425f }, + { 0.25f, 0.14425f, -0.14425f, 0.14425f }, + { 0.25f, -0.14425f, -0.14425f, 0.14425f }, + { 0.25f, 0.14425f, -0.14425f, -0.14425f }, + { 0.25f, -0.14425f, -0.14425f, -0.14425f }, + }; + ALuint lidx[8], ridx[8]; + ALuint min_delay = HRTF_HISTORY_LENGTH; ALuint max_length = 0; - ALuint eidx, aidx, i, j; - ALfloat scale; + ALuint i, j, c; assert(NumChannels == 4); - for(eidx = 0;eidx < Hrtf->evCount;++eidx) + for(c = 0;c < 8;c++) { - const ALfloat elev = (ALfloat)eidx/(ALfloat)(Hrtf->evCount-1)*F_PI - F_PI_2; - const ALuint evoffset = Hrtf->evOffset[eidx]; - const ALuint azcount = Hrtf->azCount[eidx]; + ALuint evidx[2]; + ALuint evoffset; + ALuint azidx[2]; + ALuint azcount; + ALfloat mu; - for(aidx = 0;aidx < azcount;++aidx) - { - ALfloat ambcoeffs[4]; - const ALshort *fir; - ALuint length, delay; - ALuint lidx, ridx; - ALfloat x, y, z; - ALfloat azi; - - lidx = evoffset + aidx; - ridx = evoffset + ((azcount - aidx) % azcount); - - azi = (ALfloat)aidx/(ALfloat)azcount * -F_TAU; - x = cosf(azi) * cosf(elev); - y = sinf(azi) * cosf(elev); - z = sinf(elev); - - ambcoeffs[0] = 1.0f; - ambcoeffs[1] = y / 1.732050808f; - ambcoeffs[2] = z / 1.732050808f; - ambcoeffs[3] = x / 1.732050808f; - - /* Apply left ear response */ - delay = Hrtf->delays[lidx]; - fir = &Hrtf->coeffs[lidx * Hrtf->irSize]; - length = minu(delay + Hrtf->irSize, HRIR_LENGTH); - for(i = 0;i < NumChannels;++i) - { - for(j = delay;j < length;++j) - coeffs[i][j][0] += fir[j-delay]/32767.0f * ambcoeffs[i]; - } - max_length = maxu(max_length, length); + /* Calculate elevation index. */ + CalcEvIndices(Hrtf->evCount, CubePoints[c].elevation, evidx, &mu); + if(mu >= 0.5f) evidx[0] = evidx[1]; - /* Apply right ear response */ - delay = Hrtf->delays[ridx]; - fir = &Hrtf->coeffs[ridx * Hrtf->irSize]; - length = minu(delay + Hrtf->irSize, HRIR_LENGTH); - for(i = 0;i < NumChannels;++i) - { - for(j = delay;j < length;++j) - coeffs[i][j][1] += fir[j-delay]/32767.0f * ambcoeffs[i]; - } - max_length = maxu(max_length, length); + azcount = Hrtf->azCount[evidx[0]]; + evoffset = Hrtf->evOffset[evidx[0]]; - total_hrirs++; - } + /* Calculate azimuth index for this elevation. */ + CalcAzIndices(azcount, CubePoints[c].azimuth, azidx, &mu); + if(mu >= 0.5f) azidx[0] = azidx[1]; + + /* Calculate indices for left and right channels. */ + lidx[c] = evoffset + azidx[0]; + ridx[c] = evoffset + ((azcount-azidx[0]) % azcount); + + min_delay = minu(min_delay, minu(Hrtf->delays[lidx[c]], Hrtf->delays[ridx[c]])); } - scale = (ALfloat)total_hrirs; - for(i = 0;i < NumChannels;++i) + for(c = 0;c < 8;c++) { - for(j = 0;j < max_length;++j) + const ALshort *fir; + ALuint length; + ALuint delay; + + fir = &Hrtf->coeffs[lidx[c] * Hrtf->irSize]; + delay = Hrtf->delays[lidx[c]] - min_delay; + length = minu(delay + Hrtf->irSize, HRIR_LENGTH); + for(i = 0;i < NumChannels;++i) + { + ALuint k = 0; + for(j = delay;j < length;++j) + coeffs[i][j][0] += fir[k++]/32767.0f * CubeMatrix[c][i]; + } + max_length = maxu(max_length, length); + + fir = &Hrtf->coeffs[ridx[c] * Hrtf->irSize]; + delay = Hrtf->delays[ridx[c]] - min_delay; + length = minu(delay + Hrtf->irSize, HRIR_LENGTH); + for(i = 0;i < NumChannels;++i) { - coeffs[i][j][0] /= scale; - coeffs[i][j][1] /= scale; + ALuint k = 0; + for(j = delay;j < length;++j) + coeffs[i][j][1] += fir[k++]/32767.0f * CubeMatrix[c][i]; } + max_length = maxu(max_length, length); } + TRACE("Skipped min delay: %u, new combined length: %u\n", min_delay, max_length); + return max_length; } |