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-rw-r--r--Alc/hrtf.c128
1 files changed, 72 insertions, 56 deletions
diff --git a/Alc/hrtf.c b/Alc/hrtf.c
index ed99554c..46d814d9 100644
--- a/Alc/hrtf.c
+++ b/Alc/hrtf.c
@@ -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;
}