Use an 8-channel cube for HRTF's virtual format.

There were phase issues caused by applying HRTF directly to the B-Format
channels, since the HRIR delays were all averaged which removed the inter-aural
time-delay, which in turn removed significant spatial information.

1 files changed, 0 insertions, 102 deletions

diff --git a/Alc/hrtf.c b/Alc/hrtf.c
index c4cacf87..e4052f52 100644
--- a/Alc/hrtf.c
+++ b/Alc/hrtf.c
@@ -181,108 +181,6 @@ void GetLerpedHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azi
     }
 }
 
-/* Calculates HRTF coefficients for B-Format channels (only up to first-order).
- * Note that these will decode a B-Format output mix, which uses FuMa ordering
- * and scaling, not N3D!
- */
-void GetBFormatHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat (*coeffs_list[4])[2], ALuint *delay_list[4])
-{
-    ALuint elev_idx, azi_idx;
-    ALfloat scale;
-    ALuint i, c;
-
-    for(c = 0;c < 4;c++)
-    {
-        ALfloat (*coeffs)[2] = coeffs_list[c];
-        ALuint *delay = delay_list[c];
-
-        for(i = 0;i < Hrtf->irSize;i++)
-        {
-            coeffs[i][0] = 0.0f;
-            coeffs[i][1] = 0.0f;
-        }
-        delay[0] = 0;
-        delay[1] = 0;
-    }
-
-    /* NOTE: HRTF coefficients are generated by combining all the HRIRs in the
-     * dataset, with each entry scaled according to how much it contributes to
-     * the given B-Format channel based on its direction (including negative
-     * contributions!).
-     */
-    scale = 0.0f;
-    for(elev_idx = 0;elev_idx < Hrtf->evCount;elev_idx++)
-    {
-        ALfloat elev = (ALfloat)elev_idx/(ALfloat)(Hrtf->evCount-1)*F_PI - F_PI_2;
-        ALuint evoffset = Hrtf->evOffset[elev_idx];
-        ALuint azcount = Hrtf->azCount[elev_idx];
-
-        scale += (ALfloat)azcount;
-
-        for(azi_idx = 0;azi_idx < azcount;azi_idx++)
-        {
-            ALuint lidx, ridx;
-            ALfloat ambi_coeffs[4];
-            ALfloat az, gain;
-            ALfloat x, y, z;
-
-            lidx = evoffset + azi_idx;
-            ridx = evoffset + ((azcount-azi_idx) % azcount);
-
-            az = (ALfloat)azi_idx / (ALfloat)azcount * F_TAU;
-            if(az > F_PI) az -= F_TAU;
-
-            x = cosf(-az) * cosf(elev);
-            y = sinf(-az) * cosf(elev);
-            z = sinf(elev);
-
-            ambi_coeffs[0] = 1.414213562f;
-            ambi_coeffs[1] = x;
-            ambi_coeffs[2] = y;
-            ambi_coeffs[3] = z;
-
-            for(c = 0;c < 4;c++)
-            {
-                ALfloat (*coeffs)[2] = coeffs_list[c];
-                ALuint *delay = delay_list[c];
-
-                /* NOTE: Always include the total delay average since the
-                 * channels need to have matching delays. */
-                delay[0] += Hrtf->delays[lidx];
-                delay[1] += Hrtf->delays[ridx];
-
-                gain = ambi_coeffs[c];
-                if(!(fabsf(gain) > GAIN_SILENCE_THRESHOLD))
-                    continue;
-
-                for(i = 0;i < Hrtf->irSize;i++)
-                {
-                    coeffs[i][0] += Hrtf->coeffs[lidx*Hrtf->irSize + i]*(1.0f/32767.0f) * gain;
-                    coeffs[i][1] += Hrtf->coeffs[ridx*Hrtf->irSize + i]*(1.0f/32767.0f) * gain;
-                }
-            }
-        }
-    }
-
-    scale = 1.0f/scale;
-
-    for(c = 0;c < 4;c++)
-    {
-        ALfloat (*coeffs)[2] = coeffs_list[c];
-        ALuint *delay = delay_list[c];
-
-        for(i = 0;i < Hrtf->irSize;i++)
-        {
-            coeffs[i][0] *= scale;
-            coeffs[i][1] *= scale;
-        }
-        delay[0] = minu((ALuint)((ALfloat)delay[0] * scale), HRTF_HISTORY_LENGTH-1);
-        delay[0] <<= HRTFDELAY_BITS;
-        delay[1] = minu((ALuint)((ALfloat)delay[1] * scale), HRTF_HISTORY_LENGTH-1);
-        delay[1] <<= HRTFDELAY_BITS;
-    }
-}
-
 
 static struct Hrtf *LoadHrtf00(FILE *f)
 {