diff options
Diffstat (limited to 'Alc')
| -rw-r--r-- | Alc/ALu.c | 8 | ||||
| -rw-r--r-- | Alc/hrtf.c | 113 | ||||
| -rw-r--r-- | Alc/hrtf.h | 2 |
3 files changed, 43 insertions, 80 deletions
@@ -657,7 +657,7 @@ static void CalcNonAttnSourceParams(ALvoice *voice, const struct ALsourceProps * } /* Get the static HRIR coefficients and delays for this channel. */ - GetLerpedHrtfCoeffs(Device->Hrtf.Handle, + GetHrtfCoeffs(Device->Hrtf.Handle, chans[c].elevation, chans[c].angle, 0.0f, DryGain, voice->Chan[c].Direct.Hrtf.Target.Coeffs, voice->Chan[c].Direct.Hrtf.Target.Delay @@ -1172,9 +1172,9 @@ static void CalcAttnSourceParams(ALvoice *voice, const struct ALsourceProps *pro spread = asinf(radius / Distance) * 2.0f; /* Get the HRIR coefficients and delays. */ - GetLerpedHrtfCoeffs(Device->Hrtf.Handle, ev, az, spread, DryGain, - voice->Chan[0].Direct.Hrtf.Target.Coeffs, - voice->Chan[0].Direct.Hrtf.Target.Delay); + GetHrtfCoeffs(Device->Hrtf.Handle, ev, az, spread, DryGain, + voice->Chan[0].Direct.Hrtf.Target.Coeffs, + voice->Chan[0].Direct.Hrtf.Target.Delay); CalcDirectionCoeffs(dir, spread, coeffs); @@ -55,111 +55,74 @@ static const ALfloat PassthruCoeff = 32767.0f * 0.707106781187f/*sqrt(0.5)*/; static struct Hrtf *LoadedHrtfs = NULL; -/* Calculate the elevation indices given the polar elevation in radians. - * This will return two indices between 0 and (evcount - 1) and an - * interpolation factor between 0.0 and 1.0. + +/* Calculate the elevation index given the polar elevation in radians. This + * will return an index between 0 and (evcount - 1). Assumes the FPU is in + * round-to-zero mode. */ -static void CalcEvIndices(ALuint evcount, ALfloat ev, ALuint *evidx, ALfloat *evmu) +static ALuint CalcEvIndex(ALuint evcount, ALfloat ev) { ev = (F_PI_2 + ev) * (evcount-1) / F_PI; - evidx[0] = fastf2u(ev); - evidx[1] = minu(evidx[0] + 1, evcount-1); - *evmu = ev - evidx[0]; + return minu(fastf2u(ev + 0.5f), evcount-1); } -/* Calculate the azimuth indices given the polar azimuth in radians. This - * will return two indices between 0 and (azcount - 1) and an interpolation - * factor between 0.0 and 1.0. +/* Calculate the azimuth index given the polar azimuth in radians. This will + * return an index between 0 and (azcount - 1). Assumes the FPU is in round-to- + * zero mode. */ -static void CalcAzIndices(ALuint azcount, ALfloat az, ALuint *azidx, ALfloat *azmu) +static ALuint CalcAzIndex(ALuint azcount, ALfloat az) { az = (F_TAU + az) * azcount / F_TAU; - azidx[0] = fastf2u(az) % azcount; - azidx[1] = (azidx[0] + 1) % azcount; - *azmu = az - floorf(az); + return fastf2u(az + 0.5f) % azcount; } -/* Calculates static HRIR coefficients and delays for the given polar - * elevation and azimuth in radians. Linear interpolation is used to - * increase the apparent resolution of the HRIR data set. The coefficients - * are also normalized and attenuated by the specified gain. +/* Calculates static HRIR coefficients and delays for the given polar elevation + * and azimuth in radians. The coefficients are normalized and attenuated by + * the specified gain. */ -void GetLerpedHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azimuth, ALfloat spread, ALfloat gain, ALfloat (*coeffs)[2], ALuint *delays) +void GetHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azimuth, ALfloat spread, ALfloat gain, ALfloat (*coeffs)[2], ALuint *delays) { - ALuint evidx[2], lidx[4], ridx[4]; - ALfloat mu[3], blend[4]; + ALuint evidx, azidx, lidx, ridx; + ALuint azcount, evoffset; ALfloat dirfact; ALuint i; dirfact = 1.0f - (spread / F_TAU); - /* Claculate elevation indices and interpolation factor. */ - CalcEvIndices(Hrtf->evCount, elevation, evidx, &mu[2]); + /* Claculate elevation index. */ + evidx = CalcEvIndex(Hrtf->evCount, elevation); + azcount = Hrtf->azCount[evidx]; + evoffset = Hrtf->evOffset[evidx]; - for(i = 0;i < 2;i++) - { - ALuint azcount = Hrtf->azCount[evidx[i]]; - ALuint evoffset = Hrtf->evOffset[evidx[i]]; - ALuint azidx[2]; - - /* Calculate azimuth indices and interpolation factor for this elevation. */ - CalcAzIndices(azcount, azimuth, azidx, &mu[i]); - - /* Calculate a set of linear HRIR indices for left and right channels. */ - lidx[i*2 + 0] = evoffset + azidx[0]; - lidx[i*2 + 1] = evoffset + azidx[1]; - ridx[i*2 + 0] = evoffset + ((azcount-azidx[0]) % azcount); - ridx[i*2 + 1] = evoffset + ((azcount-azidx[1]) % azcount); - } + /* Calculate azimuth index. */ + azidx = CalcAzIndex(Hrtf->azCount[evidx], azimuth); - /* Calculate 4 blending weights for 2D bilinear interpolation. */ - blend[0] = (1.0f-mu[0]) * (1.0f-mu[2]); - blend[1] = ( mu[0]) * (1.0f-mu[2]); - blend[2] = (1.0f-mu[1]) * ( mu[2]); - blend[3] = ( mu[1]) * ( mu[2]); + /* Calculate the HRIR indices for left and right channels. */ + lidx = evoffset + azidx; + ridx = evoffset + ((azcount-azidx) % azcount); - /* Calculate the HRIR delays using linear interpolation. */ - delays[0] = fastf2u((Hrtf->delays[lidx[0]]*blend[0] + Hrtf->delays[lidx[1]]*blend[1] + - Hrtf->delays[lidx[2]]*blend[2] + Hrtf->delays[lidx[3]]*blend[3]) * - dirfact + 0.5f) << HRTFDELAY_BITS; - delays[1] = fastf2u((Hrtf->delays[ridx[0]]*blend[0] + Hrtf->delays[ridx[1]]*blend[1] + - Hrtf->delays[ridx[2]]*blend[2] + Hrtf->delays[ridx[3]]*blend[3]) * - dirfact + 0.5f) << HRTFDELAY_BITS; + /* Calculate the HRIR delays. */ + delays[0] = fastf2u(Hrtf->delays[lidx]*dirfact + 0.5f) << HRTFDELAY_BITS; + delays[1] = fastf2u(Hrtf->delays[ridx]*dirfact + 0.5f) << HRTFDELAY_BITS; /* Calculate the sample offsets for the HRIR indices. */ - lidx[0] *= Hrtf->irSize; - lidx[1] *= Hrtf->irSize; - lidx[2] *= Hrtf->irSize; - lidx[3] *= Hrtf->irSize; - ridx[0] *= Hrtf->irSize; - ridx[1] *= Hrtf->irSize; - ridx[2] *= Hrtf->irSize; - ridx[3] *= Hrtf->irSize; - - /* Calculate the normalized and attenuated HRIR coefficients using linear - * interpolation when there is enough gain to warrant it. Zero the + lidx *= Hrtf->irSize; + ridx *= Hrtf->irSize; + + /* Calculate the normalized and attenuated HRIR coefficients. Zero the * coefficients if gain is too low. */ if(gain > 0.0001f) { - ALfloat c; + gain /= 32767.0f; i = 0; - c = (Hrtf->coeffs[lidx[0]+i]*blend[0] + Hrtf->coeffs[lidx[1]+i]*blend[1] + - Hrtf->coeffs[lidx[2]+i]*blend[2] + Hrtf->coeffs[lidx[3]+i]*blend[3]); - coeffs[i][0] = lerp(PassthruCoeff, c, dirfact) * gain * (1.0f/32767.0f); - c = (Hrtf->coeffs[ridx[0]+i]*blend[0] + Hrtf->coeffs[ridx[1]+i]*blend[1] + - Hrtf->coeffs[ridx[2]+i]*blend[2] + Hrtf->coeffs[ridx[3]+i]*blend[3]); - coeffs[i][1] = lerp(PassthruCoeff, c, dirfact) * gain * (1.0f/32767.0f); - + coeffs[i][0] = lerp(PassthruCoeff, Hrtf->coeffs[lidx+i], dirfact)*gain; + coeffs[i][1] = lerp(PassthruCoeff, Hrtf->coeffs[ridx+i], dirfact)*gain; for(i = 1;i < Hrtf->irSize;i++) { - c = (Hrtf->coeffs[lidx[0]+i]*blend[0] + Hrtf->coeffs[lidx[1]+i]*blend[1] + - Hrtf->coeffs[lidx[2]+i]*blend[2] + Hrtf->coeffs[lidx[3]+i]*blend[3]); - coeffs[i][0] = lerp(0.0f, c, dirfact) * gain * (1.0f/32767.0f); - c = (Hrtf->coeffs[ridx[0]+i]*blend[0] + Hrtf->coeffs[ridx[1]+i]*blend[1] + - Hrtf->coeffs[ridx[2]+i]*blend[2] + Hrtf->coeffs[ridx[3]+i]*blend[3]); - coeffs[i][1] = lerp(0.0f, c, dirfact) * gain * (1.0f/32767.0f); + coeffs[i][0] = Hrtf->coeffs[lidx+i]*gain * dirfact; + coeffs[i][1] = Hrtf->coeffs[ridx+i]*gain * dirfact; } } else @@ -40,7 +40,7 @@ void FreeHrtfs(void); vector_HrtfEntry EnumerateHrtf(const_al_string devname); void FreeHrtfList(vector_HrtfEntry *list); -void GetLerpedHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azimuth, ALfloat spread, ALfloat gain, ALfloat (*coeffs)[2], ALuint *delays); +void GetHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azimuth, ALfloat spread, ALfloat gain, ALfloat (*coeffs)[2], ALuint *delays); /* Produces HRTF filter coefficients for decoding B-Format. The result will * have ACN ordering with N3D normalization. NumChannels must currently be 4, |