diff options
Diffstat (limited to 'Alc/hrtf.c')
| -rw-r--r-- | Alc/hrtf.c | 134 |
1 files changed, 0 insertions, 134 deletions
@@ -181,140 +181,6 @@ void GetLerpedHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azi } } -/* Calculates the moving HRIR target coefficients, target delays, and - * stepping values 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. Stepping resolution and count is determined using the - * given delta factor between 0.0 and 1.0. - */ -ALuint GetMovingHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azimuth, ALfloat dirfact, ALfloat gain, ALfloat delta, ALint counter, ALfloat (*coeffs)[2], ALuint *delays, ALfloat (*coeffStep)[2], ALint *delayStep) -{ - ALuint evidx[2], lidx[4], ridx[4]; - ALfloat mu[3], blend[4]; - ALfloat left, right; - ALfloat steps; - ALuint i; - - /* Claculate elevation indices and interpolation factor. */ - CalcEvIndices(Hrtf->evCount, elevation, evidx, &mu[2]); - - 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 the stepping parameters. - steps = maxf(floorf(delta*Hrtf->sampleRate + 0.5f), 1.0f); - delta = 1.0f / steps; - - /* 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 delays using linear interpolation. Then calculate - * the delay stepping values using the target and previous running - * delays. - */ - left = (ALfloat)(delays[0] - (delayStep[0] * counter)); - right = (ALfloat)(delays[1] - (delayStep[1] * counter)); - - 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; - - delayStep[0] = fastf2i(delta * (delays[0] - left)); - delayStep[1] = fastf2i(delta * (delays[1] - right)); - - /* 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 target HRIR coefficients using - * linear interpolation when there is enough gain to warrant it. Zero - * the target coefficients if gain is too low. Then calculate the - * coefficient stepping values using the target and previous running - * coefficients. - */ - if(gain > 0.0001f) - { - ALfloat c; - - i = 0; - left = coeffs[i][0] - (coeffStep[i][0] * counter); - right = coeffs[i][1] - (coeffStep[i][1] * counter); - - 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); - - coeffStep[i][0] = delta * (coeffs[i][0] - left); - coeffStep[i][1] = delta * (coeffs[i][1] - right); - - for(i = 1;i < Hrtf->irSize;i++) - { - left = coeffs[i][0] - (coeffStep[i][0] * counter); - right = coeffs[i][1] - (coeffStep[i][1] * counter); - - 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); - - coeffStep[i][0] = delta * (coeffs[i][0] - left); - coeffStep[i][1] = delta * (coeffs[i][1] - right); - } - } - else - { - for(i = 0;i < Hrtf->irSize;i++) - { - left = coeffs[i][0] - (coeffStep[i][0] * counter); - right = coeffs[i][1] - (coeffStep[i][1] * counter); - - coeffs[i][0] = 0.0f; - coeffs[i][1] = 0.0f; - - coeffStep[i][0] = delta * -left; - coeffStep[i][1] = delta * -right; - } - } - - /* The stepping count is the number of samples necessary for the HRIR to - * complete its transition. The mixer will only apply stepping for this - * many samples. - */ - return fastf2u(steps); -} - - /* 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! |