diff options
author | Chris Robinson <[email protected]> | 2009-03-13 22:58:54 -0700 |
---|---|---|
committer | Chris Robinson <[email protected]> | 2009-03-13 22:58:54 -0700 |
commit | 8a857c35ee593c082bed91abcf407a0337a5db29 (patch) | |
tree | 68dbf34385f8f270d055777c38e7e56098fa1f5a /Alc | |
parent | 89ddd7d8e5a3338467c72dce291d8b5531aa6ae2 (diff) |
Calculate filter coefficients in aluMixData
Diffstat (limited to 'Alc')
-rw-r--r-- | Alc/ALu.c | 82 |
1 files changed, 44 insertions, 38 deletions
@@ -575,7 +575,6 @@ static ALvoid CalcSourceParams(ALCcontext *ALContext, ALsource *ALSource, ALfloat DirGain, AmbientGain; const ALfloat *SpeakerGain; ALint pos, s; - ALfloat cw, a, g; //Get context properties DopplerFactor = ALContext->DopplerFactor * ALSource->DopplerFactor; @@ -850,25 +849,6 @@ static ALvoid CalcSourceParams(ALCcontext *ALContext, ALsource *ALSource, } *wetsend = WetMix; - // Update filter coefficients. Calculations based on the I3DL2 spec. - cw = cos(2.0*M_PI * LOWPASSFREQCUTOFF / ALContext->Frequency); - // We use four chained one-pole filters, so we need to take the fourth - // root of the squared gain, which is the same as the square root of - // the base gain. - // Be careful with gains < 0.0001, as that causes the coefficient to - // head towards 1, which will flatten the signal - g = aluSqrt(__max(DryGainHF, 0.0001f)); - a = 0.0f; - if(g < 0.9999f) // 1-epsilon - a = (1 - g*cw - aluSqrt(2*g*(1-cw) - g*g*(1 - cw*cw))) / (1 - g); - ALSource->iirFilter.coeff = a; - - g = aluSqrt(__max(WetGainHF, 0.0001f)); - a = 0.0f; - if(g < 0.9999f) // 1-epsilon - a = (1 - g*cw - aluSqrt(2*g*(1-cw) - g*g*(1 - cw*cw))) / (1 - g); - ALSource->Send[0].iirFilter.coeff = a; - *drygainhf = DryGainHF; *wetgainhf = WetGainHF; } @@ -900,14 +880,6 @@ static ALvoid CalcSourceParams(ALCcontext *ALContext, ALsource *ALSource, drysend[LFE] = DryMix * ListenerGain; *wetsend = 0.0f; - cw = cos(2.0*M_PI * LOWPASSFREQCUTOFF / ALContext->Frequency); - g = __max(DryGainHF, 0.01f); - a = 0.0f; - if(g < 0.9999f) // 1-epsilon - a = (1 - g*cw - aluSqrt(2*g*(1-cw) - g*g*(1 - cw*cw))) / (1 - g); - ALSource->iirFilter.coeff = a; - ALSource->Send[0].iirFilter.coeff = 0.0f; - *drygainhf = DryGainHF; *wetgainhf = WetGainHF; } @@ -947,6 +919,7 @@ ALvoid aluMixData(ALCcontext *ALContext,ALvoid *buffer,ALsizei size,ALenum forma ALfloat value; ALshort *Data; ALuint i,j,k,out; + ALfloat cw, a, g; ALbufferlistitem *BufferListItem; ALuint loop; ALint64 DataSize64,DataPos64; @@ -1020,23 +993,62 @@ ALvoid aluMixData(ALCcontext *ALContext,ALvoid *buffer,ALsizei size,ALenum forma if(DataPosInt >= DataSize) goto skipmix; + //Get source info + DryFilter = &ALSource->iirFilter; + WetFilter = &ALSource->Send[0].iirFilter; + DrySend = ALSource->DryGains; + WetSend = &ALSource->WetGain; + CalcSourceParams(ALContext, ALSource, (Channels==1) ? AL_TRUE : AL_FALSE, newDrySend, &newWetSend, &Pitch, &DryGainHF, &WetGainHF); - Pitch = (Pitch*Frequency) / ALContext->Frequency; - if(DuplicateStereo && Channels > 1) + if(Channels == 1) { - if(Channels == 2) + // Update filter coefficients. Calculations based on + // the I3DL2 spec. + cw = cos(2.0*M_PI * LOWPASSFREQCUTOFF / ALContext->Frequency); + // We use four chained one-pole filters, so we need to + // take the fourth root of the squared gain, which is + // the same as the square root of the base gain. + // Be careful with gains < 0.0001, as that causes the + // coefficient to head towards 1, which will flatten + // the signal + g = aluSqrt(__max(DryGainHF, 0.0001f)); + a = 0.0f; + if(g < 0.9999f) // 1-epsilon + a = (1 - g*cw - aluSqrt(2*g*(1-cw) - g*g*(1 - cw*cw))) / (1 - g); + DryFilter->coeff = a; + + g = aluSqrt(__max(WetGainHF, 0.0001f)); + a = 0.0f; + if(g < 0.9999f) // 1-epsilon + a = (1 - g*cw - aluSqrt(2*g*(1-cw) - g*g*(1 - cw*cw))) / (1 - g); + WetFilter->coeff = a; + } + else + { + // Multi-channel sources use two chained one-pole + // filters, so take the base gain (square root of the + // squared gain) + cw = cos(2.0*M_PI * LOWPASSFREQCUTOFF / ALContext->Frequency); + g = __max(DryGainHF, 0.01f); + a = 0.0f; + if(g < 0.9999f) // 1-epsilon + a = (1 - g*cw - aluSqrt(2*g*(1-cw) - g*g*(1 - cw*cw))) / (1 - g); + DryFilter->coeff = a; + WetFilter->coeff = 0.0f; + + if(DuplicateStereo && Channels == 2) { Matrix[FRONT_LEFT][SIDE_LEFT] = 1.0f; Matrix[FRONT_RIGHT][SIDE_RIGHT] = 1.0f; Matrix[FRONT_LEFT][BACK_LEFT] = 1.0f; Matrix[FRONT_RIGHT][BACK_RIGHT] = 1.0f; } - else + else if(DuplicateStereo) { Matrix[FRONT_LEFT][SIDE_LEFT] = 0.0f; Matrix[FRONT_RIGHT][SIDE_RIGHT] = 0.0f; @@ -1045,12 +1057,6 @@ ALvoid aluMixData(ALCcontext *ALContext,ALvoid *buffer,ALsizei size,ALenum forma } } - //Get source info - DryFilter = &ALSource->iirFilter; - WetFilter = &ALSource->Send[0].iirFilter; - DrySend = ALSource->DryGains; - WetSend = &ALSource->WetGain; - //Compute the gain steps for each output channel if(ALSource->FirstStart && DataPosInt == 0 && DataPosFrac == 0) { |