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Calculate source filter coefficients with the source parameters

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This commit is contained in:
Chris Robinson
2009-10-21 13:08:50 -07:00
parent bdec1e037f
commit 4e399b41cd
1 changed files with 65 additions and 75 deletions
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Alc/ALu.c
+65 -75
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@@ -416,8 +416,8 @@ static __inline ALint aluCart2LUTpos(ALfloat re, ALfloat im)
static ALvoid CalcSourceParams(const ALCcontext *ALContext,
const ALsource *ALSource, ALenum isMono,
ALfloat *drysend, ALfloat *wetsend,
ALfloat *pitch, ALfloat *drygainhf,
ALfloat *wetgainhf)
ALfloat *pitch, FILTER *DryFilter,
FILTER *WetFilter[MAX_SENDS])
{
ALfloat InnerAngle,OuterAngle,Angle,Distance,DryMix;
ALfloat Direction[3],Position[3],SourceToListener[3];
@@ -431,17 +431,21 @@ static ALvoid CalcSourceParams(const ALCcontext *ALContext,
ALfloat MetersPerUnit;
ALfloat RoomRolloff[MAX_SENDS];
ALfloat DryGainHF = 1.0f;
ALfloat WetGainHF[MAX_SENDS];
ALfloat DirGain, AmbientGain;
ALfloat length;
const ALfloat *SpeakerGain;
ALuint Frequency;
ALint NumSends;
ALint pos, s, i;
ALfloat cw, a, g;
//Get context properties
DopplerFactor = ALContext->DopplerFactor * ALSource->DopplerFactor;
DopplerVelocity = ALContext->DopplerVelocity;
flSpeedOfSound = ALContext->flSpeedOfSound;
NumSends = ALContext->Device->NumAuxSends;
Frequency = ALContext->Device->Frequency;
//Get listener properties
ListenerGain = ALContext->Listener.Gain;
@@ -487,13 +491,25 @@ static ALvoid CalcSourceParams(const ALCcontext *ALContext,
drysend[FRONT_CENTER] = DryMix * ListenerGain;
drysend[BACK_CENTER] = DryMix * ListenerGain;
drysend[LFE] = DryMix * ListenerGain;
*drygainhf = DryGainHF;
for(i = 0;i < MAX_SENDS;i++)
{
wetsend[i] = 0.0f;
wetgainhf[i] = 1.0f;
}
/* Update filter coefficients. Calculations based on the I3DL2
* spec. */
cw = cos(2.0*M_PI * LOWPASSFREQCUTOFF / Frequency);
/* We use two chained one-pole filters, so we need to take the
* square root of the squared gain, which is the same as the base
* gain. */
g = __max(DryGainHF, 0.01f);
a = 0.0f;
/* Be careful with gains < 0.0001, as that causes the coefficient
* head towards 1, which will flatten the signal */
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;
for(i = 0;i < MAX_SENDS;i++)
WetFilter[i]->coeff = 0.0f;
return;
}
@@ -617,7 +633,7 @@ static ALvoid CalcSourceParams(const ALCcontext *ALContext,
ALfloat WetMix = SourceVolume * RoomAttenuation[i];
WetMix = __min(WetMix,MaxVolume);
wetsend[i] = __max(WetMix,MinVolume);
wetgainhf[i] = 1.0f;
WetGainHF[i] = 1.0f;
}
// Distance-based air absorption
@@ -634,7 +650,7 @@ static ALvoid CalcSourceParams(const ALCcontext *ALContext,
absorb = pow(10.0, absorb/20.0);
DryGainHF *= absorb;
for(i = 0;i < MAX_SENDS;i++)
wetgainhf[i] *= absorb;
WetGainHF[i] *= absorb;
}
//3. Apply directional soundcones
@@ -699,7 +715,7 @@ static ALvoid CalcSourceParams(const ALCcontext *ALContext,
if(ALSource->WetGainAuto)
wetsend[i] *= ConeVolume;
if(ALSource->WetGainHFAuto)
wetgainhf[i] *= ConeHF;
WetGainHF[i] *= ConeHF;
if(ALSource->Send[i].Slot->AuxSendAuto)
{
@@ -713,14 +729,14 @@ static ALvoid CalcSourceParams(const ALCcontext *ALContext,
// the effect slot is the same as the dry path, sans filter
// effects
wetsend[i] = DryMix;
wetgainhf[i] = DryGainHF;
WetGainHF[i] = DryGainHF;
}
switch(ALSource->Send[i].WetFilter.type)
{
case AL_FILTER_LOWPASS:
wetsend[i] *= ALSource->Send[i].WetFilter.Gain;
wetgainhf[i] *= ALSource->Send[i].WetFilter.GainHF;
WetGainHF[i] *= ALSource->Send[i].WetFilter.GainHF;
break;
}
wetsend[i] *= ListenerGain;
@@ -728,13 +744,13 @@ static ALvoid CalcSourceParams(const ALCcontext *ALContext,
else
{
wetsend[i] = 0.0f;
wetgainhf[i] = 1.0f;
WetGainHF[i] = 1.0f;
}
}
for(i = NumSends;i < MAX_SENDS;i++)
{
wetsend[i] = 0.0f;
wetgainhf[i] = 1.0f;
WetGainHF[i] = 1.0f;
}
//5. Apply filter gains and filters
@@ -771,7 +787,30 @@ static ALvoid CalcSourceParams(const ALCcontext *ALContext,
ALfloat gain = SpeakerGain[s]*DirGain + AmbientGain;
drysend[s] = DryMix * gain;
}
*drygainhf = DryGainHF;
/* Update filter coefficients. */
cw = cos(2.0*M_PI * LOWPASSFREQCUTOFF / Frequency);
/* Spatialized sources 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. */
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;
for(i = 0;i < NumSends;i++)
{
/* The wet path uses two chained one-pole filters, so take the
* base gain (square root of the squared gain) */
g = __max(WetGainHF[i], 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);
WetFilter[i]->coeff = a;
}
}
static __inline ALshort lerp(ALshort val1, ALshort val2, ALint frac)
@@ -795,8 +834,6 @@ static void MixSomeSources(ALCcontext *ALContext, float (*DryBuffer)[OUTPUTCHANN
ALint64 DataSize64,DataPos64;
FILTER *DryFilter, *WetFilter[MAX_SENDS];
ALfloat WetSend[MAX_SENDS];
ALfloat DryGainHF = 0.0f;
ALfloat WetGainHF[MAX_SENDS];
ALuint rampLength;
ALuint frequency;
ALint Looping,State;
@@ -851,69 +888,22 @@ another_source:
}
CalcSourceParams(ALContext, ALSource, (Channels==1)?AL_TRUE:AL_FALSE,
DrySend, WetSend, &Pitch, &DryGainHF, WetGainHF);
DrySend, WetSend, &Pitch, DryFilter, WetFilter);
Pitch = (Pitch*ALBuffer->frequency) / frequency;
if(Channels == 1)
if(DuplicateStereo && Channels == 2)
{
ALfloat cw, a, g;
/* Update filter coefficients. Calculations based on the I3DL2
* spec. */
cw = cos(2.0*M_PI * LOWPASSFREQCUTOFF / 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
* 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;
for(i = 0;i < MAX_SENDS;i++)
{
/* The wet path uses two chained one-pole filters, so take the
* base gain (square root of the squared gain) */
g = __max(WetGainHF[i], 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);
WetFilter[i]->coeff = a;
}
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)
{
ALfloat cw, a, g;
/* Multi-channel sources use two chained one-pole filters */
cw = cos(2.0*M_PI * LOWPASSFREQCUTOFF / 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;
for(i = 0;i < MAX_SENDS;i++)
WetFilter[i]->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 if(DuplicateStereo)
{
Matrix[FRONT_LEFT][SIDE_LEFT] = 0.0f;
Matrix[FRONT_RIGHT][SIDE_RIGHT] = 0.0f;
Matrix[FRONT_LEFT][BACK_LEFT] = 0.0f;
Matrix[FRONT_RIGHT][BACK_RIGHT] = 0.0f;
}
Matrix[FRONT_LEFT][SIDE_LEFT] = 0.0f;
Matrix[FRONT_RIGHT][SIDE_RIGHT] = 0.0f;
Matrix[FRONT_LEFT][BACK_LEFT] = 0.0f;
Matrix[FRONT_RIGHT][BACK_RIGHT] = 0.0f;
}
/* Compute the gain steps for each output channel */