예제 #1
0
static void InitHrtfPanning(ALCdevice *device)
{
    static const enum Channel CubeChannels[MAX_OUTPUT_CHANNELS] = {
        UpperFrontLeft, UpperFrontRight, UpperBackLeft, UpperBackRight,
        LowerFrontLeft, LowerFrontRight, LowerBackLeft, LowerBackRight,
        InvalidChannel, InvalidChannel, InvalidChannel, InvalidChannel,
        InvalidChannel, InvalidChannel, InvalidChannel, InvalidChannel
    };
    static const ChannelMap Cube8Cfg[8] = {
        { UpperFrontLeft,  { 0.176776695f,  0.072168784f,  0.072168784f,  0.072168784f } },
        { UpperFrontRight, { 0.176776695f,  0.072168784f, -0.072168784f,  0.072168784f } },
        { UpperBackLeft,   { 0.176776695f, -0.072168784f,  0.072168784f,  0.072168784f } },
        { UpperBackRight,  { 0.176776695f, -0.072168784f, -0.072168784f,  0.072168784f } },
        { LowerFrontLeft,  { 0.176776695f,  0.072168784f,  0.072168784f, -0.072168784f } },
        { LowerFrontRight, { 0.176776695f,  0.072168784f, -0.072168784f, -0.072168784f } },
        { LowerBackLeft,   { 0.176776695f, -0.072168784f,  0.072168784f, -0.072168784f } },
        { LowerBackRight,  { 0.176776695f, -0.072168784f, -0.072168784f, -0.072168784f } },
    };
    static const struct {
        enum Channel Channel;
        ALfloat Angle;
        ALfloat Elevation;
    } CubeInfo[8] = {
        { UpperFrontLeft,  DEG2RAD( -45.0f), DEG2RAD( 45.0f) },
        { UpperFrontRight, DEG2RAD(  45.0f), DEG2RAD( 45.0f) },
        { UpperBackLeft,   DEG2RAD(-135.0f), DEG2RAD( 45.0f) },
        { UpperBackRight,  DEG2RAD( 135.0f), DEG2RAD( 45.0f) },
        { LowerFrontLeft,  DEG2RAD( -45.0f), DEG2RAD(-45.0f) },
        { LowerFrontRight, DEG2RAD(  45.0f), DEG2RAD(-45.0f) },
        { LowerBackLeft,   DEG2RAD(-135.0f), DEG2RAD(-45.0f) },
        { LowerBackRight,  DEG2RAD( 135.0f), DEG2RAD(-45.0f) },
    };
    const ChannelMap *chanmap = Cube8Cfg;
    size_t count = COUNTOF(Cube8Cfg);
    ALuint i;

    SetChannelMap(CubeChannels, device->Dry.Ambi.Coeffs, chanmap, count,
                  &device->Dry.NumChannels, AL_TRUE);
    device->Dry.CoeffCount = 4;

    memcpy(&device->FOAOut.Ambi, &device->Dry.Ambi, sizeof(device->FOAOut.Ambi));
    device->FOAOut.CoeffCount = device->Dry.CoeffCount;

    for(i = 0;i < device->Dry.NumChannels;i++)
    {
        int chan = GetChannelIndex(CubeChannels, CubeInfo[i].Channel);
        GetLerpedHrtfCoeffs(device->Hrtf, CubeInfo[i].Elevation, CubeInfo[i].Angle, 1.0f, 0.0f,
                            device->Hrtf_Params[chan].Coeffs, device->Hrtf_Params[chan].Delay);
    }
}
예제 #2
0
파일: ALu.c 프로젝트: johndpope/Medusa
ALvoid CalcSourceParams(ALvoice *voice, const ALsource *ALSource, const ALCcontext *ALContext)
{
    ALCdevice *Device = ALContext->Device;
    aluVector Position, Velocity, Direction, SourceToListener;
    ALfloat InnerAngle,OuterAngle,Angle,Distance,ClampedDist;
    ALfloat MinVolume,MaxVolume,MinDist,MaxDist,Rolloff;
    ALfloat ConeVolume,ConeHF,SourceVolume,ListenerGain;
    ALfloat DopplerFactor, SpeedOfSound;
    ALfloat AirAbsorptionFactor;
    ALfloat RoomAirAbsorption[MAX_SENDS];
    ALbufferlistitem *BufferListItem;
    ALfloat Attenuation;
    ALfloat RoomAttenuation[MAX_SENDS];
    ALfloat MetersPerUnit;
    ALfloat RoomRolloffBase;
    ALfloat RoomRolloff[MAX_SENDS];
    ALfloat DecayDistance[MAX_SENDS];
    ALfloat DryGain;
    ALfloat DryGainHF;
    ALfloat DryGainLF;
    ALboolean DryGainHFAuto;
    ALfloat WetGain[MAX_SENDS];
    ALfloat WetGainHF[MAX_SENDS];
    ALfloat WetGainLF[MAX_SENDS];
    ALboolean WetGainAuto;
    ALboolean WetGainHFAuto;
    ALfloat Pitch;
    ALuint Frequency;
    ALint NumSends;
    ALint i, j;

    DryGainHF = 1.0f;
    DryGainLF = 1.0f;
    for(i = 0;i < MAX_SENDS;i++)
    {
        WetGainHF[i] = 1.0f;
        WetGainLF[i] = 1.0f;
    }

    /* Get context/device properties */
    DopplerFactor = ALContext->DopplerFactor * ALSource->DopplerFactor;
    SpeedOfSound  = ALContext->SpeedOfSound * ALContext->DopplerVelocity;
    NumSends      = Device->NumAuxSends;
    Frequency     = Device->Frequency;

    /* Get listener properties */
    ListenerGain  = ALContext->Listener->Gain;
    MetersPerUnit = ALContext->Listener->MetersPerUnit;

    /* Get source properties */
    SourceVolume   = ALSource->Gain;
    MinVolume      = ALSource->MinGain;
    MaxVolume      = ALSource->MaxGain;
    Pitch          = ALSource->Pitch;
    Position       = ALSource->Position;
    Direction      = ALSource->Direction;
    Velocity       = ALSource->Velocity;
    MinDist        = ALSource->RefDistance;
    MaxDist        = ALSource->MaxDistance;
    Rolloff        = ALSource->RollOffFactor;
    InnerAngle     = ALSource->InnerAngle;
    OuterAngle     = ALSource->OuterAngle;
    AirAbsorptionFactor = ALSource->AirAbsorptionFactor;
    DryGainHFAuto   = ALSource->DryGainHFAuto;
    WetGainAuto     = ALSource->WetGainAuto;
    WetGainHFAuto   = ALSource->WetGainHFAuto;
    RoomRolloffBase = ALSource->RoomRolloffFactor;

    voice->Direct.OutBuffer = Device->DryBuffer;
    voice->Direct.OutChannels = Device->NumChannels;
    for(i = 0;i < NumSends;i++)
    {
        ALeffectslot *Slot = ALSource->Send[i].Slot;

        if(!Slot && i == 0)
            Slot = Device->DefaultSlot;
        if(!Slot || Slot->EffectType == AL_EFFECT_NULL)
        {
            Slot = NULL;
            RoomRolloff[i] = 0.0f;
            DecayDistance[i] = 0.0f;
            RoomAirAbsorption[i] = 1.0f;
        }
        else if(Slot->AuxSendAuto)
        {
            RoomRolloff[i] = RoomRolloffBase;
            if(IsReverbEffect(Slot->EffectType))
            {
                RoomRolloff[i] += Slot->EffectProps.Reverb.RoomRolloffFactor;
                DecayDistance[i] = Slot->EffectProps.Reverb.DecayTime *
                                   SPEEDOFSOUNDMETRESPERSEC;
                RoomAirAbsorption[i] = Slot->EffectProps.Reverb.AirAbsorptionGainHF;
            }
            else
            {
                DecayDistance[i] = 0.0f;
                RoomAirAbsorption[i] = 1.0f;
            }
        }
        else
        {
            /* If the slot's auxiliary send auto is off, the data sent to the
             * effect slot is the same as the dry path, sans filter effects */
            RoomRolloff[i] = Rolloff;
            DecayDistance[i] = 0.0f;
            RoomAirAbsorption[i] = AIRABSORBGAINHF;
        }

        if(!Slot || Slot->EffectType == AL_EFFECT_NULL)
            voice->Send[i].OutBuffer = NULL;
        else
            voice->Send[i].OutBuffer = Slot->WetBuffer;
    }

    /* Transform source to listener space (convert to head relative) */
    if(ALSource->HeadRelative == AL_FALSE)
    {
        const aluMatrix *Matrix = &ALContext->Listener->Params.Matrix;
        /* Transform source vectors */
        aluMatrixVector(&Position, Matrix);
        aluMatrixVector(&Velocity, Matrix);
        aluMatrixVector(&Direction, Matrix);
    }
    else
    {
        const aluVector *lvelocity = &ALContext->Listener->Params.Velocity;
        /* Offset the source velocity to be relative of the listener velocity */
        Velocity.v[0] += lvelocity->v[0];
        Velocity.v[1] += lvelocity->v[1];
        Velocity.v[2] += lvelocity->v[2];
    }

    aluNormalize(Direction.v);
    SourceToListener.v[0] = -Position.v[0];
    SourceToListener.v[1] = -Position.v[1];
    SourceToListener.v[2] = -Position.v[2];
    SourceToListener.v[3] = 0.0f;
    Distance = aluNormalize(SourceToListener.v);

    /* Calculate distance attenuation */
    ClampedDist = Distance;

    Attenuation = 1.0f;
    for(i = 0;i < NumSends;i++)
        RoomAttenuation[i] = 1.0f;
    switch(ALContext->SourceDistanceModel ? ALSource->DistanceModel :
                                            ALContext->DistanceModel)
    {
        case InverseDistanceClamped:
            ClampedDist = clampf(ClampedDist, MinDist, MaxDist);
            if(MaxDist < MinDist)
                break;
            /*fall-through*/
        case InverseDistance:
            if(MinDist > 0.0f)
            {
                ALfloat dist = lerp(MinDist, ClampedDist, Rolloff);
                if(dist > 0.0f) Attenuation = MinDist / dist;
                for(i = 0;i < NumSends;i++)
                {
                    dist = lerp(MinDist, ClampedDist, RoomRolloff[i]);
                    if(dist > 0.0f) RoomAttenuation[i] = MinDist / dist;
                }
            }
            break;

        case LinearDistanceClamped:
            ClampedDist = clampf(ClampedDist, MinDist, MaxDist);
            if(MaxDist < MinDist)
                break;
            /*fall-through*/
        case LinearDistance:
            if(MaxDist != MinDist)
            {
                Attenuation = 1.0f - (Rolloff*(ClampedDist-MinDist)/(MaxDist - MinDist));
                Attenuation = maxf(Attenuation, 0.0f);
                for(i = 0;i < NumSends;i++)
                {
                    RoomAttenuation[i] = 1.0f - (RoomRolloff[i]*(ClampedDist-MinDist)/(MaxDist - MinDist));
                    RoomAttenuation[i] = maxf(RoomAttenuation[i], 0.0f);
                }
            }
            break;

        case ExponentDistanceClamped:
            ClampedDist = clampf(ClampedDist, MinDist, MaxDist);
            if(MaxDist < MinDist)
                break;
            /*fall-through*/
        case ExponentDistance:
            if(ClampedDist > 0.0f && MinDist > 0.0f)
            {
                Attenuation = powf(ClampedDist/MinDist, -Rolloff);
                for(i = 0;i < NumSends;i++)
                    RoomAttenuation[i] = powf(ClampedDist/MinDist, -RoomRolloff[i]);
            }
            break;

        case DisableDistance:
            ClampedDist = MinDist;
            break;
    }

    /* Source Gain + Attenuation */
    DryGain = SourceVolume * Attenuation;
    for(i = 0;i < NumSends;i++)
        WetGain[i] = SourceVolume * RoomAttenuation[i];

    /* Distance-based air absorption */
    if(AirAbsorptionFactor > 0.0f && ClampedDist > MinDist)
    {
        ALfloat meters = (ClampedDist-MinDist) * MetersPerUnit;
        DryGainHF *= powf(AIRABSORBGAINHF, AirAbsorptionFactor*meters);
        for(i = 0;i < NumSends;i++)
            WetGainHF[i] *= powf(RoomAirAbsorption[i], AirAbsorptionFactor*meters);
    }

    if(WetGainAuto)
    {
        ALfloat ApparentDist = 1.0f/maxf(Attenuation, 0.00001f) - 1.0f;

        /* Apply a decay-time transformation to the wet path, based on the
         * attenuation of the dry path.
         *
         * Using the apparent distance, based on the distance attenuation, the
         * initial decay of the reverb effect is calculated and applied to the
         * wet path.
         */
        for(i = 0;i < NumSends;i++)
        {
            if(DecayDistance[i] > 0.0f)
                WetGain[i] *= powf(0.001f/*-60dB*/, ApparentDist/DecayDistance[i]);
        }
    }

    /* Calculate directional soundcones */
    Angle = RAD2DEG(acosf(aluDotproduct(&Direction, &SourceToListener)) * ConeScale) * 2.0f;
    if(Angle > InnerAngle && Angle <= OuterAngle)
    {
        ALfloat scale = (Angle-InnerAngle) / (OuterAngle-InnerAngle);
        ConeVolume = lerp(1.0f, ALSource->OuterGain, scale);
        ConeHF = lerp(1.0f, ALSource->OuterGainHF, scale);
    }
    else if(Angle > OuterAngle)
    {
        ConeVolume = ALSource->OuterGain;
        ConeHF = ALSource->OuterGainHF;
    }
    else
    {
        ConeVolume = 1.0f;
        ConeHF = 1.0f;
    }

    DryGain *= ConeVolume;
    if(WetGainAuto)
    {
        for(i = 0;i < NumSends;i++)
            WetGain[i] *= ConeVolume;
    }
    if(DryGainHFAuto)
        DryGainHF *= ConeHF;
    if(WetGainHFAuto)
    {
        for(i = 0;i < NumSends;i++)
            WetGainHF[i] *= ConeHF;
    }

    /* Clamp to Min/Max Gain */
    DryGain = clampf(DryGain, MinVolume, MaxVolume);
    for(i = 0;i < NumSends;i++)
        WetGain[i] = clampf(WetGain[i], MinVolume, MaxVolume);

    /* Apply gain and frequency filters */
    DryGain   *= ALSource->Direct.Gain * ListenerGain;
    DryGainHF *= ALSource->Direct.GainHF;
    DryGainLF *= ALSource->Direct.GainLF;
    for(i = 0;i < NumSends;i++)
    {
        WetGain[i]   *= ALSource->Send[i].Gain * ListenerGain;
        WetGainHF[i] *= ALSource->Send[i].GainHF;
        WetGainLF[i] *= ALSource->Send[i].GainLF;
    }

    /* Calculate velocity-based doppler effect */
    if(DopplerFactor > 0.0f)
    {
        const aluVector *lvelocity = &ALContext->Listener->Params.Velocity;
        ALfloat VSS, VLS;

        if(SpeedOfSound < 1.0f)
        {
            DopplerFactor *= 1.0f/SpeedOfSound;
            SpeedOfSound   = 1.0f;
        }

        VSS = aluDotproduct(&Velocity, &SourceToListener) * DopplerFactor;
        VLS = aluDotproduct(lvelocity, &SourceToListener) * DopplerFactor;

        Pitch *= clampf(SpeedOfSound-VLS, 1.0f, SpeedOfSound*2.0f - 1.0f) /
                 clampf(SpeedOfSound-VSS, 1.0f, SpeedOfSound*2.0f - 1.0f);
    }

    BufferListItem = ATOMIC_LOAD(&ALSource->queue);
    while(BufferListItem != NULL)
    {
        ALbuffer *ALBuffer;
        if((ALBuffer=BufferListItem->buffer) != NULL)
        {
            /* Calculate fixed-point stepping value, based on the pitch, buffer
             * frequency, and output frequency. */
            Pitch = Pitch * ALBuffer->Frequency / Frequency;
            if(Pitch > (ALfloat)MAX_PITCH)
                voice->Step = MAX_PITCH<<FRACTIONBITS;
            else
            {
                voice->Step = fastf2i(Pitch*FRACTIONONE);
                if(voice->Step == 0)
                    voice->Step = 1;
            }

            break;
        }
        BufferListItem = BufferListItem->next;
    }

    if(Device->Hrtf_Mode == FullHrtf)
    {
        /* Use a binaural HRTF algorithm for stereo headphone playback */
        aluVector dir = {{ 0.0f, 0.0f, -1.0f, 0.0f }};
        ALfloat ev = 0.0f, az = 0.0f;
        ALfloat radius = ALSource->Radius;
        ALfloat dirfact = 1.0f;

        voice->Direct.OutBuffer += voice->Direct.OutChannels;
        voice->Direct.OutChannels = 2;

        if(Distance > FLT_EPSILON)
        {
            dir.v[0] = -SourceToListener.v[0];
            dir.v[1] = -SourceToListener.v[1];
            dir.v[2] = -SourceToListener.v[2] * ZScale;

            /* Calculate elevation and azimuth only when the source is not at
             * the listener. This prevents +0 and -0 Z from producing
             * inconsistent panning. Also, clamp Y in case FP precision errors
             * cause it to land outside of -1..+1. */
            ev = asinf(clampf(dir.v[1], -1.0f, 1.0f));
            az = atan2f(dir.v[0], -dir.v[2]);
        }
        if(radius > 0.0f)
        {
            if(radius >= Distance)
                dirfact *= Distance / radius * 0.5f;
            else
                dirfact *= 1.0f - (asinf(radius / Distance) / F_PI);
        }

        /* Check to see if the HRIR is already moving. */
        if(voice->Direct.Moving)
        {
            ALfloat delta;
            delta = CalcFadeTime(voice->Direct.LastGain, DryGain,
                                 &voice->Direct.LastDir, &dir);
            /* If the delta is large enough, get the moving HRIR target
             * coefficients, target delays, steppping values, and counter. */
            if(delta > 0.000015f)
            {
                ALuint counter = GetMovingHrtfCoeffs(Device->Hrtf,
                    ev, az, dirfact, DryGain, delta, voice->Direct.Counter,
                    voice->Direct.Hrtf[0].Params.Coeffs, voice->Direct.Hrtf[0].Params.Delay,
                    voice->Direct.Hrtf[0].Params.CoeffStep, voice->Direct.Hrtf[0].Params.DelayStep
                );
                voice->Direct.Counter = counter;
                voice->Direct.LastGain = DryGain;
                voice->Direct.LastDir = dir;
            }
        }
        else
        {
            /* Get the initial (static) HRIR coefficients and delays. */
            GetLerpedHrtfCoeffs(Device->Hrtf, ev, az, dirfact, DryGain,
                                voice->Direct.Hrtf[0].Params.Coeffs,
                                voice->Direct.Hrtf[0].Params.Delay);
            voice->Direct.Counter = 0;
            voice->Direct.Moving  = AL_TRUE;
            voice->Direct.LastGain = DryGain;
            voice->Direct.LastDir = dir;
        }

        voice->IsHrtf = AL_TRUE;
    }
    else
    {
        MixGains *gains = voice->Direct.Gains[0];
        ALfloat dir[3] = { 0.0f, 0.0f, -1.0f };
        ALfloat radius = ALSource->Radius;
        ALfloat Target[MAX_OUTPUT_CHANNELS];

        /* Get the localized direction, and compute panned gains. */
        if(Distance > FLT_EPSILON)
        {
            dir[0] = -SourceToListener.v[0];
            dir[1] = -SourceToListener.v[1];
            dir[2] = -SourceToListener.v[2] * ZScale;
        }
        if(radius > 0.0f)
        {
            ALfloat dirfact;
            if(radius >= Distance)
                dirfact = Distance / radius * 0.5f;
            else
                dirfact = 1.0f - (asinf(radius / Distance) / F_PI);
            dir[0] *= dirfact;
            dir[1] *= dirfact;
            dir[2] *= dirfact;
        }
        ComputeDirectionalGains(Device, dir, DryGain, Target);

        for(j = 0;j < MAX_OUTPUT_CHANNELS;j++)
            gains[j].Target = Target[j];
        UpdateDryStepping(&voice->Direct, 1, (voice->Direct.Moving ? 64 : 0));
        voice->Direct.Moving = AL_TRUE;

        voice->IsHrtf = AL_FALSE;
    }
    for(i = 0;i < NumSends;i++)
    {
        voice->Send[i].Gain.Target = WetGain[i];
        UpdateWetStepping(&voice->Send[i], (voice->Send[i].Moving ? 64 : 0));
        voice->Send[i].Moving = AL_TRUE;
    }

    {
        ALfloat gainhf = maxf(0.01f, DryGainHF);
        ALfloat gainlf = maxf(0.01f, DryGainLF);
        ALfloat hfscale = ALSource->Direct.HFReference / Frequency;
        ALfloat lfscale = ALSource->Direct.LFReference / Frequency;
        voice->Direct.Filters[0].ActiveType = AF_None;
        if(gainhf != 1.0f) voice->Direct.Filters[0].ActiveType |= AF_LowPass;
        if(gainlf != 1.0f) voice->Direct.Filters[0].ActiveType |= AF_HighPass;
        ALfilterState_setParams(
            &voice->Direct.Filters[0].LowPass, ALfilterType_HighShelf, gainhf,
            hfscale, 0.0f
        );
        ALfilterState_setParams(
            &voice->Direct.Filters[0].HighPass, ALfilterType_LowShelf, gainlf,
            lfscale, 0.0f
        );
    }
    for(i = 0;i < NumSends;i++)
    {
        ALfloat gainhf = maxf(0.01f, WetGainHF[i]);
        ALfloat gainlf = maxf(0.01f, WetGainLF[i]);
        ALfloat hfscale = ALSource->Send[i].HFReference / Frequency;
        ALfloat lfscale = ALSource->Send[i].LFReference / Frequency;
        voice->Send[i].Filters[0].ActiveType = AF_None;
        if(gainhf != 1.0f) voice->Send[i].Filters[0].ActiveType |= AF_LowPass;
        if(gainlf != 1.0f) voice->Send[i].Filters[0].ActiveType |= AF_HighPass;
        ALfilterState_setParams(
            &voice->Send[i].Filters[0].LowPass, ALfilterType_HighShelf, gainhf,
            hfscale, 0.0f
        );
        ALfilterState_setParams(
            &voice->Send[i].Filters[0].HighPass, ALfilterType_LowShelf, gainlf,
            lfscale, 0.0f
        );
    }
}
예제 #3
0
파일: ALu.c 프로젝트: johndpope/Medusa
ALvoid CalcNonAttnSourceParams(ALvoice *voice, const ALsource *ALSource, const ALCcontext *ALContext)
{
    static const struct ChanMap MonoMap[1] = {
        { FrontCenter, 0.0f, 0.0f }
    }, StereoMap[2] = {
        { FrontLeft,  DEG2RAD(-30.0f), DEG2RAD(0.0f) },
        { FrontRight, DEG2RAD( 30.0f), DEG2RAD(0.0f) }
    }, StereoWideMap[2] = {
        { FrontLeft,  DEG2RAD(-90.0f), DEG2RAD(0.0f) },
        { FrontRight, DEG2RAD( 90.0f), DEG2RAD(0.0f) }
    }, RearMap[2] = {
        { BackLeft,  DEG2RAD(-150.0f), DEG2RAD(0.0f) },
        { BackRight, DEG2RAD( 150.0f), DEG2RAD(0.0f) }
    }, QuadMap[4] = {
        { FrontLeft,  DEG2RAD( -45.0f), DEG2RAD(0.0f) },
        { FrontRight, DEG2RAD(  45.0f), DEG2RAD(0.0f) },
        { BackLeft,   DEG2RAD(-135.0f), DEG2RAD(0.0f) },
        { BackRight,  DEG2RAD( 135.0f), DEG2RAD(0.0f) }
    }, X51Map[6] = {
        { FrontLeft,   DEG2RAD( -30.0f), DEG2RAD(0.0f) },
        { FrontRight,  DEG2RAD(  30.0f), DEG2RAD(0.0f) },
        { FrontCenter, DEG2RAD(   0.0f), DEG2RAD(0.0f) },
        { LFE, 0.0f, 0.0f },
        { SideLeft,    DEG2RAD(-110.0f), DEG2RAD(0.0f) },
        { SideRight,   DEG2RAD( 110.0f), DEG2RAD(0.0f) }
    }, X61Map[7] = {
        { FrontLeft,    DEG2RAD(-30.0f), DEG2RAD(0.0f) },
        { FrontRight,   DEG2RAD( 30.0f), DEG2RAD(0.0f) },
        { FrontCenter,  DEG2RAD(  0.0f), DEG2RAD(0.0f) },
        { LFE, 0.0f, 0.0f },
        { BackCenter,   DEG2RAD(180.0f), DEG2RAD(0.0f) },
        { SideLeft,     DEG2RAD(-90.0f), DEG2RAD(0.0f) },
        { SideRight,    DEG2RAD( 90.0f), DEG2RAD(0.0f) }
    }, X71Map[8] = {
        { FrontLeft,   DEG2RAD( -30.0f), DEG2RAD(0.0f) },
        { FrontRight,  DEG2RAD(  30.0f), DEG2RAD(0.0f) },
        { FrontCenter, DEG2RAD(   0.0f), DEG2RAD(0.0f) },
        { LFE, 0.0f, 0.0f },
        { BackLeft,    DEG2RAD(-150.0f), DEG2RAD(0.0f) },
        { BackRight,   DEG2RAD( 150.0f), DEG2RAD(0.0f) },
        { SideLeft,    DEG2RAD( -90.0f), DEG2RAD(0.0f) },
        { SideRight,   DEG2RAD(  90.0f), DEG2RAD(0.0f) }
    };

    ALCdevice *Device = ALContext->Device;
    ALfloat SourceVolume,ListenerGain,MinVolume,MaxVolume;
    ALbufferlistitem *BufferListItem;
    enum FmtChannels Channels;
    ALfloat DryGain, DryGainHF, DryGainLF;
    ALfloat WetGain[MAX_SENDS];
    ALfloat WetGainHF[MAX_SENDS];
    ALfloat WetGainLF[MAX_SENDS];
    ALuint NumSends, Frequency;
    ALboolean Relative;
    const struct ChanMap *chans = NULL;
    ALuint num_channels = 0;
    ALboolean DirectChannels;
    ALboolean isbformat = AL_FALSE;
    ALfloat Pitch;
    ALuint i, j, c;

    /* Get device properties */
    NumSends  = Device->NumAuxSends;
    Frequency = Device->Frequency;

    /* Get listener properties */
    ListenerGain = ALContext->Listener->Gain;

    /* Get source properties */
    SourceVolume    = ALSource->Gain;
    MinVolume       = ALSource->MinGain;
    MaxVolume       = ALSource->MaxGain;
    Pitch           = ALSource->Pitch;
    Relative        = ALSource->HeadRelative;
    DirectChannels  = ALSource->DirectChannels;

    voice->Direct.OutBuffer = Device->DryBuffer;
    voice->Direct.OutChannels = Device->NumChannels;
    for(i = 0;i < NumSends;i++)
    {
        ALeffectslot *Slot = ALSource->Send[i].Slot;
        if(!Slot && i == 0)
            Slot = Device->DefaultSlot;
        if(!Slot || Slot->EffectType == AL_EFFECT_NULL)
            voice->Send[i].OutBuffer = NULL;
        else
            voice->Send[i].OutBuffer = Slot->WetBuffer;
    }

    /* Calculate the stepping value */
    Channels = FmtMono;
    BufferListItem = ATOMIC_LOAD(&ALSource->queue);
    while(BufferListItem != NULL)
    {
        ALbuffer *ALBuffer;
        if((ALBuffer=BufferListItem->buffer) != NULL)
        {
            Pitch = Pitch * ALBuffer->Frequency / Frequency;
            if(Pitch > (ALfloat)MAX_PITCH)
                voice->Step = MAX_PITCH<<FRACTIONBITS;
            else
            {
                voice->Step = fastf2i(Pitch*FRACTIONONE);
                if(voice->Step == 0)
                    voice->Step = 1;
            }

            Channels = ALBuffer->FmtChannels;
            break;
        }
        BufferListItem = BufferListItem->next;
    }

    /* Calculate gains */
    DryGain  = clampf(SourceVolume, MinVolume, MaxVolume);
    DryGain  *= ALSource->Direct.Gain * ListenerGain;
    DryGainHF = ALSource->Direct.GainHF;
    DryGainLF = ALSource->Direct.GainLF;
    for(i = 0;i < NumSends;i++)
    {
        WetGain[i] = clampf(SourceVolume, MinVolume, MaxVolume);
        WetGain[i]  *= ALSource->Send[i].Gain * ListenerGain;
        WetGainHF[i] = ALSource->Send[i].GainHF;
        WetGainLF[i] = ALSource->Send[i].GainLF;
    }

    switch(Channels)
    {
    case FmtMono:
        chans = MonoMap;
        num_channels = 1;
        break;

    case FmtStereo:
        /* HACK: Place the stereo channels at +/-90 degrees when using non-
         * HRTF stereo output. This helps reduce the "monoization" caused
         * by them panning towards the center. */
        if(Device->FmtChans == DevFmtStereo && !Device->Hrtf)
            chans = StereoWideMap;
        else
            chans = StereoMap;
        num_channels = 2;
        break;

    case FmtRear:
        chans = RearMap;
        num_channels = 2;
        break;

    case FmtQuad:
        chans = QuadMap;
        num_channels = 4;
        break;

    case FmtX51:
        chans = X51Map;
        num_channels = 6;
        break;

    case FmtX61:
        chans = X61Map;
        num_channels = 7;
        break;

    case FmtX71:
        chans = X71Map;
        num_channels = 8;
        break;

    case FmtBFormat2D:
        num_channels = 3;
        isbformat = AL_TRUE;
        DirectChannels = AL_FALSE;
        break;

    case FmtBFormat3D:
        num_channels = 4;
        isbformat = AL_TRUE;
        DirectChannels = AL_FALSE;
        break;
    }

    if(isbformat)
    {
        ALfloat N[3], V[3], U[3];
        aluMatrix matrix;

        /* AT then UP */
        N[0] = ALSource->Orientation[0][0];
        N[1] = ALSource->Orientation[0][1];
        N[2] = ALSource->Orientation[0][2];
        aluNormalize(N);
        V[0] = ALSource->Orientation[1][0];
        V[1] = ALSource->Orientation[1][1];
        V[2] = ALSource->Orientation[1][2];
        aluNormalize(V);
        if(!Relative)
        {
            const aluMatrix *lmatrix = &ALContext->Listener->Params.Matrix;
            aluVector at, up;
            aluVectorSet(&at, N[0], N[1], N[2], 0.0f);
            aluVectorSet(&up, V[0], V[1], V[2], 0.0f);
            aluMatrixVector(&at, lmatrix);
            aluMatrixVector(&up, lmatrix);
            N[0] = at.v[0]; N[1] = at.v[1]; N[2] = at.v[2];
            V[0] = up.v[0]; V[1] = up.v[1]; V[2] = up.v[2];
        }
        /* Build and normalize right-vector */
        aluCrossproduct(N, V, U);
        aluNormalize(U);

        aluMatrixSet(&matrix,
            1.0f,  0.0f,  0.0f,  0.0f,
            0.0f, -N[2], -N[0],  N[1],
            0.0f,  U[2],  U[0], -U[1],
            0.0f, -V[2], -V[0],  V[1]
        );

        for(c = 0;c < num_channels;c++)
        {
            MixGains *gains = voice->Direct.Gains[c];
            ALfloat Target[MAX_OUTPUT_CHANNELS];

            ComputeBFormatGains(Device, matrix.m[c], DryGain, Target);
            for(i = 0;i < MAX_OUTPUT_CHANNELS;i++)
                gains[i].Target = Target[i];
        }
        UpdateDryStepping(&voice->Direct, num_channels, (voice->Direct.Moving ? 64 : 0));
        voice->Direct.Moving = AL_TRUE;

        voice->IsHrtf = AL_FALSE;
        for(i = 0;i < NumSends;i++)
            WetGain[i] *= 1.4142f;
    }
    else if(DirectChannels != AL_FALSE)
    {
        if(Device->Hrtf)
        {
            voice->Direct.OutBuffer += voice->Direct.OutChannels;
            voice->Direct.OutChannels = 2;
            for(c = 0;c < num_channels;c++)
            {
                MixGains *gains = voice->Direct.Gains[c];

                for(j = 0;j < MAX_OUTPUT_CHANNELS;j++)
                    gains[j].Target = 0.0f;

                if(chans[c].channel == FrontLeft)
                    gains[0].Target = DryGain;
                else if(chans[c].channel == FrontRight)
                    gains[1].Target = DryGain;
            }
        }
        else for(c = 0;c < num_channels;c++)
        {
            MixGains *gains = voice->Direct.Gains[c];
            int idx;

            for(j = 0;j < MAX_OUTPUT_CHANNELS;j++)
                gains[j].Target = 0.0f;
            if((idx=GetChannelIdxByName(Device, chans[c].channel)) != -1)
                gains[idx].Target = DryGain;
        }
        UpdateDryStepping(&voice->Direct, num_channels, (voice->Direct.Moving ? 64 : 0));
        voice->Direct.Moving = AL_TRUE;

        voice->IsHrtf = AL_FALSE;
    }
    else if(Device->Hrtf_Mode == FullHrtf)
    {
        voice->Direct.OutBuffer += voice->Direct.OutChannels;
        voice->Direct.OutChannels = 2;
        for(c = 0;c < num_channels;c++)
        {
            if(chans[c].channel == LFE)
            {
                /* Skip LFE */
                voice->Direct.Hrtf[c].Params.Delay[0] = 0;
                voice->Direct.Hrtf[c].Params.Delay[1] = 0;
                for(i = 0;i < HRIR_LENGTH;i++)
                {
                    voice->Direct.Hrtf[c].Params.Coeffs[i][0] = 0.0f;
                    voice->Direct.Hrtf[c].Params.Coeffs[i][1] = 0.0f;
                }
            }
            else
            {
                /* Get the static HRIR coefficients and delays for this
                 * channel. */
                GetLerpedHrtfCoeffs(Device->Hrtf,
                                    chans[c].elevation, chans[c].angle, 1.0f, DryGain,
                                    voice->Direct.Hrtf[c].Params.Coeffs,
                                    voice->Direct.Hrtf[c].Params.Delay);
            }
        }
        voice->Direct.Counter = 0;
        voice->Direct.Moving  = AL_TRUE;

        voice->IsHrtf = AL_TRUE;
    }
    else
    {
        for(c = 0;c < num_channels;c++)
        {
            MixGains *gains = voice->Direct.Gains[c];
            ALfloat Target[MAX_OUTPUT_CHANNELS];

            /* Special-case LFE */
            if(chans[c].channel == LFE)
            {
                int idx;
                for(i = 0;i < MAX_OUTPUT_CHANNELS;i++)
                    gains[i].Target = 0.0f;
                if((idx=GetChannelIdxByName(Device, chans[c].channel)) != -1)
                    gains[idx].Target = DryGain;
                continue;
            }

            ComputeAngleGains(Device, chans[c].angle, chans[c].elevation, DryGain, Target);
            for(i = 0;i < MAX_OUTPUT_CHANNELS;i++)
                gains[i].Target = Target[i];
        }
        UpdateDryStepping(&voice->Direct, num_channels, (voice->Direct.Moving ? 64 : 0));
        voice->Direct.Moving = AL_TRUE;

        voice->IsHrtf = AL_FALSE;
    }
    for(i = 0;i < NumSends;i++)
    {
        voice->Send[i].Gain.Target = WetGain[i];
        UpdateWetStepping(&voice->Send[i], (voice->Send[i].Moving ? 64 : 0));
        voice->Send[i].Moving = AL_TRUE;
    }

    {
        ALfloat gainhf = maxf(0.01f, DryGainHF);
        ALfloat gainlf = maxf(0.01f, DryGainLF);
        ALfloat hfscale = ALSource->Direct.HFReference / Frequency;
        ALfloat lfscale = ALSource->Direct.LFReference / Frequency;
        for(c = 0;c < num_channels;c++)
        {
            voice->Direct.Filters[c].ActiveType = AF_None;
            if(gainhf != 1.0f) voice->Direct.Filters[c].ActiveType |= AF_LowPass;
            if(gainlf != 1.0f) voice->Direct.Filters[c].ActiveType |= AF_HighPass;
            ALfilterState_setParams(
                &voice->Direct.Filters[c].LowPass, ALfilterType_HighShelf, gainhf,
                hfscale, 0.0f
            );
            ALfilterState_setParams(
                &voice->Direct.Filters[c].HighPass, ALfilterType_LowShelf, gainlf,
                lfscale, 0.0f
            );
        }
    }
    for(i = 0;i < NumSends;i++)
    {
        ALfloat gainhf = maxf(0.01f, WetGainHF[i]);
        ALfloat gainlf = maxf(0.01f, WetGainLF[i]);
        ALfloat hfscale = ALSource->Send[i].HFReference / Frequency;
        ALfloat lfscale = ALSource->Send[i].LFReference / Frequency;
        for(c = 0;c < num_channels;c++)
        {
            voice->Send[i].Filters[c].ActiveType = AF_None;
            if(gainhf != 1.0f) voice->Send[i].Filters[c].ActiveType |= AF_LowPass;
            if(gainlf != 1.0f) voice->Send[i].Filters[c].ActiveType |= AF_HighPass;
            ALfilterState_setParams(
                &voice->Send[i].Filters[c].LowPass, ALfilterType_HighShelf, gainhf,
                hfscale, 0.0f
            );
            ALfilterState_setParams(
                &voice->Send[i].Filters[c].HighPass, ALfilterType_LowShelf, gainlf,
                lfscale, 0.0f
            );
        }
    }
}