/**
 * OpenAL cross platform audio library
 * Copyright (C) 1999-2007 by authors.
 * This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the
 *  Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 *  Boston, MA  02111-1307, USA.
 * Or go to http://www.gnu.org/copyleft/lgpl.html
 */

#include "config.h"

#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <assert.h>

#include "alMain.h"
#include "AL/al.h"
#include "AL/alc.h"
#include "alSource.h"
#include "alBuffer.h"
#include "alThunk.h"
#include "alListener.h"
#include "alAuxEffectSlot.h"
#include "alu.h"
#include "bs2b.h"
#include "alReverb.h"

#if defined(HAVE_STDINT_H)
#include <stdint.h>
typedef int64_t ALint64;
#elif defined(HAVE___INT64)
typedef __int64 ALint64;
#elif (SIZEOF_LONG == 8)
typedef long ALint64;
#elif (SIZEOF_LONG_LONG == 8)
typedef long long ALint64;
#endif

#define FRACTIONBITS 14
#define FRACTIONMASK ((1L<<FRACTIONBITS)-1)
#define MAX_PITCH 65536

/* Minimum ramp length in milliseconds. The value below was chosen to
 * adequately reduce clicks and pops from harsh gain changes. */
#define MIN_RAMP_LENGTH  16

ALboolean DuplicateStereo = AL_FALSE;

/* NOTE: The AL_FORMAT_REAR* enums aren't handled here be cause they're
 *       converted to AL_FORMAT_QUAD* when loaded */
__inline ALuint aluBytesFromFormat(ALenum format)
{
    switch(format)
    {
        case AL_FORMAT_MONO8:
        case AL_FORMAT_STEREO8:
        case AL_FORMAT_QUAD8_LOKI:
        case AL_FORMAT_QUAD8:
        case AL_FORMAT_51CHN8:
        case AL_FORMAT_61CHN8:
        case AL_FORMAT_71CHN8:
            return 1;

        case AL_FORMAT_MONO16:
        case AL_FORMAT_STEREO16:
        case AL_FORMAT_QUAD16_LOKI:
        case AL_FORMAT_QUAD16:
        case AL_FORMAT_51CHN16:
        case AL_FORMAT_61CHN16:
        case AL_FORMAT_71CHN16:
            return 2;

        case AL_FORMAT_MONO_FLOAT32:
        case AL_FORMAT_STEREO_FLOAT32:
        case AL_FORMAT_QUAD32:
        case AL_FORMAT_51CHN32:
        case AL_FORMAT_61CHN32:
        case AL_FORMAT_71CHN32:
            return 4;

        default:
            return 0;
    }
}

__inline ALuint aluChannelsFromFormat(ALenum format)
{
    switch(format)
    {
        case AL_FORMAT_MONO8:
        case AL_FORMAT_MONO16:
        case AL_FORMAT_MONO_FLOAT32:
            return 1;

        case AL_FORMAT_STEREO8:
        case AL_FORMAT_STEREO16:
        case AL_FORMAT_STEREO_FLOAT32:
            return 2;

        case AL_FORMAT_QUAD8_LOKI:
        case AL_FORMAT_QUAD16_LOKI:
        case AL_FORMAT_QUAD8:
        case AL_FORMAT_QUAD16:
        case AL_FORMAT_QUAD32:
            return 4;

        case AL_FORMAT_51CHN8:
        case AL_FORMAT_51CHN16:
        case AL_FORMAT_51CHN32:
            return 6;

        case AL_FORMAT_61CHN8:
        case AL_FORMAT_61CHN16:
        case AL_FORMAT_61CHN32:
            return 7;

        case AL_FORMAT_71CHN8:
        case AL_FORMAT_71CHN16:
        case AL_FORMAT_71CHN32:
            return 8;

        default:
            return 0;
    }
}


static __inline ALshort aluF2S(ALfloat Value)
{
    ALint i;

    i = (ALint)Value;
    i = __min( 32767, i);
    i = __max(-32768, i);
    return ((ALshort)i);
}

static __inline ALvoid aluCrossproduct(const ALfloat *inVector1, const ALfloat *inVector2, ALfloat *outVector)
{
    outVector[0] = inVector1[1]*inVector2[2] - inVector1[2]*inVector2[1];
    outVector[1] = inVector1[2]*inVector2[0] - inVector1[0]*inVector2[2];
    outVector[2] = inVector1[0]*inVector2[1] - inVector1[1]*inVector2[0];
}

static __inline ALfloat aluDotproduct(const ALfloat *inVector1, const ALfloat *inVector2)
{
    return inVector1[0]*inVector2[0] + inVector1[1]*inVector2[1] +
           inVector1[2]*inVector2[2];
}

static __inline ALvoid aluNormalize(ALfloat *inVector)
{
    ALfloat length, inverse_length;

    length = aluSqrt(aluDotproduct(inVector, inVector));
    if(length != 0.0f)
    {
        inverse_length = 1.0f/length;
        inVector[0] *= inverse_length;
        inVector[1] *= inverse_length;
        inVector[2] *= inverse_length;
    }
}

static __inline ALvoid aluMatrixVector(ALfloat *vector,ALfloat matrix[3][3])
{
    ALfloat result[3];

    result[0] = vector[0]*matrix[0][0] + vector[1]*matrix[1][0] + vector[2]*matrix[2][0];
    result[1] = vector[0]*matrix[0][1] + vector[1]*matrix[1][1] + vector[2]*matrix[2][1];
    result[2] = vector[0]*matrix[0][2] + vector[1]*matrix[1][2] + vector[2]*matrix[2][2];
    memcpy(vector, result, sizeof(result));
}

static ALvoid SetSpeakerArrangement(const char *name, ALfloat SpeakerAngle[OUTPUTCHANNELS],
                                    ALint Speaker2Chan[OUTPUTCHANNELS], ALint chans)
{
    const char *confkey;
    const char *next;
    const char *sep;
    const char *end;
    int i, val;

    confkey = GetConfigValue(NULL, name, "");
    next = confkey;
    while(next && *next)
    {
        confkey = next;
        next = strchr(confkey, ',');
        if(next)
        {
            do {
                next++;
            } while(isspace(*next));
        }

        sep = strchr(confkey, '=');
        if(!sep || confkey == sep)
            continue;

        end = sep - 1;
        while(isspace(*end) && end != confkey)
            end--;

        if(strncmp(confkey, "fl", end-confkey) == 0)
            val = FRONT_LEFT;
        else if(strncmp(confkey, "fr", end-confkey) == 0)
            val = FRONT_RIGHT;
        else if(strncmp(confkey, "fc", end-confkey) == 0)
            val = FRONT_CENTER;
        else if(strncmp(confkey, "bl", end-confkey) == 0)
            val = BACK_LEFT;
        else if(strncmp(confkey, "br", end-confkey) == 0)
            val = BACK_RIGHT;
        else if(strncmp(confkey, "bc", end-confkey) == 0)
            val = BACK_CENTER;
        else if(strncmp(confkey, "sl", end-confkey) == 0)
            val = SIDE_LEFT;
        else if(strncmp(confkey, "sr", end-confkey) == 0)
            val = SIDE_RIGHT;
        else
        {
            AL_PRINT("Unknown speaker for %s: \"%c%c\"\n", name, confkey[0], confkey[1]);
            continue;
        }

        sep++;
        while(isspace(*sep))
            sep++;

        for(i = 0;i < chans;i++)
        {
            if(Speaker2Chan[i] == val)
            {
                val = strtol(sep, NULL, 10);
                if(val >= -180 && val <= 180)
                    SpeakerAngle[i] = val * M_PI/180.0f;
                else
                    AL_PRINT("Invalid angle for speaker \"%c%c\": %d\n", confkey[0], confkey[1], val);
                break;
            }
        }
    }

    for(i = 1;i < chans;i++)
    {
        if(SpeakerAngle[i] <= SpeakerAngle[i-1])
        {
            AL_PRINT("Speaker %d of %d does not follow previous: %f > %f\n", i, chans,
                     SpeakerAngle[i-1] * 180.0f/M_PI, SpeakerAngle[i] * 180.0f/M_PI);
            SpeakerAngle[i] = SpeakerAngle[i-1] + 1 * 180.0f/M_PI;
        }
    }
}

static __inline ALfloat aluLUTpos2Angle(ALint pos)
{
    if(pos < QUADRANT_NUM)
        return aluAtan((ALfloat)pos / (ALfloat)(QUADRANT_NUM - pos));
    if(pos < 2 * QUADRANT_NUM)
        return M_PI_2 + aluAtan((ALfloat)(pos - QUADRANT_NUM) / (ALfloat)(2 * QUADRANT_NUM - pos));
    if(pos < 3 * QUADRANT_NUM)
        return aluAtan((ALfloat)(pos - 2 * QUADRANT_NUM) / (ALfloat)(3 * QUADRANT_NUM - pos)) - M_PI;
    return aluAtan((ALfloat)(pos - 3 * QUADRANT_NUM) / (ALfloat)(4 * QUADRANT_NUM - pos)) - M_PI_2;
}

ALvoid aluInitPanning(ALCcontext *Context)
{
    ALint pos, offset, s;
    ALfloat Alpha, Theta;
    ALfloat SpeakerAngle[OUTPUTCHANNELS];
    ALint Speaker2Chan[OUTPUTCHANNELS];

    for(s = 0;s < OUTPUTCHANNELS;s++)
    {
        int s2;
        for(s2 = 0;s2 < OUTPUTCHANNELS;s2++)
            Context->ChannelMatrix[s][s2] = ((s==s2) ? 1.0f : 0.0f);
    }

    switch(Context->Device->Format)
    {
        /* Mono is rendered as stereo, then downmixed during post-process */
        case AL_FORMAT_MONO8:
        case AL_FORMAT_MONO16:
        case AL_FORMAT_MONO_FLOAT32:
            Context->ChannelMatrix[FRONT_CENTER][FRONT_LEFT]  = aluSqrt(0.5);
            Context->ChannelMatrix[FRONT_CENTER][FRONT_RIGHT] = aluSqrt(0.5);
            Context->ChannelMatrix[SIDE_LEFT][FRONT_LEFT]     = 1.0f;
            Context->ChannelMatrix[SIDE_RIGHT][FRONT_RIGHT]   = 1.0f;
            Context->ChannelMatrix[BACK_LEFT][FRONT_LEFT]     = 1.0f;
            Context->ChannelMatrix[BACK_RIGHT][FRONT_RIGHT]   = 1.0f;
            Context->ChannelMatrix[BACK_CENTER][FRONT_LEFT]   = aluSqrt(0.5);
            Context->ChannelMatrix[BACK_CENTER][FRONT_RIGHT]  = aluSqrt(0.5);
            Context->NumChan = 2;
            Speaker2Chan[0] = FRONT_LEFT;
            Speaker2Chan[1] = FRONT_RIGHT;
            SpeakerAngle[0] = -90.0f * M_PI/180.0f;
            SpeakerAngle[1] =  90.0f * M_PI/180.0f;
            break;

        case AL_FORMAT_STEREO8:
        case AL_FORMAT_STEREO16:
        case AL_FORMAT_STEREO_FLOAT32:
            Context->ChannelMatrix[FRONT_CENTER][FRONT_LEFT]  = aluSqrt(0.5);
            Context->ChannelMatrix[FRONT_CENTER][FRONT_RIGHT] = aluSqrt(0.5);
            Context->ChannelMatrix[SIDE_LEFT][FRONT_LEFT]     = 1.0f;
            Context->ChannelMatrix[SIDE_RIGHT][FRONT_RIGHT]   = 1.0f;
            Context->ChannelMatrix[BACK_LEFT][FRONT_LEFT]     = 1.0f;
            Context->ChannelMatrix[BACK_RIGHT][FRONT_RIGHT]   = 1.0f;
            Context->ChannelMatrix[BACK_CENTER][FRONT_LEFT]   = aluSqrt(0.5);
            Context->ChannelMatrix[BACK_CENTER][FRONT_RIGHT]  = aluSqrt(0.5);
            Context->NumChan = 2;
            Speaker2Chan[0] = FRONT_LEFT;
            Speaker2Chan[1] = FRONT_RIGHT;
            SpeakerAngle[0] = -90.0f * M_PI/180.0f;
            SpeakerAngle[1] =  90.0f * M_PI/180.0f;
            SetSpeakerArrangement("layout_STEREO", SpeakerAngle, Speaker2Chan, Context->NumChan);
            break;

        case AL_FORMAT_QUAD8:
        case AL_FORMAT_QUAD16:
        case AL_FORMAT_QUAD32:
            Context->ChannelMatrix[FRONT_CENTER][FRONT_LEFT]  = aluSqrt(0.5);
            Context->ChannelMatrix[FRONT_CENTER][FRONT_RIGHT] = aluSqrt(0.5);
            Context->ChannelMatrix[SIDE_LEFT][FRONT_LEFT]     = aluSqrt(0.5);
            Context->ChannelMatrix[SIDE_LEFT][BACK_LEFT]      = aluSqrt(0.5);
            Context->ChannelMatrix[SIDE_RIGHT][FRONT_RIGHT]   = aluSqrt(0.5);
            Context->ChannelMatrix[SIDE_RIGHT][BACK_RIGHT]    = aluSqrt(0.5);
            Context->ChannelMatrix[BACK_CENTER][BACK_LEFT]    = aluSqrt(0.5);
            Context->ChannelMatrix[BACK_CENTER][BACK_RIGHT]   = aluSqrt(0.5);
            Context->NumChan = 4;
            Speaker2Chan[0] = BACK_LEFT;
            Speaker2Chan[1] = FRONT_LEFT;
            Speaker2Chan[2] = FRONT_RIGHT;
            Speaker2Chan[3] = BACK_RIGHT;
            SpeakerAngle[0] = -135.0f * M_PI/180.0f;
            SpeakerAngle[1] =  -45.0f * M_PI/180.0f;
            SpeakerAngle[2] =   45.0f * M_PI/180.0f;
            SpeakerAngle[3] =  135.0f * M_PI/180.0f;
            SetSpeakerArrangement("layout_QUAD", SpeakerAngle, Speaker2Chan, Context->NumChan);
            break;

        case AL_FORMAT_51CHN8:
        case AL_FORMAT_51CHN16:
        case AL_FORMAT_51CHN32:
            Context->ChannelMatrix[SIDE_LEFT][FRONT_LEFT]   = aluSqrt(0.5);
            Context->ChannelMatrix[SIDE_LEFT][BACK_LEFT]    = aluSqrt(0.5);
            Context->ChannelMatrix[SIDE_RIGHT][FRONT_RIGHT] = aluSqrt(0.5);
            Context->ChannelMatrix[SIDE_RIGHT][BACK_RIGHT]  = aluSqrt(0.5);
            Context->ChannelMatrix[BACK_CENTER][BACK_LEFT]  = aluSqrt(0.5);
            Context->ChannelMatrix[BACK_CENTER][BACK_RIGHT] = aluSqrt(0.5);
            Context->NumChan = 5;
            Speaker2Chan[0] = BACK_LEFT;
            Speaker2Chan[1] = FRONT_LEFT;
            Speaker2Chan[2] = FRONT_CENTER;
            Speaker2Chan[3] = FRONT_RIGHT;
            Speaker2Chan[4] = BACK_RIGHT;
            SpeakerAngle[0] = -110.0f * M_PI/180.0f;
            SpeakerAngle[1] =  -30.0f * M_PI/180.0f;
            SpeakerAngle[2] =    0.0f * M_PI/180.0f;
            SpeakerAngle[3] =   30.0f * M_PI/180.0f;
            SpeakerAngle[4] =  110.0f * M_PI/180.0f;
            SetSpeakerArrangement("layout_51CHN", SpeakerAngle, Speaker2Chan, Context->NumChan);
            break;

        case AL_FORMAT_61CHN8:
        case AL_FORMAT_61CHN16:
        case AL_FORMAT_61CHN32:
            Context->ChannelMatrix[BACK_LEFT][BACK_CENTER]  = aluSqrt(0.5);
            Context->ChannelMatrix[BACK_LEFT][SIDE_LEFT]    = aluSqrt(0.5);
            Context->ChannelMatrix[BACK_RIGHT][BACK_CENTER] = aluSqrt(0.5);
            Context->ChannelMatrix[BACK_RIGHT][SIDE_RIGHT]  = aluSqrt(0.5);
            Context->NumChan = 6;
            Speaker2Chan[0] = SIDE_LEFT;
            Speaker2Chan[1] = FRONT_LEFT;
            Speaker2Chan[2] = FRONT_CENTER;
            Speaker2Chan[3] = FRONT_RIGHT;
            Speaker2Chan[4] = SIDE_RIGHT;
            Speaker2Chan[5] = BACK_CENTER;
            SpeakerAngle[0] = -90.0f * M_PI/180.0f;
            SpeakerAngle[1] = -30.0f * M_PI/180.0f;
            SpeakerAngle[2] =   0.0f * M_PI/180.0f;
            SpeakerAngle[3] =  30.0f * M_PI/180.0f;
            SpeakerAngle[4] =  90.0f * M_PI/180.0f;
            SpeakerAngle[5] = 180.0f * M_PI/180.0f;
            SetSpeakerArrangement("layout_61CHN", SpeakerAngle, Speaker2Chan, Context->NumChan);
            break;

        case AL_FORMAT_71CHN8:
        case AL_FORMAT_71CHN16:
        case AL_FORMAT_71CHN32:
            Context->ChannelMatrix[BACK_CENTER][BACK_LEFT]  = aluSqrt(0.5);
            Context->ChannelMatrix[BACK_CENTER][BACK_RIGHT] = aluSqrt(0.5);
            Context->NumChan = 7;
            Speaker2Chan[0] = BACK_LEFT;
            Speaker2Chan[1] = SIDE_LEFT;
            Speaker2Chan[2] = FRONT_LEFT;
            Speaker2Chan[3] = FRONT_CENTER;
            Speaker2Chan[4] = FRONT_RIGHT;
            Speaker2Chan[5] = SIDE_RIGHT;
            Speaker2Chan[6] = BACK_RIGHT;
            SpeakerAngle[0] = -150.0f * M_PI/180.0f;
            SpeakerAngle[1] =  -90.0f * M_PI/180.0f;
            SpeakerAngle[2] =  -30.0f * M_PI/180.0f;
            SpeakerAngle[3] =    0.0f * M_PI/180.0f;
            SpeakerAngle[4] =   30.0f * M_PI/180.0f;
            SpeakerAngle[5] =   90.0f * M_PI/180.0f;
            SpeakerAngle[6] =  150.0f * M_PI/180.0f;
            SetSpeakerArrangement("layout_71CHN", SpeakerAngle, Speaker2Chan, Context->NumChan);
            break;

        default:
            assert(0);
    }

    for(pos = 0; pos < LUT_NUM; pos++)
    {
        /* source angle */
        Theta = aluLUTpos2Angle(pos);

        /* clear all values */
        offset = OUTPUTCHANNELS * pos;
        for(s = 0; s < OUTPUTCHANNELS; s++)
            Context->PanningLUT[offset+s] = 0.0f;

        /* set panning values */
        for(s = 0; s < Context->NumChan - 1; s++)
        {
            if(Theta >= SpeakerAngle[s] && Theta < SpeakerAngle[s+1])
            {
                /* source between speaker s and speaker s+1 */
                Alpha = M_PI_2 * (Theta-SpeakerAngle[s]) /
                                 (SpeakerAngle[s+1]-SpeakerAngle[s]);
                Context->PanningLUT[offset + Speaker2Chan[s]]   = cos(Alpha);
                Context->PanningLUT[offset + Speaker2Chan[s+1]] = sin(Alpha);
                break;
            }
        }
        if(s == Context->NumChan - 1)
        {
            /* source between last and first speaker */
            if(Theta < SpeakerAngle[0])
                Theta += 2.0f * M_PI;
            Alpha = M_PI_2 * (Theta-SpeakerAngle[s]) /
                             (2.0f * M_PI + SpeakerAngle[0]-SpeakerAngle[s]);
            Context->PanningLUT[offset + Speaker2Chan[s]] = cos(Alpha);
            Context->PanningLUT[offset + Speaker2Chan[0]] = sin(Alpha);
        }
    }
}

static __inline ALint aluCart2LUTpos(ALfloat re, ALfloat im)
{
    ALint pos = 0;
    ALfloat denom = aluFabs(re) + aluFabs(im);
    if(denom > 0.0f)
        pos = (ALint)(QUADRANT_NUM*aluFabs(im) / denom + 0.5);

    if(re < 0.0)
        pos = 2 * QUADRANT_NUM - pos;
    if(im < 0.0)
        pos = LUT_NUM - pos;
    return pos%LUT_NUM;
}

static ALvoid CalcSourceParams(const ALCcontext *ALContext,
                               const ALsource *ALSource, ALenum isMono,
                               ALfloat *drysend, ALfloat *wetsend,
                               ALfloat *pitch, ALfloat *drygainhf,
                               ALfloat *wetgainhf)
{
    ALfloat InnerAngle,OuterAngle,Angle,Distance,DryMix;
    ALfloat Direction[3],Position[3],SourceToListener[3];
    ALfloat MinVolume,MaxVolume,MinDist,MaxDist,Rolloff,OuterGainHF;
    ALfloat ConeVolume,ConeHF,SourceVolume,ListenerGain;
    ALfloat U[3],V[3],N[3];
    ALfloat DopplerFactor, DopplerVelocity, flSpeedOfSound, flMaxVelocity;
    ALfloat Matrix[3][3];
    ALfloat flAttenuation;
    ALfloat RoomAttenuation[MAX_SENDS];
    ALfloat MetersPerUnit;
    ALfloat RoomRolloff[MAX_SENDS];
    ALfloat DryGainHF = 1.0f;
    ALfloat DirGain, AmbientGain;
    ALfloat length;
    const ALfloat *SpeakerGain;
    ALint NumSends;
    ALint pos, s, i;

    //Get context properties
    DopplerFactor   = ALContext->DopplerFactor * ALSource->DopplerFactor;
    DopplerVelocity = ALContext->DopplerVelocity;
    flSpeedOfSound  = ALContext->flSpeedOfSound;
    NumSends        = ALContext->NumSends;

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

    //Get source properties
    SourceVolume = ALSource->flGain;
    memcpy(Position,  ALSource->vPosition,    sizeof(ALSource->vPosition));
    memcpy(Direction, ALSource->vOrientation, sizeof(ALSource->vOrientation));
    MinVolume    = ALSource->flMinGain;
    MaxVolume    = ALSource->flMaxGain;
    MinDist      = ALSource->flRefDistance;
    MaxDist      = ALSource->flMaxDistance;
    Rolloff      = ALSource->flRollOffFactor;
    InnerAngle   = ALSource->flInnerAngle;
    OuterAngle   = ALSource->flOuterAngle;
    OuterGainHF  = ALSource->OuterGainHF;

    //Only apply 3D calculations for mono buffers
    if(isMono != AL_FALSE)
    {
        //1. Translate Listener to origin (convert to head relative)
        // Note that Direction and SourceToListener are *not* transformed.
        // SourceToListener is used with the source and listener velocities,
        // which are untransformed, and Direction is used with SourceToListener
        // for the sound cone
        if(ALSource->bHeadRelative==AL_FALSE)
        {
            // Build transform matrix
            aluCrossproduct(ALContext->Listener.Forward, ALContext->Listener.Up, U); // Right-vector
            aluNormalize(U);  // Normalized Right-vector
            memcpy(V, ALContext->Listener.Up, sizeof(V));   // Up-vector
            aluNormalize(V);  // Normalized Up-vector
            memcpy(N, ALContext->Listener.Forward, sizeof(N));  // At-vector
            aluNormalize(N);  // Normalized At-vector
            Matrix[0][0] = U[0]; Matrix[0][1] = V[0]; Matrix[0][2] = -N[0];
            Matrix[1][0] = U[1]; Matrix[1][1] = V[1]; Matrix[1][2] = -N[1];
            Matrix[2][0] = U[2]; Matrix[2][1] = V[2]; Matrix[2][2] = -N[2];

            // Translate source position into listener space
            Position[0] -= ALContext->Listener.Position[0];
            Position[1] -= ALContext->Listener.Position[1];
            Position[2] -= ALContext->Listener.Position[2];

            SourceToListener[0] = -Position[0];
            SourceToListener[1] = -Position[1];
            SourceToListener[2] = -Position[2];

            // Transform source position into listener space
            aluMatrixVector(Position, Matrix);
        }
        else
        {
            SourceToListener[0] = -Position[0];
            SourceToListener[1] = -Position[1];
            SourceToListener[2] = -Position[2];
        }
        aluNormalize(SourceToListener);
        aluNormalize(Direction);

        //2. Calculate distance attenuation
        Distance = aluSqrt(aluDotproduct(Position, Position));

        flAttenuation = 1.0f;
        for(i = 0;i < MAX_SENDS;i++)
        {
            RoomAttenuation[i] = 1.0f;

            RoomRolloff[i] = ALSource->RoomRolloffFactor;
            if(ALSource->Send[i].Slot &&
               ALSource->Send[i].Slot->effect.type == AL_EFFECT_REVERB)
                RoomRolloff[i] += ALSource->Send[i].Slot->effect.Reverb.RoomRolloffFactor;
        }

        switch (ALSource->DistanceModel)
        {
            case AL_INVERSE_DISTANCE_CLAMPED:
                Distance=__max(Distance,MinDist);
                Distance=__min(Distance,MaxDist);
                if (MaxDist < MinDist)
                    break;
                //fall-through
            case AL_INVERSE_DISTANCE:
                if (MinDist > 0.0f)
                {
                    if ((MinDist + (Rolloff * (Distance - MinDist))) > 0.0f)
                        flAttenuation = MinDist / (MinDist + (Rolloff * (Distance - MinDist)));
                    for(i = 0;i < NumSends;i++)
                    {
                        if ((MinDist + (RoomRolloff[i] * (Distance - MinDist))) > 0.0f)
                            RoomAttenuation[i] = MinDist / (MinDist + (RoomRolloff[i] * (Distance - MinDist)));
                    }
                }
                break;

            case AL_LINEAR_DISTANCE_CLAMPED:
                Distance=__max(Distance,MinDist);
                Distance=__min(Distance,MaxDist);
                if (MaxDist < MinDist)
                    break;
                //fall-through
            case AL_LINEAR_DISTANCE:
                Distance=__min(Distance,MaxDist);
                if (MaxDist != MinDist)
                {
                    flAttenuation = 1.0f - (Rolloff*(Distance-MinDist)/(MaxDist - MinDist));
                    for(i = 0;i < NumSends;i++)
                        RoomAttenuation[i] = 1.0f - (RoomRolloff[i]*(Distance-MinDist)/(MaxDist - MinDist));
                }
                break;

            case AL_EXPONENT_DISTANCE_CLAMPED:
                Distance=__max(Distance,MinDist);
                Distance=__min(Distance,MaxDist);
                if (MaxDist < MinDist)
                    break;
                //fall-through
            case AL_EXPONENT_DISTANCE:
                if ((Distance > 0.0f) && (MinDist > 0.0f))
                {
                    flAttenuation = (ALfloat)pow(Distance/MinDist, -Rolloff);
                    for(i = 0;i < NumSends;i++)
                        RoomAttenuation[i] = (ALfloat)pow(Distance/MinDist, -RoomRolloff[i]);
                }
                break;

            case AL_NONE:
                break;
        }

        // Source Gain + Attenuation and clamp to Min/Max Gain
        DryMix = SourceVolume * flAttenuation;
        DryMix = __min(DryMix,MaxVolume);
        DryMix = __max(DryMix,MinVolume);

        for(i = 0;i < NumSends;i++)
        {
            ALfloat WetMix = SourceVolume * RoomAttenuation[i];
            WetMix = __min(WetMix,MaxVolume);
            wetsend[i] = __max(WetMix,MinVolume);
            wetgainhf[i] = 1.0f;
        }

        // Distance-based air absorption
        if(ALSource->AirAbsorptionFactor > 0.0f && ALSource->DistanceModel != AL_NONE)
        {
            ALfloat dist = Distance-MinDist;
            ALfloat absorb;

            if(dist < 0.0f) dist = 0.0f;
            // Absorption calculation is done in dB
            absorb = (ALSource->AirAbsorptionFactor*AIRABSORBGAINDBHF) *
                     (dist*MetersPerUnit);
            // Convert dB to linear gain before applying
            absorb = pow(10.0, absorb/20.0);
            DryGainHF *= absorb;
            for(i = 0;i < MAX_SENDS;i++)
                wetgainhf[i] *= absorb;
        }

        //3. Apply directional soundcones
        Angle = aluAcos(aluDotproduct(Direction,SourceToListener)) * 180.0f/M_PI;
        if(Angle >= InnerAngle && Angle <= OuterAngle)
        {
            ALfloat scale = (Angle-InnerAngle) / (OuterAngle-InnerAngle);
            ConeVolume = (1.0f+(ALSource->flOuterGain-1.0f)*scale);
            ConeHF = (1.0f+(OuterGainHF-1.0f)*scale);
            DryMix *= ConeVolume;
            if(ALSource->DryGainHFAuto)
                DryGainHF *= ConeHF;
        }
        else if(Angle > OuterAngle)
        {
            ConeVolume = (1.0f+(ALSource->flOuterGain-1.0f));
            ConeHF = (1.0f+(OuterGainHF-1.0f));
            DryMix *= ConeVolume;
            if(ALSource->DryGainHFAuto)
                DryGainHF *= ConeHF;
        }
        else
        {
            ConeVolume = 1.0f;
            ConeHF = 1.0f;
        }

        //4. Calculate Velocity
        if(DopplerFactor != 0.0f)
        {
            ALfloat flVSS, flVLS = 0.0f;

            if(ALSource->bHeadRelative==AL_FALSE)
                flVLS = aluDotproduct(ALContext->Listener.Velocity, SourceToListener);
            flVSS = aluDotproduct(ALSource->vVelocity, SourceToListener);

            flMaxVelocity = (DopplerVelocity * flSpeedOfSound) / DopplerFactor;

            if (flVSS >= flMaxVelocity)
                flVSS = (flMaxVelocity - 1.0f);
            else if (flVSS <= -flMaxVelocity)
                flVSS = -flMaxVelocity + 1.0f;

            if (flVLS >= flMaxVelocity)
                flVLS = (flMaxVelocity - 1.0f);
            else if (flVLS <= -flMaxVelocity)
                flVLS = -flMaxVelocity + 1.0f;

            pitch[0] = ALSource->flPitch *
                       ((flSpeedOfSound * DopplerVelocity) - (DopplerFactor * flVLS)) /
                       ((flSpeedOfSound * DopplerVelocity) - (DopplerFactor * flVSS));
        }
        else
            pitch[0] = ALSource->flPitch;

        for(i = 0;i < NumSends;i++)
        {
            if(ALSource->Send[i].Slot &&
               ALSource->Send[i].Slot->effect.type != AL_EFFECT_NULL)
            {
                if(ALSource->WetGainAuto)
                    wetsend[i] *= ConeVolume;
                if(ALSource->WetGainHFAuto)
                    wetgainhf[i] *= ConeHF;

                if(ALSource->Send[i].Slot->AuxSendAuto)
                {
                    // Apply minimal attenuation in place of missing
                    // statistical reverb model.
                    wetsend[i] *= pow(DryMix, 1.0f / 2.0f);
                }
                else
                {
                    // If the slot's auxilliary send auto is off, the data sent to the
                    // effect slot is the same as the dry path, sans filter effects
                    wetsend[i] = DryMix;
                    wetgainhf[i] = DryGainHF;
                }

                // Note that this is really applied by the effect slot. However,
                // it's easier (more optimal) to handle it here.
                if(ALSource->Send[i].Slot->effect.type == AL_EFFECT_REVERB)
                    wetgainhf[i] *= ALSource->Send[0].Slot->effect.Reverb.GainHF;

                switch(ALSource->Send[i].WetFilter.type)
                {
                    case AL_FILTER_LOWPASS:
                        wetsend[i] *= ALSource->Send[i].WetFilter.Gain;
                        wetgainhf[i] *= ALSource->Send[i].WetFilter.GainHF;
                        break;
                }
                wetsend[i] *= ListenerGain;
            }
            else
            {
                wetsend[i] = 0.0f;
                wetgainhf[i] = 1.0f;
            }
        }
        for(i = NumSends;i < MAX_SENDS;i++)
        {
            wetsend[i] = 0.0f;
            wetgainhf[i] = 1.0f;
        }

        //5. Apply filter gains and filters
        switch(ALSource->DirectFilter.type)
        {
            case AL_FILTER_LOWPASS:
                DryMix *= ALSource->DirectFilter.Gain;
                DryGainHF *= ALSource->DirectFilter.GainHF;
                break;
        }
        DryMix *= ListenerGain;

        // Use energy-preserving panning algorithm for multi-speaker playback
        length = aluSqrt(Position[0]*Position[0] + Position[1]*Position[1] +
                         Position[2]*Position[2]);
        length = __max(length, MinDist);
        if(length > 0.0f)
        {
            ALfloat invlen = 1.0f/length;
            Position[0] *= invlen;
            Position[1] *= invlen;
            Position[2] *= invlen;
        }

        pos = aluCart2LUTpos(-Position[2], Position[0]);
        SpeakerGain = &ALContext->PanningLUT[OUTPUTCHANNELS * pos];

        DirGain = aluSqrt(Position[0]*Position[0] + Position[2]*Position[2]);
        // elevation adjustment for directional gain. this sucks, but
        // has low complexity
        AmbientGain = 1.0/aluSqrt(ALContext->NumChan) * (1.0-DirGain);
        for(s = 0; s < OUTPUTCHANNELS; s++)
        {
            ALfloat gain = SpeakerGain[s]*DirGain + AmbientGain;
            drysend[s] = DryMix * gain;
        }
        *drygainhf = DryGainHF;
    }
    else
    {
        //1. Multi-channel buffers always play "normal"
        pitch[0] = ALSource->flPitch;

        DryMix = SourceVolume;
        DryMix = __min(DryMix,MaxVolume);
        DryMix = __max(DryMix,MinVolume);

        switch(ALSource->DirectFilter.type)
        {
            case AL_FILTER_LOWPASS:
                DryMix *= ALSource->DirectFilter.Gain;
                DryGainHF *= ALSource->DirectFilter.GainHF;
                break;
        }

        drysend[FRONT_LEFT]   = DryMix * ListenerGain;
        drysend[FRONT_RIGHT]  = DryMix * ListenerGain;
        drysend[SIDE_LEFT]    = DryMix * ListenerGain;
        drysend[SIDE_RIGHT]   = DryMix * ListenerGain;
        drysend[BACK_LEFT]    = DryMix * ListenerGain;
        drysend[BACK_RIGHT]   = DryMix * ListenerGain;
        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;
        }
    }
}

static __inline ALshort lerp(ALshort val1, ALshort val2, ALint frac)
{
    return val1 + (((val2-val1)*frac)>>FRACTIONBITS);
}

ALvoid aluMixData(ALCcontext *ALContext,ALvoid *buffer,ALsizei size,ALenum format)
{
    static float DryBuffer[BUFFERSIZE][OUTPUTCHANNELS];
    static float DummyBuffer[BUFFERSIZE];
    ALfloat *WetBuffer[MAX_SENDS];
    ALfloat (*Matrix)[OUTPUTCHANNELS] = ALContext->ChannelMatrix;
    ALfloat newDrySend[OUTPUTCHANNELS] = { 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f };
    ALfloat newWetSend[MAX_SENDS];
    ALfloat DryGainHF = 0.0f;
    ALfloat WetGainHF[MAX_SENDS];
    ALfloat *DrySend;
    ALfloat *WetSend;
    ALuint rampLength;
    ALfloat dryGainStep[OUTPUTCHANNELS];
    ALfloat wetGainStep[MAX_SENDS];
    ALuint BlockAlign,BufferSize;
    ALuint DataSize=0,DataPosInt=0,DataPosFrac=0;
    ALuint Channels,Frequency,ulExtraSamples;
    ALfloat Pitch;
    ALint Looping,State;
    ALint increment;
    ALuint Buffer;
    ALuint SamplesToDo;
    ALsource *ALSource;
    ALbuffer *ALBuffer;
    ALeffectslot *ALEffectSlot;
    ALfloat values[OUTPUTCHANNELS];
    ALfloat value;
    ALshort *Data;
    ALuint i,j,k,out;
    ALfloat cw, a, g;
    ALbufferlistitem *BufferListItem;
    ALuint loop;
    ALint64 DataSize64,DataPos64;
    FILTER *DryFilter, *WetFilter[MAX_SENDS];
    int fpuState;

    SuspendContext(ALContext);

#if defined(HAVE_FESETROUND)
    fpuState = fegetround();
    fesetround(FE_TOWARDZERO);
#elif defined(HAVE__CONTROLFP)
    fpuState = _controlfp(0, 0);
    _controlfp(_RC_CHOP, _MCW_RC);
#else
    (void)fpuState;
#endif

    //Figure output format variables
    BlockAlign  = aluChannelsFromFormat(format);
    BlockAlign *= aluBytesFromFormat(format);

    size /= BlockAlign;
    while(size > 0)
    {
        //Setup variables
        SamplesToDo = min(size, BUFFERSIZE);
        if(ALContext)
        {
            ALEffectSlot = ALContext->AuxiliaryEffectSlot;
            ALSource = ALContext->Source;
            rampLength = ALContext->Frequency * MIN_RAMP_LENGTH / 1000;
        }
        else
        {
            ALEffectSlot = NULL;
            ALSource = NULL;
            rampLength = 0;
        }
        rampLength = max(rampLength, SamplesToDo);

        //Clear mixing buffer
        memset(DryBuffer, 0, SamplesToDo*OUTPUTCHANNELS*sizeof(ALfloat));

        //Actual mixing loop
        while(ALSource)
        {
            j = 0;
            State = ALSource->state;

            while(State == AL_PLAYING && j < SamplesToDo)
            {
                DataSize = 0;
                DataPosInt = 0;
                DataPosFrac = 0;

                //Get buffer info
                if((Buffer = ALSource->ulBufferID))
                {
                    ALBuffer = (ALbuffer*)ALTHUNK_LOOKUPENTRY(Buffer);

                    Data      = ALBuffer->data;
                    Channels  = aluChannelsFromFormat(ALBuffer->format);
                    DataSize  = ALBuffer->size;
                    DataSize /= Channels * aluBytesFromFormat(ALBuffer->format);
                    Frequency = ALBuffer->frequency;
                    DataPosInt = ALSource->position;
                    DataPosFrac = ALSource->position_fraction;

                    if(DataPosInt >= DataSize)
                        goto skipmix;

                    //Get source info
                    DryFilter = &ALSource->iirFilter;
                    for(i = 0;i < MAX_SENDS;i++)
                    {
                        WetFilter[i] = &ALSource->Send[i].iirFilter;
                        WetBuffer[i] = (ALSource->Send[i].Slot ?
                                        ALSource->Send[i].Slot->WetBuffer :
                                        DummyBuffer);
                    }
                    DrySend = ALSource->DryGains;
                    WetSend = ALSource->WetGains;

                    CalcSourceParams(ALContext, ALSource,
                                     (Channels==1) ? AL_TRUE : AL_FALSE,
                                     newDrySend, newWetSend, &Pitch,
                                     &DryGainHF, WetGainHF);
                    Pitch = (Pitch*Frequency) / ALContext->Frequency;

                    if(Channels == 1)
                    {
                        // 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;

                        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;
                        }
                    }
                    else
                    {
                        // Multi-channel sources use two chained one-pole
                        // filters
                        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;
                        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;
                        }
                    }

                    //Compute the gain steps for each output channel
                    if(ALSource->FirstStart && DataPosInt == 0 && DataPosFrac == 0)
                    {
                        for(i = 0;i < OUTPUTCHANNELS;i++)
                        {
                            DrySend[i] = newDrySend[i];
                            dryGainStep[i] = 0;
                        }
                        for(i = 0;i < MAX_SENDS;i++)
                        {
                            WetSend[i] = newWetSend[i];
                            wetGainStep[i] = 0;
                        }
                    }
                    else
                    {
                        for(i = 0;i < OUTPUTCHANNELS;i++)
                            dryGainStep[i] = (newDrySend[i]-DrySend[i]) / rampLength;
                        for(i = 0;i < MAX_SENDS;i++)
                            wetGainStep[i] = (newWetSend[i]-WetSend[i]) / rampLength;
                    }
                    ALSource->FirstStart = AL_FALSE;

                    //Compute 18.14 fixed point step
                    if(Pitch > (float)MAX_PITCH)
                        Pitch = (float)MAX_PITCH;
                    increment = (ALint)(Pitch*(ALfloat)(1L<<FRACTIONBITS));
                    if(increment <= 0)
                        increment = (1<<FRACTIONBITS);

                    //Figure out how many samples we can mix.
                    DataSize64 = DataSize;
                    DataSize64 <<= FRACTIONBITS;
                    DataPos64 = DataPosInt;
                    DataPos64 <<= FRACTIONBITS;
                    DataPos64 += DataPosFrac;
                    BufferSize = (ALuint)((DataSize64-DataPos64+(increment-1)) / increment);

                    BufferListItem = ALSource->queue;
                    for(loop = 0; loop < ALSource->BuffersPlayed; loop++)
                    {
                        if(BufferListItem)
                            BufferListItem = BufferListItem->next;
                    }
                    if (BufferListItem)
                    {
                        if (BufferListItem->next)
                        {
                            ALbuffer *NextBuf = (ALbuffer*)ALTHUNK_LOOKUPENTRY(BufferListItem->next->buffer);
                            if(NextBuf && NextBuf->data)
                            {
                                ulExtraSamples = min(NextBuf->size, (ALint)(ALBuffer->padding*Channels*2));
                                memcpy(&Data[DataSize*Channels], NextBuf->data, ulExtraSamples);
                            }
                        }
                        else if (ALSource->bLooping)
                        {
                            ALbuffer *NextBuf = (ALbuffer*)ALTHUNK_LOOKUPENTRY(ALSource->queue->buffer);
                            if (NextBuf && NextBuf->data)
                            {
                                ulExtraSamples = min(NextBuf->size, (ALint)(ALBuffer->padding*Channels*2));
                                memcpy(&Data[DataSize*Channels], NextBuf->data, ulExtraSamples);
                            }
                        }
                        else
                            memset(&Data[DataSize*Channels], 0, (ALBuffer->padding*Channels*2));
                    }
                    BufferSize = min(BufferSize, (SamplesToDo-j));

                    //Actual sample mixing loop
                    k = 0;
                    Data += DataPosInt*Channels;

                    if(Channels == 1) /* Mono */
                    {
                        ALfloat outsamp;

                        while(BufferSize--)
                        {
                            for(i = 0;i < OUTPUTCHANNELS;i++)
                                DrySend[i] += dryGainStep[i];
                            for(i = 0;i < MAX_SENDS;i++)
                                WetSend[i] += wetGainStep[i];

                            //First order interpolator
                            value = lerp(Data[k], Data[k+1], DataPosFrac);

                            //Direct path final mix buffer and panning
                            outsamp = lpFilter4P(DryFilter, 0, value);
                            DryBuffer[j][FRONT_LEFT]   += outsamp*DrySend[FRONT_LEFT];
                            DryBuffer[j][FRONT_RIGHT]  += outsamp*DrySend[FRONT_RIGHT];
                            DryBuffer[j][SIDE_LEFT]    += outsamp*DrySend[SIDE_LEFT];
                            DryBuffer[j][SIDE_RIGHT]   += outsamp*DrySend[SIDE_RIGHT];
                            DryBuffer[j][BACK_LEFT]    += outsamp*DrySend[BACK_LEFT];
                            DryBuffer[j][BACK_RIGHT]   += outsamp*DrySend[BACK_RIGHT];
                            DryBuffer[j][FRONT_CENTER] += outsamp*DrySend[FRONT_CENTER];
                            DryBuffer[j][BACK_CENTER]  += outsamp*DrySend[BACK_CENTER];

                            //Room path final mix buffer and panning
                            for(i = 0;i < MAX_SENDS;i++)
                            {
                                outsamp = lpFilter2P(WetFilter[i], 0, value);
                                WetBuffer[i][j] += outsamp*WetSend[i];
                            }

                            DataPosFrac += increment;
                            k += DataPosFrac>>FRACTIONBITS;
                            DataPosFrac &= FRACTIONMASK;
                            j++;
                        }
                    }
                    else if(Channels == 2) /* Stereo */
                    {
                        const int chans[] = {
                            FRONT_LEFT, FRONT_RIGHT
                        };

#define DO_MIX() do { \
    for(i = 0;i < MAX_SENDS;i++) \
        WetSend[i] += wetGainStep[i]*BufferSize; \
    while(BufferSize--) \
    { \
        for(i = 0;i < OUTPUTCHANNELS;i++) \
            DrySend[i] += dryGainStep[i]; \
 \
        for(i = 0;i < Channels;i++) \
        { \
            value = lerp(Data[k*Channels + i], Data[(k+1)*Channels + i], DataPosFrac); \
            values[i] = lpFilter2P(DryFilter, chans[i]*2, value)*DrySend[chans[i]]; \
        } \
        for(out = 0;out < OUTPUTCHANNELS;out++) \
        { \
            ALfloat sum = 0.0f; \
            for(i = 0;i < Channels;i++) \
                sum += values[i]*Matrix[chans[i]][out]; \
            DryBuffer[j][out] += sum; \
        } \
 \
        DataPosFrac += increment; \
        k += DataPosFrac>>FRACTIONBITS; \
        DataPosFrac &= FRACTIONMASK; \
        j++; \
    } \
} while(0)

                        DO_MIX();
                    }
                    else if(Channels == 4) /* Quad */
                    {
                        const int chans[] = {
                            FRONT_LEFT, FRONT_RIGHT,
                            BACK_LEFT,  BACK_RIGHT
                        };

                        DO_MIX();
                    }
                    else if(Channels == 6) /* 5.1 */
                    {
                        const int chans[] = {
                            FRONT_LEFT,   FRONT_RIGHT,
                            FRONT_CENTER, LFE,
                            BACK_LEFT,    BACK_RIGHT
                        };

                        DO_MIX();
                    }
                    else if(Channels == 7) /* 6.1 */
                    {
                        const int chans[] = {
                            FRONT_LEFT,   FRONT_RIGHT,
                            FRONT_CENTER, LFE,
                            BACK_CENTER,
                            SIDE_LEFT,    SIDE_RIGHT
                        };

                        DO_MIX();
                    }
                    else if(Channels == 8) /* 7.1 */
                    {
                        const int chans[] = {
                            FRONT_LEFT,   FRONT_RIGHT,
                            FRONT_CENTER, LFE,
                            BACK_LEFT,    BACK_RIGHT,
                            SIDE_LEFT,    SIDE_RIGHT
                        };

                        DO_MIX();
#undef DO_MIX
                    }
                    else /* Unknown? */
                    {
                        for(i = 0;i < OUTPUTCHANNELS;i++)
                            DrySend[i] += dryGainStep[i]*BufferSize;
                        for(i = 0;i < MAX_SENDS;i++)
                            WetSend[i] += wetGainStep[i]*BufferSize;
                        while(BufferSize--)
                        {
                            DataPosFrac += increment;
                            k += DataPosFrac>>FRACTIONBITS;
                            DataPosFrac &= FRACTIONMASK;
                            j++;
                        }
                    }
                    DataPosInt += k;

                    //Update source info
                    ALSource->position = DataPosInt;
                    ALSource->position_fraction = DataPosFrac;

                skipmix: ;
                }

                //Handle looping sources
                if(!Buffer || DataPosInt >= DataSize)
                {
                    //queueing
                    if(ALSource->queue)
                    {
                        Looping = ALSource->bLooping;
                        if(ALSource->BuffersPlayed < (ALSource->BuffersInQueue-1))
                        {
                            BufferListItem = ALSource->queue;
                            for(loop = 0; loop <= ALSource->BuffersPlayed; loop++)
                            {
                                if(BufferListItem)
                                {
                                    if(!Looping)
                                        BufferListItem->bufferstate = PROCESSED;
                                    BufferListItem = BufferListItem->next;
                                }
                            }
                            if(BufferListItem)
                                ALSource->ulBufferID = BufferListItem->buffer;
                            ALSource->position = DataPosInt-DataSize;
                            ALSource->position_fraction = DataPosFrac;
                            ALSource->BuffersPlayed++;
                        }
                        else
                        {
                            if(!Looping)
                            {
                                /* alSourceStop */
                                ALSource->state = AL_STOPPED;
                                ALSource->inuse = AL_FALSE;
                                ALSource->BuffersPlayed = ALSource->BuffersInQueue;
                                BufferListItem = ALSource->queue;
                                while(BufferListItem != NULL)
                                {
                                    BufferListItem->bufferstate = PROCESSED;
                                    BufferListItem = BufferListItem->next;
                                }
                                ALSource->position = DataSize;
                                ALSource->position_fraction = 0;
                            }
                            else
                            {
                                /* alSourceRewind */
                                /* alSourcePlay */
                                ALSource->state = AL_PLAYING;
                                ALSource->inuse = AL_TRUE;
                                ALSource->play = AL_TRUE;
                                ALSource->BuffersPlayed = 0;
                                BufferListItem = ALSource->queue;
                                while(BufferListItem != NULL)
                                {
                                    BufferListItem->bufferstate = PENDING;
                                    BufferListItem = BufferListItem->next;
                                }
                                ALSource->ulBufferID = ALSource->queue->buffer;

                                if(ALSource->BuffersInQueue == 1)
                                    ALSource->position = DataPosInt%DataSize;
                                else
                                    ALSource->position = DataPosInt-DataSize;
                                ALSource->position_fraction = DataPosFrac;
                            }
                        }
                    }
                }

                //Get source state
                State = ALSource->state;
            }

            ALSource = ALSource->next;
        }

        // effect slot processing
        while(ALEffectSlot)
        {
            if(ALEffectSlot->effect.type == AL_EFFECT_REVERB)
                VerbProcess(ALEffectSlot->ReverbState, SamplesToDo, ALEffectSlot->WetBuffer, DryBuffer);
            else if(ALEffectSlot->effect.type == AL_EFFECT_ECHO)
                EchoProcess(ALEffectSlot->EchoState, SamplesToDo, ALEffectSlot->WetBuffer, DryBuffer);

            for(i = 0;i < SamplesToDo;i++)
                ALEffectSlot->WetBuffer[i] = 0.0f;
            ALEffectSlot = ALEffectSlot->next;
        }

        //Post processing loop
        switch(format)
        {
            case AL_FORMAT_MONO8:
                for(i = 0;i < SamplesToDo;i++)
                {
                    ((ALubyte*)buffer)[0] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_LEFT]+DryBuffer[i][FRONT_RIGHT])>>8)+128);
                    buffer = ((ALubyte*)buffer) + 1;
                }
                break;
            case AL_FORMAT_STEREO8:
                if(ALContext && ALContext->bs2b)
                {
                    for(i = 0;i < SamplesToDo;i++)
                    {
                        float samples[2];
                        samples[0] = DryBuffer[i][FRONT_LEFT];
                        samples[1] = DryBuffer[i][FRONT_RIGHT];
                        bs2b_cross_feed(ALContext->bs2b, samples);
                        ((ALubyte*)buffer)[0] = (ALubyte)((aluF2S(samples[0])>>8)+128);
                        ((ALubyte*)buffer)[1] = (ALubyte)((aluF2S(samples[1])>>8)+128);
                        buffer = ((ALubyte*)buffer) + 2;
                    }
                }
                else
                {
                    for(i = 0;i < SamplesToDo;i++)
                    {
                        ((ALubyte*)buffer)[0] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_LEFT])>>8)+128);
                        ((ALubyte*)buffer)[1] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_RIGHT])>>8)+128);
                        buffer = ((ALubyte*)buffer) + 2;
                    }
                }
                break;
            case AL_FORMAT_QUAD8:
                for(i = 0;i < SamplesToDo;i++)
                {
                    ((ALubyte*)buffer)[0] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_LEFT])>>8)+128);
                    ((ALubyte*)buffer)[1] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_RIGHT])>>8)+128);
                    ((ALubyte*)buffer)[2] = (ALubyte)((aluF2S(DryBuffer[i][BACK_LEFT])>>8)+128);
                    ((ALubyte*)buffer)[3] = (ALubyte)((aluF2S(DryBuffer[i][BACK_RIGHT])>>8)+128);
                    buffer = ((ALubyte*)buffer) + 4;
                }
                break;
            case AL_FORMAT_51CHN8:
                for(i = 0;i < SamplesToDo;i++)
                {
                    ((ALubyte*)buffer)[0] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_LEFT])>>8)+128);
                    ((ALubyte*)buffer)[1] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_RIGHT])>>8)+128);
#ifdef _WIN32 /* Of course, Windows can't use the same ordering... */
                    ((ALubyte*)buffer)[2] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_CENTER])>>8)+128);
                    ((ALubyte*)buffer)[3] = (ALubyte)((aluF2S(DryBuffer[i][LFE])>>8)+128);
                    ((ALubyte*)buffer)[4] = (ALubyte)((aluF2S(DryBuffer[i][BACK_LEFT])>>8)+128);
                    ((ALubyte*)buffer)[5] = (ALubyte)((aluF2S(DryBuffer[i][BACK_RIGHT])>>8)+128);
#else
                    ((ALubyte*)buffer)[2] = (ALubyte)((aluF2S(DryBuffer[i][BACK_LEFT])>>8)+128);
                    ((ALubyte*)buffer)[3] = (ALubyte)((aluF2S(DryBuffer[i][BACK_RIGHT])>>8)+128);
                    ((ALubyte*)buffer)[4] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_CENTER])>>8)+128);
                    ((ALubyte*)buffer)[5] = (ALubyte)((aluF2S(DryBuffer[i][LFE])>>8)+128);
#endif
                    buffer = ((ALubyte*)buffer) + 6;
                }
                break;
            case AL_FORMAT_61CHN8:
                for(i = 0;i < SamplesToDo;i++)
                {
                    ((ALubyte*)buffer)[0] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_LEFT])>>8)+128);
                    ((ALubyte*)buffer)[1] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_RIGHT])>>8)+128);
                    ((ALubyte*)buffer)[2] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_CENTER])>>8)+128);
                    ((ALubyte*)buffer)[3] = (ALubyte)((aluF2S(DryBuffer[i][LFE])>>8)+128);
                    ((ALubyte*)buffer)[4] = (ALubyte)((aluF2S(DryBuffer[i][BACK_CENTER])>>8)+128);
                    ((ALubyte*)buffer)[5] = (ALubyte)((aluF2S(DryBuffer[i][SIDE_LEFT])>>8)+128);
                    ((ALubyte*)buffer)[6] = (ALubyte)((aluF2S(DryBuffer[i][SIDE_RIGHT])>>8)+128);
                    buffer = ((ALubyte*)buffer) + 7;
                }
                break;
            case AL_FORMAT_71CHN8:
                for(i = 0;i < SamplesToDo;i++)
                {
                    ((ALubyte*)buffer)[0] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_LEFT])>>8)+128);
                    ((ALubyte*)buffer)[1] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_RIGHT])>>8)+128);
#ifdef _WIN32
                    ((ALubyte*)buffer)[2] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_CENTER])>>8)+128);
                    ((ALubyte*)buffer)[3] = (ALubyte)((aluF2S(DryBuffer[i][LFE])>>8)+128);
                    ((ALubyte*)buffer)[4] = (ALubyte)((aluF2S(DryBuffer[i][BACK_LEFT])>>8)+128);
                    ((ALubyte*)buffer)[5] = (ALubyte)((aluF2S(DryBuffer[i][BACK_RIGHT])>>8)+128);
#else
                    ((ALubyte*)buffer)[2] = (ALubyte)((aluF2S(DryBuffer[i][BACK_LEFT])>>8)+128);
                    ((ALubyte*)buffer)[3] = (ALubyte)((aluF2S(DryBuffer[i][BACK_RIGHT])>>8)+128);
                    ((ALubyte*)buffer)[4] = (ALubyte)((aluF2S(DryBuffer[i][FRONT_CENTER])>>8)+128);
                    ((ALubyte*)buffer)[5] = (ALubyte)((aluF2S(DryBuffer[i][LFE])>>8)+128);
#endif
                    ((ALubyte*)buffer)[6] = (ALubyte)((aluF2S(DryBuffer[i][SIDE_LEFT])>>8)+128);
                    ((ALubyte*)buffer)[7] = (ALubyte)((aluF2S(DryBuffer[i][SIDE_RIGHT])>>8)+128);
                    buffer = ((ALubyte*)buffer) + 8;
                }
                break;

            case AL_FORMAT_MONO16:
                for(i = 0;i < SamplesToDo;i++)
                {
                    ((ALshort*)buffer)[0] = aluF2S(DryBuffer[i][FRONT_LEFT]+DryBuffer[i][FRONT_RIGHT]);
                    buffer = ((ALshort*)buffer) + 1;
                }
                break;
            case AL_FORMAT_STEREO16:
                if(ALContext && ALContext->bs2b)
                {
                    for(i = 0;i < SamplesToDo;i++)
                    {
                        float samples[2];
                        samples[0] = DryBuffer[i][FRONT_LEFT];
                        samples[1] = DryBuffer[i][FRONT_RIGHT];
                        bs2b_cross_feed(ALContext->bs2b, samples);
                        ((ALshort*)buffer)[0] = aluF2S(samples[0]);
                        ((ALshort*)buffer)[1] = aluF2S(samples[1]);
                        buffer = ((ALshort*)buffer) + 2;
                    }
                }
                else
                {
                    for(i = 0;i < SamplesToDo;i++)
                    {
                        ((ALshort*)buffer)[0] = aluF2S(DryBuffer[i][FRONT_LEFT]);
                        ((ALshort*)buffer)[1] = aluF2S(DryBuffer[i][FRONT_RIGHT]);
                        buffer = ((ALshort*)buffer) + 2;
                    }
                }
                break;
            case AL_FORMAT_QUAD16:
                for(i = 0;i < SamplesToDo;i++)
                {
                    ((ALshort*)buffer)[0] = aluF2S(DryBuffer[i][FRONT_LEFT]);
                    ((ALshort*)buffer)[1] = aluF2S(DryBuffer[i][FRONT_RIGHT]);
                    ((ALshort*)buffer)[2] = aluF2S(DryBuffer[i][BACK_LEFT]);
                    ((ALshort*)buffer)[3] = aluF2S(DryBuffer[i][BACK_RIGHT]);
                    buffer = ((ALshort*)buffer) + 4;
                }
                break;
            case AL_FORMAT_51CHN16:
                for(i = 0;i < SamplesToDo;i++)
                {
                    ((ALshort*)buffer)[0] = aluF2S(DryBuffer[i][FRONT_LEFT]);
                    ((ALshort*)buffer)[1] = aluF2S(DryBuffer[i][FRONT_RIGHT]);
#ifdef _WIN32
                    ((ALshort*)buffer)[2] = aluF2S(DryBuffer[i][FRONT_CENTER]);
                    ((ALshort*)buffer)[3] = aluF2S(DryBuffer[i][LFE]);
                    ((ALshort*)buffer)[4] = aluF2S(DryBuffer[i][BACK_LEFT]);
                    ((ALshort*)buffer)[5] = aluF2S(DryBuffer[i][BACK_RIGHT]);
#else
                    ((ALshort*)buffer)[2] = aluF2S(DryBuffer[i][BACK_LEFT]);
                    ((ALshort*)buffer)[3] = aluF2S(DryBuffer[i][BACK_RIGHT]);
                    ((ALshort*)buffer)[4] = aluF2S(DryBuffer[i][FRONT_CENTER]);
                    ((ALshort*)buffer)[5] = aluF2S(DryBuffer[i][LFE]);
#endif
                    buffer = ((ALshort*)buffer) + 6;
                }
                break;
            case AL_FORMAT_61CHN16:
                for(i = 0;i < SamplesToDo;i++)
                {
                    ((ALshort*)buffer)[0] = aluF2S(DryBuffer[i][FRONT_LEFT]);
                    ((ALshort*)buffer)[1] = aluF2S(DryBuffer[i][FRONT_RIGHT]);
                    ((ALshort*)buffer)[2] = aluF2S(DryBuffer[i][FRONT_CENTER]);
                    ((ALshort*)buffer)[3] = aluF2S(DryBuffer[i][LFE]);
                    ((ALshort*)buffer)[4] = aluF2S(DryBuffer[i][BACK_CENTER]);
                    ((ALshort*)buffer)[5] = aluF2S(DryBuffer[i][SIDE_LEFT]);
                    ((ALshort*)buffer)[6] = aluF2S(DryBuffer[i][SIDE_RIGHT]);
                    buffer = ((ALshort*)buffer) + 7;
                }
                break;
            case AL_FORMAT_71CHN16:
                for(i = 0;i < SamplesToDo;i++)
                {
                    ((ALshort*)buffer)[0] = aluF2S(DryBuffer[i][FRONT_LEFT]);
                    ((ALshort*)buffer)[1] = aluF2S(DryBuffer[i][FRONT_RIGHT]);
#ifdef _WIN32
                    ((ALshort*)buffer)[2] = aluF2S(DryBuffer[i][FRONT_CENTER]);
                    ((ALshort*)buffer)[3] = aluF2S(DryBuffer[i][LFE]);
                    ((ALshort*)buffer)[4] = aluF2S(DryBuffer[i][BACK_LEFT]);
                    ((ALshort*)buffer)[5] = aluF2S(DryBuffer[i][BACK_RIGHT]);
#else
                    ((ALshort*)buffer)[2] = aluF2S(DryBuffer[i][BACK_LEFT]);
                    ((ALshort*)buffer)[3] = aluF2S(DryBuffer[i][BACK_RIGHT]);
                    ((ALshort*)buffer)[4] = aluF2S(DryBuffer[i][FRONT_CENTER]);
                    ((ALshort*)buffer)[5] = aluF2S(DryBuffer[i][LFE]);
#endif
                    ((ALshort*)buffer)[6] = aluF2S(DryBuffer[i][SIDE_LEFT]);
                    ((ALshort*)buffer)[7] = aluF2S(DryBuffer[i][SIDE_RIGHT]);
                    buffer = ((ALshort*)buffer) + 8;
                }
                break;

            default:
                break;
        }

        size -= SamplesToDo;
    }

#if defined(HAVE_FESETROUND)
    fesetround(fpuState);
#elif defined(HAVE__CONTROLFP)
    _controlfp(fpuState, 0xfffff);
#endif

    ProcessContext(ALContext);
}