#ifndef _ALU_H_
#define _ALU_H_

#include <limits.h>
#include <math.h>
#ifdef HAVE_FLOAT_H
#include <float.h>
#endif
#ifdef HAVE_IEEEFP_H
#include <ieeefp.h>
#endif

#include "alMain.h"
#include "alBuffer.h"
#include "alFilter.h"
#include "alAuxEffectSlot.h"

#include "hrtf.h"
#include "align.h"
#include "math_defs.h"


#define MAX_PITCH  (255)

/* Maximum number of buffer samples before the current pos needed for resampling. */
#define MAX_PRE_SAMPLES 12

/* Maximum number of buffer samples after the current pos needed for resampling. */
#define MAX_POST_SAMPLES 12


#ifdef __cplusplus
extern "C" {
#endif

struct ALsource;
struct ALsourceProps;
struct ALvoice;
struct ALeffectslot;
struct ALbuffer;


/* The number of distinct scale and phase intervals within the filter table. */
#define BSINC_SCALE_BITS  4
#define BSINC_SCALE_COUNT (1<<BSINC_SCALE_BITS)
#define BSINC_PHASE_BITS  4
#define BSINC_PHASE_COUNT (1<<BSINC_PHASE_BITS)

/* Interpolator state.  Kind of a misnomer since the interpolator itself is
 * stateless.  This just keeps it from having to recompute scale-related
 * mappings for every sample.
 */
typedef struct BsincState {
    ALfloat sf; /* Scale interpolation factor. */
    ALuint m;   /* Coefficient count. */
    ALint l;    /* Left coefficient offset. */
    struct {
        const ALfloat *filter;   /* Filter coefficients. */
        const ALfloat *scDelta;  /* Scale deltas. */
        const ALfloat *phDelta;  /* Phase deltas. */
        const ALfloat *spDelta;  /* Scale-phase deltas. */
    } coeffs[BSINC_PHASE_COUNT];
} BsincState;


typedef union aluVector {
    alignas(16) ALfloat v[4];
} aluVector;

inline void aluVectorSet(aluVector *vector, ALfloat x, ALfloat y, ALfloat z, ALfloat w)
{
    vector->v[0] = x;
    vector->v[1] = y;
    vector->v[2] = z;
    vector->v[3] = w;
}


typedef union aluMatrixf {
    alignas(16) ALfloat m[4][4];
} aluMatrixf;
extern const aluMatrixf IdentityMatrixf;

inline void aluMatrixfSetRow(aluMatrixf *matrix, ALuint row,
                             ALfloat m0, ALfloat m1, ALfloat m2, ALfloat m3)
{
    matrix->m[row][0] = m0;
    matrix->m[row][1] = m1;
    matrix->m[row][2] = m2;
    matrix->m[row][3] = m3;
}

inline void aluMatrixfSet(aluMatrixf *matrix, ALfloat m00, ALfloat m01, ALfloat m02, ALfloat m03,
                                              ALfloat m10, ALfloat m11, ALfloat m12, ALfloat m13,
                                              ALfloat m20, ALfloat m21, ALfloat m22, ALfloat m23,
                                              ALfloat m30, ALfloat m31, ALfloat m32, ALfloat m33)
{
    aluMatrixfSetRow(matrix, 0, m00, m01, m02, m03);
    aluMatrixfSetRow(matrix, 1, m10, m11, m12, m13);
    aluMatrixfSetRow(matrix, 2, m20, m21, m22, m23);
    aluMatrixfSetRow(matrix, 3, m30, m31, m32, m33);
}


enum ActiveFilters {
    AF_None = 0,
    AF_LowPass = 1,
    AF_HighPass = 2,
    AF_BandPass = AF_LowPass | AF_HighPass
};


typedef struct MixGains {
    ALfloat Current;
    ALfloat Step;
    ALfloat Target;
} MixGains;

typedef struct MixHrtfParams {
    const HrtfParams *Target;
    HrtfParams *Current;
    struct {
        alignas(16) ALfloat Coeffs[HRIR_LENGTH][2];
        ALint Delay[2];
    } Steps;
} MixHrtfParams;

typedef struct DirectParams {
    enum ActiveFilters FilterType;
    ALfilterState LowPass;
    ALfilterState HighPass;

    struct {
        HrtfParams Current;
        HrtfParams Target;
        HrtfState State;
    } Hrtf;

    struct {
        ALfloat Current[MAX_OUTPUT_CHANNELS];
        ALfloat Target[MAX_OUTPUT_CHANNELS];
    } Gains;
} DirectParams;

typedef struct SendParams {
    enum ActiveFilters FilterType;
    ALfilterState LowPass;
    ALfilterState HighPass;

    struct {
        ALfloat Current[MAX_OUTPUT_CHANNELS];
        ALfloat Target[MAX_OUTPUT_CHANNELS];
    } Gains;
} SendParams;


typedef const ALfloat* (*ResamplerFunc)(const BsincState *state,
    const ALfloat *src, ALuint frac, ALuint increment, ALfloat *restrict dst, ALuint dstlen
);

typedef void (*MixerFunc)(const ALfloat *data, ALuint OutChans,
                          ALfloat (*restrict OutBuffer)[BUFFERSIZE], struct MixGains *Gains,
                          ALuint Counter, ALuint OutPos, ALuint BufferSize);
typedef void (*RowMixerFunc)(ALfloat *OutBuffer, const ALfloat *gains,
                             ALfloat (*restrict data)[BUFFERSIZE], ALuint InChans,
                             ALuint BufferSize);
typedef void (*HrtfMixerFunc)(ALfloat (*restrict OutBuffer)[BUFFERSIZE], ALuint lidx, ALuint ridx,
                              const ALfloat *data, ALuint Counter, ALuint Offset, ALuint OutPos,
                              const ALuint IrSize, const MixHrtfParams *hrtfparams,
                              HrtfState *hrtfstate, ALuint BufferSize);
typedef void (*HrtfDirectMixerFunc)(ALfloat (*restrict OutBuffer)[BUFFERSIZE],
                                    ALuint lidx, ALuint ridx, const ALfloat *data, ALuint Offset,
                                    const ALuint IrSize, ALfloat (*restrict Coeffs)[2],
                                    ALfloat (*restrict Values)[2], ALuint BufferSize);


#define GAIN_MIX_MAX  (16.0f) /* +24dB */

#define GAIN_SILENCE_THRESHOLD  (0.00001f) /* -100dB */

#define SPEEDOFSOUNDMETRESPERSEC  (343.3f)
#define AIRABSORBGAINHF           (0.99426f) /* -0.05dB */

#define FRACTIONBITS (12)
#define FRACTIONONE  (1<<FRACTIONBITS)
#define FRACTIONMASK (FRACTIONONE-1)


inline ALfloat minf(ALfloat a, ALfloat b)
{ return ((a > b) ? b : a); }
inline ALfloat maxf(ALfloat a, ALfloat b)
{ return ((a > b) ? a : b); }
inline ALfloat clampf(ALfloat val, ALfloat min, ALfloat max)
{ return minf(max, maxf(min, val)); }

inline ALdouble mind(ALdouble a, ALdouble b)
{ return ((a > b) ? b : a); }
inline ALdouble maxd(ALdouble a, ALdouble b)
{ return ((a > b) ? a : b); }
inline ALdouble clampd(ALdouble val, ALdouble min, ALdouble max)
{ return mind(max, maxd(min, val)); }

inline ALuint minu(ALuint a, ALuint b)
{ return ((a > b) ? b : a); }
inline ALuint maxu(ALuint a, ALuint b)
{ return ((a > b) ? a : b); }
inline ALuint clampu(ALuint val, ALuint min, ALuint max)
{ return minu(max, maxu(min, val)); }

inline ALint mini(ALint a, ALint b)
{ return ((a > b) ? b : a); }
inline ALint maxi(ALint a, ALint b)
{ return ((a > b) ? a : b); }
inline ALint clampi(ALint val, ALint min, ALint max)
{ return mini(max, maxi(min, val)); }

inline ALint64 mini64(ALint64 a, ALint64 b)
{ return ((a > b) ? b : a); }
inline ALint64 maxi64(ALint64 a, ALint64 b)
{ return ((a > b) ? a : b); }
inline ALint64 clampi64(ALint64 val, ALint64 min, ALint64 max)
{ return mini64(max, maxi64(min, val)); }

inline ALuint64 minu64(ALuint64 a, ALuint64 b)
{ return ((a > b) ? b : a); }
inline ALuint64 maxu64(ALuint64 a, ALuint64 b)
{ return ((a > b) ? a : b); }
inline ALuint64 clampu64(ALuint64 val, ALuint64 min, ALuint64 max)
{ return minu64(max, maxu64(min, val)); }


union ResamplerCoeffs {
    ALfloat FIR4[FRACTIONONE][4];
    ALfloat FIR8[FRACTIONONE][8];
};
extern alignas(16) union ResamplerCoeffs ResampleCoeffs;

extern alignas(16) const ALfloat bsincTab[18840];


inline ALfloat lerp(ALfloat val1, ALfloat val2, ALfloat mu)
{
    return val1 + (val2-val1)*mu;
}
inline ALfloat resample_fir4(ALfloat val0, ALfloat val1, ALfloat val2, ALfloat val3, ALuint frac)
{
    const ALfloat *k = ResampleCoeffs.FIR4[frac];
    return k[0]*val0 + k[1]*val1 + k[2]*val2 + k[3]*val3;
}
inline ALfloat resample_fir8(ALfloat val0, ALfloat val1, ALfloat val2, ALfloat val3, ALfloat val4, ALfloat val5, ALfloat val6, ALfloat val7, ALuint frac)
{
    const ALfloat *k = ResampleCoeffs.FIR8[frac];
    return k[0]*val0 + k[1]*val1 + k[2]*val2 + k[3]*val3 +
           k[4]*val4 + k[5]*val5 + k[6]*val6 + k[7]*val7;
}


enum HrtfRequestMode {
    Hrtf_Default = 0,
    Hrtf_Enable = 1,
    Hrtf_Disable = 2,
};


void aluInitMixer(void);

MixerFunc SelectMixer(void);

/* aluInitRenderer
 *
 * Set up the appropriate panning method and mixing method given the device
 * properties.
 */
void aluInitRenderer(ALCdevice *device, ALint hrtf_id, enum HrtfRequestMode hrtf_appreq, enum HrtfRequestMode hrtf_userreq);

void aluInitEffectPanning(struct ALeffectslot *slot);

/**
 * CalcDirectionCoeffs
 *
 * Calculates ambisonic coefficients based on a direction vector. The vector
 * must be normalized (unit length), and the spread is the angular width of the
 * sound (0...tau).
 */
void CalcDirectionCoeffs(const ALfloat dir[3], ALfloat spread, ALfloat coeffs[MAX_AMBI_COEFFS]);

/**
 * CalcXYZCoeffs
 *
 * Same as CalcDirectionCoeffs except the direction is specified as separate x,
 * y, and z parameters instead of an array.
 */
inline void CalcXYZCoeffs(ALfloat x, ALfloat y, ALfloat z, ALfloat spread, ALfloat coeffs[MAX_AMBI_COEFFS])
{
    ALfloat dir[3] = { x, y, z };
    CalcDirectionCoeffs(dir, spread, coeffs);
}

/**
 * CalcAngleCoeffs
 *
 * Calculates ambisonic coefficients based on azimuth and elevation. The
 * azimuth and elevation parameters are in radians, going right and up
 * respectively.
 */
void CalcAngleCoeffs(ALfloat azimuth, ALfloat elevation, ALfloat spread, ALfloat coeffs[MAX_AMBI_COEFFS]);

/**
 * ComputeAmbientGains
 *
 * Computes channel gains for ambient, omni-directional sounds.
 */
#define ComputeAmbientGains(b, g, o) do {                                     \
    if((b).CoeffCount > 0)                                                    \
        ComputeAmbientGainsMC((b).Ambi.Coeffs, (b).NumChannels, g, o);        \
    else                                                                      \
        ComputeAmbientGainsBF((b).Ambi.Map, (b).NumChannels, g, o);           \
} while (0)
void ComputeAmbientGainsMC(const ChannelConfig *chancoeffs, ALuint numchans, ALfloat ingain, ALfloat gains[MAX_OUTPUT_CHANNELS]);
void ComputeAmbientGainsBF(const BFChannelConfig *chanmap, ALuint numchans, ALfloat ingain, ALfloat gains[MAX_OUTPUT_CHANNELS]);

/**
 * ComputePanningGains
 *
 * Computes panning gains using the given channel decoder coefficients and the
 * pre-calculated direction or angle coefficients.
 */
#define ComputePanningGains(b, c, g, o) do {                                  \
    if((b).CoeffCount > 0)                                                    \
        ComputePanningGainsMC((b).Ambi.Coeffs, (b).NumChannels, (b).CoeffCount, c, g, o);\
    else                                                                      \
        ComputePanningGainsBF((b).Ambi.Map, (b).NumChannels, c, g, o);        \
} while (0)
void ComputePanningGainsMC(const ChannelConfig *chancoeffs, ALuint numchans, ALuint numcoeffs, const ALfloat coeffs[MAX_AMBI_COEFFS], ALfloat ingain, ALfloat gains[MAX_OUTPUT_CHANNELS]);
void ComputePanningGainsBF(const BFChannelConfig *chanmap, ALuint numchans, const ALfloat coeffs[MAX_AMBI_COEFFS], ALfloat ingain, ALfloat gains[MAX_OUTPUT_CHANNELS]);

/**
 * ComputeFirstOrderGains
 *
 * Sets channel gains for a first-order ambisonics input channel. The matrix is
 * a 1x4 'slice' of a transform matrix for the input channel, used to scale and
 * orient the sound samples.
 */
#define ComputeFirstOrderGains(b, m, g, o) do {                               \
    if((b).CoeffCount > 0)                                                    \
        ComputeFirstOrderGainsMC((b).Ambi.Coeffs, (b).NumChannels, m, g, o);  \
    else                                                                      \
        ComputeFirstOrderGainsBF((b).Ambi.Map, (b).NumChannels, m, g, o);     \
} while (0)
void ComputeFirstOrderGainsMC(const ChannelConfig *chancoeffs, ALuint numchans, const ALfloat mtx[4], ALfloat ingain, ALfloat gains[MAX_OUTPUT_CHANNELS]);
void ComputeFirstOrderGainsBF(const BFChannelConfig *chanmap, ALuint numchans, const ALfloat mtx[4], ALfloat ingain, ALfloat gains[MAX_OUTPUT_CHANNELS]);


ALvoid MixSource(struct ALvoice *voice, struct ALsource *source, ALCdevice *Device, ALuint SamplesToDo);

ALvoid aluMixData(ALCdevice *device, ALvoid *buffer, ALsizei size);
/* Caller must lock the device. */
ALvoid aluHandleDisconnect(ALCdevice *device);

extern ALfloat ConeScale;
extern ALfloat ZScale;

#ifdef __cplusplus
}
#endif

#endif