#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 InterpState {
    BsincState bsinc;
} InterpState;


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 MixHrtfParams {
    const HrtfParams *Target;
    HrtfParams *Current;
    struct {
        alignas(16) ALfloat Coeffs[HRIR_LENGTH][2];
        ALsizei 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 InterpState *state,
    const ALfloat *restrict src, ALuint frac, ALint increment,
    ALfloat *restrict dst, ALsizei dstlen
);

typedef void (*MixerFunc)(const ALfloat *data, ALsizei OutChans,
                          ALfloat (*restrict OutBuffer)[BUFFERSIZE], ALfloat *CurrentGains,
                          const ALfloat *TargetGains, ALsizei Counter, ALsizei OutPos,
                          ALsizei BufferSize);
typedef void (*RowMixerFunc)(ALfloat *OutBuffer, const ALfloat *gains,
                             const ALfloat (*restrict data)[BUFFERSIZE], ALsizei InChans,
                             ALsizei InPos, ALsizei BufferSize);
typedef void (*HrtfMixerFunc)(ALfloat *restrict LeftOut, ALfloat *restrict RightOut,
                              const ALfloat *data, ALsizei Counter, ALsizei Offset, ALsizei OutPos,
                              const ALsizei IrSize, const MixHrtfParams *hrtfparams,
                              HrtfState *hrtfstate, ALsizei BufferSize);
typedef void (*HrtfDirectMixerFunc)(ALfloat *restrict LeftOut, ALfloat *restrict RightOut,
                                    const ALfloat *data, ALsizei Offset, const ALsizei IrSize,
                                    ALfloat (*restrict Coeffs)[2], ALfloat (*restrict Values)[2],
                                    ALsizei 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)); }


extern alignas(16) ALfloat ResampleCoeffs_FIR4[FRACTIONONE][4];

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;
}


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


void aluInitMixer(void);

MixerFunc SelectMixer(void);
RowMixerFunc SelectRowMixer(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]);

/**
 * CalcAngleCoeffs
 *
 * Calculates ambisonic coefficients based on azimuth and elevation. The
 * azimuth and elevation parameters are in radians, going right and up
 * respectively.
 */
inline void CalcAngleCoeffs(ALfloat azimuth, ALfloat elevation, ALfloat spread, ALfloat coeffs[MAX_AMBI_COEFFS])
{
    ALfloat dir[3] = {
        sinf(azimuth) * cosf(elevation),
        sinf(elevation),
        -cosf(azimuth) * cosf(elevation)
    };
    CalcDirectionCoeffs(dir, spread, coeffs);
}

/**
 * CalcAnglePairwiseCoeffs
 *
 * Calculates ambisonic coefficients based on azimuth and elevation. The
 * azimuth and elevation parameters are in radians, going right and up
 * respectively. This pairwise variant warps the result such that +30 azimuth
 * is full right, and -30 azimuth is full left.
 */
void CalcAnglePairwiseCoeffs(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, ALsizei numchans, ALfloat ingain, ALfloat gains[MAX_OUTPUT_CHANNELS]);
void ComputeAmbientGainsBF(const BFChannelConfig *chanmap, ALsizei 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, ALsizei numchans, ALsizei numcoeffs, const ALfloat coeffs[MAX_AMBI_COEFFS], ALfloat ingain, ALfloat gains[MAX_OUTPUT_CHANNELS]);
void ComputePanningGainsBF(const BFChannelConfig *chanmap, ALsizei 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, ALsizei numchans, const ALfloat mtx[4], ALfloat ingain, ALfloat gains[MAX_OUTPUT_CHANNELS]);
void ComputeFirstOrderGainsBF(const BFChannelConfig *chanmap, ALsizei numchans, const ALfloat mtx[4], ALfloat ingain, ALfloat gains[MAX_OUTPUT_CHANNELS]);


ALboolean MixSource(struct ALvoice *voice, struct ALsource *Source, ALCdevice *Device, ALsizei SamplesToDo);

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

extern ALfloat ConeScale;
extern ALfloat ZScale;

#ifdef __cplusplus
}
#endif

#endif