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


#define F_PI    (3.14159265358979323846f)
#define F_PI_2  (1.57079632679489661923f)
#define F_TAU   (6.28318530717958647692f)

#ifndef FLT_EPSILON
#define FLT_EPSILON (1.19209290e-07f)
#endif

#define DEG2RAD(x)  ((ALfloat)(x) * (F_PI/180.0f))
#define RAD2DEG(x)  ((ALfloat)(x) * (180.0f/F_PI))


#define MAX_PITCH  (255)


#ifdef __cplusplus
extern "C" {
#endif

struct ALsource;
struct ALvoice;


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 aluMatrix {
    alignas(16) ALfloat m[4][4];
} aluMatrix;

inline void aluMatrixSetRow(aluMatrix *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 aluMatrixSet(aluMatrix *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)
{
    aluMatrixSetRow(matrix, 0, m00, m01, m02, m03);
    aluMatrixSetRow(matrix, 1, m10, m11, m12, m13);
    aluMatrixSetRow(matrix, 2, m20, m21, m22, m23);
    aluMatrixSetRow(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 DirectParams {
    ALfloat (*OutBuffer)[BUFFERSIZE];
    ALuint OutChannels;

    /* If not 'moving', gain/coefficients are set directly without fading. */
    ALboolean Moving;
    /* Stepping counter for gain/coefficient fading. */
    ALuint Counter;
    /* Last direction (relative to listener) and gain of a moving source. */
    aluVector LastDir;
    ALfloat LastGain;

    struct {
        enum ActiveFilters ActiveType;
        ALfilterState LowPass;
        ALfilterState HighPass;
    } Filters[MAX_INPUT_CHANNELS];

    struct {
        HrtfParams Params;
        HrtfState State;
    } Hrtf[MAX_INPUT_CHANNELS];
    MixGains Gains[MAX_INPUT_CHANNELS][MAX_OUTPUT_CHANNELS];
} DirectParams;

typedef struct SendParams {
    ALfloat (*OutBuffer)[BUFFERSIZE];

    ALboolean Moving;
    ALuint Counter;

    struct {
        enum ActiveFilters ActiveType;
        ALfilterState LowPass;
        ALfilterState HighPass;
    } Filters[MAX_INPUT_CHANNELS];

    /* Gain control, which applies to all input channels to a single (mono)
     * output buffer. */
    MixGains Gain;
} SendParams;


typedef const ALfloat* (*ResamplerFunc)(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 (*HrtfMixerFunc)(ALfloat (*restrict OutBuffer)[BUFFERSIZE], const ALfloat *data,
                              ALuint Counter, ALuint Offset, ALuint OutPos,
                              const ALuint IrSize, const HrtfParams *hrtfparams,
                              HrtfState *hrtfstate, ALuint BufferSize);


#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 FIR6[FRACTIONONE][6];
};
extern alignas(16) union ResamplerCoeffs ResampleCoeffs;


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_fir6(ALfloat val0, ALfloat val1, ALfloat val2, ALfloat val3, ALfloat val4, ALfloat val5, ALuint frac)
{
    const ALfloat *k = ResampleCoeffs.FIR6[frac];
    return k[0]*val0 + k[1]*val1 + k[2]*val2 + k[3]*val3 + k[4]*val4 + k[5]*val5;
}


void aluInitMixer(void);

ALvoid aluInitPanning(ALCdevice *Device);

/**
 * ComputeDirectionalGains
 *
 * Sets channel gains based on a direction. The direction must be a 3-component
 * vector no longer than 1 unit.
 */
void ComputeDirectionalGains(const ALCdevice *device, const ALfloat dir[3], ALfloat ingain, ALfloat gains[MAX_OUTPUT_CHANNELS]);

/**
 * ComputeAngleGains
 *
 * Sets channel gains based on angle and elevation. The angle and elevation
 * parameters are in radians, going right and up respectively.
 */
void ComputeAngleGains(const ALCdevice *device, ALfloat angle, ALfloat elevation, ALfloat ingain, ALfloat gains[MAX_OUTPUT_CHANNELS]);

/**
 * ComputeAmbientGains
 *
 * Sets channel gains for ambient, omni-directional sounds.
 */
void ComputeAmbientGains(const ALCdevice *device, ALfloat ingain, ALfloat gains[MAX_OUTPUT_CHANNELS]);

/**
 * ComputeBFormatGains
 *
 * Sets channel gains for a given (first-order) B-Format channel. The matrix is
 * a 1x4 'slice' of the rotation matrix for a given channel used to orient the
 * coefficients.
 */
void ComputeBFormatGains(const ALCdevice *device, const ALfloat mtx[4], ALfloat ingain, ALfloat gains[MAX_OUTPUT_CHANNELS]);


ALvoid UpdateContextSources(ALCcontext *context);

ALvoid CalcSourceParams(struct ALvoice *voice, const struct ALsource *source, const ALCcontext *ALContext);
ALvoid CalcNonAttnSourceParams(struct ALvoice *voice, const struct ALsource *source, const ALCcontext *ALContext);

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