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#ifndef ALC_HRTF_H
#define ALC_HRTF_H
#include "AL/al.h"
#include "AL/alc.h"
#include "alMain.h"
#include "atomic.h"
#ifdef __cplusplus
extern "C" {
#endif
#define HRTF_HISTORY_BITS (6)
#define HRTF_HISTORY_LENGTH (1<<HRTF_HISTORY_BITS)
#define HRTF_HISTORY_MASK (HRTF_HISTORY_LENGTH-1)
#define HRIR_BITS (7)
#define HRIR_LENGTH (1<<HRIR_BITS)
#define HRIR_MASK (HRIR_LENGTH-1)
struct HrtfEntry;
struct Hrtf {
RefCount ref;
ALuint sampleRate;
ALsizei irSize;
ALfloat distance;
ALubyte evCount;
const ALubyte *azCount;
const ALushort *evOffset;
const ALfloat (*coeffs)[2];
const ALubyte (*delays)[2];
};
typedef struct HrtfState {
alignas(16) ALfloat History[HRTF_HISTORY_LENGTH];
alignas(16) ALfloat Values[HRIR_LENGTH][2];
} HrtfState;
typedef struct HrtfParams {
alignas(16) ALfloat Coeffs[HRIR_LENGTH][2];
ALsizei Delay[2];
ALfloat Gain;
} HrtfParams;
typedef struct DirectHrtfState {
/* HRTF filter state for dry buffer content */
ALsizei Offset;
ALsizei IrSize;
struct {
alignas(16) ALfloat Values[HRIR_LENGTH][2];
alignas(16) ALfloat Coeffs[HRIR_LENGTH][2];
} Chan[];
} DirectHrtfState;
struct AngularPoint {
ALfloat Elev;
ALfloat Azim;
};
void FreeHrtfs(void);
vector_EnumeratedHrtf EnumerateHrtf(const char *devname);
void FreeHrtfList(vector_EnumeratedHrtf *list);
struct Hrtf *GetLoadedHrtf(struct HrtfEntry *entry);
void Hrtf_IncRef(struct Hrtf *hrtf);
void Hrtf_DecRef(struct Hrtf *hrtf);
void GetHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azimuth, ALfloat spread, ALfloat (*RESTRICT coeffs)[2], ALsizei *delays);
/**
* Produces HRTF filter coefficients for decoding B-Format, given a set of
* virtual speaker positions, a matching decoding matrix, and per-order high-
* frequency gains for the decoder. The calculated impulse responses are
* ordered and scaled according to the matrix input.
*/
void BuildBFormatHrtf(const struct Hrtf *Hrtf, DirectHrtfState *state, ALsizei NumChannels, const struct AngularPoint *AmbiPoints, const ALfloat (*RESTRICT AmbiMatrix)[MAX_AMBI_COEFFS], ALsizei AmbiCount, const ALfloat *RESTRICT AmbiOrderHFGain);
#ifdef __cplusplus
} // extern "C"
#endif
#endif /* ALC_HRTF_H */
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