AuroraOpenALSoft/Alc/hrtf.h
2018-01-11 03:53:25 -08:00

85 lines
2.2 KiB
C

#ifndef ALC_HRTF_H
#define ALC_HRTF_H
#include "AL/al.h"
#include "AL/alc.h"
#include "alMain.h"
#include "alstring.h"
#include "atomic.h"
/* The maximum number of virtual speakers used to generate HRTF coefficients
* for decoding B-Format.
*/
#define HRTF_AMBI_MAX_CHANNELS 16
#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;
void FreeHrtfs(void);
vector_EnumeratedHrtf EnumerateHrtf(const_al_string 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 (*coeffs)[2], ALsizei *delays);
/**
* Produces HRTF filter coefficients for decoding B-Format, given a set of
* virtual speaker positions and HF/LF matrices for decoding to them. The
* returned coefficients are ordered and scaled according to the matrices.
*/
void BuildBFormatHrtf(const struct Hrtf *Hrtf, DirectHrtfState *state, ALsizei NumChannels, const ALfloat (*restrict AmbiPoints)[2], const ALfloat (*restrict AmbiMatrix)[2][MAX_AMBI_COEFFS], ALsizei AmbiCount);
#endif /* ALC_HRTF_H */