Alc/hrtf.h

   1 #ifndef ALC_HRTF_H
   2 #define ALC_HRTF_H
   3
   4 #include "AL/al.h"
   5 #include "AL/alc.h"
   6
   7 #include "alMain.h"
   8 #include "atomic.h"
   9 #include "vector.h"
  10
  11
  12 #define HRTF_HISTORY_BITS   (6)
  13 #define HRTF_HISTORY_LENGTH (1<<HRTF_HISTORY_BITS)
  14 #define HRTF_HISTORY_MASK   (HRTF_HISTORY_LENGTH-1)
  15
  16 #define HRIR_BITS        (7)
  17 #define HRIR_LENGTH      (1<<HRIR_BITS)
  18 #define HRIR_MASK        (HRIR_LENGTH-1)
  19
  20
  21 struct HrtfEntry;
  22
  23 struct Hrtf {
  24     RefCount ref;
  25
  26     ALuint sampleRate;
  27     ALsizei irSize;
  28
  29     ALfloat distance;
  30     ALubyte evCount;
  31
  32     const ALubyte *azCount;
  33     const ALushort *evOffset;
  34     const ALfloat (*coeffs)[2];
  35     const ALubyte (*delays)[2];
  36 };
  37
  38
  39 typedef struct HrtfState {
  40     alignas(16) ALfloat History[HRTF_HISTORY_LENGTH];
  41     alignas(16) ALfloat Values[HRIR_LENGTH][2];
  42 } HrtfState;
  43
  44 typedef struct HrtfParams {
  45     alignas(16) ALfloat Coeffs[HRIR_LENGTH][2];
  46     ALsizei Delay[2];
  47     ALfloat Gain;
  48 } HrtfParams;
  49
  50 typedef struct DirectHrtfState {
  51     /* HRTF filter state for dry buffer content */
  52     ALsizei Offset;
  53     ALsizei IrSize;
  54     struct {
  55         alignas(16) ALfloat Values[HRIR_LENGTH][2];
  56         alignas(16) ALfloat Coeffs[HRIR_LENGTH][2];
  57     } Chan[];
  58 } DirectHrtfState;
  59
  60 struct AngularPoint {
  61     ALfloat Elev;
  62     ALfloat Azim;
  63 };
  64
  65
  66 void FreeHrtfs(void);
  67
  68 al::vector<EnumeratedHrtf> EnumerateHrtf(const char *devname);
  69 struct Hrtf *GetLoadedHrtf(struct HrtfEntry *entry);
  70 void Hrtf_IncRef(struct Hrtf *hrtf);
  71 void Hrtf_DecRef(struct Hrtf *hrtf);
  72
  73 void GetHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azimuth, ALfloat spread, ALfloat (*RESTRICT coeffs)[2], ALsizei *delays);
  74
  75 /**
  76  * Produces HRTF filter coefficients for decoding B-Format, given a set of
  77  * virtual speaker positions, a matching decoding matrix, and per-order high-
  78  * frequency gains for the decoder. The calculated impulse responses are
  79  * ordered and scaled according to the matrix input.
  80  */
  81 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);
  82
  83 #endif /* ALC_HRTF_H */