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 #include "almalloc.h"
  11
  12
  13 #define HRTF_HISTORY_BITS   (6)
  14 #define HRTF_HISTORY_LENGTH (1<<HRTF_HISTORY_BITS)
  15 #define HRTF_HISTORY_MASK   (HRTF_HISTORY_LENGTH-1)
  16
  17 #define HRIR_BITS        (7)
  18 #define HRIR_LENGTH      (1<<HRIR_BITS)
  19 #define HRIR_MASK        (HRIR_LENGTH-1)
  20
  21
  22 struct HrtfEntry;
  23
  24 struct Hrtf {
  25     RefCount ref;
  26
  27     ALuint sampleRate;
  28     ALsizei irSize;
  29
  30     ALfloat distance;
  31     ALubyte evCount;
  32
  33     const ALubyte *azCount;
  34     const ALushort *evOffset;
  35     const ALfloat (*coeffs)[2];
  36     const ALubyte (*delays)[2];
  37 };
  38
  39
  40 struct HrtfState {
  41     alignas(16) ALfloat History[HRTF_HISTORY_LENGTH];
  42     alignas(16) ALfloat Values[HRIR_LENGTH][2];
  43 };
  44
  45 struct HrtfParams {
  46     alignas(16) ALfloat Coeffs[HRIR_LENGTH][2];
  47     ALsizei Delay[2];
  48     ALfloat Gain;
  49 };
  50
  51 struct DirectHrtfState {
  52     /* HRTF filter state for dry buffer content */
  53     ALsizei Offset{0};
  54     ALsizei IrSize{0};
  55     struct {
  56         alignas(16) ALfloat Values[HRIR_LENGTH][2];
  57         alignas(16) ALfloat Coeffs[HRIR_LENGTH][2];
  58     } Chan[];
  59
  60     DirectHrtfState() noexcept { }
  61
  62     DEF_PLACE_NEWDEL()
  63 };
  64
  65 struct AngularPoint {
  66     ALfloat Elev;
  67     ALfloat Azim;
  68 };
  69
  70
  71 void FreeHrtfs(void);
  72
  73 al::vector<EnumeratedHrtf> EnumerateHrtf(const char *devname);
  74 struct Hrtf *GetLoadedHrtf(struct HrtfEntry *entry);
  75 void Hrtf_IncRef(struct Hrtf *hrtf);
  76 void Hrtf_DecRef(struct Hrtf *hrtf);
  77
  78 void GetHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azimuth, ALfloat spread, ALfloat (*RESTRICT coeffs)[2], ALsizei *delays);
  79
  80 /**
  81  * Produces HRTF filter coefficients for decoding B-Format, given a set of
  82  * virtual speaker positions, a matching decoding matrix, and per-order high-
  83  * frequency gains for the decoder. The calculated impulse responses are
  84  * ordered and scaled according to the matrix input.
  85  */
  86 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);
  87
  88 #endif /* ALC_HRTF_H */