Don't convert the HRTF decoder virtual speaker positions to radians

3 files changed, 32 insertions, 33 deletions

diff --git a/Alc/hrtf.cpp b/Alc/hrtf.cpp
index 5cc1e8b4..ab202e53 100644
--- a/Alc/hrtf.cpp
+++ b/Alc/hrtf.cpp
@@ -275,7 +275,7 @@ void GetHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azimuth,
 }
 
 
-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)
+void BuildBFormatHrtf(const struct Hrtf *Hrtf, DirectHrtfState *state, const ALsizei NumChannels, const AngularPoint *AmbiPoints, const ALfloat (*RESTRICT AmbiMatrix)[MAX_AMBI_COEFFS], const ALsizei AmbiCount, const ALfloat *RESTRICT AmbiOrderHFGain)
 {
 /* Set this to 2 for dual-band HRTF processing. May require a higher quality
  * band-splitter, or better calculation of the new IR length to deal with the
@@ -287,19 +287,17 @@ void BuildBFormatHrtf(const struct Hrtf *Hrtf, DirectHrtfState *state, ALsizei N
     al::vector<ALsizei> idx(AmbiCount);
     for(ALsizei c{0};c < AmbiCount;c++)
     {
-        ALuint evidx, azidx;
-        ALuint evoffset;
-        ALuint azcount;
-
         /* Calculate elevation index. */
-        evidx = (ALsizei)((F_PI_2+AmbiPoints[c].Elev) * (Hrtf->evCount-1) / F_PI + 0.5f);
-        evidx = clampi(evidx, 0, Hrtf->evCount-1);
+        const auto evidx = clampi(
+            static_cast<ALsizei>((90.0f+AmbiPoints[c].Elev)*(Hrtf->evCount-1)/180.0f + 0.5f),
+            0, Hrtf->evCount-1);
 
-        azcount = Hrtf->azCount[evidx];
-        evoffset = Hrtf->evOffset[evidx];
+        const ALsizei azcount{Hrtf->azCount[evidx]};
+        const ALsizei evoffset{Hrtf->evOffset[evidx]};
 
         /* Calculate azimuth index for this elevation. */
-        azidx = (ALsizei)((F_TAU+AmbiPoints[c].Azim) * azcount / F_TAU + 0.5f) % azcount;
+        const auto azidx = static_cast<ALsizei>(
+            (360.0f+AmbiPoints[c].Azim)*azcount/360.0f + 0.5f) % azcount;
 
         /* Calculate indices for left and right channels. */
         idx[c] = evoffset + azidx;
diff --git a/Alc/hrtf.h b/Alc/hrtf.h
index b814c282..756795c9 100644
--- a/Alc/hrtf.h
+++ b/Alc/hrtf.h
@@ -79,8 +79,9 @@ void GetHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azimuth,
  * 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.
+ * ordered and scaled according to the matrix input. Note the specified virtual
+ * positions should be in degrees, not radians!
  */
-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);
+void BuildBFormatHrtf(const struct Hrtf *Hrtf, DirectHrtfState *state, const ALsizei NumChannels, const AngularPoint *AmbiPoints, const ALfloat (*RESTRICT AmbiMatrix)[MAX_AMBI_COEFFS], const ALsizei AmbiCount, const ALfloat *RESTRICT AmbiOrderHFGain);
 
 #endif /* ALC_HRTF_H */
diff --git a/Alc/panning.cpp b/Alc/panning.cpp
index 9c3be106..e4a9d787 100644
--- a/Alc/panning.cpp
+++ b/Alc/panning.cpp
@@ -617,28 +617,28 @@ void InitHQPanning(ALCdevice *device, const AmbDecConf *conf, const ALsizei (&sp
 
 void InitHrtfPanning(ALCdevice *device)
 {
-    /* NOTE: azimuth goes clockwise. */
+    /* NOTE: In degrees, and azimuth goes clockwise. */
     static constexpr AngularPoint AmbiPoints[]{
-        { DEG2RAD( 35.264390f), DEG2RAD( -45.000000f) },
-        { DEG2RAD( 35.264390f), DEG2RAD(  45.000000f) },
-        { DEG2RAD( 35.264390f), DEG2RAD( 135.000000f) },
-        { DEG2RAD( 35.264390f), DEG2RAD(-135.000000f) },
-        { DEG2RAD(-35.264390f), DEG2RAD( -45.000000f) },
-        { DEG2RAD(-35.264390f), DEG2RAD(  45.000000f) },
-        { DEG2RAD(-35.264390f), DEG2RAD( 135.000000f) },
-        { DEG2RAD(-35.264390f), DEG2RAD(-135.000000f) },
-        { DEG2RAD(  0.000000f), DEG2RAD( -20.905157f) },
-        { DEG2RAD(  0.000000f), DEG2RAD(  20.905157f) },
-        { DEG2RAD(  0.000000f), DEG2RAD( 159.094843f) },
-        { DEG2RAD(  0.000000f), DEG2RAD(-159.094843f) },
-        { DEG2RAD( 20.905157f), DEG2RAD( -90.000000f) },
-        { DEG2RAD(-20.905157f), DEG2RAD( -90.000000f) },
-        { DEG2RAD(-20.905157f), DEG2RAD(  90.000000f) },
-        { DEG2RAD( 20.905157f), DEG2RAD(  90.000000f) },
-        { DEG2RAD( 69.094843f), DEG2RAD(   0.000000f) },
-        { DEG2RAD(-69.094843f), DEG2RAD(   0.000000f) },
-        { DEG2RAD(-69.094843f), DEG2RAD( 180.000000f) },
-        { DEG2RAD( 69.094843f), DEG2RAD( 180.000000f) },
+        {  35.264390f,  -45.000000f },
+        {  35.264390f,   45.000000f },
+        {  35.264390f,  135.000000f },
+        {  35.264390f, -135.000000f },
+        { -35.264390f,  -45.000000f },
+        { -35.264390f,   45.000000f },
+        { -35.264390f,  135.000000f },
+        { -35.264390f, -135.000000f },
+        {   0.000000f,  -20.905157f },
+        {   0.000000f,   20.905157f },
+        {   0.000000f,  159.094843f },
+        {   0.000000f, -159.094843f },
+        {  20.905157f,  -90.000000f },
+        { -20.905157f,  -90.000000f },
+        { -20.905157f,   90.000000f },
+        {  20.905157f,   90.000000f },
+        {  69.094843f,    0.000000f },
+        { -69.094843f,    0.000000f },
+        { -69.094843f,  180.000000f },
+        {  69.094843f,  180.000000f },
     };
     static constexpr ALfloat AmbiMatrix[][MAX_AMBI_COEFFS]{
         { 5.00000000e-02f,  5.00000000e-02f,  5.00000000e-02f,  5.00000000e-02f,  6.45497224e-02f,  6.45497224e-02f,  0.00000000e+00f,  6.45497224e-02f,  0.00000000e+00f,  1.48264644e-02f,  6.33865691e-02f,  1.01126676e-01f, -7.36485380e-02f, -1.09260065e-02f,  7.08683387e-02f, -1.01622099e-01f },