Update the HRTF second-order ambisonic decoder

This only needs 14 virtual channels instead of 20.

1 files changed, 27 insertions, 42 deletions

diff --git a/alc/panning.cpp b/alc/panning.cpp
index eefcc867..17475160 100644
--- a/alc/panning.cpp
+++ b/alc/panning.cpp
@@ -662,10 +662,7 @@ void InitHrtfPanning(ALCdevice *device)
     constexpr float Deg_90{Deg180 / 2.0f /* 90 degrees*/};
     constexpr float Deg_45{Deg_90 / 2.0f /* 45 degrees*/};
     constexpr float Deg135{Deg_45 * 3.0f /*135 degrees*/};
-    constexpr float Deg_35{6.154797086e-01f /* 35~ 36 degrees*/};
-    constexpr float Deg_69{1.205932499e+00f /* 69~ 70 degrees*/};
-    constexpr float Deg111{1.935660155e+00f /*110~111 degrees*/};
-    constexpr float Deg_21{3.648638281e-01f /* 20~ 21 degrees*/};
+    constexpr float Deg_35{6.154797087e-01f /* 35~ 36 degrees*/};
     static const AngularPoint AmbiPoints1O[]{
         { EvRadians{ Deg_35}, AzRadians{-Deg_45} },
         { EvRadians{ Deg_35}, AzRadians{-Deg135} },
@@ -676,26 +673,20 @@ void InitHrtfPanning(ALCdevice *device)
         { EvRadians{-Deg_35}, AzRadians{ Deg_45} },
         { EvRadians{-Deg_35}, AzRadians{ Deg135} },
     }, AmbiPoints2O[]{
-        { EvRadians{-Deg_35}, AzRadians{-Deg_45} },
-        { EvRadians{-Deg_35}, AzRadians{-Deg135} },
+        { EvRadians{   0.0f}, AzRadians{   0.0f} },
+        { EvRadians{   0.0f}, AzRadians{ Deg180} },
+        { EvRadians{   0.0f}, AzRadians{-Deg_90} },
+        { EvRadians{   0.0f}, AzRadians{ Deg_90} },
+        { EvRadians{ Deg_90}, AzRadians{   0.0f} },
+        { EvRadians{-Deg_90}, AzRadians{   0.0f} },
+        { EvRadians{ Deg_35}, AzRadians{-Deg_45} },
         { EvRadians{ Deg_35}, AzRadians{-Deg135} },
-        { EvRadians{ Deg_35}, AzRadians{ Deg135} },
         { EvRadians{ Deg_35}, AzRadians{ Deg_45} },
+        { EvRadians{ Deg_35}, AzRadians{ Deg135} },
+        { EvRadians{-Deg_35}, AzRadians{-Deg_45} },
+        { EvRadians{-Deg_35}, AzRadians{-Deg135} },
         { EvRadians{-Deg_35}, AzRadians{ Deg_45} },
         { EvRadians{-Deg_35}, AzRadians{ Deg135} },
-        { EvRadians{ Deg_35}, AzRadians{-Deg_45} },
-        { EvRadians{-Deg_69}, AzRadians{-Deg_90} },
-        { EvRadians{ Deg_69}, AzRadians{ Deg_90} },
-        { EvRadians{-Deg_69}, AzRadians{ Deg_90} },
-        { EvRadians{ Deg_69}, AzRadians{-Deg_90} },
-        { EvRadians{   0.0f}, AzRadians{-Deg_69} },
-        { EvRadians{   0.0f}, AzRadians{-Deg111} },
-        { EvRadians{   0.0f}, AzRadians{ Deg_69} },
-        { EvRadians{   0.0f}, AzRadians{ Deg111} },
-        { EvRadians{-Deg_21}, AzRadians{ Deg180} },
-        { EvRadians{ Deg_21}, AzRadians{ Deg180} },
-        { EvRadians{ Deg_21}, AzRadians{   0.0f} },
-        { EvRadians{-Deg_21}, AzRadians{   0.0f} },
     };
     static const float AmbiMatrix1O[][MaxAmbiChannels]{
         { 1.250000000e-01f,  1.250000000e-01f,  1.250000000e-01f,  1.250000000e-01f },
@@ -707,33 +698,27 @@ void InitHrtfPanning(ALCdevice *device)
         { 1.250000000e-01f, -1.250000000e-01f, -1.250000000e-01f,  1.250000000e-01f },
         { 1.250000000e-01f, -1.250000000e-01f, -1.250000000e-01f, -1.250000000e-01f },
     }, AmbiMatrix2O[][MaxAmbiChannels]{
-        { 5.000000000e-02f,  5.000000000e-02f, -5.000000000e-02f,  5.000000000e-02f,  6.454972244e-02f, -6.454972244e-02f,  0.000000000e+00f, -6.454972244e-02f,  0.000000000e+00f },
-        { 5.000000000e-02f,  5.000000000e-02f, -5.000000000e-02f, -5.000000000e-02f, -6.454972244e-02f, -6.454972244e-02f,  0.000000000e+00f,  6.454972244e-02f,  0.000000000e+00f },
-        { 5.000000000e-02f,  5.000000000e-02f,  5.000000000e-02f, -5.000000000e-02f, -6.454972244e-02f,  6.454972244e-02f,  0.000000000e+00f, -6.454972244e-02f,  0.000000000e+00f },
-        { 5.000000000e-02f, -5.000000000e-02f,  5.000000000e-02f, -5.000000000e-02f,  6.454972244e-02f, -6.454972244e-02f,  0.000000000e+00f, -6.454972244e-02f,  0.000000000e+00f },
-        { 5.000000000e-02f, -5.000000000e-02f,  5.000000000e-02f,  5.000000000e-02f, -6.454972244e-02f, -6.454972244e-02f,  0.000000000e+00f,  6.454972244e-02f,  0.000000000e+00f },
-        { 5.000000000e-02f, -5.000000000e-02f, -5.000000000e-02f,  5.000000000e-02f, -6.454972244e-02f,  6.454972244e-02f,  0.000000000e+00f, -6.454972244e-02f,  0.000000000e+00f },
-        { 5.000000000e-02f, -5.000000000e-02f, -5.000000000e-02f, -5.000000000e-02f,  6.454972244e-02f,  6.454972244e-02f,  0.000000000e+00f,  6.454972244e-02f,  0.000000000e+00f },
-        { 5.000000000e-02f,  5.000000000e-02f,  5.000000000e-02f,  5.000000000e-02f,  6.454972244e-02f,  6.454972244e-02f,  0.000000000e+00f,  6.454972244e-02f,  0.000000000e+00f },
-        { 5.000000000e-02f,  3.090169944e-02f, -8.090169944e-02f,  0.000000000e+00f,  0.000000000e+00f, -6.454972244e-02f,  9.045084972e-02f,  0.000000000e+00f, -1.232790000e-02f },
-        { 5.000000000e-02f, -3.090169944e-02f,  8.090169944e-02f,  0.000000000e+00f,  0.000000000e+00f, -6.454972244e-02f,  9.045084972e-02f,  0.000000000e+00f, -1.232790000e-02f },
-        { 5.000000000e-02f, -3.090169944e-02f, -8.090169944e-02f,  0.000000000e+00f,  0.000000000e+00f,  6.454972244e-02f,  9.045084972e-02f,  0.000000000e+00f, -1.232790000e-02f },
-        { 5.000000000e-02f,  3.090169944e-02f,  8.090169944e-02f,  0.000000000e+00f,  0.000000000e+00f,  6.454972244e-02f,  9.045084972e-02f,  0.000000000e+00f, -1.232790000e-02f },
-        { 5.000000000e-02f,  8.090169944e-02f,  0.000000000e+00f,  3.090169944e-02f,  6.454972244e-02f,  0.000000000e+00f, -5.590169944e-02f,  0.000000000e+00f, -7.216878365e-02f },
-        { 5.000000000e-02f,  8.090169944e-02f,  0.000000000e+00f, -3.090169944e-02f, -6.454972244e-02f,  0.000000000e+00f, -5.590169944e-02f,  0.000000000e+00f, -7.216878365e-02f },
-        { 5.000000000e-02f, -8.090169944e-02f,  0.000000000e+00f,  3.090169944e-02f, -6.454972244e-02f,  0.000000000e+00f, -5.590169944e-02f,  0.000000000e+00f, -7.216878365e-02f },
-        { 5.000000000e-02f, -8.090169944e-02f,  0.000000000e+00f, -3.090169944e-02f,  6.454972244e-02f,  0.000000000e+00f, -5.590169944e-02f,  0.000000000e+00f, -7.216878365e-02f },
-        { 5.000000000e-02f,  0.000000000e+00f, -3.090169944e-02f, -8.090169944e-02f,  0.000000000e+00f,  0.000000000e+00f, -3.454915028e-02f,  6.454972244e-02f,  8.449668365e-02f },
-        { 5.000000000e-02f,  0.000000000e+00f,  3.090169944e-02f, -8.090169944e-02f,  0.000000000e+00f,  0.000000000e+00f, -3.454915028e-02f, -6.454972244e-02f,  8.449668365e-02f },
-        { 5.000000000e-02f,  0.000000000e+00f,  3.090169944e-02f,  8.090169944e-02f,  0.000000000e+00f,  0.000000000e+00f, -3.454915028e-02f,  6.454972244e-02f,  8.449668365e-02f },
-        { 5.000000000e-02f,  0.000000000e+00f, -3.090169944e-02f,  8.090169944e-02f,  0.000000000e+00f,  0.000000000e+00f, -3.454915028e-02f, -6.454972244e-02f,  8.449668365e-02f },
+        { 7.142857143e-02f,  0.000000000e+00f,  0.000000000e+00f,  1.237179148e-01f,  0.000000000e+00f,  0.000000000e+00f, -7.453559925e-02f,  0.000000000e+00f,  1.290994449e-01f, },
+        { 7.142857143e-02f,  0.000000000e+00f,  0.000000000e+00f, -1.237179148e-01f,  0.000000000e+00f,  0.000000000e+00f, -7.453559925e-02f,  0.000000000e+00f,  1.290994449e-01f, },
+        { 7.142857143e-02f,  1.237179148e-01f,  0.000000000e+00f,  0.000000000e+00f,  0.000000000e+00f,  0.000000000e+00f, -7.453559925e-02f,  0.000000000e+00f, -1.290994449e-01f, },
+        { 7.142857143e-02f, -1.237179148e-01f,  0.000000000e+00f,  0.000000000e+00f,  0.000000000e+00f,  0.000000000e+00f, -7.453559925e-02f,  0.000000000e+00f, -1.290994449e-01f, },
+        { 7.142857143e-02f,  0.000000000e+00f,  1.237179148e-01f,  0.000000000e+00f,  0.000000000e+00f,  0.000000000e+00f,  1.490711985e-01f,  0.000000000e+00f,  0.000000000e+00f, },
+        { 7.142857143e-02f,  0.000000000e+00f, -1.237179148e-01f,  0.000000000e+00f,  0.000000000e+00f,  0.000000000e+00f,  1.490711985e-01f,  0.000000000e+00f,  0.000000000e+00f, },
+        { 7.142857143e-02f,  7.142857143e-02f,  7.142857143e-02f,  7.142857143e-02f,  9.682458366e-02f,  9.682458366e-02f,  0.000000000e+00f,  9.682458366e-02f,  0.000000000e+00f, },
+        { 7.142857143e-02f,  7.142857143e-02f,  7.142857143e-02f, -7.142857143e-02f, -9.682458366e-02f,  9.682458366e-02f,  0.000000000e+00f, -9.682458366e-02f,  0.000000000e+00f, },
+        { 7.142857143e-02f, -7.142857143e-02f,  7.142857143e-02f,  7.142857143e-02f, -9.682458366e-02f, -9.682458366e-02f,  0.000000000e+00f,  9.682458366e-02f,  0.000000000e+00f, },
+        { 7.142857143e-02f, -7.142857143e-02f,  7.142857143e-02f, -7.142857143e-02f,  9.682458366e-02f, -9.682458366e-02f,  0.000000000e+00f, -9.682458366e-02f,  0.000000000e+00f, },
+        { 7.142857143e-02f,  7.142857143e-02f, -7.142857143e-02f,  7.142857143e-02f,  9.682458366e-02f, -9.682458366e-02f,  0.000000000e+00f, -9.682458366e-02f,  0.000000000e+00f, },
+        { 7.142857143e-02f,  7.142857143e-02f, -7.142857143e-02f, -7.142857143e-02f, -9.682458366e-02f, -9.682458366e-02f,  0.000000000e+00f,  9.682458366e-02f,  0.000000000e+00f, },
+        { 7.142857143e-02f, -7.142857143e-02f, -7.142857143e-02f,  7.142857143e-02f, -9.682458366e-02f,  9.682458366e-02f,  0.000000000e+00f, -9.682458366e-02f,  0.000000000e+00f, },
+        { 7.142857143e-02f, -7.142857143e-02f, -7.142857143e-02f, -7.142857143e-02f,  9.682458366e-02f,  9.682458366e-02f,  0.000000000e+00f,  9.682458366e-02f,  0.000000000e+00f, },
     };
     static const float AmbiOrderHFGain1O[MaxAmbiOrder+1]{
-        2.000000000e+00f, 1.154700538e+00f
+        /*ENRGY*/ 2.000000000e+00f, 1.154700538e+00f
     }, AmbiOrderHFGain2O[MaxAmbiOrder+1]{
+        /*ENRGY 2.357022604e+00f, 1.825741858e+00f, 9.428090416e-01f*/
         /*AMP   1.000000000e+00f, 7.745966692e-01f, 4.000000000e-01f*/
         /*RMS*/ 9.128709292e-01f, 7.071067812e-01f, 3.651483717e-01f
-        /*ENRGY 2.357022604e+00f, 1.825741858e+00f, 9.428090416e-01f*/
     };
 
     static_assert(al::size(AmbiPoints1O) == al::size(AmbiMatrix1O), "First-Order Ambisonic HRTF mismatch");