Update the second-order decoder for HRTF

This uses fewer virtual speakers to help with clarity. The fewer speakers used
for the response, the less destructive phase interference there should be.

1 files changed, 45 insertions, 57 deletions

diff --git a/alc/panning.cpp b/alc/panning.cpp
index 38674f5e..1a06c264 100644
--- a/alc/panning.cpp
+++ b/alc/panning.cpp
@@ -523,10 +523,10 @@ void InitCustomPanning(ALCdevice *device, bool hqdec, const AmbDecConf *conf,
 void InitHrtfPanning(ALCdevice *device)
 {
     constexpr float PI{al::MathDefs<float>::Pi()};
-    constexpr float PI_2{al::MathDefs<float>::Pi() / 2.0f};
-    constexpr float PI_4{al::MathDefs<float>::Pi() / 4.0f};
-    constexpr float PI3_4{al::MathDefs<float>::Pi() * 3.0f / 4.0f};
-    const float CornerElev{static_cast<float>(std::atan2(1.0, std::sqrt(2.0)))};
+    constexpr float PI_2{PI / 2.0f};
+    constexpr float PI_4{PI_2 / 2.0f};
+    constexpr float PI3_4{PI_4 * 3.0f};
+    static const float CornerElev{static_cast<float>(std::atan2(1.0, std::sqrt(2.0)))};
     static const AngularPoint AmbiPoints1O[]{
         { ElevRadius{ CornerElev}, AzimRadius{ -PI_4} },
         { ElevRadius{ CornerElev}, AzimRadius{-PI3_4} },
@@ -537,32 +537,26 @@ void InitHrtfPanning(ALCdevice *device)
         { ElevRadius{-CornerElev}, AzimRadius{  PI_4} },
         { ElevRadius{-CornerElev}, AzimRadius{ PI3_4} },
     }, AmbiPoints2O[]{
-        { ElevRadius{       0.0f}, AzimRadius{  0.0f} },
-        { ElevRadius{       0.0f}, AzimRadius{    PI} },
-        { ElevRadius{       0.0f}, AzimRadius{ -PI_2} },
-        { ElevRadius{       0.0f}, AzimRadius{  PI_2} },
-        { ElevRadius{       PI_2}, AzimRadius{  0.0f} },
-        { ElevRadius{      -PI_2}, AzimRadius{  0.0f} },
-        { ElevRadius{       PI_4}, AzimRadius{ -PI_2} },
-        { ElevRadius{       PI_4}, AzimRadius{  PI_2} },
-        { ElevRadius{      -PI_4}, AzimRadius{ -PI_2} },
-        { ElevRadius{      -PI_4}, AzimRadius{  PI_2} },
-        { ElevRadius{       PI_4}, AzimRadius{  0.0f} },
-        { ElevRadius{       PI_4}, AzimRadius{    PI} },
-        { ElevRadius{      -PI_4}, AzimRadius{  0.0f} },
-        { ElevRadius{      -PI_4}, AzimRadius{    PI} },
-        { ElevRadius{       0.0f}, AzimRadius{ -PI_4} },
-        { ElevRadius{       0.0f}, AzimRadius{-PI3_4} },
-        { ElevRadius{       0.0f}, AzimRadius{  PI_4} },
-        { ElevRadius{       0.0f}, AzimRadius{ PI3_4} },
-        { ElevRadius{ CornerElev}, AzimRadius{ -PI_4} },
-        { ElevRadius{ CornerElev}, AzimRadius{-PI3_4} },
-        { ElevRadius{ CornerElev}, AzimRadius{  PI_4} },
-        { ElevRadius{ CornerElev}, AzimRadius{ PI3_4} },
-        { ElevRadius{-CornerElev}, AzimRadius{ -PI_4} },
-        { ElevRadius{-CornerElev}, AzimRadius{-PI3_4} },
-        { ElevRadius{-CornerElev}, AzimRadius{  PI_4} },
-        { ElevRadius{-CornerElev}, AzimRadius{ PI3_4} },
+        { ElevRadius{      -CornerElev}, AzimRadius{            -PI_4} },
+        { ElevRadius{      -CornerElev}, AzimRadius{           -PI3_4} },
+        { ElevRadius{       CornerElev}, AzimRadius{           -PI3_4} },
+        { ElevRadius{       CornerElev}, AzimRadius{            PI3_4} },
+        { ElevRadius{       CornerElev}, AzimRadius{             PI_4} },
+        { ElevRadius{      -CornerElev}, AzimRadius{             PI_4} },
+        { ElevRadius{      -CornerElev}, AzimRadius{            PI3_4} },
+        { ElevRadius{       CornerElev}, AzimRadius{            -PI_4} },
+        { ElevRadius{-1.205932499e+00f}, AzimRadius{            -PI_2} },
+        { ElevRadius{ 1.205932499e+00f}, AzimRadius{             PI_2} },
+        { ElevRadius{-1.205932499e+00f}, AzimRadius{             PI_2} },
+        { ElevRadius{ 1.205932499e+00f}, AzimRadius{            -PI_2} },
+        { ElevRadius{             0.0f}, AzimRadius{-1.205932499e+00f} },
+        { ElevRadius{             0.0f}, AzimRadius{-1.935660155e+00f} },
+        { ElevRadius{             0.0f}, AzimRadius{ 1.205932499e+00f} },
+        { ElevRadius{             0.0f}, AzimRadius{ 1.935660155e+00f} },
+        { ElevRadius{-3.648638281e-01f}, AzimRadius{               PI} },
+        { ElevRadius{ 3.648638281e-01f}, AzimRadius{               PI} },
+        { ElevRadius{ 3.648638281e-01f}, AzimRadius{             0.0f} },
+        { ElevRadius{-3.648638281e-01f}, AzimRadius{             0.0f} },
     };
     static const float AmbiMatrix1O[][MAX_AMBI_CHANNELS]{
         { 1.250000000e-01f,  1.250000000e-01f,  1.250000000e-01f,  1.250000000e-01f },
@@ -574,37 +568,31 @@ 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[][MAX_AMBI_CHANNELS]{
-        { 3.846153846e-02f,  0.000000000e+00f,  0.000000000e+00f,  6.661733875e-02f,  0.000000000e+00f,  0.000000000e+00f, -4.969039950e-02f,  0.000000000e+00f,  8.606629658e-02f },
-        { 3.846153846e-02f,  0.000000000e+00f,  0.000000000e+00f, -6.661733875e-02f,  0.000000000e+00f,  0.000000000e+00f, -4.969039950e-02f,  0.000000000e+00f,  8.606629658e-02f },
-        { 3.846153846e-02f,  6.661733875e-02f,  0.000000000e+00f,  0.000000000e+00f,  0.000000000e+00f,  0.000000000e+00f, -4.969039950e-02f,  0.000000000e+00f, -8.606629658e-02f },
-        { 3.846153846e-02f, -6.661733875e-02f,  0.000000000e+00f,  0.000000000e+00f,  0.000000000e+00f,  0.000000000e+00f, -4.969039950e-02f,  0.000000000e+00f, -8.606629658e-02f },
-        { 3.846153846e-02f,  0.000000000e+00f,  6.661733875e-02f,  0.000000000e+00f,  0.000000000e+00f,  0.000000000e+00f,  9.938079900e-02f,  0.000000000e+00f,  0.000000000e+00f },
-        { 3.846153846e-02f,  0.000000000e+00f, -6.661733875e-02f,  0.000000000e+00f,  0.000000000e+00f,  0.000000000e+00f,  9.938079900e-02f,  0.000000000e+00f,  0.000000000e+00f },
-        { 3.846153846e-02f,  4.710557198e-02f,  4.710557198e-02f,  0.000000000e+00f,  0.000000000e+00f,  6.834676493e-02f,  2.484519975e-02f,  0.000000000e+00f, -4.303314829e-02f },
-        { 3.846153846e-02f, -4.710557198e-02f,  4.710557198e-02f,  0.000000000e+00f,  0.000000000e+00f, -6.834676493e-02f,  2.484519975e-02f,  0.000000000e+00f, -4.303314829e-02f },
-        { 3.846153846e-02f,  4.710557198e-02f, -4.710557198e-02f,  0.000000000e+00f,  0.000000000e+00f, -6.834676493e-02f,  2.484519975e-02f,  0.000000000e+00f, -4.303314829e-02f },
-        { 3.846153846e-02f, -4.710557198e-02f, -4.710557198e-02f,  0.000000000e+00f,  0.000000000e+00f,  6.834676493e-02f,  2.484519975e-02f,  0.000000000e+00f, -4.303314829e-02f },
-        { 3.846153846e-02f,  0.000000000e+00f,  4.710557198e-02f,  4.710557198e-02f,  0.000000000e+00f,  0.000000000e+00f,  2.484519975e-02f,  6.834676493e-02f,  4.303314829e-02f },
-        { 3.846153846e-02f,  0.000000000e+00f,  4.710557198e-02f, -4.710557198e-02f,  0.000000000e+00f,  0.000000000e+00f,  2.484519975e-02f, -6.834676493e-02f,  4.303314829e-02f },
-        { 3.846153846e-02f,  0.000000000e+00f, -4.710557198e-02f,  4.710557198e-02f,  0.000000000e+00f,  0.000000000e+00f,  2.484519975e-02f, -6.834676493e-02f,  4.303314829e-02f },
-        { 3.846153846e-02f,  0.000000000e+00f, -4.710557198e-02f, -4.710557198e-02f,  0.000000000e+00f,  0.000000000e+00f,  2.484519975e-02f,  6.834676493e-02f,  4.303314829e-02f },
-        { 3.846153846e-02f,  4.710557198e-02f,  0.000000000e+00f,  4.710557198e-02f,  6.834676493e-02f,  0.000000000e+00f, -4.969039950e-02f,  0.000000000e+00f,  0.000000000e+00f },
-        { 3.846153846e-02f,  4.710557198e-02f,  0.000000000e+00f, -4.710557198e-02f, -6.834676493e-02f,  0.000000000e+00f, -4.969039950e-02f,  0.000000000e+00f,  0.000000000e+00f },
-        { 3.846153846e-02f, -4.710557198e-02f,  0.000000000e+00f,  4.710557198e-02f, -6.834676493e-02f,  0.000000000e+00f, -4.969039950e-02f,  0.000000000e+00f,  0.000000000e+00f },
-        { 3.846153846e-02f, -4.710557198e-02f,  0.000000000e+00f, -4.710557198e-02f,  6.834676493e-02f,  0.000000000e+00f, -4.969039950e-02f,  0.000000000e+00f,  0.000000000e+00f },
-        { 3.846153846e-02f,  3.846153846e-02f,  3.846153846e-02f,  3.846153846e-02f,  4.556450996e-02f,  4.556450996e-02f,  0.000000000e+00f,  4.556450996e-02f,  0.000000000e+00f },
-        { 3.846153846e-02f,  3.846153846e-02f,  3.846153846e-02f, -3.846153846e-02f, -4.556450996e-02f,  4.556450996e-02f,  0.000000000e+00f, -4.556450996e-02f,  0.000000000e+00f },
-        { 3.846153846e-02f, -3.846153846e-02f,  3.846153846e-02f,  3.846153846e-02f, -4.556450996e-02f, -4.556450996e-02f,  0.000000000e+00f,  4.556450996e-02f,  0.000000000e+00f },
-        { 3.846153846e-02f, -3.846153846e-02f,  3.846153846e-02f, -3.846153846e-02f,  4.556450996e-02f, -4.556450996e-02f,  0.000000000e+00f, -4.556450996e-02f,  0.000000000e+00f },
-        { 3.846153846e-02f,  3.846153846e-02f, -3.846153846e-02f,  3.846153846e-02f,  4.556450996e-02f, -4.556450996e-02f,  0.000000000e+00f, -4.556450996e-02f,  0.000000000e+00f },
-        { 3.846153846e-02f,  3.846153846e-02f, -3.846153846e-02f, -3.846153846e-02f, -4.556450996e-02f, -4.556450996e-02f,  0.000000000e+00f,  4.556450996e-02f,  0.000000000e+00f },
-        { 3.846153846e-02f, -3.846153846e-02f, -3.846153846e-02f,  3.846153846e-02f, -4.556450996e-02f,  4.556450996e-02f,  0.000000000e+00f, -4.556450996e-02f,  0.000000000e+00f },
-        { 3.846153846e-02f, -3.846153846e-02f, -3.846153846e-02f, -3.846153846e-02f,  4.556450996e-02f,  4.556450996e-02f,  0.000000000e+00f,  4.556450996e-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,  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 },
     };
     static const float AmbiOrderHFGain1O[MAX_AMBI_ORDER+1]{
         2.000000000e+00f, 1.154700538e+00f
     }, AmbiOrderHFGain2O[MAX_AMBI_ORDER+1]{
-        2.687419249e+00f, 2.081665999e+00f, 1.074967700e+00f
+        2.357022604e+00f, 1.825741858e+00f, 9.428090416e-01f
     };
     static const ALuint ChansPerOrder[MAX_AMBI_ORDER+1]{ 1, 3, 5, 7 };