Add helpers to get the channel count from an ambisonic order

3 files changed, 20 insertions, 16 deletions

diff --git a/Alc/ambidefs.h b/Alc/ambidefs.h
index 2b04d70b..bdecfae0 100644
--- a/Alc/ambidefs.h
+++ b/Alc/ambidefs.h
@@ -8,7 +8,9 @@
  * order has 9, third-order has 16, and fourth-order has 25.
  */
 #define MAX_AMBI_ORDER 3
-#define MAX_AMBI_CHANNELS ((MAX_AMBI_ORDER+1) * (MAX_AMBI_ORDER+1))
+constexpr inline size_t AmbiChannelsFromOrder(size_t order) noexcept
+{ return (order+1) * (order+1); }
+#define MAX_AMBI_CHANNELS AmbiChannelsFromOrder(MAX_AMBI_ORDER)
 
 /* A bitmask of ambisonic channels for 0 to 4th order. This only specifies up
  * to 4th order, which is the highest order a 32-bit mask value can specify (a
@@ -30,7 +32,9 @@
  * representation. This is 2 per each order above zero-order, plus 1 for zero-
  * order. Or simply, o*2 + 1.
  */
-#define MAX_AMBI2D_CHANNELS (MAX_AMBI_ORDER*2 + 1)
+constexpr inline size_t Ambi2DChannelsFromOrder(size_t order) noexcept
+{ return order*2 + 1; }
+#define MAX_AMBI2D_CHANNELS Ambi2DChannelsFromOrder(MAX_AMBI_CHANNELS)
 
 
 /* NOTE: These are scale factors as applied to Ambisonics content. Decoder
diff --git a/Alc/bformatdec.cpp b/Alc/bformatdec.cpp
index d735b94c..efac73ca 100644
--- a/Alc/bformatdec.cpp
+++ b/Alc/bformatdec.cpp
@@ -92,17 +92,17 @@ void BFormatDec::reset(const AmbDecConf *conf, bool allow_2band, ALsizei inchans
 
     const bool periphonic{(conf->ChanMask&AMBI_PERIPHONIC_MASK) != 0};
     const std::array<float,MAX_AMBI_CHANNELS> &coeff_scale = GetAmbiScales(conf->CoeffScale);
-    const ALsizei coeff_count{periphonic ? MAX_AMBI_CHANNELS : MAX_AMBI2D_CHANNELS};
+    const size_t coeff_count{periphonic ? MAX_AMBI_CHANNELS : MAX_AMBI2D_CHANNELS};
 
     if(!mDualBand)
     {
         for(size_t i{0u};i < conf->Speakers.size();i++)
         {
             ALfloat (&mtx)[MAX_AMBI_CHANNELS] = mMatrix.Single[chanmap[i]];
-            for(ALsizei j{0},k{0};j < coeff_count;j++)
+            for(size_t j{0},k{0};j < coeff_count;j++)
             {
-                const ALsizei l{periphonic ? j : AmbiIndex::From2D[j]};
-                if(!(conf->ChanMask&(1<<l))) continue;
+                const size_t l{periphonic ? j : AmbiIndex::From2D[j]};
+                if(!(conf->ChanMask&(1u<<l))) continue;
                 mtx[j] = conf->HFMatrix[i][k] / coeff_scale[l] *
                     ((l>=9) ? conf->HFOrderGain[3] :
                     (l>=4) ? conf->HFOrderGain[2] :
@@ -120,10 +120,10 @@ void BFormatDec::reset(const AmbDecConf *conf, bool allow_2band, ALsizei inchans
         for(size_t i{0u};i < conf->Speakers.size();i++)
         {
             ALfloat (&mtx)[sNumBands][MAX_AMBI_CHANNELS] = mMatrix.Dual[chanmap[i]];
-            for(ALsizei j{0},k{0};j < coeff_count;j++)
+            for(size_t j{0},k{0};j < coeff_count;j++)
             {
-                const ALsizei l{periphonic ? j : AmbiIndex::From2D[j]};
-                if(!(conf->ChanMask&(1<<l))) continue;
+                const size_t l{periphonic ? j : AmbiIndex::From2D[j]};
+                if(!(conf->ChanMask&(1u<<l))) continue;
                 mtx[sHFBand][j] = conf->HFMatrix[i][k] / coeff_scale[l] *
                     ((l>=9) ? conf->HFOrderGain[3] :
                     (l>=4) ? conf->HFOrderGain[2] :
diff --git a/Alc/panning.cpp b/Alc/panning.cpp
index af480184..7e8accff 100644
--- a/Alc/panning.cpp
+++ b/Alc/panning.cpp
@@ -496,7 +496,7 @@ void InitCustomPanning(ALCdevice *device, const AmbDecConf *conf, const ALsizei
     ALsizei count;
     if((conf->ChanMask&AMBI_PERIPHONIC_MASK))
     {
-        count = (order+1) * (order+1);
+        count = AmbiChannelsFromOrder(order);
         std::transform(AmbiIndex::From3D.begin(), AmbiIndex::From3D.begin()+count,
             std::begin(device->Dry.AmbiMap),
             [](const ALsizei &index) noexcept { return BFChannelConfig{1.0f, index}; }
@@ -504,7 +504,7 @@ void InitCustomPanning(ALCdevice *device, const AmbDecConf *conf, const ALsizei
     }
     else
     {
-        count = order*2 + 1;
+        count = Ambi2DChannelsFromOrder(order);
         std::transform(AmbiIndex::From2D.begin(), AmbiIndex::From2D.begin()+count,
             std::begin(device->Dry.AmbiMap),
             [](const ALsizei &index) noexcept { return BFChannelConfig{1.0f, index}; }
@@ -567,7 +567,7 @@ void InitHQPanning(ALCdevice *device, const AmbDecConf *conf, const ALsizei (&sp
     ALsizei count;
     if((conf->ChanMask&AMBI_PERIPHONIC_MASK))
     {
-        count = (order+1) * (order+1);
+        count = AmbiChannelsFromOrder(order);
         std::transform(AmbiIndex::From3D.begin(), AmbiIndex::From3D.begin()+count,
             std::begin(device->Dry.AmbiMap),
             [](const ALsizei &index) noexcept { return BFChannelConfig{1.0f, index}; }
@@ -575,7 +575,7 @@ void InitHQPanning(ALCdevice *device, const AmbDecConf *conf, const ALsizei (&sp
     }
     else
     {
-        count = order*2 + 1;
+        count = Ambi2DChannelsFromOrder(order);
         std::transform(AmbiIndex::From2D.begin(), AmbiIndex::From2D.begin()+count,
             std::begin(device->Dry.AmbiMap),
             [](const ALsizei &index) noexcept { return BFChannelConfig{1.0f, index}; }
@@ -714,7 +714,7 @@ void InitHrtfPanning(ALCdevice *device)
     }
     device->mAmbiOrder = ambi_order;
 
-    const ALsizei count{(ambi_order+1) * (ambi_order+1)};
+    const size_t count{AmbiChannelsFromOrder(ambi_order)};
     device->mHrtfState = DirectHrtfState::Create(count);
 
     std::transform(std::begin(IndexMap), std::begin(IndexMap)+count, std::begin(device->Dry.AmbiMap),
@@ -749,9 +749,9 @@ void InitHrtfPanning(ALCdevice *device)
 void InitUhjPanning(ALCdevice *device)
 {
     /* UHJ is always 2D first-order. */
-    static constexpr ALsizei count{3};
+    static constexpr size_t count{Ambi2DChannelsFromOrder(1)};
 
-    device->mAmbiOrder = (count-1) / 2;
+    device->mAmbiOrder = 1;
 
     auto acnmap_end = AmbiIndex::FromFuMa.begin() + count;
     std::transform(AmbiIndex::FromFuMa.begin(), acnmap_end, std::begin(device->Dry.AmbiMap),