Use a tri-state optional for the stereo output mode

4 files changed, 40 insertions, 20 deletions

diff --git a/alc/alc.cpp b/alc/alc.cpp
index 8f065bd2..2745869d 100644
--- a/alc/alc.cpp
+++ b/alc/alc.cpp
@@ -1522,8 +1522,7 @@ ALCenum UpdateDeviceParams(ALCdevice *device, const int *attrList)
 {
     ALCenum gainLimiter{device->LimiterState};
     uint new_sends{device->NumAuxSends};
-    al::optional<bool> hrtfreq{};
-    al::optional<bool> uhjreq{};
+    al::optional<StereoEncoding> stereomode{};
     DevFmtChannels oldChans;
     DevFmtType oldType;
     int hrtf_id{-1};
@@ -1546,6 +1545,7 @@ ALCenum UpdateDeviceParams(ALCdevice *device, const int *attrList)
         al::optional<DevFmtType> opttype;
         al::optional<DevAmbiLayout> optlayout;
         al::optional<DevAmbiScaling> optscale;
+        al::optional<bool> opthrtf;
 
         uint aorder{0u};
         uint freq{0u};
@@ -1608,11 +1608,11 @@ ALCenum UpdateDeviceParams(ALCdevice *device, const int *attrList)
             case ALC_HRTF_SOFT:
                 TRACE_ATTR(ALC_HRTF_SOFT, attrList[attrIdx + 1]);
                 if(attrList[attrIdx + 1] == ALC_FALSE)
-                    hrtfreq = al::make_optional(false);
+                    opthrtf = al::make_optional(false);
                 else if(attrList[attrIdx + 1] == ALC_TRUE)
-                    hrtfreq = al::make_optional(true);
+                    opthrtf = al::make_optional(true);
                 else
-                    hrtfreq = al::nullopt;
+                    opthrtf = al::nullopt;
                 break;
 
             case ALC_HRTF_ID_SOFT:
@@ -1663,6 +1663,12 @@ ALCenum UpdateDeviceParams(ALCdevice *device, const int *attrList)
 
         UpdateClockBase(device);
 
+        if(!stereomode && opthrtf)
+        {
+            auto mode = *opthrtf ? StereoEncoding::Hrtf : StereoEncoding::Normal;
+            stereomode = al::make_optional(mode);
+        }
+
         if(loopback)
         {
             device->Frequency = freq;
@@ -1758,7 +1764,7 @@ ALCenum UpdateDeviceParams(ALCdevice *device, const int *attrList)
     device->DitherSeed = DitherRNGSeed;
 
     /*************************************************************************
-     * Update device format request if HRTF is requested
+     * Update device format request if HRTF or UHJ is requested
      */
     device->mHrtfStatus = ALC_HRTF_DISABLED_SOFT;
     if(device->Type != DeviceType::Loopback)
@@ -1767,15 +1773,18 @@ ALCenum UpdateDeviceParams(ALCdevice *device, const int *attrList)
         {
             const char *hrtf{hrtfopt->c_str()};
             if(al::strcasecmp(hrtf, "true") == 0)
-                hrtfreq = al::make_optional(true);
+                stereomode = al::make_optional(StereoEncoding::Hrtf);
             else if(al::strcasecmp(hrtf, "false") == 0)
-                hrtfreq = al::make_optional(false);
+            {
+                if(!stereomode || *stereomode == StereoEncoding::Hrtf)
+                    stereomode = al::make_optional(StereoEncoding::Normal);
+            }
             else if(al::strcasecmp(hrtf, "auto") != 0)
                 ERR("Unexpected hrtf value: %s\n", hrtf);
         }
 
-        /* If the app or user wants HRTF, try to set stereo playback. */
-        if(hrtfreq && hrtfreq.value())
+        /* If the app or user wants HRTF or UHJ, try to set stereo playback. */
+        if(stereomode && *stereomode != StereoEncoding::Normal)
         {
             device->FmtChans = DevFmtStereo;
             device->Flags.set(ChannelsRequest);
@@ -1852,16 +1861,18 @@ ALCenum UpdateDeviceParams(ALCdevice *device, const int *attrList)
         if(auto encopt = device->configValue<std::string>(nullptr, "stereo-encoding"))
         {
             const char *mode{encopt->c_str()};
-            if(al::strcasecmp(mode, "uhj") == 0)
-                uhjreq = al::make_optional(true);
-            else if(al::strcasecmp(mode, "panpot") == 0)
-                uhjreq = al::make_optional(false);
+            if(al::strcasecmp(mode, "panpot") == 0)
+                stereomode = al::make_optional(StereoEncoding::Normal);
+            else if(al::strcasecmp(mode, "uhj") == 0)
+                stereomode = al::make_optional(StereoEncoding::Uhj);
+            else if(al::strcasecmp(mode, "hrtf") == 0)
+                stereomode = al::make_optional(StereoEncoding::Hrtf);
             else
                 ERR("Unexpected stereo-encoding: %s\n", mode);
         }
     }
 
-    aluInitRenderer(device, hrtf_id, hrtfreq, uhjreq.value_or(false));
+    aluInitRenderer(device, hrtf_id, stereomode);
 
     device->NumAuxSends = new_sends;
     TRACE("Max sources: %d (%d + %d), effect slots: %d, sends: %d\n",
diff --git a/alc/alu.h b/alc/alu.h
index addf6942..7b92bba1 100644
--- a/alc/alu.h
+++ b/alc/alu.h
@@ -7,6 +7,8 @@ struct ALCcontext;
 struct ALCdevice;
 struct EffectSlot;
 
+enum class StereoEncoding : unsigned char;
+
 
 constexpr float GainMixMax{1000.0f}; /* +60dB */
 
@@ -20,7 +22,7 @@ void aluInit(void);
  * Set up the appropriate panning method and mixing method given the device
  * properties.
  */
-void aluInitRenderer(ALCdevice *device, int hrtf_id, al::optional<bool> hrtfreq, bool useuhj);
+void aluInitRenderer(ALCdevice *device, int hrtf_id, al::optional<StereoEncoding> stereomode);
 
 void aluInitEffectPanning(EffectSlot *slot, ALCcontext *context);
 
diff --git a/alc/panning.cpp b/alc/panning.cpp
index 151e86e8..83b6716d 100644
--- a/alc/panning.cpp
+++ b/alc/panning.cpp
@@ -822,7 +822,7 @@ void InitUhjPanning(ALCdevice *device)
 
 } // namespace
 
-void aluInitRenderer(ALCdevice *device, int hrtf_id, al::optional<bool> hrtfreq, bool useuhj)
+void aluInitRenderer(ALCdevice *device, int hrtf_id, al::optional<StereoEncoding> stereomode)
 {
     /* Hold the HRTF the device last used, in case it's used again. */
     HrtfStorePtr old_hrtf{std::move(device->mHrtf)};
@@ -837,7 +837,7 @@ void aluInitRenderer(ALCdevice *device, int hrtf_id, al::optional<bool> hrtfreq,
     if(device->FmtChans != DevFmtStereo)
     {
         old_hrtf = nullptr;
-        if(hrtfreq && hrtfreq.value())
+        if(stereomode && *stereomode == StereoEncoding::Hrtf)
             device->mHrtfStatus = ALC_HRTF_UNSUPPORTED_FORMAT_SOFT;
 
         const char *layout{nullptr};
@@ -925,7 +925,8 @@ void aluInitRenderer(ALCdevice *device, int hrtf_id, al::optional<bool> hrtfreq,
     /* If there's no request for HRTF or UHJ and the device is headphones, or
      * if HRTF is explicitly requested, try to enable it.
      */
-    if((!hrtfreq && !useuhj && device->Flags.test(DirectEar)) || hrtfreq.value_or(false))
+    if((!stereomode && device->Flags.test(DirectEar))
+        || (stereomode && *stereomode == StereoEncoding::Hrtf))
     {
         if(device->mHrtfList.empty())
             device->enumerateHrtfs();
@@ -973,7 +974,7 @@ void aluInitRenderer(ALCdevice *device, int hrtf_id, al::optional<bool> hrtfreq,
     }
     old_hrtf = nullptr;
 
-    if(useuhj)
+    if(stereomode && *stereomode == StereoEncoding::Uhj)
     {
         device->mUhjEncoder = std::make_unique<UhjEncoder>();
         TRACE("UHJ enabled\n");
diff --git a/core/device.h b/core/device.h
index 5e2a3bfd..88d146aa 100644
--- a/core/device.h
+++ b/core/device.h
@@ -57,6 +57,12 @@ enum class RenderMode : unsigned char {
     Hrtf
 };
 
+enum class StereoEncoding : unsigned char {
+    Normal,
+    Uhj,
+    Hrtf
+};
+
 
 struct InputRemixMap {
     struct TargetMix { Channel channel; float mix; };