2 files changed, 10 insertions, 3 deletions
diff --git a/Alc/ALc.c b/Alc/ALc.c
index df1a3ec2..f3096b73 100644
--- a/Alc/ALc.c
+++ b/Alc/ALc.c
@@ -393,6 +393,9 @@ static FILE *LogFile;
 // Cone scalar
 ALdouble ConeScale = 0.5;
 
+// Localized Z scalar for mono sources
+ALdouble ZScale = 1.0;
+
 ///////////////////////////////////////////////////////
 
 
@@ -466,6 +469,10 @@ static void alc_init(void)
     if(str && (strcasecmp(str, "true") == 0 || strtol(str, NULL, 0) == 1))
         ConeScale = 1.0;
 
+    str = getenv("__ALSOFT_REVERSE_Z");
+    if(str && (strcasecmp(str, "true") == 0 || strtol(str, NULL, 0) == 1))
+        ZScale = -1.0;
+
     InitializeCriticalSection(&g_csMutex);
     ALTHUNK_INIT();
     ReadALConfig();
diff --git a/Alc/ALu.c b/Alc/ALu.c
index 96fa8579..dc37bcfa 100644
--- a/Alc/ALu.c
+++ b/Alc/ALu.c
@@ -822,8 +822,8 @@ ALvoid CalcSourceParams(ALsource *ALSource, const ALCcontext *ALContext)
     {
         const ALshort *hrtf_left, *hrtf_right;
 
-        GetHrtfCoeffs(atan2(Position[1], -Position[2]) * (180.0/M_PI),
-                      atan2(Position[0], -Position[2]) * (180.0/M_PI),
+        GetHrtfCoeffs(atan2(Position[1], -Position[2]*ZScale) * (180.0/M_PI),
+                      atan2(Position[0], -Position[2]*ZScale) * (180.0/M_PI),
                       &hrtf_left, &hrtf_right);
         for(i = 0;i < HRTF_LENGTH;i++)
         {
@@ -835,7 +835,7 @@ ALvoid CalcSourceParams(ALsource *ALSource, const ALCcontext *ALContext)
     }
     else
     {
-        pos = aluCart2LUTpos(-Position[2], Position[0]);
+        pos = aluCart2LUTpos(-Position[2]*ZScale, Position[0]);
         SpeakerGain = &Device->PanningLUT[MAXCHANNELS * pos];
 
         DirGain = aluSqrt(Position[0]*Position[0] + Position[2]*Position[2]);