From 5d08563975ff07696f4e0ac184d7a0f74f70dbc6 Mon Sep 17 00:00:00 2001
From: Chris Robinson <chris.kcat@gmail.com>
Date: Sun, 18 Mar 2012 08:20:08 -0700
Subject: [PATCH] Handle very small speed of sound values

---
 Alc/ALu.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/Alc/ALu.c b/Alc/ALu.c
index fc0980e8..4a0d4d38 100644
--- a/Alc/ALu.c
+++ b/Alc/ALu.c
@@ -636,10 +636,16 @@ ALvoid CalcSourceParams(ALsource *ALSource, const ALCcontext *ALContext)
     }
 
     // Calculate Velocity
-    if(DopplerFactor > 0.0f && SpeedOfSound > 0.5f)
+    if(DopplerFactor > 0.0f)
     {
         ALfloat VSS, VLS;
 
+        if(SpeedOfSound < 1.0f)
+        {
+            DopplerFactor *= 1.0f/SpeedOfSound;
+            SpeedOfSound   = 1.0f;
+        }
+
         VSS = aluDotproduct(Velocity, SourceToListener) * DopplerFactor;
         VLS = aluDotproduct(ListenerVel, SourceToListener) * DopplerFactor;