Introduce "PRESERVE" flag to protect properties on sim reset.

[simgear.git] / simgear / sound / xmlsound.cxx

diff --git a/simgear/sound/xmlsound.cxx b/simgear/sound/xmlsound.cxx
index 2ca9cdfa8f2f6379726149264e0e4309033a8ad8..0c54798f7562612a854a63bd2676bb4b816de321 100644 (file)
--- a/simgear/sound/xmlsound.cxx
+++ b/simgear/sound/xmlsound.cxx
@@ -68,7 +68,8 @@ SGXmlSound::SGXmlSound()
     _dt_play(0.0),
     _dt_stop(0.0),
     _delay(0.0),
-    _stopping(0.0)
+    _stopping(0.0),
+    _initialized(false)
 {
 }
 
@@ -298,6 +299,13 @@ SGXmlSound::update (double dt)
    if (_property)
        curr_value = _property->getDoubleValue();
 
+   if (!_initialized)
+   {
+       // update initial value before detecting changes
+       _prev_value  = curr_value;
+       _initialized = true;
+   }
+
    // If a condition is defined, test whether it is FALSE,
    // else
    //   if a property is defined then test if it's value is FALSE