Added volumeToMidi() helper function

include/volume.h

@@ -29,6 +29,7 @@
 #include "lmmsconfig.h"
 
 #include "lmms_basics.h"
+#include "midi.h"
 
 const volume_t MinVolume = 0;
 const volume_t MaxVolume = 200;
@@ -50,4 +51,9 @@ typedef struct
 } surroundVolumeVector;
 
 
+inline int volumeToMidi( volume_t vol )
+{
+	return vol * MidiMaxVelocity / DefaultVolume;
+}
+
 #endif