added instrument::applyRelease(...)

git-svn-id: https://lmms.svn.sf.net/svnroot/lmms/trunk/lmms@519 0778d3d1-df1d-0410-868b-ea421aaaa00d

include/instrument.h

@@ -49,6 +49,7 @@
 
 
 #include "plugin.h"
+#include "mixer.h"
 
 
 // forward-declarations
@@ -131,6 +132,11 @@ protected:
 		return( m_instrumentTrack );
 	}
 
+	// instruments may use this to apply a soft fade out at the end of
+	// notes - method does this only if really less or equal
+	// desiredReleaseFrames() frames are left
+	void applyRelease( sampleFrame * buf, const notePlayHandle * _n );
+
 
 private:
 	instrumentTrack * m_instrumentTrack;