InstrumentTrack, NotePlayHandle: fixed note detuning processing

Note detuning did not work properly for patterns starting after the
first bar in the song editor. This has been fixed by introducing
additional information about parent's song-global offset to
NotePlayHandle objects.

Closes #3462555.

include/note_play_handle.h

@@ -2,7 +2,7 @@
  * note_play_handle.h - declaration of class notePlayHandle which is needed
  *                      by LMMS-Play-Engine
  *
- * Copyright (c) 2004-2010 Tobias Doerffel <tobydox/at/users.sourceforge.net>
+ * Copyright (c) 2004-2012 Tobias Doerffel <tobydox/at/users.sourceforge.net>
  * 
  * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
  *
@@ -192,6 +192,16 @@ public:
 	void processMidiTime( const midiTime & _time );
 	void resize( const bpm_t _new_tempo );
 
+	void setSongGlobalParentOffset( const midiTime &offset )
+	{
+		m_songGlobalParentOffset = offset;
+	}
+
+	const midiTime &songGlobalParentOffset() const
+	{
+		return m_songGlobalParentOffset;
+	}
+
 #ifdef LMMS_SINGERBOT_SUPPORT
 	int patternIndex()
 	{
@@ -263,6 +273,7 @@ private:
 	float m_unpitchedFrequency;
 
 	BaseDetuning * m_baseDetuning;
+	midiTime m_songGlobalParentOffset;
 
 } ;