Differentiate between pitch-shift (for audio) and transpose (for MIDI). Fixes #3940.

git-svn-id: svn://localhost/ardour2/branches/3.0@9299 d708f5d6-7413-0410-9779-e7cbd77b26cf

libs/ardour/ardour/midi_model.h

@@ -261,6 +261,7 @@ public:
 	boost::shared_ptr<Evoral::Control> control_factory(const Evoral::Parameter& id);
 
 	void insert_silence_at_start (TimeType);
+	void transpose (TimeType, TimeType, int);
 
 protected:
         int resolve_overlaps_unlocked (const NotePtr, void* arg = 0);

libs/ardour/ardour/midi_region.h

@@ -109,6 +109,7 @@ class MidiRegion : public Region
 	boost::shared_ptr<const MidiModel> model() const { return midi_source()->model(); }
 
 	void fix_negative_start ();
+	void transpose (int);
 
   protected:
 	

libs/ardour/midi_model.cc

@@ -1899,3 +1899,43 @@ MidiModel::insert_silence_at_start (TimeType t)
 		apply_command_as_subcommand (s->session(), c);
 	}
 }
+
+/** Transpose notes in a time range by a given number of semitones.  Notes
+ *  will be clamped at 0 and 127 if the transposition would make them exceed
+ *  that range.
+ *
+ *  @param from Start time.
+ *  @param end End time.
+ *  @param semitones Number of semitones to transpose by (+ve is higher, -ve is lower).
+ */
+void
+MidiModel::transpose (TimeType from, TimeType to, int semitones)
+{
+	boost::shared_ptr<const MidiSource> s = midi_source ();
+	
+	NoteDiffCommand* c = new_note_diff_command (_("transpose"));
+	
+	for (Notes::iterator i = notes().begin(); i != notes().end(); ++i) {
+
+		if ((*i)->time() >= to) {
+			
+			/* finished */
+			break;
+			
+		} else if ((*i)->time() >= from) {
+
+			int new_note = (*i)->note() + semitones;
+			
+			if (new_note < 0) {
+				new_note = 0;
+			} else if (new_note > 127) {
+				new_note = 127;
+			}
+
+			c->change (*i, NoteDiffCommand::NoteNumber, (uint8_t) new_note);
+			
+		}
+	}
+
+	apply_command (s->session (), c);
+}

libs/ardour/midi_region.cc

@@ -378,3 +378,11 @@ MidiRegion::fix_negative_start ()
 	model()->insert_silence_at_start (c.from (-_start));
 	_start = 0;
 }
+
+/** Transpose the notes in this region by a given number of semitones */
+void
+MidiRegion::transpose (int semitones)
+{
+	BeatsFramesConverter c (_session.tempo_map(), _start);
+	model()->transpose (c.from (_start), c.from (_start + _length), semitones);
+}