From 34a4eea0d579f0fdb5d5fb460a1505fac582d8ce Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Tue, 4 Mar 2025 17:07:16 +0100
Subject: [PATCH] Step-edit: improve overlapping note handling

* no need to shift notes during normal edit
* prevent duplicate (overlapping) chord notes
---
 gtk2_ardour/step_editor.cc | 48 +++++++++++++++++++++-----------------
 gtk2_ardour/step_editor.h  |  9 +++----
 2 files changed, 31 insertions(+), 26 deletions(-)

diff --git a/gtk2_ardour/step_editor.cc b/gtk2_ardour/step_editor.cc
index e8c150aac0..d1349a4599 100644
--- a/gtk2_ardour/step_editor.cc
+++ b/gtk2_ardour/step_editor.cc
@@ -66,9 +66,9 @@ StepEditor::start_step_editing ()
 	_step_edit_chord_duration = Temporal::Beats();
 	step_edit_region.reset ();
 	step_edit_region_view = 0;
-	last_added_pitch = -1;
-	last_added_end = Temporal::Beats();
+	_last_added_beat = Temporal::Beats();
 	_tracker.reset ();
+	_chord_tracker.reset ();
 
 	resync_step_edit_position ();
 	prepare_step_edit_region ();
@@ -212,10 +212,7 @@ StepEditor::check_step_edit ()
 
 		/* note-off w/chord .. move to next beat */
 		if ((buf[0] & 0xf0) == MIDI_CMD_NOTE_OFF && size == 3 && _tracker.empty ()) {
-			if (step_edit_region_view && _step_edit_within_chord) {
-				step_edit_beat_pos += _step_edit_chord_duration;
-				step_edit_region_view->move_step_edit_cursor (step_edit_beat_pos);
-			}
+			step_to_next_chord ();
 		}
 	}
 	delete [] buf;
@@ -303,20 +300,18 @@ StepEditor::step_add_note (uint8_t channel, uint8_t pitch, uint8_t velocity, Tem
 	Temporal::Beats at = step_edit_beat_pos;
 	Temporal::Beats len = beat_duration;
 
-	if ((last_added_pitch >= 0) && (pitch == last_added_pitch) && (last_added_end == step_edit_beat_pos)) {
-
-		/* avoid any apparent note overlap - move the start of this note
-		   up by 1 tick from where the last note ended
-		*/
-
-		at  += Temporal::Beats::ticks(1);
-		len -= Temporal::Beats::ticks(1);
+	if (_last_added_beat != step_edit_beat_pos) {
+		_chord_tracker.reset ();
+		_last_added_beat = step_edit_beat_pos;
 	}
 
-	step_edit_region_view->step_add_note (channel, pitch, velocity, at, len);
+	if (!_step_edit_within_chord || !_chord_tracker.active (pitch, channel)) {
+		step_edit_region_view->step_add_note (channel, pitch, velocity, at, len);
+	}
 
-	last_added_pitch = pitch;
-	last_added_end = at+len;
+	if (_step_edit_within_chord) {
+		_chord_tracker.add (pitch, channel);
+	}
 
 	if (_step_edit_triplet_countdown > 0) {
 		_step_edit_triplet_countdown--;
@@ -330,7 +325,6 @@ StepEditor::step_add_note (uint8_t channel, uint8_t pitch, uint8_t velocity, Tem
 		step_edit_beat_pos += beat_duration;
 		step_edit_region_view->move_step_edit_cursor (step_edit_beat_pos);
 	} else {
-		step_edit_beat_pos += Temporal::Beats::ticks(1); // tiny, but no longer overlapping
 		_step_edit_chord_duration = max (_step_edit_chord_duration, beat_duration);
 	}
 
@@ -339,6 +333,17 @@ StepEditor::step_add_note (uint8_t channel, uint8_t pitch, uint8_t velocity, Tem
 	return 0;
 }
 
+void
+StepEditor::step_to_next_chord ()
+{
+	if (!step_edit_region_view || !_step_edit_within_chord) {
+		return;
+	}
+	step_edit_beat_pos += _step_edit_chord_duration;
+	step_edit_region_view->move_step_edit_cursor (step_edit_beat_pos);
+	_chord_tracker.reset ();
+}
+
 void
 StepEditor::set_step_edit_cursor_width (Temporal::Beats beats)
 {
@@ -374,14 +379,13 @@ void
 StepEditor::step_edit_toggle_chord ()
 {
 	if (_step_edit_within_chord) {
+		step_to_next_chord ();
 		_step_edit_within_chord = false;
-		if (step_edit_region_view) {
-			step_edit_beat_pos += _step_edit_chord_duration;
-			step_edit_region_view->move_step_edit_cursor (step_edit_beat_pos);
-		}
+		_step_edit_chord_duration = Temporal::Beats();
 	} else {
 		_step_edit_triplet_countdown = 0;
 		_step_edit_within_chord = true;
+		_chord_tracker.reset ();
 	}
 }
 
diff --git a/gtk2_ardour/step_editor.h b/gtk2_ardour/step_editor.h
index 1ba1224495..80971be5f9 100644
--- a/gtk2_ardour/step_editor.h
+++ b/gtk2_ardour/step_editor.h
@@ -70,6 +70,7 @@ public:
 	int  step_add_program_change (uint8_t channel, uint8_t program);
 	int  step_add_note (uint8_t channel, uint8_t pitch, uint8_t velocity,
 	                    Temporal::Beats beat_duration);
+	void step_to_next_chord ();
 	void step_edit_sustain (Temporal::Beats beats);
 	bool step_edit_within_triplet () const;
 	void step_edit_toggle_triplet ();
@@ -95,11 +96,11 @@ private:
 	Temporal::Beats                       _step_edit_chord_duration;
 	PBD::ScopedConnection                  step_edit_region_connection;
 	PublicEditor&                         _editor;
-	std::shared_ptr<ARDOUR::MidiTrack>  _track;
+	std::shared_ptr<ARDOUR::MidiTrack>    _track;
 	MidiTimeAxisView&                     _mtv;
-	int8_t                                 last_added_pitch;
-	Temporal::Beats                        last_added_end;
-	ARDOUR::MidiNoteTracker                _tracker;
+	Temporal::Beats                       _last_added_beat;
+	ARDOUR::MidiNoteTracker               _tracker;
+	ARDOUR::MidiNoteTracker               _chord_tracker;
 
 	sigc::connection delete_connection;
 	sigc::connection hide_connection;