Exact beat - provide audio->music mapping for region split.

	- for those not in the know, this series provides a way to
	  remove the temporal distortion introduced when using an
	  audio frame-based gui for music-locked objects.

	  In short, the gui uses an audio frame representation to move
	  objects. It displays the object using frame_at_beat(), quantizing
	  the time value to audio frames. This is fine until the user selects
	  that frame but expects it to be interpreted as a beat.
	  Thus beat_at_frame() would not produce the user-expected beat
	  (temporal quantization error of up to 0.5 audio samples).
	  This is one method of mapping audio time to music time accurately.

11 files changed, 32 insertions, 23 deletions

diff --git a/gtk2_ardour/audio_streamview.cc b/gtk2_ardour/audio_streamview.cc
index ed9ec23b02..511b4296eb 100644
--- a/gtk2_ardour/audio_streamview.cc
+++ b/gtk2_ardour/audio_streamview.cc
@@ -353,8 +353,9 @@ AudioStreamView::update_rec_regions (framepos_t start, framecnt_t cnt)
 				if (nlen != region->length()) {
 
 					region->suspend_property_changes ();
+					/* set non-musical position / length */
 					region->set_position (_trackview.track()->get_capture_start_frame(n));
-					region->set_length (nlen);
+					region->set_length (nlen, 0);
 					region->resume_property_changes ();
 
 					if (origlen == 1) {
@@ -381,7 +382,7 @@ AudioStreamView::update_rec_regions (framepos_t start, framecnt_t cnt)
 
 						region->suspend_property_changes ();
 						region->set_position (_trackview.track()->get_capture_start_frame(n));
-						region->set_length (nlen);
+						region->set_length (nlen, 0);
 						region->resume_property_changes ();
 
 						if (origlen == 1) {
diff --git a/gtk2_ardour/editor.h b/gtk2_ardour/editor.h
index 8bbc7fee2b..af781f019c 100644
--- a/gtk2_ardour/editor.h
+++ b/gtk2_ardour/editor.h
@@ -534,7 +534,7 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 
 	/* editing operations that need to be public */
 	void mouse_add_new_marker (framepos_t where, bool is_cd=false);
-	void split_regions_at (framepos_t, RegionSelection&);
+	void split_regions_at (framepos_t, RegionSelection&, const int32_t& sub_num);
 	void split_region_at_points (boost::shared_ptr<ARDOUR::Region>, ARDOUR::AnalysisFeatureList&, bool can_ferret, bool select_new = false);
 	RegionSelection get_regions_from_selection_and_mouse (framepos_t);
 
diff --git a/gtk2_ardour/editor_drag.cc b/gtk2_ardour/editor_drag.cc
index d87388e888..11809af788 100644
--- a/gtk2_ardour/editor_drag.cc
+++ b/gtk2_ardour/editor_drag.cc
@@ -2323,7 +2323,7 @@ RegionCreateDrag::motion (GdkEvent* event, bool first_move)
 			*/
 
 			framecnt_t const len = (framecnt_t) fabs ((double)(f - grab_frame () - 1));
-			_region->set_length (len < 1 ? 1 : len);
+			_region->set_length (len < 1 ? 1 : len, _editor->get_grid_music_divisions (event->button.state));
 		}
 	}
 }
@@ -2934,7 +2934,7 @@ TrimDrag::motion (GdkEvent* event, bool first_move)
 
 	case EndTrim:
 		for (list<DraggingView>::iterator i = _views.begin(); i != _views.end(); ++i) {
-			bool changed = i->view->trim_end (i->initial_end + dt, non_overlap_trim);
+			bool changed = i->view->trim_end (i->initial_end + dt, non_overlap_trim, _editor->get_grid_music_divisions (event->button.state));
 			if (changed && _preserve_fade_anchor) {
 				AudioRegionView* arv = dynamic_cast<AudioRegionView*> (i->view);
 				if (arv) {
@@ -6333,7 +6333,7 @@ RegionCutDrag::motion (GdkEvent*, bool)
 }
 
 void
-RegionCutDrag::finished (GdkEvent*, bool)
+RegionCutDrag::finished (GdkEvent* event, bool)
 {
 	_editor->get_track_canvas()->canvas()->re_enter();
 
@@ -6347,7 +6347,7 @@ RegionCutDrag::finished (GdkEvent*, bool)
 		return;
 	}
 
-	_editor->split_regions_at (pos, rs);
+	_editor->split_regions_at (pos, rs, _editor->get_grid_music_divisions (event->button.state));
 }
 
 void
diff --git a/gtk2_ardour/editor_mouse.cc b/gtk2_ardour/editor_mouse.cc
index dfdd7d995f..86386c21fb 100644
--- a/gtk2_ardour/editor_mouse.cc
+++ b/gtk2_ardour/editor_mouse.cc
@@ -1037,7 +1037,7 @@ Editor::button_press_handler_1 (ArdourCanvas::Item* item, GdkEvent* event, ItemT
 						if (!prev) {
 							_drags->set (new RegionCreateDrag (this, item, parent), event);
 						} else {
-							prev->set_length (t - prev->position ());
+							prev->set_length (t - prev->position (), get_grid_music_divisions (event->button.state));
 						}
 					}
 				} else {
diff --git a/gtk2_ardour/editor_ops.cc b/gtk2_ardour/editor_ops.cc
index d22df0a0bf..80a5ee399e 100644
--- a/gtk2_ardour/editor_ops.cc
+++ b/gtk2_ardour/editor_ops.cc
@@ -151,7 +151,7 @@ Editor::redo (uint32_t n)
 }
 
 void
-Editor::split_regions_at (framepos_t where, RegionSelection& regions)
+Editor::split_regions_at (framepos_t where, RegionSelection& regions, const int32_t& sub_num)
 {
 	bool frozen = false;
 
@@ -226,7 +226,7 @@ Editor::split_regions_at (framepos_t where, RegionSelection& regions)
 
 		if (pl) {
 			pl->clear_changes ();
-			pl->split_region ((*a)->region(), where);
+			pl->split_region ((*a)->region(), where, sub_num);
 			_session->add_command (new StatefulDiffCommand (pl));
 		}
 
@@ -6151,7 +6151,11 @@ Editor::split_region ()
 			return;
 		}
 
-		split_regions_at (where, rs);
+		if (snap_musical()) {
+			split_regions_at (where, rs, get_grid_music_divisions (0));
+		} else {
+			split_regions_at (where, rs, 0);
+		}
 	}
 }
 
@@ -7294,7 +7298,8 @@ Editor::insert_time (
 			(*i)->clear_owned_changes ();
 
 			if (opt == SplitIntersected) {
-				(*i)->split (pos);
+				/* non musical split */
+				(*i)->split (pos, 0);
 			}
 
 			(*i)->shift (pos, frames, (opt == MoveIntersected), ignore_music_glue);
diff --git a/gtk2_ardour/midi_region_view.cc b/gtk2_ardour/midi_region_view.cc
index 9e271cc398..6ffba154f4 100644
--- a/gtk2_ardour/midi_region_view.cc
+++ b/gtk2_ardour/midi_region_view.cc
@@ -1872,7 +1872,8 @@ MidiRegionView::step_add_note (uint8_t channel, uint8_t number, uint8_t velocity
 	framepos_t region_end = _region->last_frame();
 
 	if (end_frame > region_end) {
-		_region->set_length (end_frame - _region->position());
+		/* XX sets length in beats from audio space. make musical */
+		_region->set_length (end_frame - _region->position(), 0);
 	}
 
 	MidiTimeAxisView* const mtv = dynamic_cast<MidiTimeAxisView*>(&trackview);
@@ -2877,13 +2878,13 @@ MidiRegionView::commit_resizing (NoteBase* primary, bool at_front, double delta_
 		/* Convert the new x position to a frame within the source */
 		framepos_t current_fr;
 		if (with_snap) {
-			current_fr = snap_pixel_to_sample (current_x, ensure_snap) + _region->start ();
+			current_fr = snap_pixel_to_sample (current_x, ensure_snap);
 		} else {
-			current_fr = trackview.editor().pixel_to_sample (current_x) + _region->start ();
+			current_fr = trackview.editor().pixel_to_sample (current_x);
 		}
 
 		/* and then to beats */
-		const Evoral::Beats x_beats = region_frames_to_region_beats (current_fr);
+		const Evoral::Beats x_beats = region_frames_to_region_beats (current_fr + _region->start());
 
 		if (at_front && x_beats < canvas_note->note()->end_time()) {
 			note_diff_add_change (canvas_note, MidiModel::NoteDiffCommand::StartTime, x_beats - (sign * snap_delta_beats));
@@ -3568,7 +3569,8 @@ MidiRegionView::paste_internal (framepos_t pos, unsigned paste_count, float time
 		DEBUG_TRACE (DEBUG::CutNPaste, string_compose ("Paste extended region from %1 to %2\n", region_end, end_frame));
 
 		_region->clear_changes ();
-		_region->set_length (end_frame - _region->position());
+		/* we probably need to get the snap modifier somehow to make this correct for non-musical use */
+		_region->set_length (end_frame - _region->position(), trackview.editor().get_grid_music_divisions (0));
 		trackview.session()->add_command (new StatefulDiffCommand (_region));
 	}
 
diff --git a/gtk2_ardour/midi_streamview.cc b/gtk2_ardour/midi_streamview.cc
index e369c5842d..88947e7e3d 100644
--- a/gtk2_ardour/midi_streamview.cc
+++ b/gtk2_ardour/midi_streamview.cc
@@ -610,7 +610,7 @@ MidiStreamView::update_rec_box ()
 
 	/* Update the region being recorded to reflect where we currently are */
 	boost::shared_ptr<ARDOUR::Region> region = rec_regions.back().first;
-	region->set_length (_trackview.track()->current_capture_end () - _trackview.track()->current_capture_start());
+	region->set_length (_trackview.track()->current_capture_end () - _trackview.track()->current_capture_start(), 0);
 
 	MidiRegionView* mrv = dynamic_cast<MidiRegionView*> (rec_regions.back().second);
 	mrv->extend_active_notes ();
diff --git a/gtk2_ardour/midi_time_axis.cc b/gtk2_ardour/midi_time_axis.cc
index 074f2a115b..4b709c4e5c 100644
--- a/gtk2_ardour/midi_time_axis.cc
+++ b/gtk2_ardour/midi_time_axis.cc
@@ -1526,6 +1526,7 @@ MidiTimeAxisView::add_region (framepos_t pos, framecnt_t length, bool commit, co
 	plist.add (ARDOUR::Properties::name, PBD::basename_nosuffix(src->name()));
 
 	boost::shared_ptr<Region> region = (RegionFactory::create (src, plist));
+	/* sets beat position */
 	region->set_position (pos, sub_num);
 	playlist()->add_region (region, pos);
 	_session->add_command (new StatefulDiffCommand (playlist()));
diff --git a/gtk2_ardour/public_editor.h b/gtk2_ardour/public_editor.h
index e562e1cb37..a86169b4db 100644
--- a/gtk2_ardour/public_editor.h
+++ b/gtk2_ardour/public_editor.h
@@ -289,7 +289,7 @@ class PublicEditor : public Gtkmm2ext::Tabbable {
 	virtual void restore_editing_space () = 0;
 	virtual framepos_t get_preferred_edit_position (Editing::EditIgnoreOption = Editing::EDIT_IGNORE_NONE, bool from_context_menu = false, bool from_outside_canvas = false) = 0;
 	virtual void toggle_meter_updating() = 0;
-	virtual void split_regions_at (framepos_t, RegionSelection&) = 0;
+	virtual void split_regions_at (framepos_t, RegionSelection&, const int32_t& sub_num) = 0;
 	virtual void split_region_at_points (boost::shared_ptr<ARDOUR::Region>, ARDOUR::AnalysisFeatureList&, bool can_ferret, bool select_new = false) = 0;
 	virtual void mouse_add_new_marker (framepos_t where, bool is_cd=false) = 0;
 	virtual void foreach_time_axis_view (sigc::slot<void,TimeAxisView&>) = 0;
diff --git a/gtk2_ardour/region_view.cc b/gtk2_ardour/region_view.cc
index b9648bbbc3..4f904d9f2b 100644
--- a/gtk2_ardour/region_view.cc
+++ b/gtk2_ardour/region_view.cc
@@ -861,7 +861,7 @@ RegionView::trim_front (framepos_t new_bound, bool no_overlap, const int32_t& su
 }
 
 bool
-RegionView::trim_end (framepos_t new_bound, bool no_overlap)
+RegionView::trim_end (framepos_t new_bound, bool no_overlap, const int32_t& sub_num)
 {
 	if (_region->locked()) {
 		return false;
@@ -872,7 +872,7 @@ RegionView::trim_end (framepos_t new_bound, bool no_overlap)
 
 	framepos_t const pre_trim_last_frame = _region->last_frame();
 
-	_region->trim_end ((framepos_t) (new_bound * speed));
+	_region->trim_end ((framepos_t) (new_bound * speed), sub_num);
 
 	if (no_overlap) {
 		// Get the next region on the right of this region and shrink/expand it.
@@ -887,7 +887,7 @@ RegionView::trim_end (framepos_t new_bound, bool no_overlap)
 
 		// Only trim region on the right if the last frame has gone beyond the right region's first frame.
 		if (region_right != 0 && (region_right->first_frame() < _region->last_frame() || regions_touching)) {
-			region_right->trim_front (_region->last_frame() + 1);
+			region_right->trim_front (_region->last_frame() + 1, sub_num);
 		}
 
 		region_changed (ARDOUR::bounds_change);
diff --git a/gtk2_ardour/region_view.h b/gtk2_ardour/region_view.h
index 43608c31d1..40485f93cf 100644
--- a/gtk2_ardour/region_view.h
+++ b/gtk2_ardour/region_view.h
@@ -107,7 +107,7 @@ class RegionView : public TimeAxisViewItem
 	/** Called when a start trim has finished */
 	virtual void trim_front_ending () {}
 
-	bool trim_end (framepos_t, bool);
+	bool trim_end (framepos_t, bool, const int32_t& sub_num);
         void move_contents (ARDOUR::frameoffset_t);
 	virtual void thaw_after_trim ();