rework snap

snap now fills in a struct (MusicFrame) which contins a snapped frame
along with a music divisor.
this gives useful information wrt magnetic snap which may or may not
have rounded to an exact musical position.

region position may now be set musically (using quarter notes for now).

this patch fixes several problems in the current code:

	- dragging a list of music-locked regions now maintains correct
	  musical offsets within the list.

	- splitting regions using magnetic snap works correctly (#7192)

	- cut drag should now work correctly with magnetic snap.

	- musical length of split midi regions is no longer frame based.

1 files changed, 60 insertions, 62 deletions

diff --git a/gtk2_ardour/editor_ops.cc b/gtk2_ardour/editor_ops.cc
index 4df88b9025..288d12219f 100644
--- a/gtk2_ardour/editor_ops.cc
+++ b/gtk2_ardour/editor_ops.cc
@@ -166,8 +166,7 @@ Editor::redo (uint32_t n)
 }
 
 void
-Editor::split_regions_at (framepos_t where, RegionSelection& regions, const int32_t sub_num,
-                          bool snap_frame)
+Editor::split_regions_at (MusicFrame where, RegionSelection& regions, bool snap_frame)
 {
 	bool frozen = false;
 
@@ -214,7 +213,7 @@ Editor::split_regions_at (framepos_t where, RegionSelection& regions, const int3
 		   have something to split.
 		*/
 
-		if (!(*a)->region()->covers (where)) {
+		if (!(*a)->region()->covers (where.frame)) {
 			++a;
 			continue;
 		}
@@ -246,7 +245,7 @@ Editor::split_regions_at (framepos_t where, RegionSelection& regions, const int3
 
 		if (pl) {
 			pl->clear_changes ();
-			pl->split_region ((*a)->region(), where, sub_num);
+			pl->split_region ((*a)->region(), where);
 			_session->add_command (new StatefulDiffCommand (pl));
 		}
 
@@ -292,7 +291,7 @@ Editor::split_regions_at (framepos_t where, RegionSelection& regions, const int3
 		}
 
 		for (RegionSelection::iterator ri = latest_regionviews.begin(); ri != latest_regionviews.end(); ri++) {
-			if ((*ri)->region()->position() < where) {
+			if ((*ri)->region()->position() < where.frame) {
 				// new regions created before the split
 				if (rsas & NewlyCreatedLeft) {
 					selection->add (*ri);
@@ -4260,7 +4259,7 @@ Editor::cut_copy_points (Editing::CutCopyOp op, Evoral::Beats earliest, bool mid
 		}
 
 		/* Add all selected points to the relevant copy ControlLists */
-		framepos_t start = std::numeric_limits<framepos_t>::max();
+		MusicFrame start (std::numeric_limits<framepos_t>::max(), 0);
 		for (PointSelection::iterator sel_point = selection->points.begin(); sel_point != selection->points.end(); ++sel_point) {
 			boost::shared_ptr<AutomationList>    al = (*sel_point)->line().the_list();
 			AutomationList::const_iterator ctrl_evt = (*sel_point)->model ();
@@ -4271,7 +4270,7 @@ Editor::cut_copy_points (Editing::CutCopyOp op, Evoral::Beats earliest, bool mid
 				earliest = std::min(earliest, Evoral::Beats((*ctrl_evt)->when));
 			} else {
 				/* Update earliest session start time in frames */
-				start = std::min(start, (*sel_point)->line().session_position(ctrl_evt));
+				start.frame = std::min(start.frame, (*sel_point)->line().session_position(ctrl_evt));
 			}
 		}
 
@@ -4282,13 +4281,13 @@ Editor::cut_copy_points (Editing::CutCopyOp op, Evoral::Beats earliest, bool mid
 			}
 			earliest.round_down_to_beat();
 		} else {
-			if (start == std::numeric_limits<double>::max()) {
-				start = 0;  // Weird... don't offset
+			if (start.frame == std::numeric_limits<double>::max()) {
+				start.frame = 0;  // Weird... don't offset
 			}
 			snap_to(start, RoundDownMaybe);
 		}
 
-		const double line_offset = midi ? earliest.to_double() : start;
+		const double line_offset = midi ? earliest.to_double() : start.frame;
 		for (Lists::iterator i = lists.begin(); i != lists.end(); ++i) {
 			/* Correct this copy list so that it is relative to the earliest
 			   start time, so relative ordering between points is preserved
@@ -4691,22 +4690,21 @@ void
 Editor::paste (float times, bool from_context)
 {
         DEBUG_TRACE (DEBUG::CutNPaste, "paste to preferred edit pos\n");
-
-	paste_internal (get_preferred_edit_position (EDIT_IGNORE_NONE, from_context), times, get_grid_music_divisions (0));
+	MusicFrame where (get_preferred_edit_position (EDIT_IGNORE_NONE, from_context), 0);
+	paste_internal (where.frame, times, 0);
 }
 
 void
 Editor::mouse_paste ()
 {
-	framepos_t where;
+	MusicFrame where (0, 0);
 	bool ignored;
-
-	if (!mouse_frame (where, ignored)) {
+	if (!mouse_frame (where.frame, ignored)) {
 		return;
 	}
 
 	snap_to (where);
-	paste_internal (where, 1, get_grid_music_divisions (0));
+	paste_internal (where.frame, 1, where.division);
 }
 
 void
@@ -6171,10 +6169,10 @@ Editor::update_region_fade_visibility ()
 void
 Editor::set_edit_point ()
 {
-	framepos_t where;
 	bool ignored;
+	MusicFrame where (0, 0);
 
-	if (!mouse_frame (where, ignored)) {
+	if (!mouse_frame (where.frame, ignored)) {
 		return;
 	}
 
@@ -6182,7 +6180,7 @@ Editor::set_edit_point ()
 
 	if (selection->markers.empty()) {
 
-		mouse_add_new_marker (where);
+		mouse_add_new_marker (where.frame);
 
 	} else {
 		bool ignored;
@@ -6190,7 +6188,7 @@ Editor::set_edit_point ()
 		Location* loc = find_location_from_marker (selection->markers.front(), ignored);
 
 		if (loc) {
-			loc->move_to (where, get_grid_music_divisions(0));
+			loc->move_to (where.frame, where.division);
 		}
 	}
 }
@@ -6201,17 +6199,17 @@ Editor::set_playhead_cursor ()
 	if (entered_marker) {
 		_session->request_locate (entered_marker->position(), _session->transport_rolling());
 	} else {
-		framepos_t where;
+		MusicFrame where (0, 0);
 		bool ignored;
 
-		if (!mouse_frame (where, ignored)) {
+		if (!mouse_frame (where.frame, ignored)) {
 			return;
 		}
 
 		snap_to (where);
 
 		if (_session) {
-			_session->request_locate (where, _session->transport_rolling());
+			_session->request_locate (where.frame, _session->transport_rolling());
 		}
 	}
 
@@ -6239,18 +6237,16 @@ Editor::split_region ()
 	if (current_mouse_mode() == MouseObject) {  //don't try this for Internal Edit, Stretch, Draw, etc.
 
 		RegionSelection rs = get_regions_from_selection_and_edit_point ();
-
-		framepos_t where = get_preferred_edit_position ();
+		const framepos_t pos = get_preferred_edit_position();
+		const int32_t division = get_grid_music_divisions (0);
+		MusicFrame where (pos, division);
 
 		if (rs.empty()) {
 			return;
 		}
 
-		if (snap_musical()) {
-			split_regions_at (where, rs, get_grid_music_divisions (0));
-		} else {
-			split_regions_at (where, rs, 0);
-		}
+		split_regions_at (where, rs);
+
 	}
 }
 
@@ -6458,7 +6454,7 @@ Editor::set_punch_start_from_edit_point ()
 {
 	if (_session) {
 
-		framepos_t start = 0;
+		MusicFrame start (0, 0);
 		framepos_t end = max_framepos;
 
 		//use the existing punch end, if any
@@ -6468,20 +6464,20 @@ Editor::set_punch_start_from_edit_point ()
 		}
 
 		if ((_edit_point == EditAtPlayhead) && _session->transport_rolling()) {
-			start = _session->audible_frame();
+			start.frame = _session->audible_frame();
 		} else {
-			start = get_preferred_edit_position();
+			start.frame = get_preferred_edit_position();
 		}
 
 		//snap the selection start/end
 		snap_to(start);
 
 		//if there's not already a sensible selection endpoint, go "forever"
-		if ( start > end ) {
+		if (start.frame > end ) {
 			end = max_framepos;
 		}
 
-		set_punch_range (start, end, _("set punch start from EP"));
+		set_punch_range (start.frame, end, _("set punch start from EP"));
 	}
 
 }
@@ -6492,7 +6488,7 @@ Editor::set_punch_end_from_edit_point ()
 	if (_session) {
 
 		framepos_t start = 0;
-		framepos_t end = max_framepos;
+		MusicFrame end (max_framepos, 0);
 
 		//use the existing punch start, if any
 		Location* tpl = transport_punch_location();
@@ -6501,15 +6497,15 @@ Editor::set_punch_end_from_edit_point ()
 		}
 
 		if ((_edit_point == EditAtPlayhead) && _session->transport_rolling()) {
-			end = _session->audible_frame();
+			end.frame = _session->audible_frame();
 		} else {
-			end = get_preferred_edit_position();
+			end.frame = get_preferred_edit_position();
 		}
 
 		//snap the selection start/end
-		snap_to(end);
+		snap_to (end);
 
-		set_punch_range (start, end, _("set punch end from EP"));
+		set_punch_range (start, end.frame, _("set punch end from EP"));
 
 	}
 }
@@ -6519,7 +6515,7 @@ Editor::set_loop_start_from_edit_point ()
 {
 	if (_session) {
 
-		framepos_t start = 0;
+		MusicFrame start (0, 0);
 		framepos_t end = max_framepos;
 
 		//use the existing loop end, if any
@@ -6529,20 +6525,20 @@ Editor::set_loop_start_from_edit_point ()
 		}
 
 		if ((_edit_point == EditAtPlayhead) && _session->transport_rolling()) {
-			start = _session->audible_frame();
+			start.frame = _session->audible_frame();
 		} else {
-			start = get_preferred_edit_position();
+			start.frame = get_preferred_edit_position();
 		}
 
 		//snap the selection start/end
-		snap_to(start);
+		snap_to (start);
 
 		//if there's not already a sensible selection endpoint, go "forever"
-		if ( start > end ) {
+		if (start.frame > end ) {
 			end = max_framepos;
 		}
 
-		set_loop_range (start, end, _("set loop start from EP"));
+		set_loop_range (start.frame, end, _("set loop start from EP"));
 	}
 
 }
@@ -6553,7 +6549,7 @@ Editor::set_loop_end_from_edit_point ()
 	if (_session) {
 
 		framepos_t start = 0;
-		framepos_t end = max_framepos;
+		MusicFrame end (max_framepos, 0);
 
 		//use the existing loop start, if any
 		Location* tpl = transport_loop_location();
@@ -6562,15 +6558,15 @@ Editor::set_loop_end_from_edit_point ()
 		}
 
 		if ((_edit_point == EditAtPlayhead) && _session->transport_rolling()) {
-			end = _session->audible_frame();
+			end.frame = _session->audible_frame();
 		} else {
-			end = get_preferred_edit_position();
+			end.frame = get_preferred_edit_position();
 		}
 
 		//snap the selection start/end
 		snap_to(end);
 
-		set_loop_range (start, end, _("set loop end from EP"));
+		set_loop_range (start, end.frame, _("set loop end from EP"));
 	}
 }
 
@@ -6985,9 +6981,9 @@ Editor::snap_regions_to_grid ()
 			pl->freeze();
 		}
 
-		framepos_t start_frame = (*r)->region()->first_frame ();
-		snap_to (start_frame);
-		(*r)->region()->set_position (start_frame);
+		MusicFrame start ((*r)->region()->first_frame (), 0);
+		snap_to (start);
+		(*r)->region()->set_position (start.frame, start.division);
 	}
 
 	while (used_playlists.size() > 0) {
@@ -7187,11 +7183,12 @@ Editor::playhead_forward_to_grid ()
 		return;
 	}
 
-	framepos_t pos = playhead_cursor->current_frame ();
-	if (pos < max_framepos - 1) {
-		pos += 2;
+	MusicFrame pos (playhead_cursor->current_frame (), 0);
+
+	if (pos.frame < max_framepos - 1) {
+		pos.frame += 2;
 		snap_to_internal (pos, RoundUpAlways, false);
-		_session->request_locate (pos);
+		_session->request_locate (pos.frame);
 	}
 }
 
@@ -7203,11 +7200,12 @@ Editor::playhead_backward_to_grid ()
 		return;
 	}
 
-	framepos_t pos = playhead_cursor->current_frame ();
-	if (pos > 2) {
-		pos -= 2;
+	MusicFrame pos  (playhead_cursor->current_frame (), 0);
+
+	if (pos.frame > 2) {
+		pos.frame -= 2;
 		snap_to_internal (pos, RoundDownAlways, false);
-		_session->request_locate (pos);
+		_session->request_locate (pos.frame);
 	}
 }
 
@@ -7472,7 +7470,7 @@ Editor::insert_time (
 
 			if (opt == SplitIntersected) {
 				/* non musical split */
-				(*i)->split (pos, 0);
+				(*i)->split (MusicFrame (pos, 0));
 			}
 
 			(*i)->shift (pos, frames, (opt == MoveIntersected), ignore_music_glue);