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, 27 insertions, 26 deletions

diff --git a/libs/ardour/playlist.cc b/libs/ardour/playlist.cc
index 7cea903d5d..99e65ab3e2 100644
--- a/libs/ardour/playlist.cc
+++ b/libs/ardour/playlist.cc
@@ -669,7 +669,7 @@ Playlist::clear_pending ()
 
 /** Note: this calls set_layer (..., DBL_MAX) so it will reset the layering index of region */
 void
-Playlist::add_region (boost::shared_ptr<Region> region, framepos_t position, float times, bool auto_partition, const int32_t sub_num)
+Playlist::add_region (boost::shared_ptr<Region> region, framepos_t position, float times, bool auto_partition, int32_t sub_num, double quarter_note, bool for_music)
 {
 	RegionWriteLock rlock (this);
 	times = fabs (times);
@@ -688,19 +688,18 @@ Playlist::add_region (boost::shared_ptr<Region> region, framepos_t position, flo
 	}
 
 	if (itimes >= 1) {
-		add_region_internal (region, pos, sub_num);
+		add_region_internal (region, pos, sub_num, quarter_note, for_music);
 		set_layer (region, DBL_MAX);
 		pos += region->length();
 		--itimes;
 	}
 
-
 	/* note that itimes can be zero if we being asked to just
 	   insert a single fraction of the region.
 	*/
 
 	for (int i = 0; i < itimes; ++i) {
-		boost::shared_ptr<Region> copy = RegionFactory::create (region, true, sub_num);
+		boost::shared_ptr<Region> copy = RegionFactory::create (region, true);
 		add_region_internal (copy, pos, sub_num);
 		set_layer (copy, DBL_MAX);
 		pos += region->length();
@@ -743,7 +742,7 @@ Playlist::set_region_ownership ()
 }
 
 bool
-Playlist::add_region_internal (boost::shared_ptr<Region> region, framepos_t position, const int32_t sub_num)
+Playlist::add_region_internal (boost::shared_ptr<Region> region, framepos_t position, int32_t sub_num, double quarter_note, bool for_music)
 {
 	if (region->data_type() != _type) {
 		return false;
@@ -755,8 +754,11 @@ Playlist::add_region_internal (boost::shared_ptr<Region> region, framepos_t posi
 		boost::shared_ptr<Playlist> foo (shared_from_this());
 		region->set_playlist (boost::weak_ptr<Playlist>(foo));
 	}
-
-	region->set_position (position, sub_num);
+	if (for_music) {
+		region->set_position_music (quarter_note);
+	} else {
+		region->set_position (position, sub_num);
+	}
 
 	regions.insert (upper_bound (regions.begin(), regions.end(), region, cmp), region);
 	all_regions.insert (region);
@@ -1411,7 +1413,7 @@ Playlist::duplicate_ranges (std::list<AudioRange>& ranges, float times)
  }
 
  void
- Playlist::split (framepos_t at, const int32_t sub_num)
+ Playlist::split (MusicFrame at)
  {
 	 RegionWriteLock rlock (this);
 	 RegionList copy (regions.rlist());
@@ -1420,33 +1422,34 @@ Playlist::duplicate_ranges (std::list<AudioRange>& ranges, float times)
 	  */
 
 	 for (RegionList::iterator r = copy.begin(); r != copy.end(); ++r) {
-		 _split_region (*r, at, sub_num);
+		 _split_region (*r, at);
 	 }
  }
 
  void
- Playlist::split_region (boost::shared_ptr<Region> region, framepos_t playlist_position, const int32_t sub_num)
+ Playlist::split_region (boost::shared_ptr<Region> region, MusicFrame playlist_position)
  {
 	 RegionWriteLock rl (this);
-	 _split_region (region, playlist_position, sub_num);
+	 _split_region (region, playlist_position);
  }
 
  void
- Playlist::_split_region (boost::shared_ptr<Region> region, framepos_t playlist_position, const int32_t sub_num)
+ Playlist::_split_region (boost::shared_ptr<Region> region, MusicFrame playlist_position)
  {
-	 if (!region->covers (playlist_position)) {
+	 if (!region->covers (playlist_position.frame)) {
 		 return;
 	 }
 
-	 if (region->position() == playlist_position ||
-	     region->last_frame() == playlist_position) {
+	 if (region->position() == playlist_position.frame ||
+	     region->last_frame() == playlist_position.frame) {
 		 return;
 	 }
 
 	 boost::shared_ptr<Region> left;
 	 boost::shared_ptr<Region> right;
-	 frameoffset_t before;
-	 frameoffset_t after;
+
+	 MusicFrame before (playlist_position.frame - region->position(), playlist_position.division);
+	 MusicFrame after (region->length() - before.frame, 0);
 	 string before_name;
 	 string after_name;
 
@@ -1455,15 +1458,12 @@ Playlist::duplicate_ranges (std::list<AudioRange>& ranges, float times)
 	 bool old_sp = _splicing;
 	 _splicing = true;
 
-	 before = playlist_position - region->position();
-	 after = region->length() - before;
-
 	 RegionFactory::region_name (before_name, region->name(), false);
 
 	 {
 		 PropertyList plist;
 
-		 plist.add (Properties::length, before);
+		 plist.add (Properties::length, before.frame);
 		 plist.add (Properties::name, before_name);
 		 plist.add (Properties::left_of_split, true);
 		 plist.add (Properties::layering_index, region->layering_index ());
@@ -1473,7 +1473,7 @@ Playlist::duplicate_ranges (std::list<AudioRange>& ranges, float times)
 		    since it supplies that offset to the Region constructor, which
 		    is necessary to get audio region gain envelopes right.
 		 */
-		 left = RegionFactory::create (region, 0, plist, true, sub_num);
+		 left = RegionFactory::create (region, MusicFrame (0, 0), plist, true);
 	 }
 
 	 RegionFactory::region_name (after_name, region->name(), false);
@@ -1481,18 +1481,19 @@ Playlist::duplicate_ranges (std::list<AudioRange>& ranges, float times)
 	 {
 		 PropertyList plist;
 
-		 plist.add (Properties::length, after);
+		 plist.add (Properties::length, after.frame);
 		 plist.add (Properties::name, after_name);
 		 plist.add (Properties::right_of_split, true);
 		 plist.add (Properties::layering_index, region->layering_index ());
 		 plist.add (Properties::layer, region->layer ());
 
 		 /* same note as above */
-		 right = RegionFactory::create (region, before, plist, true, sub_num);
+		 right = RegionFactory::create (region, before, plist, true);
 	 }
 
-	 add_region_internal (left, region->position());
-	 add_region_internal (right, region->position() + before);
+	 add_region_internal (left, region->position(), 0);
+	 add_region_internal (right, region->position() + before.frame, before.division);
+
 	 remove_region_internal (region);
 
 	 _splicing = old_sp;