changes to use overwrite-buffers when loop is disabled or loop range changed

5 files changed, 89 insertions, 92 deletions

diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index 3a3f16dfdf..6c34a1b93f 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -1683,8 +1683,8 @@ private:
 
 	bool should_ignore_transport_request (TransportRequestSource, TransportRequestType) const;
 
-	void set_play_loop (bool yn);
-	void unset_play_loop ();
+	void set_play_loop (bool yn, bool change_transport_state);
+	void unset_play_loop (bool change_transport_state = false);
 	void overwrite_some_buffers (boost::shared_ptr<Route>);
 	void flush_all_inserts ();
 	int  micro_locate (samplecnt_t distance);
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index d5579eb6fc..7e107b3056 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -1425,28 +1425,29 @@ Session::auto_loop_changed (Location* location)
 		(*i)->reload_loop ();
 	}
 
+
 	if (rolling) {
 
 		if (play_loop) {
 
+			/* Set this so that when/if we have to stop the
+			 * transport for a locate, we know that it is triggered
+			 * by loop-changing, and we do not cancel play loop
+			 */
+
+			loop_changing = true;
+
 			if (_transport_sample < location->start() || _transport_sample > location->end()) {
 				// new loop range excludes current transport
 				// sample => relocate to beginning of loop and roll.
-				request_locate (location->start(), true);
 
-			} else if (!loop_changing) {
+				request_locate (location->start(), true);
 
-				// schedule a locate-roll to refill the diskstreams at the
-				// previous loop end
+			}
 
-				loop_changing = true;
+			// schedule a buffer overwrite to refill buffers with the new loop.
 
-				if (location->end() > last_loopend) {
-					clear_events (SessionEvent::LocateRoll);
-					SessionEvent *ev = new SessionEvent (SessionEvent::LocateRoll, SessionEvent::Add, last_loopend, last_loopend, 0, true);
-					queue_event (ev);
-				}
-			}
+			request_overwrite_buffer (boost::shared_ptr<Track>());
 		}
 
 	} else {
diff --git a/libs/ardour/session_butler.cc b/libs/ardour/session_butler.cc
index b36d5459f3..0e9aa128dd 100644
--- a/libs/ardour/session_butler.cc
+++ b/libs/ardour/session_butler.cc
@@ -89,10 +89,15 @@ Session::request_overwrite_buffer (boost::shared_ptr<Track> t)
 	queue_event (ev);
 }
 
-/** Process thread. */
 void
 Session::overwrite_some_buffers (boost::shared_ptr<Route> r)
 {
+	/* this is called from the process thread while handling queued
+	 * SessionEvents. Therefore neither playback sample or read offsets in
+	 * tracks will change while we "queue" them all for an upcoming
+	 * overwrite.
+	 */
+
 	if (actively_recording()) {
 		return;
 	}
diff --git a/libs/ardour/session_process.cc b/libs/ardour/session_process.cc
index 020deb41e9..a7e8a068af 100644
--- a/libs/ardour/session_process.cc
+++ b/libs/ardour/session_process.cc
@@ -852,7 +852,7 @@ Session::process_event (SessionEvent* ev)
 
 	switch (ev->type) {
 	case SessionEvent::SetLoop:
-		set_play_loop (ev->yes_or_no);
+		set_play_loop (ev->yes_or_no, true);
 		break;
 
 	case SessionEvent::AutoLoop:
@@ -937,6 +937,10 @@ Session::process_event (SessionEvent* ev)
 		overwrite_some_buffers (ev->track);
 		break;
 
+	case SessionEvent::OverwriteAll:
+		overwrite_some_buffers (boost::shared_ptr<Route>());
+		break;
+
 	case SessionEvent::Audition:
 		set_audition (ev->region);
 		// drop reference to region
diff --git a/libs/ardour/session_transport.cc b/libs/ardour/session_transport.cc
index 6d9f99127a..6fd3114be6 100644
--- a/libs/ardour/session_transport.cc
+++ b/libs/ardour/session_transport.cc
@@ -302,7 +302,7 @@ Session::locate (samplepos_t target_sample, bool with_roll, bool with_flush, boo
 				have_looped = false;
 
 				if (!Config->get_loop_is_mode()) {
-					set_play_loop (false);
+					set_play_loop (false, false);
 				} else {
 					/* this will make the non_realtime_locate() in the butler
 					   which then causes seek() in tracks actually do the right
@@ -808,63 +808,10 @@ Session::flush_all_inserts ()
 	}
 }
 
-void
-Session::set_play_loop (bool yn)
-{
-	ENSURE_PROCESS_THREAD;
-	/* Called from event-handling context */
-
-	DEBUG_TRACE (DEBUG::Transport, string_compose ("set_play_loop (%1)\n", yn));
-
-	Location *loc;
-
-	if (yn == play_loop || (actively_recording() && yn) || (loc = _locations->auto_loop_location()) == 0) {
-		/* nothing to do, or can't change loop status while recording */
-		return;
-	}
-
-	if (yn && synced_to_engine()) {
-		warning << string_compose (
-			_("Looping cannot be supported while %1 is using JACK transport.\n"
-			  "Recommend changing the configured options"), PROGRAM_NAME)
-			<< endmsg;
-		return;
-	}
-
-	if (yn) {
-
-		play_loop = true;
-		have_looped = false;
-
-		if (loc) {
-
-			unset_play_range ();
-			/* set all tracks to use internal looping */
-			set_track_loop (true);
-
-			merge_event (new SessionEvent (SessionEvent::AutoLoop, SessionEvent::Replace, loc->end(), loc->start(), 0.0f));
-
-			if (!Config->get_loop_is_mode()) {
-				/* args: positition, roll=true, flush=true, for_loop_end=false, force buffer, refill  looping */
-
-				TFSM_LOCATE (loc->start(), true, true, false, true);
-			}
-		}
-
-	} else {
-
-		unset_play_loop ();
-	}
-
-	DEBUG_TRACE (DEBUG::Transport, string_compose ("send TSC2 with speed = %1\n", _transport_speed));
-	TransportStateChange ();
-}
-
 /* *****************************************************************************
  * END REALTIME ACTIONS
  * ****************************************************************************/
 
-
 void
 Session::add_post_transport_work (PostTransportWork ptw)
 {
@@ -1069,28 +1016,9 @@ Session::request_play_loop (bool yn, bool change_transport_roll)
 		target_speed = transport_speed ();
 	}
 
-	ev = new SessionEvent (SessionEvent::SetLoop, SessionEvent::Add, SessionEvent::Immediate, 0, target_speed, yn);
+	ev = new SessionEvent (SessionEvent::SetLoop, SessionEvent::Add, SessionEvent::Immediate, 0, target_speed, yn, change_transport_roll);
 	DEBUG_TRACE (DEBUG::Transport, string_compose ("Request set loop = %1, change roll state ? %2\n", yn, change_transport_roll));
 	queue_event (ev);
-
-	if (yn) {
-
-		if (!change_transport_roll) {
-			if (!Config->get_loop_is_mode() && !transport_rolling()) {
-				/* we're not changing transport state, but we do want
-				   to set up position for the new loop. Don't
-				   do this if we're rolling already.
-				*/
-				request_locate (location->start(), false);
-			}
-		}
-	} else {
-		if (!change_transport_roll && transport_rolling()) {
-			// request an immediate locate to refresh the tracks
-			// after disabling looping
-			request_locate (_transport_sample-1, false);
-		}
-	}
 }
 
 void
@@ -1646,15 +1574,74 @@ Session::non_realtime_stop (bool abort, int on_entry, bool& finished)
 }
 
 void
-Session::unset_play_loop ()
+Session::set_play_loop (bool yn, bool change_transport_state)
+{
+	ENSURE_PROCESS_THREAD;
+	/* Called from event-handling context */
+
+	DEBUG_TRACE (DEBUG::Transport, string_compose ("set_play_loop (%1)\n", yn));
+
+	Location *loc;
+
+	if (yn == play_loop || (actively_recording() && yn) || (loc = _locations->auto_loop_location()) == 0) {
+		/* nothing to do, or can't change loop status while recording */
+		return;
+	}
+
+	if (yn && synced_to_engine()) {
+		warning << string_compose (
+			_("Looping cannot be supported while %1 is using JACK transport.\n"
+			  "Recommend changing the configured options"), PROGRAM_NAME)
+			<< endmsg;
+		return;
+	}
+
+	if (yn) {
+
+		play_loop = true;
+		have_looped = false;
+
+		if (loc) {
+
+			unset_play_range ();
+			/* set all tracks to use internal looping */
+			set_track_loop (true);
+
+			merge_event (new SessionEvent (SessionEvent::AutoLoop, SessionEvent::Replace, loc->end(), loc->start(), 0.0f));
+
+			if (!Config->get_loop_is_mode() && !transport_rolling()) {
+				/* args: positition, roll=true, flush=true, for_loop_end=false, force buffer, refill  looping */
+
+				TFSM_LOCATE (loc->start(), true, true, false, true);
+			}
+		}
+
+	} else {
+
+		unset_play_loop ();
+	}
+
+	DEBUG_TRACE (DEBUG::Transport, string_compose ("send TSC2 with speed = %1\n", _transport_speed));
+	TransportStateChange ();
+}
+
+void
+Session::unset_play_loop (bool change_transport_state)
 {
 	if (play_loop) {
+
 		play_loop = false;
 		clear_events (SessionEvent::AutoLoop);
 		set_track_loop (false);
+
 		/* likely need to flush track buffers: this will locate us to wherever we are */
-		add_post_transport_work (PostTransportLocate);
-		TFSM_EVENT (TransportFSM::ButlerRequired);
+
+		if (change_transport_state && transport_rolling ()) {
+			TFSM_EVENT (TransportFSM::StopTransport);
+		}
+
+		overwrite_some_buffers (boost::shared_ptr<Route>());
+
 		TransportStateChange (); /* EMIT SIGNAL */
 	}
 }