fix xfade logic and use shared_ptr for xfades

git-svn-id: svn://localhost/ardour2/trunk@1297 d708f5d6-7413-0410-9779-e7cbd77b26cf

15 files changed, 347 insertions, 330 deletions

diff --git a/gtk2_ardour/ardev b/gtk2_ardour/ardev
index 3b65b2ec79..ff68e11fbe 100755
--- a/gtk2_ardour/ardev
+++ b/gtk2_ardour/ardev
@@ -1,3 +1,3 @@
 #!/bin/sh
 . `dirname "$0"`/ardev_common.sh
-exec $EXECUTABLE "$*"
+exec $EXECUTABLE $*
diff --git a/gtk2_ardour/audio_streamview.cc b/gtk2_ardour/audio_streamview.cc
index 89d6d394c4..349f472e6e 100644
--- a/gtk2_ardour/audio_streamview.cc
+++ b/gtk2_ardour/audio_streamview.cc
@@ -224,7 +224,7 @@ AudioStreamView::remove_region_view (boost::weak_ptr<Region> weak_r)
 			++tmp;
 			
 			boost::shared_ptr<AudioRegion> ar = boost::dynamic_pointer_cast<AudioRegion>(r);
-			if (ar && (*i)->crossfade.involves (ar)) {
+			if (ar && (*i)->crossfade->involves (ar)) {
 				delete *i;
 				crossfade_views.erase (i);
 			}
@@ -276,17 +276,17 @@ AudioStreamView::playlist_changed (boost::shared_ptr<Diskstream> ds)
 }
 
 void
-AudioStreamView::add_crossfade (Crossfade *crossfade)
+AudioStreamView::add_crossfade (boost::shared_ptr<Crossfade> crossfade)
 {
 	AudioRegionView* lview = 0;
 	AudioRegionView* rview = 0;
-
+	
 	ENSURE_GUI_THREAD (bind (mem_fun (*this, &AudioStreamView::add_crossfade), crossfade));
 
 	/* first see if we already have a CrossfadeView for this Crossfade */
 
 	for (list<CrossfadeView *>::iterator i = crossfade_views.begin(); i != crossfade_views.end(); ++i) {
-		if ((*i)->crossfade == *crossfade) {
+		if ((*i)->crossfade == crossfade) {
 			if (!crossfades_visible) {
 				(*i)->hide();
 			} else {
@@ -312,7 +312,7 @@ AudioStreamView::add_crossfade (Crossfade *crossfade)
 
 	CrossfadeView *cv = new CrossfadeView (_trackview.canvas_display,
 					       _trackview,
-					       *crossfade,
+					        crossfade,
 					       _samples_per_unit,
 					       region_color,
 					       *lview, *rview);
@@ -326,12 +326,12 @@ AudioStreamView::add_crossfade (Crossfade *crossfade)
 }
 
 void
-AudioStreamView::remove_crossfade (Crossfade *xfade)
+AudioStreamView::remove_crossfade (boost::shared_ptr<Crossfade> xfade)
 {
 	ENSURE_GUI_THREAD (bind (mem_fun (*this, &AudioStreamView::remove_crossfade), xfade));
 
 	for (list<CrossfadeView*>::iterator i = crossfade_views.begin(); i != crossfade_views.end(); ++i) {
-		if (&(*i)->crossfade == xfade) {
+		if ((*i)->crossfade == xfade) {
 			delete *i;
 			crossfade_views.erase (i);
 			break;
@@ -715,7 +715,7 @@ void
 AudioStreamView::hide_xfades_involving (AudioRegionView& rv)
 {
 	for (list<CrossfadeView *>::iterator i = crossfade_views.begin(); i != crossfade_views.end(); ++i) {
-		if ((*i)->crossfade.involves (rv.audio_region())) {
+		if ((*i)->crossfade->involves (rv.audio_region())) {
 			(*i)->fake_hide ();
 		}
 	}
@@ -725,7 +725,7 @@ void
 AudioStreamView::reveal_xfades_involving (AudioRegionView& rv)
 {
 	for (list<CrossfadeView *>::iterator i = crossfade_views.begin(); i != crossfade_views.end(); ++i) {
-		if ((*i)->crossfade.involves (rv.audio_region()) && (*i)->visible()) {
+		if ((*i)->crossfade->involves (rv.audio_region()) && (*i)->visible()) {
 			(*i)->show ();
 		}
 	}
diff --git a/gtk2_ardour/audio_streamview.h b/gtk2_ardour/audio_streamview.h
index 295e02d96a..893622116f 100644
--- a/gtk2_ardour/audio_streamview.h
+++ b/gtk2_ardour/audio_streamview.h
@@ -93,8 +93,8 @@ class AudioStreamView : public StreamView
 	void playlist_modified ();
 	void playlist_changed (boost::shared_ptr<ARDOUR::Diskstream>);
 
-	void add_crossfade (ARDOUR::Crossfade*);
-	void remove_crossfade (ARDOUR::Crossfade*);
+	void add_crossfade (boost::shared_ptr<ARDOUR::Crossfade>);
+	void remove_crossfade (boost::shared_ptr<ARDOUR::Crossfade>);
 
 	void color_handler (ColorID id, uint32_t val);
 	
diff --git a/gtk2_ardour/crossfade_edit.cc b/gtk2_ardour/crossfade_edit.cc
index f6f26c76d5..94e167282c 100644
--- a/gtk2_ardour/crossfade_edit.cc
+++ b/gtk2_ardour/crossfade_edit.cc
@@ -72,7 +72,7 @@ CrossfadeEditor::Half::Half ()
 {
 }
 
-CrossfadeEditor::CrossfadeEditor (Session& s, Crossfade& xf, double my, double mxy)
+CrossfadeEditor::CrossfadeEditor (Session& s, boost::shared_ptr<Crossfade> xf, double my, double mxy)
 	: ArdourDialog (_("ardour: x-fade edit")),
 	  xfade (xf),
 	  session (s),
@@ -279,14 +279,14 @@ CrossfadeEditor::CrossfadeEditor (Session& s, Crossfade& xf, double my, double m
 //	vpacker.pack_start (*foobut, false, false);
 
 	current = In;
-	set (xfade.fade_in(), In);
+	set (xfade->fade_in(), In);
 
 	current = Out;
-	set (xfade.fade_out(), Out);
+	set (xfade->fade_out(), Out);
 
 	curve_select_clicked (In);
 
-	xfade.StateChanged.connect (mem_fun(*this, &CrossfadeEditor::xfade_changed));
+	xfade->StateChanged.connect (mem_fun(*this, &CrossfadeEditor::xfade_changed));
 
 	session.AuditionActive.connect (mem_fun(*this, &CrossfadeEditor::audition_state_changed));
 	show_all_children();
@@ -577,21 +577,21 @@ CrossfadeEditor::canvas_allocation (Gtk::Allocation& alloc)
 	redraw ();
 	current = old_current;
 
-	double spu = xfade.length() / (double) effective_width();
+	double spu = xfade->length() / (double) effective_width();
 
 	if (fade[In].waves.empty()) {
-		make_waves (xfade.in(), In);
+		make_waves (xfade->in(), In);
 	}
 
 	if (fade[Out].waves.empty()) {
-		make_waves (xfade.out(), Out);
+		make_waves (xfade->out(), Out);
 	}
 
 	double ht;
 	vector<ArdourCanvas::WaveView*>::iterator i;
 	uint32_t n;
 
-	ht = canvas->get_allocation().get_height() / xfade.in()->n_channels();
+	ht = canvas->get_allocation().get_height() / xfade->in()->n_channels();
 
 	for (n = 0, i = fade[In].waves.begin(); i != fade[In].waves.end(); ++i, ++n) {
 		double yoff;
@@ -603,7 +603,7 @@ CrossfadeEditor::canvas_allocation (Gtk::Allocation& alloc)
 		(*i)->property_samples_per_unit() = spu;
 	}
 
-	ht = canvas->get_allocation().get_height() / xfade.out()->n_channels();
+	ht = canvas->get_allocation().get_height() / xfade->out()->n_channels();
 
 	for (n = 0, i = fade[Out].waves.begin(); i != fade[Out].waves.end(); ++i, ++n) {
 		double yoff;
@@ -621,8 +621,8 @@ CrossfadeEditor::canvas_allocation (Gtk::Allocation& alloc)
 void
 CrossfadeEditor::xfade_changed (Change ignored)
 {
-	set (xfade.fade_in(), In);
-	set (xfade.fade_out(), Out);
+	set (xfade->fade_in(), In);
+	set (xfade->fade_out(), Out);
 }
 
 void
@@ -632,7 +632,7 @@ CrossfadeEditor::redraw ()
 		return;
 	}
 
-	nframes_t len = xfade.length ();
+	nframes_t len = xfade->length ();
 
 	fade[current].normative_curve.clear ();
 	fade[current].gain_curve.clear ();
@@ -741,11 +741,11 @@ CrossfadeEditor::apply_preset (Preset *preset)
 void
 CrossfadeEditor::apply ()
 {
-	_apply_to (&xfade);
+	_apply_to (xfade);
 }
 
 void
-CrossfadeEditor::_apply_to (Crossfade* xf)
+CrossfadeEditor::_apply_to (boost::shared_ptr<Crossfade> xf)
 {
 	ARDOUR::Curve& in (xf->fade_in());
 	ARDOUR::Curve& out (xf->fade_out());
@@ -796,7 +796,7 @@ CrossfadeEditor::_apply_to (Crossfade* xf)
 }
 
 void
-CrossfadeEditor::setup (Crossfade* xfade)
+CrossfadeEditor::setup (boost::shared_ptr<Crossfade> xfade)
 {
 	_apply_to (xfade);
 	xfade->set_active (true);
@@ -819,8 +819,8 @@ CrossfadeEditor::clear ()
 void
 CrossfadeEditor::reset ()
 {
-	set (xfade.fade_in(),  In);
-	set (xfade.fade_out(), Out);
+	set (xfade->fade_in(),  In);
+	set (xfade->fade_out(), Out);
 }
 
 void
@@ -1028,7 +1028,7 @@ CrossfadeEditor::make_waves (boost::shared_ptr<AudioRegion> region, WhichFade wh
 	}
 
 	ht = canvas->get_allocation().get_height() / (double) nchans;
-	spu = xfade.length() / (double) effective_width();
+	spu = xfade->length() / (double) effective_width();
 
 	for (uint32_t n = 0; n < nchans; ++n) {
 		
@@ -1096,25 +1096,25 @@ CrossfadeEditor::audition_both ()
 		postroll = 0;
 	}
 
- 	if ((left_start_offset = xfade.out()->length() - xfade.length()) >= preroll) {
+ 	if ((left_start_offset = xfade->out()->length() - xfade->length()) >= preroll) {
   		left_start_offset -= preroll;
   	} 
 
 	length = 0;
 
- 	if ((left_length = xfade.length()) < xfade.out()->length() - left_start_offset) {
+ 	if ((left_length = xfade->length()) < xfade->out()->length() - left_start_offset) {
   		length += postroll;
   	}
 
-	right_length = xfade.length();
+	right_length = xfade->length();
 
-	if (xfade.in()->length() - right_length < postroll) {
+	if (xfade->in()->length() - right_length < postroll) {
 		right_length += postroll;
 	}
 
-	boost::shared_ptr<AudioRegion> left (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade.out(), left_start_offset, left_length, "xfade out", 
+	boost::shared_ptr<AudioRegion> left (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade->out(), left_start_offset, left_length, "xfade out", 
 													      0, Region::DefaultFlags, false)));
-	boost::shared_ptr<AudioRegion> right (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade.in(), 0, right_length, "xfade in", 
+	boost::shared_ptr<AudioRegion> right (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade->in(), 0, right_length, "xfade in", 
 													       0, Region::DefaultFlags, false)));
 	
 	pl.add_region (left, 0);
@@ -1130,7 +1130,7 @@ CrossfadeEditor::audition_both ()
 void
 CrossfadeEditor::audition_left_dry ()
 {
-	boost::shared_ptr<AudioRegion> left (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade.out(), xfade.out()->length() - xfade.length(), xfade.length(), "xfade left", 
+	boost::shared_ptr<AudioRegion> left (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade->out(), xfade->out()->length() - xfade->length(), xfade->length(), "xfade left", 
 													      0, Region::DefaultFlags, false)));
 	
 	session.audition_region (left);
@@ -1141,9 +1141,9 @@ CrossfadeEditor::audition_left ()
 {
 	AudioPlaylist& pl (session.the_auditioner()->prepare_playlist());
 
-	boost::shared_ptr<AudioRegion> left (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade.out(), xfade.out()->length() - xfade.length(), xfade.length(), "xfade left", 
+	boost::shared_ptr<AudioRegion> left (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade->out(), xfade->out()->length() - xfade->length(), xfade->length(), "xfade left", 
 													      0, Region::DefaultFlags, false)));
-	boost::shared_ptr<AudioRegion> right (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade.in(), 0, xfade.length(), "xfade in", 
+	boost::shared_ptr<AudioRegion> right (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade->in(), 0, xfade->length(), "xfade in", 
 													       0, Region::DefaultFlags, false)));
 
 	pl.add_region (left, 0);
@@ -1163,7 +1163,7 @@ CrossfadeEditor::audition_left ()
 void
 CrossfadeEditor::audition_right_dry ()
 {
-	boost::shared_ptr<AudioRegion> right (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade.in(), 0, xfade.length(), "xfade in", 
+	boost::shared_ptr<AudioRegion> right (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade->in(), 0, xfade->length(), "xfade in", 
 													       0, Region::DefaultFlags, false)));
 	session.audition_region (right);
 }
@@ -1173,9 +1173,9 @@ CrossfadeEditor::audition_right ()
 {
 	AudioPlaylist& pl (session.the_auditioner()->prepare_playlist());
 
-	boost::shared_ptr<AudioRegion> left (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade.out(), xfade.out()->length() - xfade.length(), xfade.length(), "xfade out", 
+	boost::shared_ptr<AudioRegion> left (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade->out(), xfade->out()->length() - xfade->length(), xfade->length(), "xfade out", 
 													      0, Region::DefaultFlags, false)));
-					     boost::shared_ptr<AudioRegion> right (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade.out(), 0, xfade.length(), "xfade out", 
+					     boost::shared_ptr<AudioRegion> right (boost::dynamic_pointer_cast<AudioRegion> (RegionFactory::create (xfade->out(), 0, xfade->length(), "xfade out", 
 													       0, Region::DefaultFlags, false)));
 
 	pl.add_region (left, 0);
diff --git a/gtk2_ardour/crossfade_edit.h b/gtk2_ardour/crossfade_edit.h
index ad0661c036..3c9a6a13c1 100644
--- a/gtk2_ardour/crossfade_edit.h
+++ b/gtk2_ardour/crossfade_edit.h
@@ -21,170 +21,170 @@ namespace ARDOUR
 class CrossfadeEditor : public ArdourDialog
 {
   public:
-    CrossfadeEditor (ARDOUR::Session&, ARDOUR::Crossfade&, double miny, double maxy);
-    ~CrossfadeEditor ();
-    
-    void apply ();
-
-    static const double canvas_border;
-    
-    /* these are public so that a caller/subclass can make them do the right thing.
-     */
-    
-    Gtk::Button* cancel_button;
-    Gtk::Button* ok_button;
-
-    struct PresetPoint {
-	double x;
-	double y;
-
-	PresetPoint (double a, double b) 
-		: x (a), y (b) {}
-    };
-
-    struct Preset : public list<PresetPoint> {
-	string xpm;
+	CrossfadeEditor (ARDOUR::Session&, boost::shared_ptr<ARDOUR::Crossfade>, double miny, double maxy);
+	~CrossfadeEditor ();
+	
+	void apply ();
+	
+	static const double canvas_border;
+	
+	/* these are public so that a caller/subclass can make them do the right thing.
+	 */
+	
+	Gtk::Button* cancel_button;
+	Gtk::Button* ok_button;
+	
+	struct PresetPoint {
+	    double x;
+	    double y;
+	    
+	    PresetPoint (double a, double b) 
+		    : x (a), y (b) {}
+	};
+	
+	struct Preset : public list<PresetPoint> {
+	    string xpm;
+	    
+	    Preset (string x)
+		    : xpm (x) {}
+	};
+	
+	typedef list<Preset*> Presets;
+	
+	static Presets* fade_in_presets;
+	static Presets* fade_out_presets;
 	
-	Preset (string x)
-		: xpm (x) {}
-    };
-
-    typedef list<Preset*> Presets;
-
-    static Presets* fade_in_presets;
-    static Presets* fade_out_presets;
-
   private:
-    ARDOUR::Crossfade& xfade;
-    ARDOUR::Session& session;
-
-    Gtk::VBox vpacker;
-
-    struct Point {
-	~Point();
-
-	ArdourCanvas::SimpleRect* box;
-	ArdourCanvas::Line* curve;
-	double x;
-	double y;
-
-	static const int32_t size;
-
-	void move_to (double x, double y, double xfract, double yfract);
-    };
-
-    struct PointSorter 
-    {
-	bool operator() (const CrossfadeEditor::Point* a, const CrossfadeEditor::Point *b) {
-		return a->x < b->x;
-	}
-    };
-
-    ArdourCanvas::SimpleRect*   toplevel;
-    ArdourCanvas::Canvas* canvas;
-
-    struct Half {
-	ArdourCanvas::Line*     line;
-	ArdourCanvas::Polygon*  shading;
-	list<Point*>            points;
-	ARDOUR::Curve           normative_curve; /* 0 - 1.0, linear */
-	ARDOUR::Curve           gain_curve;      /* 0 - 2.0, gain mapping */
-	vector<ArdourCanvas::WaveView*>  waves;
-
-	Half();
-    };
-
-    enum WhichFade {
-	    In = 0,
-	    Out = 1
-    };
-
-    Half fade[2];
-    WhichFade current;
-
-    bool point_grabbed;
-    vector<Gtk::Button*> fade_out_buttons;
-    vector<Gtk::Button*> fade_in_buttons;
+	boost::shared_ptr<ARDOUR::Crossfade> xfade;
+	ARDOUR::Session& session;
+	
+	Gtk::VBox vpacker;
+	
+	struct Point {
+	    ~Point();
+	    
+	    ArdourCanvas::SimpleRect* box;
+	    ArdourCanvas::Line* curve;
+	    double x;
+	    double y;
+	    
+	    static const int32_t size;
+	    
+	    void move_to (double x, double y, double xfract, double yfract);
+	};
+	
+	struct PointSorter 
+	{
+	    bool operator() (const CrossfadeEditor::Point* a, const CrossfadeEditor::Point *b) {
+		    return a->x < b->x;
+	    }
+	};
+	
+	ArdourCanvas::SimpleRect*   toplevel;
+	ArdourCanvas::Canvas* canvas;
+	
+	struct Half {
+	    ArdourCanvas::Line*     line;
+	    ArdourCanvas::Polygon*  shading;
+	    list<Point*>            points;
+	    ARDOUR::Curve           normative_curve; /* 0 - 1.0, linear */
+	    ARDOUR::Curve           gain_curve;      /* 0 - 2.0, gain mapping */
+	    vector<ArdourCanvas::WaveView*>  waves;
+	    
+	    Half();
+	};
+	
+	enum WhichFade {
+		In = 0,
+		Out = 1
+	};
+	
+	Half fade[2];
+	WhichFade current;
+	
+	bool point_grabbed;
+	vector<Gtk::Button*> fade_out_buttons;
+	vector<Gtk::Button*> fade_in_buttons;
 
-    Gtk::VBox vpacker2;
+	Gtk::VBox vpacker2;
 
-    Gtk::Button clear_button;
-    Gtk::Button revert_button;
+	Gtk::Button clear_button;
+	Gtk::Button revert_button;
 
-    Gtk::ToggleButton audition_both_button;
-    Gtk::ToggleButton audition_left_dry_button;
-    Gtk::ToggleButton audition_left_button;
-    Gtk::ToggleButton audition_right_dry_button;
-    Gtk::ToggleButton audition_right_button;
+	Gtk::ToggleButton audition_both_button;
+	Gtk::ToggleButton audition_left_dry_button;
+	Gtk::ToggleButton audition_left_button;
+	Gtk::ToggleButton audition_right_dry_button;
+	Gtk::ToggleButton audition_right_button;
 
-    Gtk::ToggleButton preroll_button;
-    Gtk::ToggleButton postroll_button;
+	Gtk::ToggleButton preroll_button;
+	Gtk::ToggleButton postroll_button;
 
-    Gtk::HBox roll_box;
+	Gtk::HBox roll_box;
 
-    gint event_handler (GdkEvent*);
+	gint event_handler (GdkEvent*);
 
-    bool canvas_event (GdkEvent* event);
-    bool point_event (GdkEvent* event, Point*);
-    bool curve_event (GdkEvent* event);
+	bool canvas_event (GdkEvent* event);
+	bool point_event (GdkEvent* event, Point*);
+	bool curve_event (GdkEvent* event);
 
-    void canvas_allocation (Gtk::Allocation&);
-    void add_control_point (double x, double y);
-    Point* make_point ();
-    void redraw ();
+	void canvas_allocation (Gtk::Allocation&);
+	void add_control_point (double x, double y);
+	Point* make_point ();
+	void redraw ();
     
-    double effective_width () const { return canvas->get_allocation().get_width() - (2.0 * canvas_border); }
-    double effective_height () const { return canvas->get_allocation().get_height() - (2.0 * canvas_border); }
+	double effective_width () const { return canvas->get_allocation().get_width() - (2.0 * canvas_border); }
+	double effective_height () const { return canvas->get_allocation().get_height() - (2.0 * canvas_border); }
 
-    void clear ();
-    void reset ();
+	void clear ();
+	void reset ();
 
-    double miny;
-    double maxy;
+	double miny;
+	double maxy;
 
-    Gtk::Table fade_in_table;
-    Gtk::Table fade_out_table;
+	Gtk::Table fade_in_table;
+	Gtk::Table fade_out_table;
 
-    void build_presets ();
-    void apply_preset (Preset*);
+	void build_presets ();
+	void apply_preset (Preset*);
     
-    Gtk::RadioButton select_in_button;
-    Gtk::RadioButton select_out_button;
-    Gtk::HBox   curve_button_box;
-    Gtk::HBox   audition_box;
+	Gtk::RadioButton select_in_button;
+	Gtk::RadioButton select_out_button;
+	Gtk::HBox   curve_button_box;
+	Gtk::HBox   audition_box;
 
-    void curve_select_clicked (WhichFade);
+	void curve_select_clicked (WhichFade);
 
-    double x_coordinate (double& xfract) const;
-    double y_coordinate (double& yfract) const;
+	double x_coordinate (double& xfract) const;
+	double y_coordinate (double& yfract) const;
     
-    void set (const ARDOUR::Curve& alist, WhichFade);
+	void set (const ARDOUR::Curve& alist, WhichFade);
 
-    sigc::connection peaks_ready_connection;
+	sigc::connection peaks_ready_connection;
 
-    void make_waves (boost::shared_ptr<ARDOUR::AudioRegion>, WhichFade);
-    void peaks_ready (boost::shared_ptr<ARDOUR::AudioRegion> r, WhichFade);
+	void make_waves (boost::shared_ptr<ARDOUR::AudioRegion>, WhichFade);
+	void peaks_ready (boost::shared_ptr<ARDOUR::AudioRegion> r, WhichFade);
     
-    void _apply_to (ARDOUR::Crossfade* xf);
-    void setup (ARDOUR::Crossfade*);
-    void cancel_audition ();
-    void audition_state_changed (bool);
-
-    void audition_toggled ();
-    void audition_right_toggled ();
-    void audition_right_dry_toggled ();
-    void audition_left_toggled ();
-    void audition_left_dry_toggled ();
-
-    void audition_both ();
-    void audition_left_dry ();
-    void audition_left ();
-    void audition_right_dry ();
-    void audition_right ();
-
-    void xfade_changed (ARDOUR::Change);
-
-    void dump ();
+	void _apply_to (boost::shared_ptr<ARDOUR::Crossfade> xf);
+	void setup (boost::shared_ptr<ARDOUR::Crossfade>);
+	void cancel_audition ();
+	void audition_state_changed (bool);
+
+	void audition_toggled ();
+	void audition_right_toggled ();
+	void audition_right_dry_toggled ();
+	void audition_left_toggled ();
+	void audition_left_dry_toggled ();
+
+	void audition_both ();
+	void audition_left_dry ();
+	void audition_left ();
+	void audition_right_dry ();
+	void audition_right ();
+
+	void xfade_changed (ARDOUR::Change);
+
+	void dump ();
 };
 
 #endif /* __gtk_ardour_xfade_edit_h__ */
diff --git a/gtk2_ardour/crossfade_view.cc b/gtk2_ardour/crossfade_view.cc
index 3c3ef4ff91..b56cedd08a 100644
--- a/gtk2_ardour/crossfade_view.cc
+++ b/gtk2_ardour/crossfade_view.cc
@@ -44,15 +44,15 @@ sigc::signal<void,CrossfadeView*> CrossfadeView::GoingAway;
 
 CrossfadeView::CrossfadeView (ArdourCanvas::Group *parent, 
 			      RouteTimeAxisView &tv, 
-			      Crossfade& xf, 
+			      boost::shared_ptr<Crossfade> xf, 
 			      double spu,
 			      Gdk::Color& basic_color,
 			      AudioRegionView& lview,
 			      AudioRegionView& rview)
 			      
 
-	: TimeAxisViewItem ("xfade" /*xf.name()*/, *parent, tv, spu, basic_color, xf.position(), 
-			    xf.length(), TimeAxisViewItem::Visibility (TimeAxisViewItem::ShowFrame)),
+	: TimeAxisViewItem ("xfade" /*xf.name()*/, *parent, tv, spu, basic_color, xf->position(), 
+			    xf->length(), TimeAxisViewItem::Visibility (TimeAxisViewItem::ShowFrame)),
 	  crossfade (xf),
 	  left_view (lview),
 	  right_view (rview)
@@ -84,7 +84,7 @@ CrossfadeView::CrossfadeView (ArdourCanvas::Group *parent,
 	
 	crossfade_changed (Change (~0));
 
-	crossfade.StateChanged.connect (mem_fun(*this, &CrossfadeView::crossfade_changed));
+	crossfade->StateChanged.connect (mem_fun(*this, &CrossfadeView::crossfade_changed));
 }
 
 CrossfadeView::~CrossfadeView ()
@@ -123,8 +123,8 @@ CrossfadeView::crossfade_changed (Change what_changed)
 	bool need_redraw_curves = false;
 
 	if (what_changed & BoundsChanged) {
-		set_position (crossfade.position(), this);
-		set_duration (crossfade.length(), this);
+		set_position (crossfade->position(), this);
+		set_duration (crossfade->length(), this);
 		need_redraw_curves = true;
 	}
 
@@ -148,7 +148,7 @@ CrossfadeView::redraw_curves ()
 	float* vec;
 	double h;
 
-	if (!crossfade.following_overlap()) {
+	if (!crossfade->following_overlap()) {
 		/* curves should not be visible */
 		fade_in->hide ();
 		fade_out->hide ();
@@ -172,10 +172,10 @@ CrossfadeView::redraw_curves ()
 		return;
 	}
 
-	npoints = get_time_axis_view().editor.frame_to_pixel (crossfade.length());
+	npoints = get_time_axis_view().editor.frame_to_pixel (crossfade->length());
 	npoints = std::min (gdk_screen_width(), npoints);
 
-	if (!_visible || !crossfade.active() || npoints < 3) {
+	if (!_visible || !crossfade->active() || npoints < 3) {
 		fade_in->hide();
 		fade_out->hide();
 		return;
@@ -187,7 +187,7 @@ CrossfadeView::redraw_curves ()
 	points = get_canvas_points ("xfade edit redraw", npoints);
 	vec = new float[npoints];
 
-	crossfade.fade_in().get_vector (0, crossfade.length(), vec, npoints);
+	crossfade->fade_in().get_vector (0, crossfade->length(), vec, npoints);
 	for (int i = 0, pci = 0; i < npoints; ++i) {
 		Art::Point &p = (*points)[pci++];
 		p.set_x(i);
@@ -195,7 +195,7 @@ CrossfadeView::redraw_curves ()
 	}
 	fade_in->property_points() = *points;
 
-	crossfade.fade_out().get_vector (0, crossfade.length(), vec, npoints);
+	crossfade->fade_out().get_vector (0, crossfade->length(), vec, npoints);
 	for (int i = 0, pci = 0; i < npoints; ++i) {
 		Art::Point &p = (*points)[pci++];
 		p.set_x(i);
@@ -217,7 +217,7 @@ CrossfadeView::redraw_curves ()
 void
 CrossfadeView::active_changed ()
 {
-	if (crossfade.active()) {
+	if (crossfade->active()) {
 		frame->property_fill_color_rgba() = color_map[cActiveCrossfade];
 	} else {
 		frame->property_fill_color_rgba() = color_map[cInactiveCrossfade];
diff --git a/gtk2_ardour/crossfade_view.h b/gtk2_ardour/crossfade_view.h
index adbd74b420..730813f78c 100644
--- a/gtk2_ardour/crossfade_view.h
+++ b/gtk2_ardour/crossfade_view.h
@@ -35,14 +35,15 @@ struct CrossfadeView : public TimeAxisViewItem
 {
     CrossfadeView (ArdourCanvas::Group*, 
 		   RouteTimeAxisView&,
-		   ARDOUR::Crossfade&,
+		   boost::shared_ptr<ARDOUR::Crossfade>,
 		   double initial_samples_per_unit, 
 		   Gdk::Color& basic_color,
 		   AudioRegionView& leftview,
 		   AudioRegionView& rightview);
     ~CrossfadeView ();
 
-    ARDOUR::Crossfade& crossfade;  // ok, let 'em have it
+    boost::shared_ptr<ARDOUR::Crossfade> crossfade;  // ok, let 'em have it
+
     AudioRegionView& left_view;    // and these too
     AudioRegionView& right_view;
 
diff --git a/gtk2_ardour/editor.cc b/gtk2_ardour/editor.cc
index 5c2acc8a2a..ebcf4ecad3 100644
--- a/gtk2_ardour/editor.cc
+++ b/gtk2_ardour/editor.cc
@@ -1649,7 +1649,7 @@ Editor::build_track_selection_context_menu (nframes_t ignored)
 }
 
 void
-Editor::add_crossfade_context_items (AudioStreamView* view, Crossfade* xfade, Menu_Helpers::MenuList& edit_items, bool many)
+Editor::add_crossfade_context_items (AudioStreamView* view, boost::shared_ptr<Crossfade> xfade, Menu_Helpers::MenuList& edit_items, bool many)
 {
 	using namespace Menu_Helpers;
 	Menu     *xfade_menu = manage (new Menu);
@@ -1663,8 +1663,8 @@ Editor::add_crossfade_context_items (AudioStreamView* view, Crossfade* xfade, Me
 		str = _("Unmute");
 	}
 
-	items.push_back (MenuElem (str, bind (mem_fun(*this, &Editor::toggle_xfade_active), xfade)));
-	items.push_back (MenuElem (_("Edit"), bind (mem_fun(*this, &Editor::edit_xfade), xfade)));
+	items.push_back (MenuElem (str, bind (mem_fun(*this, &Editor::toggle_xfade_active), boost::weak_ptr<Crossfade> (xfade))));
+	items.push_back (MenuElem (_("Edit"), bind (mem_fun(*this, &Editor::edit_xfade), boost::weak_ptr<Crossfade> (xfade))));
 
 	if (xfade->can_follow_overlap()) {
 
@@ -3900,21 +3900,33 @@ Editor::set_follow_playhead (bool yn)
 }
 
 void
-Editor::toggle_xfade_active (Crossfade* xfade)
+Editor::toggle_xfade_active (boost::weak_ptr<Crossfade> wxfade)
 {
-	xfade->set_active (!xfade->active());
+	boost::shared_ptr<Crossfade> xfade (wxfade.lock());
+	if (xfade) {
+		xfade->set_active (!xfade->active());
+	}
 }
 
 void
-Editor::toggle_xfade_length (Crossfade* xfade)
+Editor::toggle_xfade_length (boost::weak_ptr<Crossfade> wxfade)
 {
-	xfade->set_follow_overlap (!xfade->following_overlap());
+	boost::shared_ptr<Crossfade> xfade (wxfade.lock());
+	if (xfade) {
+		xfade->set_follow_overlap (!xfade->following_overlap());
+	}
 }
 
 void
-Editor::edit_xfade (Crossfade* xfade)
+Editor::edit_xfade (boost::weak_ptr<Crossfade> wxfade)
 {
-	CrossfadeEditor cew (*session, *xfade, xfade->fade_in().get_min_y(), 1.0);
+	boost::shared_ptr<Crossfade> xfade (wxfade.lock());
+
+	if (!xfade) {
+		return;
+	}
+
+	CrossfadeEditor cew (*session, xfade, xfade->fade_in().get_min_y(), 1.0);
 		
 	ensure_float (cew);
 	
diff --git a/gtk2_ardour/editor.h b/gtk2_ardour/editor.h
index 68b5bd256e..8ee9c45ed1 100644
--- a/gtk2_ardour/editor.h
+++ b/gtk2_ardour/editor.h
@@ -464,7 +464,7 @@ class Editor : public PublicEditor
 	void add_dstream_context_items (Gtk::Menu_Helpers::MenuList&);
 	void add_bus_context_items (Gtk::Menu_Helpers::MenuList&);
 	void add_region_context_items (AudioStreamView*, boost::shared_ptr<ARDOUR::Region>, Gtk::Menu_Helpers::MenuList&);
-	void add_crossfade_context_items (AudioStreamView*, ARDOUR::Crossfade*, Gtk::Menu_Helpers::MenuList&, bool many);
+	void add_crossfade_context_items (AudioStreamView*, boost::shared_ptr<ARDOUR::Crossfade>, Gtk::Menu_Helpers::MenuList&, bool many);
 	void add_selection_context_items (Gtk::Menu_Helpers::MenuList&);
 
 	void handle_new_route (ARDOUR::Session::RouteList&);
@@ -1734,9 +1734,9 @@ class Editor : public PublicEditor
 	ImageFrameSocketHandler* image_socket_listener ;
 	/* </CMT Additions> */
 
-	void toggle_xfade_active (ARDOUR::Crossfade*);
-	void toggle_xfade_length (ARDOUR::Crossfade*);
-	void edit_xfade (ARDOUR::Crossfade*);
+	void toggle_xfade_active (boost::weak_ptr<ARDOUR::Crossfade>);
+	void toggle_xfade_length (boost::weak_ptr<ARDOUR::Crossfade>);
+	void edit_xfade (boost::weak_ptr<ARDOUR::Crossfade>);
 	void xfade_edit_left_region ();
 	void xfade_edit_right_region ();
 
diff --git a/libs/ardour/ardour/audioplaylist.h b/libs/ardour/ardour/audioplaylist.h
index 2f1b127c5a..586bf6ccc6 100644
--- a/libs/ardour/ardour/audioplaylist.h
+++ b/libs/ardour/ardour/audioplaylist.h
@@ -37,7 +37,7 @@ class Source;
 class AudioPlaylist : public ARDOUR::Playlist
 {
   public:
-	typedef std::list<Crossfade*> Crossfades;
+	typedef std::list<boost::shared_ptr<Crossfade> > Crossfades;
 	
    public:
 	AudioPlaylist (Session&, const XMLNode&, bool hidden = false);
@@ -53,9 +53,9 @@ class AudioPlaylist : public ARDOUR::Playlist
 
 	int set_state (const XMLNode&);
 
-	sigc::signal<void,Crossfade *> NewCrossfade; 
+	sigc::signal<void,boost::shared_ptr<Crossfade> > NewCrossfade; 
 
-	template<class T> void foreach_crossfade (T *t, void (T::*func)(Crossfade *));
+	template<class T> void foreach_crossfade (T *t, void (T::*func)(boost::shared_ptr<Crossfade>));
 	void crossfades_at (nframes_t frame, Crossfades&);
 
 	bool destroy_region (boost::shared_ptr<Region>);
@@ -63,7 +63,7 @@ class AudioPlaylist : public ARDOUR::Playlist
     protected:
 
 	/* playlist "callbacks" */
-	void notify_crossfade_added (Crossfade *);
+	void notify_crossfade_added (boost::shared_ptr<Crossfade>);
 	void flush_notifications ();
 
 	void finalize_split_region (boost::shared_ptr<Region> orig, boost::shared_ptr<Region> left, boost::shared_ptr<Region> right);
@@ -73,16 +73,16 @@ class AudioPlaylist : public ARDOUR::Playlist
         void remove_dependents (boost::shared_ptr<Region> region);
 
     private:
-       Crossfades      _crossfades;    /* xfades currently in use */
+       Crossfades      _crossfades;
        Crossfades      _pending_xfade_adds;
 
-       void crossfade_invalidated (Crossfade*);
+       void crossfade_invalidated (boost::shared_ptr<Crossfade>);
        XMLNode& state (bool full_state);
        void dump () const;
 
        bool region_changed (Change, boost::shared_ptr<Region>);
        void crossfade_changed (Change);
-       void add_crossfade (Crossfade&);
+       void add_crossfade (boost::shared_ptr<Crossfade>);
 
        void source_offset_changed (boost::shared_ptr<AudioRegion> region);
 };
diff --git a/libs/ardour/ardour/crossfade.h b/libs/ardour/ardour/crossfade.h
index 0422698c5e..946d35b8e0 100644
--- a/libs/ardour/ardour/crossfade.h
+++ b/libs/ardour/ardour/crossfade.h
@@ -24,6 +24,7 @@
 #include <vector>
 #include <algorithm>
 #include <boost/shared_ptr.hpp>
+#include <boost/enable_shared_from_this.hpp>
 
 #include <sigc++/signal.h>
 
@@ -40,7 +41,7 @@ namespace ARDOUR {
 class AudioRegion;
 class Playlist;
 
-class Crossfade : public PBD::StatefulDestructible
+class Crossfade : public PBD::StatefulDestructible, public boost::enable_shared_from_this<ARDOUR::Crossfade>
 {
   public:
 
@@ -111,7 +112,7 @@ class Crossfade : public PBD::StatefulDestructible
 
 	void invalidate();
 
-	sigc::signal<void,Crossfade*> Invalidated;
+	sigc::signal<void,boost::shared_ptr<Crossfade> > Invalidated;
 	sigc::signal<void,Change>     StateChanged;
 
 	bool covers (nframes_t frame) const {
diff --git a/libs/ardour/ardour/playlist_templates.h b/libs/ardour/ardour/playlist_templates.h
index 7ce6c1818c..603e0bef37 100644
--- a/libs/ardour/ardour/playlist_templates.h
+++ b/libs/ardour/ardour/playlist_templates.h
@@ -23,7 +23,7 @@
 
 namespace ARDOUR {
 
-template<class T> void AudioPlaylist::foreach_crossfade (T *t, void (T::*func)(Crossfade *)) {
+template<class T> void AudioPlaylist::foreach_crossfade (T *t, void (T::*func)(boost::shared_ptr<Crossfade>)) {
 	RegionLock rlock (this, false);
 	for (Crossfades::iterator i = _crossfades.begin(); i != _crossfades.end(); i++) {	
 		(t->*func) (*i);
diff --git a/libs/ardour/audio_playlist.cc b/libs/ardour/audio_playlist.cc
index 0c35599332..06060061e0 100644
--- a/libs/ardour/audio_playlist.cc
+++ b/libs/ardour/audio_playlist.cc
@@ -62,7 +62,7 @@ AudioPlaylist::AudioPlaylist (boost::shared_ptr<const AudioPlaylist> other, stri
 		boost::shared_ptr<AudioRegion> ar = boost::dynamic_pointer_cast<AudioRegion>(*in_o);
 
 		// We look only for crossfades which begin with the current region, so we don't get doubles
-		for (list<Crossfade *>::const_iterator xfades = other->_crossfades.begin(); xfades != other->_crossfades.end(); ++xfades) {
+		for (Crossfades::const_iterator xfades = other->_crossfades.begin(); xfades != other->_crossfades.end(); ++xfades) {
 			if ((*xfades)->in() == ar) {
 				// We found one! Now copy it!
 
@@ -76,8 +76,8 @@ AudioPlaylist::AudioPlaylist (boost::shared_ptr<const AudioPlaylist> other, stri
 					if ((*xfades)->out() == ar2) {
 						boost::shared_ptr<AudioRegion>in  = boost::dynamic_pointer_cast<AudioRegion>(*in_n);
 						boost::shared_ptr<AudioRegion>out = boost::dynamic_pointer_cast<AudioRegion>(*out_n);
-						Crossfade *new_fade = new Crossfade (*(*xfades), in, out);
-						add_crossfade(*new_fade);
+						boost::shared_ptr<Crossfade> new_fade = boost::shared_ptr<Crossfade> (new Crossfade (*(*xfades), in, out));
+						add_crossfade(new_fade);
 						break;
 					}
 					
@@ -101,24 +101,13 @@ AudioPlaylist::AudioPlaylist (boost::shared_ptr<const AudioPlaylist> other, nfra
 
 AudioPlaylist::~AudioPlaylist ()
 {
-	set<Crossfade*> all_xfades;
-
   	GoingAway (); /* EMIT SIGNAL */
 
 	/* drop connections to signals */
 
 	notify_callbacks ();
 
-	for (Crossfades::iterator x = _crossfades.begin(); x != _crossfades.end(); ) {
-		Crossfades::iterator tmp;
-
-		tmp = x;
-		++tmp;
-
-		delete *x;
-
-		x = tmp;
-	}
+	_crossfades.clear ();
 }
 
 struct RegionSortByLayer {
@@ -164,7 +153,7 @@ AudioPlaylist::read (Sample *buf, Sample *mixdown_buffer, float *gain_buffer, nf
 	_read_data_count = 0;
 
 	map<uint32_t,vector<boost::shared_ptr<Region> > > relevant_regions;
-	map<uint32_t,vector<Crossfade*> > relevant_xfades;
+	map<uint32_t,vector<boost::shared_ptr<Crossfade> > > relevant_xfades;
 	vector<uint32_t> relevant_layers;
 
 	for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
@@ -194,7 +183,7 @@ AudioPlaylist::read (Sample *buf, Sample *mixdown_buffer, float *gain_buffer, nf
 	for (vector<uint32_t>::iterator l = relevant_layers.begin(); l != relevant_layers.end(); ++l) {
 
 		vector<boost::shared_ptr<Region> > r (relevant_regions[*l]);
-		vector<Crossfade*>& x (relevant_xfades[*l]);
+		vector<boost::shared_ptr<Crossfade> >& x (relevant_xfades[*l]);
 
 		for (vector<boost::shared_ptr<Region> >::iterator i = r.begin(); i != r.end(); ++i) {
 			boost::shared_ptr<AudioRegion> ar = boost::dynamic_pointer_cast<AudioRegion>(*i);
@@ -203,7 +192,7 @@ AudioPlaylist::read (Sample *buf, Sample *mixdown_buffer, float *gain_buffer, nf
 			_read_data_count += ar->read_data_count();
 		}
 		
-		for (vector<Crossfade*>::iterator i = x.begin(); i != x.end(); ++i) {
+		for (vector<boost::shared_ptr<Crossfade> >::iterator i = x.begin(); i != x.end(); ++i) {
 			(*i)->read_at (buf, mixdown_buffer, gain_buffer, start, cnt, chan_n);
 
 			/* don't JACK up _read_data_count, since its the same data as we just
@@ -219,7 +208,6 @@ AudioPlaylist::read (Sample *buf, Sample *mixdown_buffer, float *gain_buffer, nf
 void
 AudioPlaylist::remove_dependents (boost::shared_ptr<Region> region)
 {
-	Crossfades::iterator i, tmp;
 	boost::shared_ptr<AudioRegion> r = boost::dynamic_pointer_cast<AudioRegion> (region);
 
 	if (in_set_state) {
@@ -232,16 +220,13 @@ AudioPlaylist::remove_dependents (boost::shared_ptr<Region> region)
 		return;
 	}
 
-	for (i = _crossfades.begin(); i != _crossfades.end(); ) {
-		tmp = i;
-		tmp++;
-
+	for (Crossfades::iterator i = _crossfades.begin(); i != _crossfades.end(); ) {
 		
 		if ((*i)->involves (r)) {
-			delete *i;
+			i = _crossfades.erase (i);
+		} else {
+			++i;
 		}
-		
-		i = tmp;
 	}
 }
 
@@ -271,7 +256,7 @@ void
 AudioPlaylist::refresh_dependents (boost::shared_ptr<Region> r)
 {
 	boost::shared_ptr<AudioRegion> ar = boost::dynamic_pointer_cast<AudioRegion>(r);
-	set<Crossfade*> updated;
+	set<boost::shared_ptr<Crossfade> > updated;
 
 	if (ar == 0) {
 		return;
@@ -312,29 +297,29 @@ AudioPlaylist::finalize_split_region (boost::shared_ptr<Region> o, boost::shared
 		tmp = x;
 		++tmp;
 
-		Crossfade *fade = 0;
+		boost::shared_ptr<Crossfade> fade;
 		
 		if ((*x)->_in == orig) {
 			if (! (*x)->covers(right->position())) {
-				fade = new Crossfade (**x, left, (*x)->_out);
+				fade = boost::shared_ptr<Crossfade> (new Crossfade (**x, left, (*x)->_out));
 			} else {
 				// Overlap, the crossfade is copied on the left side of the right region instead
-				fade = new Crossfade (**x, right, (*x)->_out);
+				fade = boost::shared_ptr<Crossfade> (new Crossfade (**x, right, (*x)->_out));
 			}
 		}
 		
 		if ((*x)->_out == orig) {
 			if (! (*x)->covers(right->position())) {
-				fade = new Crossfade (**x, (*x)->_in, right);
+				fade = boost::shared_ptr<Crossfade> (new Crossfade (**x, (*x)->_in, right));
 			} else {
 				// Overlap, the crossfade is copied on the right side of the left region instead
-				fade = new Crossfade (**x, (*x)->_in, left);
+				fade = boost::shared_ptr<Crossfade> (new Crossfade (**x, (*x)->_in, left));
 			}
 		}
 		
 		if (fade) {
 			_crossfades.remove (*x);
-			add_crossfade (*fade);
+			add_crossfade (fade);
 		}
 		x = tmp;
 	}
@@ -347,7 +332,7 @@ AudioPlaylist::check_dependents (boost::shared_ptr<Region> r, bool norefresh)
 	boost::shared_ptr<AudioRegion> region;
 	boost::shared_ptr<AudioRegion> top;
 	boost::shared_ptr<AudioRegion> bottom;
-	Crossfade*   xfade;
+	boost::shared_ptr<Crossfade>   xfade;
 
 	if (in_set_state || in_partition) {
 		return;
@@ -369,6 +354,8 @@ AudioPlaylist::check_dependents (boost::shared_ptr<Region> r, bool norefresh)
 
 	for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
 
+		nframes_t xfade_length;
+
 		other = boost::dynamic_pointer_cast<AudioRegion> (*i);
 
 		if (other == region) {
@@ -378,6 +365,7 @@ AudioPlaylist::check_dependents (boost::shared_ptr<Region> r, bool norefresh)
 		if (other->muted() || region->muted()) {
 			continue;
 		}
+		
 
 		if (other->layer() < region->layer()) {
 			top = region;
@@ -387,50 +375,55 @@ AudioPlaylist::check_dependents (boost::shared_ptr<Region> r, bool norefresh)
 			bottom = region;
 		}
 
+
+		OverlapType c = top->coverage (bottom->position(), bottom->last_frame());
+		
 		try {
+			switch (c) {
+			case OverlapNone:
+				break;
+
+			case OverlapInternal:
+				 /* {=============== top  =============}
+				  *     [ ----- bottom  ------- ]
+				  */
+				break;
+
+			case OverlapExternal:
+
+				/*     [ -------- top ------- ]
+				 * {=========== bottom =============}
+				 */
 				
-			if (top->coverage (bottom->position(), bottom->last_frame()) != OverlapNone) {
+				/* to avoid discontinuities at the region boundaries of an internal
+				   overlap (this region is completely within another), we create
+				   two hidden crossfades at each boundary. this is not dependent
+				   on the auto-xfade option, because we require it as basic
+				   audio engineering.
+				*/
 				
-				/* check if the upper region is within the lower region */
+				xfade_length = min ((nframes_t) 720, top->length());
 				
-				if (top->first_frame() > bottom->first_frame() &&
-				    top->last_frame() < bottom->last_frame()) {
-					
-					
-					/*     [ -------- top ------- ]
-					 * {=========== bottom =============}
-					 */
-					
-					/* to avoid discontinuities at the region boundaries of an internal
-					   overlap (this region is completely within another), we create
-					   two hidden crossfades at each boundary. this is not dependent
-					   on the auto-xfade option, because we require it as basic
-					   audio engineering.
+				xfade = boost::shared_ptr<Crossfade> (new Crossfade (top, bottom, xfade_length, top->first_frame(), StartOfIn));
+				add_crossfade (xfade);
+				
+				if (top_region_at (top->last_frame() - 1) == top) {
+					/* 
+					   only add a fade out if there is no region on top of the end of 'top' (which 
+					   would cover it).
 					*/
 					
-					nframes_t xfade_length = min ((nframes_t) 720, top->length());
-					
-					                    /*  in,      out */
-					xfade = new Crossfade (top, bottom, xfade_length, top->first_frame(), StartOfIn);
-					add_crossfade (*xfade);
-
-					if (top_region_at (top->last_frame() - 1) == top) {
-					  /* 
-					     only add a fade out if there is no region on top of the end of 'top' (which 
-					     would cover it).
-					  */
-					  xfade = new Crossfade (bottom, top, xfade_length, top->last_frame() - xfade_length, EndOfOut);
-					  add_crossfade (*xfade);
-					}
-					
-				} else {
-
-					xfade = new Crossfade (other, region, Config->get_xfade_model(), Config->get_xfades_active());
-					add_crossfade (*xfade);
+					xfade = boost::shared_ptr<Crossfade> (new Crossfade (bottom, top, xfade_length, top->last_frame() - xfade_length, EndOfOut));
+					add_crossfade (xfade);
 				}
-			} 
+				break;
+				
+			default:
+				xfade = boost::shared_ptr<Crossfade> (new Crossfade (region, other, Config->get_xfade_model(), Config->get_xfades_active()));
+				add_crossfade (xfade);
+			}
 		}
-		
+
 		catch (failed_constructor& err) {
 			continue;
 		}
@@ -443,29 +436,29 @@ AudioPlaylist::check_dependents (boost::shared_ptr<Region> r, bool norefresh)
 }
 
 void
-AudioPlaylist::add_crossfade (Crossfade& xfade)
+AudioPlaylist::add_crossfade (boost::shared_ptr<Crossfade> xfade)
 {
 	Crossfades::iterator ci;
 
 	for (ci = _crossfades.begin(); ci != _crossfades.end(); ++ci) {
-		if (*(*ci) == xfade) { // Crossfade::operator==()
+		if (*(*ci) == *xfade) { // Crossfade::operator==()
 			break;
 		}
 	}
 	
 	if (ci != _crossfades.end()) {
-		delete &xfade;
+		// it will just go away
 	} else {
-		_crossfades.push_back (&xfade);
+		_crossfades.push_back (xfade);
 
-		xfade.Invalidated.connect (mem_fun (*this, &AudioPlaylist::crossfade_invalidated));
-		xfade.StateChanged.connect (mem_fun (*this, &AudioPlaylist::crossfade_changed));
+		xfade->Invalidated.connect (mem_fun (*this, &AudioPlaylist::crossfade_invalidated));
+		xfade->StateChanged.connect (mem_fun (*this, &AudioPlaylist::crossfade_changed));
 
-		notify_crossfade_added (&xfade);
+		notify_crossfade_added (xfade);
 	}
 }
 	
-void AudioPlaylist::notify_crossfade_added (Crossfade *x)
+void AudioPlaylist::notify_crossfade_added (boost::shared_ptr<Crossfade> x)
 {
 	if (g_atomic_int_get(&block_notifications)) {
 		_pending_xfade_adds.insert (_pending_xfade_adds.end(), x);
@@ -475,7 +468,7 @@ void AudioPlaylist::notify_crossfade_added (Crossfade *x)
 }
 
 void
-AudioPlaylist::crossfade_invalidated (Crossfade* xfade)
+AudioPlaylist::crossfade_invalidated (boost::shared_ptr<Crossfade> xfade)
 {
 	Crossfades::iterator i;
 
@@ -510,7 +503,7 @@ AudioPlaylist::set_state (const XMLNode& node)
 		}
 
 		try {
-			Crossfade* xfade = new Crossfade (*((const Playlist *)this), *child);
+			boost::shared_ptr<Crossfade> xfade = boost::shared_ptr<Crossfade> (new Crossfade (*((const Playlist *)this), *child));
 			_crossfades.push_back (xfade);
 			xfade->Invalidated.connect (mem_fun (*this, &AudioPlaylist::crossfade_invalidated));
 			xfade->StateChanged.connect (mem_fun (*this, &AudioPlaylist::crossfade_changed));
@@ -534,19 +527,7 @@ AudioPlaylist::set_state (const XMLNode& node)
 void
 AudioPlaylist::clear (bool with_signals)
 {
-	for (Crossfades::iterator i = _crossfades.begin(); i != _crossfades.end(); ) {
-
-		Crossfades::iterator tmp;
-		tmp = i;
-		++tmp;
-
-		delete *i;
-
-		i = tmp;
-	}
-
 	_crossfades.clear ();
-	
 	Playlist::clear (with_signals);
 }
 
@@ -568,7 +549,7 @@ void
 AudioPlaylist::dump () const
 {
 	boost::shared_ptr<Region>r;
-	Crossfade *x;
+	boost::shared_ptr<Crossfade> x;
 
 	cerr << "Playlist \"" << _name << "\" " << endl
 	     << regions.size() << " regions "
@@ -608,7 +589,7 @@ AudioPlaylist::destroy_region (boost::shared_ptr<Region> region)
 	boost::shared_ptr<AudioRegion> r = boost::dynamic_pointer_cast<AudioRegion> (region);
 	bool changed = false;
 	Crossfades::iterator c, ctmp;
-	set<Crossfade*> unique_xfades;
+	set<boost::shared_ptr<Crossfade> > unique_xfades;
 
 	if (r == 0) {
 		fatal << _("programming error: non-audio Region passed to remove_overlap in audio playlist")
@@ -661,10 +642,6 @@ AudioPlaylist::destroy_region (boost::shared_ptr<Region> region)
 		c = ctmp;
 	}
 
-	for (set<Crossfade*>::iterator c = unique_xfades.begin(); c != unique_xfades.end(); ++c) {
-		delete *c;
-	}
-
 	if (changed) {
 		/* overload this, it normally means "removed", not destroyed */
 		notify_region_removed (region);
diff --git a/libs/ardour/crossfade.cc b/libs/ardour/crossfade.cc
index 9e36702705..d2d04f8dc7 100644
--- a/libs/ardour/crossfade.cc
+++ b/libs/ardour/crossfade.cc
@@ -20,6 +20,8 @@
 
 #include <sigc++/bind.h>
 
+#include <pbd/stacktrace.h>
+
 #include <ardour/types.h>
 #include <ardour/crossfade.h>
 #include <ardour/crossfade_compare.h>
@@ -80,6 +82,7 @@ Crossfade::Crossfade (boost::shared_ptr<AudioRegion> in, boost::shared_ptr<Audio
 {
 	_in = in;
 	_out = out;
+	
 	_length = length;
 	_position = position;
 	_anchor_point = ap;
@@ -199,7 +202,8 @@ Crossfade::Crossfade (const Crossfade &orig, boost::shared_ptr<AudioRegion> newi
 
 Crossfade::~Crossfade ()
 {
-	Invalidated (this);
+	cerr << "Crossfade deleted\n";
+	notify_callbacks ();
 }
 
 void
@@ -256,6 +260,8 @@ Crossfade::compute (boost::shared_ptr<AudioRegion> a, boost::shared_ptr<AudioReg
 	/* first check for matching ends */
 	
 	if (top->first_frame() == bottom->first_frame()) {
+
+		cerr << "same start\n";
 		
 		/* Both regions start at the same point */
 		
@@ -297,6 +303,8 @@ Crossfade::compute (boost::shared_ptr<AudioRegion> a, boost::shared_ptr<AudioReg
 		
 	} else if (top->last_frame() == bottom->last_frame()) {
 		
+		cerr << "same end\n";
+
 		/* Both regions end at the same point */
 		
 		if (top->first_frame() > bottom->first_frame()) {
@@ -335,17 +343,21 @@ Crossfade::compute (boost::shared_ptr<AudioRegion> a, boost::shared_ptr<AudioReg
 
 		OverlapType ot = top->coverage (bottom->first_frame(), bottom->last_frame());
 
+		cerr << "ot = " << ot << endl;
+
 		switch (ot) {
 		case OverlapNone:
 			/* should be NOTREACHED as a precondition of creating
 			   a new crossfade, but we need to handle it here.
 			*/
+			cerr << "no sir\n";
 			throw NoCrossfadeHere();
 			break;
 			
 		case OverlapInternal:
 		case OverlapExternal:
 			/* should be NOTREACHED because of tests above */
+			cerr << "nu-uh\n";
 			throw NoCrossfadeHere();
 			break;
 			
@@ -357,15 +369,16 @@ Crossfade::compute (boost::shared_ptr<AudioRegion> a, boost::shared_ptr<AudioReg
 
 			_in = bottom;
 			_out = top;
-			_position = bottom->first_frame();
 			_anchor_point = StartOfIn;
 
 			if (model == FullCrossfade) {
+				_position = bottom->first_frame(); // "{"
 				_length = _out->first_frame() + _out->length() - _in->first_frame();
 				/* leave active alone */
 				_follow_overlap = true;
 			} else {
 				_length = min (short_xfade_length, top->length());
+				_position = top->last_frame() - _length;  // "]" - length 
 				_active = true;
 				_follow_overlap = false;
 				
@@ -499,7 +512,13 @@ Crossfade::refresh ()
 	/* crossfades must be between non-muted regions */
 	
 	if (_out->muted() || _in->muted()) {
-		Invalidated (this);
+		Invalidated (shared_from_this());
+		return false;
+	}
+
+	if (_in->layer() < _out->layer()) {
+		cerr << "layer change, invalidated\n";
+		Invalidated (shared_from_this());
 		return false;
 	}
 
@@ -508,11 +527,11 @@ Crossfade::refresh ()
 	OverlapType ot;
 	
 	ot = _in->coverage (_out->first_frame(), _out->last_frame());
-	
+
 	switch (ot) {
 	case OverlapNone:
 	case OverlapInternal:
-		Invalidated (this);
+		Invalidated (shared_from_this());
 		return false;
 		
 	default:
@@ -522,7 +541,7 @@ Crossfade::refresh ()
 	/* overlap type must not have altered */
 	
 	if (ot != overlap_type) {
-		Invalidated (this);
+		Invalidated (shared_from_this());
 		return false;
 	} 
 
@@ -543,7 +562,7 @@ Crossfade::update (bool force)
 	}
 
 	if (newlen == 0) {
-		Invalidated (this);
+		Invalidated (shared_from_this());
 		return false;
 	}
 
@@ -563,7 +582,13 @@ Crossfade::update (bool force)
 	switch (_anchor_point) {
 	case StartOfIn:
 		if (_position != _in->first_frame()) {
-			_position = _in->first_frame();
+			if (_length > _short_xfade_length) {
+				/* assume FullCrossfade */
+				_position = _in->first_frame();
+			} else {
+				/* assume short xfade */
+				_position = _out->last_frame() - _length;
+			}
 		}
 		break;
 
@@ -865,5 +890,5 @@ Crossfade::set_short_xfade_length (nframes_t n)
 void
 Crossfade::invalidate ()
 {
-	Invalidated (this); /* EMIT SIGNAL */
+	Invalidated (shared_from_this()); /* EMIT SIGNAL */
 }
diff --git a/libs/ardour/globals.cc b/libs/ardour/globals.cc
index 3f47b30c1f..41fc3db161 100644
--- a/libs/ardour/globals.cc
+++ b/libs/ardour/globals.cc
@@ -196,6 +196,7 @@ setup_hardware_optimization (bool try_optimization)
 {
         bool generic_mix_functions = true;
 
+
 	if (try_optimization) {
 
 #if defined (ARCH_X86) && defined (BUILD_SSE_OPTIMIZATIONS)
@@ -216,14 +217,14 @@ setup_hardware_optimization (bool try_optimization)
 #else
 
 		asm (
-				 "movq $1, %%rax\n"
 				 "pushq %%rbx\n"
+				 "movq $1, %%rax\n"
 				 "cpuid\n"
 				 "movq %%rdx, %0\n"
 				 "popq %%rbx\n"
 		 	     : "=l" (use_sse)
 	   		     : 
- 	    		 : "%rax", "%rcx", "%rdx", "memory");
+			 : "%rax", "%rcx", "%rdx", "memory");
 
 #endif /* USE_X86_64_ASM */
 		use_sse &= (1 << 25); // bit 25 = SSE support