add (bezier) curves to canvas, use for automation lines; fix issue with rectangles...
[ardour.git] / gtk2_ardour / automation_line.cc
index 71a29af3dcd278d142e8e9d8b58f3716cb39ed1b..460802309a2aaee1ffce52e42a3c5dc245798015 100644 (file)
 #include <vector>
 #include <fstream>
 
-#include "pbd/stl_delete.h"
+#include "boost/shared_ptr.hpp"
+
+#include "pbd/floating.h"
 #include "pbd/memento_command.h"
+#include "pbd/stl_delete.h"
 #include "pbd/stacktrace.h"
 
 #include "ardour/automation_list.h"
 #include "ardour/dB.h"
+#include "ardour/debug.h"
+
 #include "evoral/Curve.hpp"
 
-#include "simplerect.h"
 #include "automation_line.h"
 #include "control_point.h"
 #include "gui_thread.h"
@@ -41,9 +45,7 @@
 #include "selection.h"
 #include "time_axis_view.h"
 #include "point_selection.h"
-#include "automation_selectable.h"
 #include "automation_time_axis.h"
-#include "public_editor.h"
 
 #include "ardour/event_type_map.h"
 #include "ardour/session.h"
@@ -54,38 +56,46 @@ using namespace std;
 using namespace ARDOUR;
 using namespace PBD;
 using namespace Editing;
-using namespace Gnome; // for Canvas
-
-static const Evoral::IdentityConverter<double, sframes_t> default_converter;
 
+/** @param converter A TimeConverter whose origin_b is the start time of the AutomationList in session frames.
+ *  This will not be deleted by AutomationLine.
+ */
 AutomationLine::AutomationLine (const string& name, TimeAxisView& tv, ArdourCanvas::Group& parent,
                boost::shared_ptr<AutomationList> al,
-               const Evoral::TimeConverter<double, sframes_t>* converter)
+               Evoral::TimeConverter<double, framepos_t>* converter)
        : trackview (tv)
        , _name (name)
        , alist (al)
+       , _time_converter (converter ? converter : new Evoral::IdentityConverter<double, framepos_t>)
        , _parent_group (parent)
-       , _time_converter (converter ? (*converter) : default_converter)
+       , _offset (0)
+       , _maximum_time (max_framepos)
 {
-       points_visible = false;
+       if (converter) {
+               _time_converter = converter;
+               _our_time_converter = false;
+       } else {
+               _time_converter = new Evoral::IdentityConverter<double, framepos_t>;
+               _our_time_converter = true;
+       }
+       
+       _visible = Line;
+
        update_pending = false;
+       have_timeout = false;
        _uses_gain_mapping = false;
        no_draw = false;
-       _visible = true;
+       _is_boolean = false;
        terminal_points_can_slide = true;
        _height = 0;
 
-       group = new ArdourCanvas::Group (parent);
-       group->property_x() = 0.0;
-       group->property_y() = 0.0;
+       group = new ArdourCanvas::Group (&parent);
 
-       line = new ArdourCanvas::Line (*group);
-       line->property_width_pixels() = (guint)1;
+       line = new ArdourCanvas::Curve (group);
+       line->set_outline_width (1);
        line->set_data ("line", this);
 
-       line->signal_event().connect (sigc::mem_fun (*this, &AutomationLine::event_handler));
-
-       connect_to_list ();
+       line->Event.connect (sigc::mem_fun (*this, &AutomationLine::event_handler));
 
        trackview.session()->register_with_memento_command_factory(alist->id(), this);
 
@@ -103,6 +113,10 @@ AutomationLine::~AutomationLine ()
 {
        vector_delete (&control_points);
        delete group;
+
+       if (_our_time_converter) {
+               delete _time_converter;
+       }
 }
 
 bool
@@ -111,39 +125,43 @@ AutomationLine::event_handler (GdkEvent* event)
        return PublicEditor::instance().canvas_line_event (event, line, this);
 }
 
-void
-AutomationLine::queue_reset ()
-{
-       if (!update_pending) {
-               update_pending = true;
-               Gtkmm2ext::UI::instance()->call_slot (invalidator (*this), boost::bind (&AutomationLine::reset, this));
-       }
-}
-
 void
 AutomationLine::show ()
 {
-       if (alist->interpolation() != AutomationList::Discrete) {
-               line->show();
+       if (_visible & Line) {
+               /* Only show the line there are some points, otherwise we may show an out-of-date line
+                  when automation points have been removed (the line will still follow the shape of the
+                  old points).
+               */
+               if (alist->interpolation() != AutomationList::Discrete && control_points.size() >= 2) {
+                       line->show();
+               } else {
+                       line->hide ();
+               }
+       } else {
+               line->hide();
        }
 
-       if (points_visible) {
+       if (_visible & ControlPoints) {
                for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
+                       (*i)->set_visible (true);
                        (*i)->show ();
                }
+       } else if (_visible & SelectedControlPoints) {
+               for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
+                       (*i)->set_visible ((*i)->get_selected());
+               }
+       } else {
+               for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
+                       (*i)->set_visible (false);
+               }
        }
-
-       _visible = true;
 }
 
 void
 AutomationLine::hide ()
 {
-       line->hide();
-       for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-               (*i)->hide();
-       }
-       _visible = false;
+       set_visibility (VisibleAspects (0));
 }
 
 double
@@ -182,7 +200,7 @@ void
 AutomationLine::set_line_color (uint32_t color)
 {
        _line_color = color;
-       line->property_fill_color_rgba() = color;
+       line->set_outline_color (color);
 }
 
 void
@@ -204,6 +222,16 @@ AutomationLine::nth (uint32_t n)
        }
 }
 
+ControlPoint const *
+AutomationLine::nth (uint32_t n) const
+{
+       if (n < control_points.size()) {
+               return control_points[n];
+       } else {
+               return 0;
+       }
+}
+
 void
 AutomationLine::modify_point_y (ControlPoint& cp, double y)
 {
@@ -215,7 +243,7 @@ AutomationLine::modify_point_y (ControlPoint& cp, double y)
        y = min (1.0, y);
        y = _height - (y * _height);
 
-       double const x = trackview.editor().frame_to_unit (_time_converter.to((*cp.model())->when));
+       double const x = trackview.editor().frame_to_unit_unrounded (_time_converter->to((*cp.model())->when) - _offset);
 
        trackview.editor().session()->begin_reversible_command (_("automation event move"));
        trackview.editor().session()->add_command (
@@ -227,11 +255,11 @@ AutomationLine::modify_point_y (ControlPoint& cp, double y)
        reset_line_coords (cp);
 
        if (line_points.size() > 1) {
-               line->property_points() = line_points;
+               line->set (line_points);
        }
 
        alist->freeze ();
-       sync_model_with_view_point (cp, false, 0);
+       sync_model_with_view_point (cp);
        alist->thaw ();
 
        update_pending = false;
@@ -239,7 +267,7 @@ AutomationLine::modify_point_y (ControlPoint& cp, double y)
        trackview.editor().session()->add_command (
                new MementoCommand<AutomationList> (memento_command_binder(), 0, &alist->get_state())
                );
-       
+
        trackview.editor().session()->commit_reversible_command ();
        trackview.editor().session()->set_dirty ();
 }
@@ -248,251 +276,52 @@ void
 AutomationLine::reset_line_coords (ControlPoint& cp)
 {
        if (cp.view_index() < line_points.size()) {
-               line_points[cp.view_index()].set_x (cp.get_x());
-               line_points[cp.view_index()].set_y (cp.get_y());
+               line_points[cp.view_index()].x = cp.get_x ();
+               line_points[cp.view_index()].y = cp.get_y ();
        }
 }
 
 void
-AutomationLine::sync_model_with_view_points (list<ControlPoint*> cp, bool did_push, int64_t distance)
+AutomationLine::sync_model_with_view_points (list<ControlPoint*> cp)
 {
        update_pending = true;
 
        for (list<ControlPoint*>::iterator i = cp.begin(); i != cp.end(); ++i) {
-               sync_model_with_view_point (**i, did_push, distance);
+               sync_model_with_view_point (**i);
        }
 }
 
-void
-AutomationLine::model_representation (ControlPoint& cp, ModelRepresentation& mr)
+string
+AutomationLine::get_verbose_cursor_string (double fraction) const
 {
-       /* part one: find out where the visual control point is.
-          initial results are in canvas units. ask the
-          line to convert them to something relevant.
-       */
-
-       mr.xval = cp.get_x();
-       mr.yval = 1.0 - (cp.get_y() / _height);
-
-       /* if xval has not changed, set it directly from the model to avoid rounding errors */
-
-       if (mr.xval == trackview.editor().frame_to_unit(_time_converter.to((*cp.model())->when))) {
-               mr.xval = (*cp.model())->when;
-       } else {
-               mr.xval = trackview.editor().unit_to_frame (mr.xval);
-               view_to_model_coord_x (mr.xval);
-       }
-
-       /* convert y to model units; the x was already done above
-       */
-
-       view_to_model_coord_y (mr.yval);
-
-       /* part 2: find out where the model point is now
-        */
-
-       mr.xpos = (*cp.model())->when;
-       mr.ypos = (*cp.model())->value;
-
-       /* part 3: get the position of the visual control
-          points before and after us.
-       */
-
-       ControlPoint* before;
-       ControlPoint* after;
-
-       if (cp.view_index()) {
-               before = nth (cp.view_index() - 1);
-       } else {
-               before = 0;
-       }
-
-       after = nth (cp.view_index() + 1);
-
-       if (before) {
-               mr.xmin = (*before->model())->when;
-               mr.ymin = (*before->model())->value;
-               mr.start = before->model();
-               ++mr.start;
-       } else {
-               mr.xmin = mr.xpos;
-               mr.ymin = mr.ypos;
-               mr.start = cp.model();
+       std::string s = fraction_to_string (fraction);
+       if (_uses_gain_mapping) {
+               s += " dB";
        }
 
-       if (after) {
-               mr.end = after->model();
-       } else {
-               mr.xmax = mr.xpos;
-               mr.ymax = mr.ypos;
-               mr.end = cp.model();
-               ++mr.end;
-       }
+       return s;
 }
 
-void
-AutomationLine::determine_visible_control_points (ALPoints& points)
-{
-       uint32_t view_index, pi, n;
-       AutomationList::iterator model;
-       uint32_t npoints;
-       uint32_t this_rx = 0;
-       uint32_t prev_rx = 0;
-       uint32_t this_ry = 0;
-       uint32_t prev_ry = 0;
-       double* slope;
-       uint32_t box_size;
-
-       /* hide all existing points, and the line */
-
-       for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-               (*i)->hide();
-       }
-
-       line->hide ();
-
-       if (points.empty()) {
-               return;
-       }
-
-       npoints = points.size();
-
-       /* compute derivative/slope for the entire line */
-
-       slope = new double[npoints];
-
-       for (n = 0; n < npoints - 1; ++n) {
-               double xdelta = points[n+1].x - points[n].x;
-               double ydelta = points[n+1].y - points[n].y;
-               slope[n] = ydelta/xdelta;
-       }
-
-       box_size = (uint32_t) control_point_box_size ();
-
-       /* read all points and decide which ones to show as control points */
-
-       view_index = 0;
-
-       for (model = alist->begin(), pi = 0; pi < npoints; ++model, ++pi) {
-
-               double tx = points[pi].x;
-               double ty = points[pi].y;
-
-               if (find (_always_in_view.begin(), _always_in_view.end(), (*model)->when) != _always_in_view.end()) {
-                       add_visible_control_point (view_index, pi, tx, ty, model, npoints);
-                       prev_rx = this_rx;
-                       prev_ry = this_ry;
-                       ++view_index;
-                       continue;
-               }
-
-               if (isnan (tx) || isnan (ty)) {
-                       warning << string_compose (_("Ignoring illegal points on AutomationLine \"%1\""),
-                                                  _name) << endmsg;
-                       continue;
-               }
-
-               /* now ensure that the control_points vector reflects the current curve
-                  state, but don't plot control points too close together. also, don't
-                  plot a series of points all with the same value.
-
-                  always plot the first and last points, of course.
-               */
-
-               if (invalid_point (points, pi)) {
-                       /* for some reason, we are supposed to ignore this point,
-                          but still keep track of the model index.
-                       */
-                       continue;
-               }
-
-               if (pi > 0 && pi < npoints - 1) {
-                       if (slope[pi] == slope[pi-1]) {
-
-                               /* no reason to display this point */
-
-                               continue;
-                       }
-               }
-
-               /* need to round here. the ultimate coordinates are integer
-                  pixels, so tiny deltas in the coords will be eliminated
-                  and we end up with "colinear" line segments. since the
-                  line rendering code in libart doesn't like this very
-                  much, we eliminate them here. don't do this for the first and last
-                  points.
-               */
-
-               this_rx = (uint32_t) rint (tx);
-               this_ry = (uint32_t) rint (ty);
-
-               if (view_index && pi != npoints && /* not the first, not the last */
-                   (((this_rx == prev_rx) && (this_ry == prev_ry)) || /* same point */
-                    (((this_rx - prev_rx) < (box_size + 2)) &&  /* not identical, but still too close horizontally */
-                     (abs ((int)(this_ry - prev_ry)) < (int) (box_size + 2))))) { /* too close vertically */
-                       continue;
-               }
-
-               /* ok, we should display this point */
-
-               add_visible_control_point (view_index, pi, tx, ty, model, npoints);
-               
-               prev_rx = this_rx;
-               prev_ry = this_ry;
-
-               view_index++;
-       }
-
-       /* discard extra CP's to avoid confusing ourselves */
-
-       while (control_points.size() > view_index) {
-               ControlPoint* cp = control_points.back();
-               control_points.pop_back ();
-               delete cp;
-       }
-
-       if (!terminal_points_can_slide) {
-               control_points.back()->set_can_slide(false);
+string
+AutomationLine::get_verbose_cursor_relative_string (double original, double fraction) const
+{
+       std::string s = fraction_to_string (fraction);
+       if (_uses_gain_mapping) {
+               s += " dB";
        }
 
-       delete [] slope;
-
-       if (view_index > 1) {
-
-               npoints = view_index;
-
-               /* reset the line coordinates */
+       std::string d = fraction_to_relative_string (original, fraction);
 
-               while (line_points.size() < npoints) {
-                       line_points.push_back (Art::Point (0,0));
-               }
-
-               while (line_points.size() > npoints) {
-                       line_points.pop_back ();
-               }
+       if (!d.empty()) {
 
-               for (view_index = 0; view_index < npoints; ++view_index) {
-                       line_points[view_index].set_x (control_points[view_index]->get_x());
-                       line_points[view_index].set_y (control_points[view_index]->get_y());
-               }
-
-               line->property_points() = line_points;
+               s += " (\u0394";
+               s += d;
 
-               if (_visible && alist->interpolation() != AutomationList::Discrete) {
-                       line->show();
+               if (_uses_gain_mapping) {
+                       s += " dB";
                }
 
-       }
-
-       set_selected_points (trackview.editor().get_selection().points);
-}
-
-string
-AutomationLine::get_verbose_cursor_string (double fraction) const
-{
-       std::string s = fraction_to_string (fraction);
-       if (_uses_gain_mapping) {
-               s += " dB";
+               s += ')';
        }
 
        return s;
@@ -511,11 +340,10 @@ AutomationLine::fraction_to_string (double fraction) const
                if (fraction == 0.0) {
                        snprintf (buf, sizeof (buf), "-inf");
                } else {
-                       snprintf (buf, sizeof (buf), "%.1f", accurate_coefficient_to_dB (slider_position_to_gain (fraction)));
+                       snprintf (buf, sizeof (buf), "%.1f", accurate_coefficient_to_dB (slider_position_to_gain_with_max (fraction, Config->get_max_gain())));
                }
        } else {
-               double dummy = 0.0;
-               view_to_model_coord (dummy, fraction);
+               view_to_model_coord_y (fraction);
                if (EventTypeMap::instance().is_integer (alist->parameter())) {
                        snprintf (buf, sizeof (buf), "%d", (int)fraction);
                } else {
@@ -526,6 +354,45 @@ AutomationLine::fraction_to_string (double fraction) const
        return buf;
 }
 
+/**
+ *  @param original an old y-axis fraction
+ *  @param fraction the new y fraction
+ *  @return string representation of the difference between original and fraction, using dB if appropriate.
+ */
+string
+AutomationLine::fraction_to_relative_string (double original, double fraction) const
+{
+       char buf[32];
+
+       if (original == fraction) {
+               return "0";
+       }
+
+       if (_uses_gain_mapping) {
+               if (original == 0.0) {
+                       /* there is no sensible representation of a relative
+                          change from -inf dB, so return an empty string.
+                       */
+                       return "";
+               } else if (fraction == 0.0) {
+                       snprintf (buf, sizeof (buf), "-inf");
+               } else {
+                       double old_db = accurate_coefficient_to_dB (slider_position_to_gain_with_max (original, Config->get_max_gain()));
+                       double new_db = accurate_coefficient_to_dB (slider_position_to_gain_with_max (fraction, Config->get_max_gain()));
+                       snprintf (buf, sizeof (buf), "%.1f", new_db - old_db);
+               }
+       } else {
+               view_to_model_coord_y (original);
+               view_to_model_coord_y (fraction);
+               if (EventTypeMap::instance().is_integer (alist->parameter())) {
+                       snprintf (buf, sizeof (buf), "%d", (int)fraction - (int)original);
+               } else {
+                       snprintf (buf, sizeof (buf), "%.2f", fraction - original);
+               }
+       }
+
+       return buf;
+}
 
 /**
  *  @param s Value string in the form as returned by fraction_to_string.
@@ -542,7 +409,7 @@ AutomationLine::string_to_fraction (string const & s) const
        sscanf (s.c_str(), "%lf", &v);
 
        if (_uses_gain_mapping) {
-               v = gain_to_slider_position (dB_to_coefficient (v));
+               v = gain_to_slider_position_with_max (dB_to_coefficient (v), Config->get_max_gain());
        } else {
                double dummy = 0.0;
                model_to_view_coord (dummy, v);
@@ -551,19 +418,6 @@ AutomationLine::string_to_fraction (string const & s) const
        return v;
 }
 
-bool
-AutomationLine::invalid_point (ALPoints& p, uint32_t index)
-{
-       return p[index].x == max_frames && p[index].y == DBL_MAX;
-}
-
-void
-AutomationLine::invalidate_point (ALPoints& p, uint32_t index)
-{
-       p[index].x = max_frames;
-       p[index].y = DBL_MAX;
-}
-
 /** Start dragging a single point, possibly adding others if the supplied point is selected and there
  *  are other selected points.
  *
@@ -582,14 +436,14 @@ AutomationLine::start_drag_single (ControlPoint* cp, double x, float fraction)
        _drag_points.clear ();
        _drag_points.push_back (cp);
 
-       if (cp->selected ()) {
+       if (cp->get_selected ()) {
                for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-                       if (*i != cp && (*i)->selected()) {
+                       if (*i != cp && (*i)->get_selected()) {
                                _drag_points.push_back (*i);
                        }
                }
        }
-       
+
        start_drag_common (x, fraction);
 }
 
@@ -607,6 +461,7 @@ AutomationLine::start_drag_line (uint32_t i1, uint32_t i2, float fraction)
                );
 
        _drag_points.clear ();
+
        for (uint32_t i = i1; i <= i2; i++) {
                _drag_points.push_back (nth (i));
        }
@@ -630,14 +485,82 @@ AutomationLine::start_drag_multiple (list<ControlPoint*> cp, float fraction, XML
        start_drag_common (0, fraction);
 }
 
-
 struct ControlPointSorter
 {
-       bool operator() (ControlPoint const * a, ControlPoint const * b) {
+       bool operator() (ControlPoint const * a, ControlPoint const * b) const {
+               if (floateq (a->get_x(), b->get_x(), 1)) {
+                       return a->view_index() < b->view_index();
+               } 
                return a->get_x() < b->get_x();
        }
 };
 
+AutomationLine::ContiguousControlPoints::ContiguousControlPoints (AutomationLine& al)
+       : line (al), before_x (0), after_x (DBL_MAX) 
+{
+}
+
+void
+AutomationLine::ContiguousControlPoints::compute_x_bounds ()
+{
+       uint32_t sz = size();
+
+       if (sz > 0 && sz < line.npoints()) {
+
+               /* determine the limits on x-axis motion for this 
+                  contiguous range of control points
+               */
+
+               if (front()->view_index() > 0) {
+                       before_x = line.nth (front()->view_index() - 1)->get_x();
+               }
+
+               /* if our last point has a point after it in the line,
+                  we have an "after" bound
+               */
+
+               if (back()->view_index() < (line.npoints() - 2)) {
+                       after_x = line.nth (back()->view_index() + 1)->get_x();
+               }
+       }
+}
+
+double 
+AutomationLine::ContiguousControlPoints::clamp_dx (double dx) 
+{
+       if (empty()) {
+               return dx;
+       }
+
+       /* get the maximum distance we can move any of these points along the x-axis
+        */
+       
+       double tx; /* possible position a point would move to, given dx */
+       ControlPoint* cp;
+       
+       if (dx > 0) {
+               /* check the last point, since we're moving later in time */
+               cp = back();
+       } else {
+               /* check the first point, since we're moving earlier in time */
+               cp = front();
+       }
+
+       tx = cp->get_x() + dx; // new possible position if we just add the motion 
+       tx = max (tx, before_x); // can't move later than following point
+       tx = min (tx, after_x);  // can't move earlier than preceeding point
+       return  tx - cp->get_x (); 
+}
+
+void 
+AutomationLine::ContiguousControlPoints::move (double dx, double dy) 
+{
+       for (std::list<ControlPoint*>::iterator i = begin(); i != end(); ++i) {
+               (*i)->move_to ((*i)->get_x() + dx, (*i)->get_y() - line.height() * dy, ControlPoint::Full);
+               line.reset_line_coords (**i);
+       }
+}
+
 /** Common parts of starting a drag.
  *  @param x Starting x position in units, or 0 if x is being ignored.
  *  @param fraction Starting y position (as a fraction of the track height, where 0 is the bottom and 1 the top)
@@ -651,86 +574,80 @@ AutomationLine::start_drag_common (double x, float fraction)
        _drag_had_movement = false;
        did_push = false;
 
-       _drag_points.sort (ControlPointSorter ());
+       /* they are probably ordered already, but we have to make sure */
 
-       /* find the additional points that will be dragged when the user is holding
-          the "push" modifier
-       */
-
-       uint32_t i = _drag_points.back()->view_index () + 1;
-       ControlPoint* p = 0;
-       _push_points.clear ();
-       while ((p = nth (i)) != 0 && p->can_slide()) {
-               _push_points.push_back (p);
-               ++i;
-       }
+       _drag_points.sort (ControlPointSorter());
 }
 
+
 /** Should be called to indicate motion during a drag.
- *  @param x New x position of the drag in units, or undefined if ignore_x == true.
+ *  @param x New x position of the drag in canvas units, or undefined if ignore_x == true.
  *  @param fraction New y fraction.
  *  @return x position and y fraction that were actually used (once clamped).
  */
 pair<double, float>
-AutomationLine::drag_motion (double x, float fraction, bool ignore_x, bool with_push)
+AutomationLine::drag_motion (double const x, float fraction, bool ignore_x, bool with_push, uint32_t& final_index)
 {
-       /* setup the points that are to be moved this time round */
-       list<ControlPoint*> points = _drag_points;
-       if (with_push) {
-               copy (_push_points.begin(), _push_points.end(), back_inserter (points));
-               points.sort (ControlPointSorter ());
+       if (_drag_points.empty()) {
+               return pair<double,float> (x,fraction);
        }
-          
+
        double dx = ignore_x ? 0 : (x - _drag_x);
        double dy = fraction - _last_drag_fraction;
 
-       /* find x limits */
-       ControlPoint* before = 0;
-       ControlPoint* after = 0;
+       if (!_drag_had_movement) {
 
-       for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-               if ((*i)->get_x() < points.front()->get_x()) {
-                       before = *i;
-               }
-               if ((*i)->get_x() > points.back()->get_x() && after == 0) {
-                       after = *i;
+               /* "first move" ... do some stuff that we don't want to do if 
+                  no motion ever took place, but need to do before we handle
+                  motion.
+               */
+       
+               /* partition the points we are dragging into (potentially several)
+                * set(s) of contiguous points. this will not happen with a normal
+                * drag, but if the user does a discontiguous selection, it can.
+                */
+               
+               uint32_t expected_view_index = 0;
+               CCP contig;
+               
+               for (list<ControlPoint*>::iterator i = _drag_points.begin(); i != _drag_points.end(); ++i) {
+                       if (i == _drag_points.begin() || (*i)->view_index() != expected_view_index) {
+                               contig.reset (new ContiguousControlPoints (*this));
+                               contiguous_points.push_back (contig);
+                       }
+                       contig->push_back (*i);
+                       expected_view_index = (*i)->view_index() + 1;
                }
-       }
-
-       double const before_x = before ? before->get_x() : 0;
-       double const after_x = after ? after->get_x() : DBL_MAX;
 
-       /* clamp x */
-       for (list<ControlPoint*>::iterator i = points.begin(); i != points.end(); ++i) {
-
-               if ((*i)->can_slide() && !ignore_x) {
+               if (contiguous_points.back()->empty()) {
+                       contiguous_points.pop_back ();
+               }
 
-                       /* clamp min x */
-                       double const a = (*i)->get_x() + dx;
-                       double const b = before_x + 1;
-                       if (a < b) {
-                               dx += b - a;
-                       }
+               for (vector<CCP>::iterator ccp = contiguous_points.begin(); ccp != contiguous_points.end(); ++ccp) {
+                       (*ccp)->compute_x_bounds ();
+               }
+       }       
+
+       /* OK, now on to the stuff related to *this* motion event. First, for
+        * each contiguous range, figure out the maximum x-axis motion we are
+        * allowed (because of neighbouring points that are not moving.
+        * 
+        * if we are moving forwards with push, we don't need to do this, 
+        * since all later points will move too.
+        */
 
-                       /* clamp max x */
-                       if (after) {
-
-                               if (after_x - before_x < 2) {
-                                       /* after and before are very close, so just leave this alone */
-                                       dx = 0;
-                               } else {
-                                       double const a = (*i)->get_x() + dx;
-                                       double const b = after_x - 1;
-                                       if (a > b) {
-                                               dx -= a - b;
-                                       }
-                               }
+       if (dx < 0 || ((dx > 0) && !with_push)) {
+               for (vector<CCP>::iterator ccp = contiguous_points.begin(); ccp != contiguous_points.end(); ++ccp) {
+                       double dxt = (*ccp)->clamp_dx (dx);
+                       if (fabs (dxt) < fabs (dx)) {
+                               dx = dxt;
                        }
                }
        }
 
        /* clamp y */
-       for (list<ControlPoint*>::iterator i = points.begin(); i != points.end(); ++i) {
+       
+       for (list<ControlPoint*>::iterator i = _drag_points.begin(); i != _drag_points.end(); ++i) {
                double const y = ((_height - (*i)->get_y()) / _height) + dy;
                if (y < 0) {
                        dy -= y;
@@ -740,52 +657,60 @@ AutomationLine::drag_motion (double x, float fraction, bool ignore_x, bool with_
                }
        }
 
-       pair<double, float> const clamped (_drag_x + dx, _last_drag_fraction + dy);
-       _drag_distance += dx;
-       _drag_x = x;
-       _last_drag_fraction = fraction;
-
-       for (list<ControlPoint*>::iterator i = _drag_points.begin(); i != _drag_points.end(); ++i) {
-               (*i)->move_to ((*i)->get_x() + dx, (*i)->get_y() - _height * dy, ControlPoint::Full);
-               reset_line_coords (**i);
-       }
+       if (dx || dy) {
 
-       if (with_push) {
-               /* move push points, preserving their y */
-               for (list<ControlPoint*>::iterator i = _push_points.begin(); i != _push_points.end(); ++i) {
-                       (*i)->move_to ((*i)->get_x() + dx, (*i)->get_y(), ControlPoint::Full);
-                       reset_line_coords (**i);
+               /* and now move each section */
+               
+               for (vector<CCP>::iterator ccp = contiguous_points.begin(); ccp != contiguous_points.end(); ++ccp) {
+                       (*ccp)->move (dx, dy);
+               }
+               if (with_push) {
+                       final_index = contiguous_points.back()->back()->view_index () + 1;
+                       ControlPoint* p;
+                       uint32_t i = final_index;
+                       while ((p = nth (i)) != 0 && p->can_slide()) {
+                               p->move_to (p->get_x() + dx, p->get_y(), ControlPoint::Full);
+                               reset_line_coords (*p);
+                               ++i;
+                       }
                }
-       }
 
-       if (line_points.size() > 1) {
-               line->property_points() = line_points;
-       }
+               /* update actual line coordinates (will queue a redraw)
+                */
 
+               if (line_points.size() > 1) {
+                       line->set (line_points);
+               }
+       }
+       
+       _drag_distance += dx;
+       _drag_x += dx;
+       _last_drag_fraction = fraction;
        _drag_had_movement = true;
        did_push = with_push;
 
-       return clamped;
+       return pair<double, float> (_drag_x + dx, _last_drag_fraction + dy);
 }
 
 /** Should be called to indicate the end of a drag */
 void
-AutomationLine::end_drag ()
+AutomationLine::end_drag (bool with_push, uint32_t final_index)
 {
        if (!_drag_had_movement) {
                return;
        }
 
        alist->freeze ();
+       sync_model_with_view_points (_drag_points);
 
-       /* set up the points that were moved this time round */
-       list<ControlPoint*> points = _drag_points;
-       if (did_push) {
-               copy (_push_points.begin(), _push_points.end(), back_inserter (points));
-               points.sort (ControlPointSorter ());
+       if (with_push) {
+               ControlPoint* p;
+               uint32_t i = final_index;
+               while ((p = nth (i)) != 0 && p->can_slide()) {
+                       sync_model_with_view_point (*p);
+                       ++i;
+               }
        }
-       
-       sync_model_with_view_points (points, did_push, rint (_drag_distance * trackview.editor().get_current_zoom ()));
 
        alist->thaw ();
 
@@ -794,76 +719,38 @@ AutomationLine::end_drag ()
        trackview.editor().session()->add_command (
                new MementoCommand<AutomationList>(memento_command_binder (), 0, &alist->get_state())
                );
-       
-       trackview.editor().session()->commit_reversible_command ();
+
        trackview.editor().session()->set_dirty ();
+       did_push = false;
+
+       contiguous_points.clear ();
 }
 
 void
-AutomationLine::sync_model_with_view_point (ControlPoint& cp, bool did_push, int64_t distance)
+AutomationLine::sync_model_with_view_point (ControlPoint& cp)
 {
-       ModelRepresentation mr;
-       double ydelta;
-
-       model_representation (cp, mr);
-
-       /* how much are we changing the central point by */
-
-       ydelta = mr.yval - mr.ypos;
-
-       /*
-          apply the full change to the central point, and interpolate
-          on both axes to cover all model points represented
-          by the control point.
+       /* find out where the visual control point is.
+          initial results are in canvas units. ask the
+          line to convert them to something relevant.
        */
 
-       /* change all points before the primary point */
+       double view_x = cp.get_x();
+       double view_y = 1.0 - (cp.get_y() / _height);
 
-       for (AutomationList::iterator i = mr.start; i != cp.model(); ++i) {
-
-               double fract = ((*i)->when - mr.xmin) / (mr.xpos - mr.xmin);
-               double y_delta = ydelta * fract;
-               double x_delta = distance * fract;
-
-               /* interpolate */
+       /* if xval has not changed, set it directly from the model to avoid rounding errors */
 
-               if (y_delta || x_delta) {
-                       alist->modify (i, (*i)->when + x_delta, mr.ymin + y_delta);
-               }
+       if (view_x == trackview.editor().frame_to_unit_unrounded (_time_converter->to ((*cp.model())->when)) - _offset) {
+               view_x = (*cp.model())->when - _offset;
+       } else {
+               view_x = trackview.editor().unit_to_frame (view_x);
+               view_x = _time_converter->from (view_x + _offset);
        }
 
-       /* change the primary point */
-
        update_pending = true;
-       alist->modify (cp.model(), mr.xval, mr.yval);
-
-       /* change later points */
-
-       AutomationList::iterator i = cp.model();
-
-       ++i;
-
-       while (i != mr.end) {
-
-               double delta = ydelta * (mr.xmax - (*i)->when) / (mr.xmax - mr.xpos);
-
-               /* all later points move by the same distance along the x-axis as the main point */
-
-               if (delta) {
-                       alist->modify (i, (*i)->when + distance, (*i)->value + delta);
-               }
-
-               ++i;
-       }
-
-       if (did_push) {
 
-               /* move all points after the range represented by the view by the same distance
-                  as the main point moved.
-               */
+       view_to_model_coord_y (view_y);
 
-               alist->slide (mr.end, distance);
-       }
+       alist->modify (cp.model(), view_x, view_y);
 }
 
 bool
@@ -873,7 +760,7 @@ AutomationLine::control_points_adjacent (double xval, uint32_t & before, uint32_
        ControlPoint *acp = 0;
        double unit_xval;
 
-       unit_xval = trackview.editor().frame_to_unit (xval);
+       unit_xval = trackview.editor().frame_to_unit_unrounded (xval);
 
        for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
 
@@ -897,13 +784,16 @@ AutomationLine::control_points_adjacent (double xval, uint32_t & before, uint32_
 bool
 AutomationLine::is_last_point (ControlPoint& cp)
 {
-       ModelRepresentation mr;
+       // If the list is not empty, and the point is the last point in the list
 
-       model_representation (cp, mr);
+       if (alist->empty()) {
+               return false;
+       }
 
-       // If the list is not empty, and the point is the last point in the list
+       AutomationList::const_iterator i = alist->end();
+       --i;
 
-       if (!alist->empty() && mr.end == alist->end()) {
+       if (cp.model() == i) {
                return true;
        }
 
@@ -913,13 +803,9 @@ AutomationLine::is_last_point (ControlPoint& cp)
 bool
 AutomationLine::is_first_point (ControlPoint& cp)
 {
-       ModelRepresentation mr;
-
-       model_representation (cp, mr);
-
        // If the list is not empty, and the point is the first point in the list
 
-       if (!alist->empty() && mr.start == alist->begin()) {
+       if (!alist->empty() && cp.model() == alist->begin()) {
                return true;
        }
 
@@ -930,72 +816,46 @@ AutomationLine::is_first_point (ControlPoint& cp)
 void
 AutomationLine::remove_point (ControlPoint& cp)
 {
-       ModelRepresentation mr;
-
-       model_representation (cp, mr);
-
        trackview.editor().session()->begin_reversible_command (_("remove control point"));
        XMLNode &before = alist->get_state();
 
-       alist->erase (mr.start, mr.end);
-
+       alist->erase (cp.model());
+       
        trackview.editor().session()->add_command(
                new MementoCommand<AutomationList> (memento_command_binder (), &before, &alist->get_state())
                );
-       
+
        trackview.editor().session()->commit_reversible_command ();
        trackview.editor().session()->set_dirty ();
 }
 
+/** Get selectable points within an area.
+ *  @param start Start position in session frames.
+ *  @param end End position in session frames.
+ *  @param bot Bottom y range, as a fraction of line height, where 0 is the bottom of the line.
+ *  @param top Top y range, as a fraction of line height, where 0 is the bottom of the line.
+ *  @param result Filled in with selectable things; in this case, ControlPoints.
+ */
 void
-AutomationLine::get_selectables (nframes_t& start, nframes_t& end,
-               double botfrac, double topfrac, list<Selectable*>& results)
+AutomationLine::get_selectables (framepos_t start, framepos_t end, double botfrac, double topfrac, list<Selectable*>& results)
 {
-
-       double top;
-       double bot;
-       double nstart;
-       double nend;
-       bool collecting = false;
-
-       /* Curse X11 and its inverted coordinate system! */
-
-       bot = (1.0 - topfrac) * _height;
-       top = (1.0 - botfrac) * _height;
-
-       nstart = max_frames;
-       nend = 0;
+       /* convert fractions to display coordinates with 0 at the top of the track */
+       double const bot_track = (1 - topfrac) * trackview.current_height ();
+       double const top_track = (1 - botfrac) * trackview.current_height ();
 
        for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-               double when = (*(*i)->model())->when;
+               double const model_when = (*(*i)->model())->when;
 
-               if (when >= start && when <= end) {
-
-                       if ((*i)->get_y() >= bot && (*i)->get_y() <= top) {
-
-                               (*i)->show();
-                               (*i)->set_visible(true);
-                               collecting = true;
-                               nstart = min (nstart, when);
-                               nend = max (nend, when);
-
-                       } else {
-
-                               if (collecting) {
+               /* model_when is relative to the start of the source, so we just need to add on the origin_b here
+                  (as it is the session frame position of the start of the source)
+               */
+               
+               framepos_t const session_frames_when = _time_converter->to (model_when) + _time_converter->origin_b ();
 
-                                       results.push_back (new AutomationSelectable (nstart, nend, botfrac, topfrac, &trackview));
-                                       collecting = false;
-                                       nstart = max_frames;
-                                       nend = 0;
-                               }
-                       }
+               if (session_frames_when >= start && session_frames_when <= end && (*i)->get_y() >= bot_track && (*i)->get_y() <= top_track) {
+                       results.push_back (*i);
                }
        }
-
-       if (collecting) {
-               results.push_back (new AutomationSelectable (nstart, nend, botfrac, topfrac, &trackview));
-       }
-
 }
 
 void
@@ -1004,52 +864,15 @@ AutomationLine::get_inverted_selectables (Selection&, list<Selectable*>& /*resul
        // hmmm ....
 }
 
-/** Take a PointSelection and find ControlPoints that fall within it */
-list<ControlPoint*>
-AutomationLine::point_selection_to_control_points (PointSelection const & s)
-{
-       list<ControlPoint*> cp;
-       
-       for (PointSelection::const_iterator i = s.begin(); i != s.end(); ++i) {
-
-               if (i->track != &trackview) {
-                       continue;
-               }
-
-               /* Curse X11 and its inverted coordinate system! */
-
-               double const bot = (1.0 - i->high_fract) * _height;
-               double const top = (1.0 - i->low_fract) * _height;
-
-               for (vector<ControlPoint*>::iterator j = control_points.begin(); j != control_points.end(); ++j) {
-
-                       double const rstart = trackview.editor().frame_to_unit (i->start);
-                       double const rend = trackview.editor().frame_to_unit (i->end);
-
-                       if ((*j)->get_x() >= rstart && (*j)->get_x() <= rend) {
-                               if ((*j)->get_y() >= bot && (*j)->get_y() <= top) {
-                                       cp.push_back (*j);
-                               }
-                       }
-               }
-
-       }
-
-       return cp;
-}
-
 void
-AutomationLine::set_selected_points (PointSelection& points)
+AutomationLine::set_selected_points (PointSelection const & points)
 {
        for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
                (*i)->set_selected (false);
        }
 
-       if (!points.empty()) {
-               list<ControlPoint*> cp = point_selection_to_control_points (points);
-               for (list<ControlPoint*>::iterator i = cp.begin(); i != cp.end(); ++i) {
-                       (*i)->set_selected (true);
-               }
+       for (PointSelection::const_iterator i = points.begin(); i != points.end(); ++i) {
+               (*i)->set_selected (true);
        }
 
        set_colors ();
@@ -1066,16 +889,22 @@ void AutomationLine::set_colors ()
 void
 AutomationLine::list_changed ()
 {
-       queue_reset ();
+       DEBUG_TRACE (DEBUG::Automation, string_compose ("\tline changed, existing update pending? %1\n", update_pending));
+
+       if (!update_pending) {
+               update_pending = true;
+               Gtkmm2ext::UI::instance()->call_slot (invalidator (*this), boost::bind (&AutomationLine::queue_reset, this));
+       }
 }
 
 void
 AutomationLine::reset_callback (const Evoral::ControlList& events)
 {
-       ALPoints tmp_points;
-       uint32_t npoints = events.size();
+       uint32_t vp = 0;
+       uint32_t pi = 0;
+       uint32_t np;
 
-       if (npoints == 0) {
+       if (events.empty()) {
                for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
                        delete *i;
                }
@@ -1084,32 +913,97 @@ AutomationLine::reset_callback (const Evoral::ControlList& events)
                return;
        }
 
-       AutomationList::const_iterator ai;
+       /* hide all existing points, and the line */
+
+       for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
+               (*i)->hide();
+       }
+
+       line->hide ();
+       np = events.size();
+
+       Evoral::ControlList& e = const_cast<Evoral::ControlList&> (events);
+       
+       for (AutomationList::iterator ai = e.begin(); ai != e.end(); ++ai, ++pi) {
+
+               double tx = (*ai)->when;
+               double ty = (*ai)->value;
+
+               /* convert from model coordinates to canonical view coordinates */
+
+               model_to_view_coord (tx, ty);
 
-       for (ai = events.begin(); ai != events.end(); ++ai) {
+               if (std::isnan (tx) || std::isnan (ty)) {
+                       warning << string_compose (_("Ignoring illegal points on AutomationLine \"%1\""),
+                                                  _name) << endmsg;
+                       continue;
+               }
+               
+               if (tx >= max_framepos || tx < 0 || tx >= _maximum_time) {
+                       continue;
+               }
+               
+               /* convert x-coordinate to a canvas unit coordinate (this takes
+                * zoom and scroll into account).
+                */
+                       
+               tx = trackview.editor().frame_to_unit_unrounded (tx);
+               
+               /* convert from canonical view height (0..1.0) to actual
+                * height coordinates (using X11's top-left rooted system)
+                */
 
-               double translated_x = (*ai)->when;
-               double translated_y = (*ai)->value;
-               model_to_view_coord (translated_x, translated_y);
+               ty = _height - (ty * _height);
 
-               add_model_point (tmp_points, (*ai)->when, translated_y);
+               add_visible_control_point (vp, pi, tx, ty, ai, np);
+               vp++;
        }
 
-       determine_visible_control_points (tmp_points);
-}
+       /* discard extra CP's to avoid confusing ourselves */
 
+       while (control_points.size() > vp) {
+               ControlPoint* cp = control_points.back();
+               control_points.pop_back ();
+               delete cp;
+       }
 
-void
-AutomationLine::add_model_point (ALPoints& tmp_points, double frame, double yfract)
-{
-       tmp_points.push_back (ALPoint (trackview.editor().frame_to_unit (_time_converter.to(frame)),
-                                      _height - (yfract * _height)));
+       if (!terminal_points_can_slide) {
+               control_points.back()->set_can_slide(false);
+       }
+
+       if (vp > 1) {
+
+               /* reset the line coordinates given to the CanvasLine */
+
+               while (line_points.size() < vp) {
+                       line_points.push_back (ArdourCanvas::Duple (0,0));
+               }
+
+               while (line_points.size() > vp) {
+                       line_points.pop_back ();
+               }
+
+               for (uint32_t n = 0; n < vp; ++n) {
+                       line_points[n].x = control_points[n]->get_x();
+                       line_points[n].y = control_points[n]->get_y();
+               }
+
+               line->set (line_points);
+
+               if (_visible && alist->interpolation() != AutomationList::Discrete) {
+                       line->show();
+               }
+       }
+
+       set_selected_points (trackview.editor().get_selection().points);
 }
 
 void
 AutomationLine::reset ()
 {
+       DEBUG_TRACE (DEBUG::Automation, "\t\tLINE RESET\n");
        update_pending = false;
+       have_timeout = false;
 
        if (no_draw) {
                return;
@@ -1118,19 +1012,37 @@ AutomationLine::reset ()
        alist->apply_to_points (*this, &AutomationLine::reset_callback);
 }
 
+void
+AutomationLine::queue_reset ()
+{
+       /* this must be called from the GUI thread
+        */
+
+       if (trackview.editor().session()->transport_rolling() && alist->automation_write()) {
+               /* automation write pass ... defer to a timeout */
+               /* redraw in 1/4 second */
+               if (!have_timeout) {
+                       DEBUG_TRACE (DEBUG::Automation, "\tqueue timeout\n");
+                       Glib::signal_timeout().connect (sigc::bind_return (sigc::mem_fun (*this, &AutomationLine::reset), false), 250);
+                       have_timeout = true;
+               } else {
+                       DEBUG_TRACE (DEBUG::Automation, "\ttimeout already queued, change ignored\n");
+               }
+       } else {
+               reset ();
+       }
+}
+
 void
 AutomationLine::clear ()
 {
-       /* parent must create command */
+       /* parent must create and commit command */
        XMLNode &before = alist->get_state();
        alist->clear();
 
        trackview.editor().session()->add_command (
                new MementoCommand<AutomationList> (memento_command_binder (), &before, &alist->get_state())
                );
-       
-       trackview.editor().session()->commit_reversible_command ();
-       trackview.editor().session()->set_dirty ();
 }
 
 void
@@ -1147,39 +1059,31 @@ AutomationLine::set_list (boost::shared_ptr<ARDOUR::AutomationList> list)
 }
 
 void
-AutomationLine::show_all_control_points ()
+AutomationLine::add_visibility (VisibleAspects va)
 {
-       points_visible = true;
-
-       for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-               if (!(*i)->visible()) {
-                       (*i)->show ();
-                       (*i)->set_visible (true);
-               }
-       }
+       _visible = VisibleAspects (_visible | va);
+       show ();
 }
 
 void
-AutomationLine::hide_all_but_selected_control_points ()
+AutomationLine::set_visibility (VisibleAspects va)
 {
-       if (alist->interpolation() == AutomationList::Discrete) {
-               return;
-       }
-
-       points_visible = false;
+       _visible = va;
+       show ();
+}
 
-       for (vector<ControlPoint*>::iterator i = control_points.begin(); i != control_points.end(); ++i) {
-               if (!(*i)->selected()) {
-                       (*i)->set_visible (false);
-               }
-       }
+void
+AutomationLine::remove_visibility (VisibleAspects va)
+{
+       _visible = VisibleAspects (_visible & ~va);
+       show ();
 }
 
 void
 AutomationLine::track_entered()
 {
        if (alist->interpolation() != AutomationList::Discrete) {
-               show_all_control_points();
+               add_visibility (ControlPoints);
        }
 }
 
@@ -1187,7 +1091,7 @@ void
 AutomationLine::track_exited()
 {
        if (alist->interpolation() != AutomationList::Discrete) {
-               hide_all_but_selected_control_points();
+               remove_visibility (ControlPoints);
        }
 }
 
@@ -1208,32 +1112,27 @@ AutomationLine::set_state (const XMLNode &node, int version)
 void
 AutomationLine::view_to_model_coord (double& x, double& y) const
 {
-       view_to_model_coord_x (x);
+       x = _time_converter->from (x);
        view_to_model_coord_y (y);
 }
 
-void
-AutomationLine::view_to_model_coord_x (double& x) const
-{
-       x = _time_converter.from(x);
-}
-
 void
 AutomationLine::view_to_model_coord_y (double& y) const
 {
        /* TODO: This should be more generic ... */
        if (alist->parameter().type() == GainAutomation ||
            alist->parameter().type() == EnvelopeAutomation) {
-               y = slider_position_to_gain (y);
+               y = slider_position_to_gain_with_max (y, Config->get_max_gain());
                y = max (0.0, y);
                y = min (2.0, y);
-       } else if (alist->parameter().type() == PanAutomation) {
-               // vertical coordinate axis reversal
+       } else if (alist->parameter().type() == PanAzimuthAutomation ||
+                   alist->parameter().type() == PanElevationAutomation ||
+                   alist->parameter().type() == PanWidthAutomation) {
                y = 1.0 - y;
        } else if (alist->parameter().type() == PluginAutomation) {
                y = y * (double)(alist->get_max_y()- alist->get_min_y()) + alist->get_min_y();
        } else {
-               y = (int)(y * alist->parameter().max());
+               y = rint (y * alist->parameter().max());
        }
 }
 
@@ -1243,8 +1142,10 @@ AutomationLine::model_to_view_coord (double& x, double& y) const
        /* TODO: This should be more generic ... */
        if (alist->parameter().type() == GainAutomation ||
            alist->parameter().type() == EnvelopeAutomation) {
-               y = gain_to_slider_position (y);
-       } else if (alist->parameter().type() == PanAutomation) {
+               y = gain_to_slider_position_with_max (y, Config->get_max_gain());
+       } else if (alist->parameter().type() == PanAzimuthAutomation ||
+                   alist->parameter().type() == PanElevationAutomation ||
+                   alist->parameter().type() == PanWidthAutomation) {
                // vertical coordinate axis reversal
                y = 1.0 - y;
        } else if (alist->parameter().type() == PluginAutomation) {
@@ -1253,7 +1154,7 @@ AutomationLine::model_to_view_coord (double& x, double& y) const
                y = y / (double)alist->parameter().max(); /* ... like this */
        }
 
-       x = _time_converter.to(x);
+       x = _time_converter->to (x) - _offset;
 }
 
 /** Called when our list has announced that its interpolation style has changed */
@@ -1261,17 +1162,19 @@ void
 AutomationLine::interpolation_changed (AutomationList::InterpolationStyle style)
 {
        if (style == AutomationList::Discrete) {
-               show_all_control_points();
+               set_visibility (ControlPoints);
                line->hide();
        } else {
-               hide_all_but_selected_control_points();
-               line->show();
+               set_visibility (Line);
        }
 }
 
 void
-AutomationLine::add_visible_control_point (uint32_t view_index, uint32_t pi, double tx, double ty, AutomationList::iterator model, uint32_t npoints)
+AutomationLine::add_visible_control_point (uint32_t view_index, uint32_t pi, double tx, double ty, 
+                                          AutomationList::iterator model, uint32_t npoints)
 {
+       ControlPoint::ShapeType shape;
+
        if (view_index >= control_points.size()) {
 
                /* make sure we have enough control points */
@@ -1282,63 +1185,45 @@ AutomationLine::add_visible_control_point (uint32_t view_index, uint32_t pi, dou
                control_points.push_back (ncp);
        }
 
-       ControlPoint::ShapeType shape;
-
        if (!terminal_points_can_slide) {
                if (pi == 0) {
-                       control_points[view_index]->set_can_slide(false);
+                       control_points[view_index]->set_can_slide (false);
                        if (tx == 0) {
                                shape = ControlPoint::Start;
                        } else {
                                shape = ControlPoint::Full;
                        }
                } else if (pi == npoints - 1) {
-                       control_points[view_index]->set_can_slide(false);
+                       control_points[view_index]->set_can_slide (false);
                        shape = ControlPoint::End;
                } else {
-                       control_points[view_index]->set_can_slide(true);
+                       control_points[view_index]->set_can_slide (true);
                        shape = ControlPoint::Full;
                }
        } else {
-               control_points[view_index]->set_can_slide(true);
+               control_points[view_index]->set_can_slide (true);
                shape = ControlPoint::Full;
        }
 
        control_points[view_index]->reset (tx, ty, model, view_index, shape);
 
        /* finally, control visibility */
-       
-       if (_visible && points_visible) {
+
+       if (_visible & ControlPoints) {
                control_points[view_index]->show ();
                control_points[view_index]->set_visible (true);
        } else {
-               if (!points_visible) {
-                       control_points[view_index]->set_visible (false);
-               }
+               control_points[view_index]->set_visible (false);
        }
 }
 
-void
-AutomationLine::add_always_in_view (double x)
-{
-       _always_in_view.push_back (x);
-       alist->apply_to_points (*this, &AutomationLine::reset_callback);
-}
-
-void
-AutomationLine::clear_always_in_view ()
-{
-       _always_in_view.clear ();
-       alist->apply_to_points (*this, &AutomationLine::reset_callback);
-}
-
 void
 AutomationLine::connect_to_list ()
 {
        _list_connections.drop_connections ();
-       
+
        alist->StateChanged.connect (_list_connections, invalidator (*this), boost::bind (&AutomationLine::list_changed, this), gui_context());
-       
+
        alist->InterpolationChanged.connect (
                _list_connections, invalidator (*this), boost::bind (&AutomationLine::interpolation_changed, this, _1), gui_context()
                );
@@ -1349,3 +1234,49 @@ AutomationLine::memento_command_binder ()
 {
        return new SimpleMementoCommandBinder<AutomationList> (*alist.get());
 }
+
+/** Set the maximum time that points on this line can be at, relative
+ *  to the start of the track or region that it is on.
+ */
+void
+AutomationLine::set_maximum_time (framecnt_t t)
+{
+       if (_maximum_time == t) {
+               return;
+       }
+
+       _maximum_time = t;
+       reset ();
+}
+
+
+/** @return min and max x positions of points that are in the list, in session frames */
+pair<framepos_t, framepos_t>
+AutomationLine::get_point_x_range () const
+{
+       pair<framepos_t, framepos_t> r (max_framepos, 0);
+
+       for (AutomationList::const_iterator i = the_list()->begin(); i != the_list()->end(); ++i) {
+               r.first = min (r.first, session_position (i));
+               r.second = max (r.second, session_position (i));
+       }
+
+       return r;
+}
+
+framepos_t
+AutomationLine::session_position (AutomationList::const_iterator p) const
+{
+       return _time_converter->to ((*p)->when) + _offset + _time_converter->origin_b ();
+}
+
+void
+AutomationLine::set_offset (framepos_t off)
+{
+       if (_offset == off) {
+               return;
+       }
+
+       _offset = off;
+       reset ();
+}