Don't redraw the summary every time the playhead moves (if it hasn't moved visibly on the summary), and only redraw the bit that has changed when it does happen.

git-svn-id: svn://localhost/ardour2/branches/3.0@11208 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 23 insertions, 4 deletions

diff --git a/gtk2_ardour/editor_summary.cc b/gtk2_ardour/editor_summary.cc
index 8de492ddec..57a08caf88 100644
--- a/gtk2_ardour/editor_summary.cc
+++ b/gtk2_ardour/editor_summary.cc
@@ -120,7 +120,7 @@ EditorSummary::on_expose_event (GdkEventExpose* event)
 	/* XXX: colour should be set from configuration file */
 	cairo_set_source_rgba (cr, 1, 0, 0, 1);
 
-	double const p = (_editor->playhead_cursor->current_frame - _start) * _x_scale;
+	double const p = playhead_frame_to_position (_editor->playhead_cursor->current_frame);
 	cairo_move_to (cr, p, 0);
 	cairo_line_to (cr, p, get_height());
 	cairo_stroke (cr);
@@ -251,10 +251,19 @@ EditorSummary::render_region (RegionView* r, cairo_t* cr, double y) const
 void
 EditorSummary::set_overlays_dirty ()
 {
-	ENSURE_GUI_THREAD (*this, &EditorSummary::set_overlays_dirty)
+	ENSURE_GUI_THREAD (*this, &EditorSummary::set_overlays_dirty);
 	queue_draw ();
 }
 
+/** Set the summary so that just the overlays (viewbox, playhead etc.) in a given area will be re-rendered */
+void
+EditorSummary::set_overlays_dirty (int x, int y, int w, int h)
+{
+	ENSURE_GUI_THREAD (*this, &EditorSummary::set_overlays_dirty);
+	queue_draw_area (x, y, w, h);
+}
+
+
 /** Handle a size request.
  *  @param req GTK requisition
  */
@@ -859,8 +868,12 @@ EditorSummary::set_editor_y (pair<double, double> const y)
 void
 EditorSummary::playhead_position_changed (framepos_t p)
 {
-	if (_session && int (p * _x_scale) != int (_last_playhead)) {
-		set_overlays_dirty ();
+	int const o = int (_last_playhead);
+	int const n = int (playhead_frame_to_position (p));
+	if (_session && o != n) {
+		int a = min (o, n);
+		int b = max (o, n);
+		set_overlays_dirty (a - 1, 0, b + 1, get_height ());
 	}
 }
 
@@ -928,3 +941,9 @@ EditorSummary::route_gui_changed (string c)
 		set_dirty ();
 	}
 }
+
+double
+EditorSummary::playhead_frame_to_position (framepos_t t) const
+{
+	return (t - _start) * _x_scale;
+}