fix up thinko in recent raise_to_top/lower_to_bottom optimization

[ardour.git] / libs / canvas / rectangle.cc

diff --git a/libs/canvas/rectangle.cc b/libs/canvas/rectangle.cc
index 7b7f67c3c6b979836f5d11aac38841e6ab2ffe57..06a41e074c0fe6514c58b40ca12b7cdfc4778bb3 100644 (file)
--- a/libs/canvas/rectangle.cc
+++ b/libs/canvas/rectangle.cc
@@ -119,11 +119,19 @@ Rectangle::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) con
 void
 Rectangle::compute_bounding_box () const
 {
-       /* boundary is drawn inside our coordinates but expanded by 0.5 to get
-        * single-pixel drawing correct.
-        */
-       Rect r = _rect.fix();
-       _bounding_box = boost::optional<Rect> (r.expand (_outline_width/2.0));
+       if (!_rect.empty()) {
+               Rect r = _rect.fix ();
+
+               /* our outlines are always inside our coordinates, but we have
+                * to ensure that our bounding box fully *contains* the
+                * rectangle
+                *
+                * XXX: or something like that, waffle.
+                *
+                */
+               _bounding_box = r.expand (1.0);
+       }
+
        _bounding_box_dirty = false;
 }