X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fbox.cc;h=68d53b39f69b73e2cf5c783ea96795c552ee3e47;hb=9e781b7dc83b60a543ce218aa1a5f139f74c760f;hp=df4770ff7861eada58715e88cea9be1c74ae92da;hpb=d61cf3bbdb1c6670a127ba3baddf2f04d3e34fd3;p=lilypond.git

diff --git a/lily/box.cc b/lily/box.cc
index df4770ff78..68d53b39f6 100644
--- a/lily/box.cc
+++ b/lily/box.cc
@@ -1,7 +1,7 @@
 /*
   This file is part of LilyPond, the GNU music typesetter.
 
-  Copyright (C) 1996--2012 Han-Wen Nienhuys <hanwen@xs4all.nl>
+  Copyright (C) 1996--2014 Han-Wen Nienhuys <hanwen@xs4all.nl>
 
   LilyPond is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -23,7 +23,8 @@ void
 Box::translate (Offset o)
 {
   for (Axis i = X_AXIS; i < NO_AXES; incr (i))
-    interval_a_[i] += o[i];
+    if (!is_empty (i))
+      interval_a_[i] += o[i];
 }
 
 void
@@ -33,6 +34,13 @@ Box::unite (Box b)
     interval_a_[i].unite (b[i]);
 }
 
+Real
+Box::area () const
+{
+  return interval_a_[X_AXIS].length ()
+         * interval_a_[Y_AXIS].length ();
+}
+
 Box::Box ()
 {
 }
@@ -44,6 +52,21 @@ Box::set_empty ()
   interval_a_[Y_AXIS].set_empty ();
 }
 
+bool
+Box::is_empty () const
+{
+  return is_empty (X_AXIS) && is_empty (Y_AXIS);
+}
+
+bool
+Box::is_empty (Axis a) const
+{
+  Interval empty;
+  empty.set_empty ();
+  return interval_a_[a][LEFT] == empty[LEFT]
+    && interval_a_[a][RIGHT] == empty[RIGHT];
+}
+
 Box::Box (Interval ix, Interval iy)
 {
   x () = ix;
@@ -90,6 +113,13 @@ Box::widen (Real x, Real y)
   interval_a_[Y_AXIS].widen (y);
 }
 
+void
+Box::intersect (Box b)
+{
+  interval_a_[X_AXIS].intersect (b[X_AXIS]);
+  interval_a_[Y_AXIS].intersect (b[Y_AXIS]);
+}
+
 // for debugging
 
 void