Add some tests; fix failure to make DCP when there is a bit of audio right at the...

[dcpomatic.git] / src / lib / rect.h

diff --git a/src/lib/rect.h b/src/lib/rect.h
index 5758dd04e4496955af9b7cc994c492bf785c40b6..d0daec43712ab4c5cd7a0bf88cf27c3c5fc69a74 100644 (file)
--- a/src/lib/rect.h
+++ b/src/lib/rect.h
@@ -1,19 +1,20 @@
 /*
     Copyright (C) 2013 Carl Hetherington <cth@carlh.net>
 
-    This program is free software; you can redistribute it and/or modify
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 2 of the License, or
     (at your option) any later version.
 
-    This program is distributed in the hope that it will be useful,
+    DCP-o-matic is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
 
     You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
 
 */
 
@@ -21,6 +22,7 @@
 #define DCPOMATIC_RECT_H
 
 #include "position.h"
+#include <boost/optional.hpp>
 #include <algorithm>
 
 /* Put this inside a namespace as Apple put a Rect in the global namespace */
@@ -67,16 +69,24 @@ public:
                return Position<T> (x, y);
        }
 
-       Rect<T> intersection (Rect<T> const & other) const
+       boost::optional<Rect<T> > intersection (Rect<T> const & other) const
        {
-               T const tx = max (x, other.x);
-               T const ty = max (y, other.y);
+               /* This isn't exactly the paragon of mathematical precision */
+
+               T const tx = std::max (x, other.x);
+               T const ty = std::max (y, other.y);
 
-               return Rect (
+               Rect r (
                        tx, ty,
-                       min (x + width, other.x + other.width) - tx,
-                       min (y + height, other.y + other.height) - ty
+                       std::min (x + width, other.x + other.width) - tx,
+                       std::min (y + height, other.y + other.height) - ty
                        );
+
+               if (r.width < 0 || r.height < 0) {
+                       return boost::optional<Rect<T> > ();
+               }
+
+               return r;
        }
 
        void extend (Rect<T> const & other)