diff options
Diffstat (limited to 'src/lib')
| -rw-r--r-- | src/lib/rect.h | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/src/lib/rect.h b/src/lib/rect.h index 5758dd04e..602acfc4b 100644 --- a/src/lib/rect.h +++ b/src/lib/rect.h @@ -21,6 +21,7 @@ #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 +68,24 @@ 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 */ - return Rect ( + T const tx = std::max (x, other.x); + T const ty = std::max (y, other.y); + + 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) |