Canvas: fix element mouse hit detection with OSG 3.3.2.

[simgear.git] / simgear / math / SGVec4.hxx

diff --git a/simgear/math/SGVec4.hxx b/simgear/math/SGVec4.hxx
index 301aaca3ccb4ff8df41259100a409d2b50858838..4339dfd9b79879a3fab0da2b59a5cca747cc5578 100644 (file)
--- a/simgear/math/SGVec4.hxx
+++ b/simgear/math/SGVec4.hxx
@@ -244,6 +244,19 @@ max(S s, const SGVec4<T>& v)
                    SGMisc<T>::max(s, v(3)));
 }
 
+/// Add two vectors taking care of (integer) overflows. The values are limited
+/// to the respective minimum and maximum values.
+template<class T>
+SGVec4<T> addClipOverflow(SGVec4<T> const& lhs, SGVec4<T> const& rhs)
+{
+  return SGVec4<T>(
+    SGMisc<T>::addClipOverflow(lhs.x(), rhs.x()),
+    SGMisc<T>::addClipOverflow(lhs.y(), rhs.y()),
+    SGMisc<T>::addClipOverflow(lhs.z(), rhs.z()),
+    SGMisc<T>::addClipOverflow(lhs.w(), rhs.w())
+  );
+}
+
 /// Scalar dot product
 template<typename T>
 inline