added missing getVolume function to box

src/pe/rigidbody/Box.h

@@ -83,6 +83,7 @@ public:
    /*!\name Get functions */
    //@{
    inline const Vec3& getLengths() const;
+   virtual inline real_t getVolume() const;
    //@}
    //**********************************************************************************************
 
@@ -306,7 +307,16 @@ inline const Vec3& Box::getLengths() const
 }
 //*************************************************************************************************
 
-
+//*************************************************************************************************
+/*!\brief Returns the volume of the box.
+ *
+ * \return The volume of the box.
+ */
+inline real_t Box::getVolume() const
+{
+   return Box::calcVolume(getLengths());
+}
+//*************************************************************************************************
 
 
 //=================================================================================================