Add the AABBRayIntersectionTraits concept

AABB_tree/doc/AABB_tree/Concepts/AABBRayIntersectionTraits.h

@@ -0,0 +1,41 @@
+/*!
+\ingroup PkgAABB_treeConcepts
+\cgalConcept
+
+The concept `AABBRayIntersectionTraits` is a refinement of the Model
+`AABBTraits`. In addition to the types and functions required by
+`AABBTraits` it also requires function objects to calculate the
+distance of an intersection along
+
+\cgalHasModel `CGAL::AABB_traits<AABBGeomTraits,AABBPrimitive>`
+
+\sa `CGAL::AABB_traits<AABBGeomTraits,AABBPrimitive>`
+\sa `CGAL::AABB_tree<AABBTraits>`
+\sa `AABBPrimitive`
+
+*/
+class AABBRayIntersectionTraits {
+  
+  /*!
+    Type of a 3D ray. 
+  */ 
+  typedef unspecified_type Ray_3;
+
+
+  /*!
+
+    A functor object to compute the smallest ray parameter, if any, at
+    which a bounding box and a ray intersect. Provides the operator:
+    `boost::optional<FT> operator()(const Ray_3& r, const Bounding_box& bbox)`.
+
+    A common algorithm for this is <A
+    HREF="http://www.siggraph.org/education/materials/HyperGraph/raytrace/rtinter3.htm">the
+    slab method</A>.
+  */
+  typedef unspecified_type Intersection_distance;
+
+  /*!
+    Returns the intersection distance functor. 
+  */ 
+  Intersection_distance intersection_distance_object() const ;
+};