.. Documentation for the header file dolfin/geometry/BoundingBoxTree.h .. _programmers_reference_cpp_geometry_boundingboxtree: BoundingBoxTree.h ================= .. note:: The documentation on this page was automatically extracted from the DOLFIN C++ code and may need to be edited or expanded. .. cpp:class:: BoundingBoxTree This class implements a (distributed) axis aligned bounding box tree (AABB tree). Bounding box trees can be created from meshes and [other data structures, to be filled in]. .. cpp:function:: BoundingBoxTree() Create empty bounding box tree .. cpp:function:: void build(const Mesh& mesh) Build bounding box tree for cells of mesh. *Arguments* mesh (:cpp:class:`Mesh`) The mesh for which to compute the bounding box tree. .. cpp:function:: void build(const Mesh& mesh, std::size_t tdim) Build bounding box tree for mesh entities of given dimension. *Arguments* mesh (:cpp:class:`Mesh`) The mesh for which to compute the bounding box tree. dimension (std::size_t) The entity dimension (topological dimension) for which to compute the bounding box tree. .. cpp:function:: void build(const std::vector& points, std::size_t gdim) Build bounding box tree for point cloud. *Arguments* points (std::vector<:cpp:class:`Point`>) The list of points. gdim (std::size_t) The geometric dimension. .. cpp:function:: std::vector compute_collisions(const Point& point) const Compute all collisions between bounding boxes and :cpp:class:`Point`. *Returns* std::vector A list of local indices for entities contained in (leaf) bounding boxes that collide with (intersect) the given point. *Arguments* point (:cpp:class:`Point`) The point. .. cpp:function:: std::pair, std::vector > compute_collisions(const BoundingBoxTree& tree) const Compute all collisions between bounding boxes and :cpp:class:`BoundingBoxTree`. *Returns* std::vector A list of local indices for entities in this tree that collide with (intersect) entities in other tree. std::vector A list of local indices for entities in other tree that collide with (intersect) entities in this tree. The two lists have equal length and contain matching entities, such that entity `i` in the first list collides with entity `i` in the second list. Note that this means that the entity lists may contain duplicate entities since a single entity may collide with several different entities. *Arguments* tree (:cpp:class:`BoundingBoxTree`) The bounding box tree. Note that this function only checks collisions between bounding boxes of entities. It does not check that the entities themselves actually collide. To compute entity collisions, use the function compute_entity_collisions. .. cpp:function:: std::vector compute_entity_collisions(const Point& point) const Compute all collisions between entities and :cpp:class:`Point`. *Returns* std::vector A list of local indices for entities that collide with (intersect) the given point. *Arguments* point (:cpp:class:`Point`) The point. .. cpp:function:: std::vector compute_process_collisions(const Point& point) const Compute all collisions between process bounding boxes and :cpp:class:`Point`. Effectively a list of processes which may contain the :cpp:class:`Point`. *Returns* std::vector A list of process numbers where the :cpp:class:`Mesh` may collide with (intersect) the given point. *Arguments* point (:cpp:class:`Point`) The point. .. cpp:function:: std::pair, std::vector > compute_entity_collisions(const BoundingBoxTree& tree) const Compute all collisions between entities and :cpp:class:`BoundingBoxTree`. *Returns* std::vector A list of local indices for entities in this tree that collide with (intersect) entities in other tree. std::vector A list of local indices for entities in other tree that collide with (intersect) entities in this tree. The two lists have equal length and contain matching entities, such that entity `i` in the first list collides with entity `i` in the second list. Note that this means that the entity lists may contain duplicate entities since a single entity may collide with several different entities. *Arguments* tree (:cpp:class:`BoundingBoxTree`) The bounding box tree. .. cpp:function:: unsigned int compute_first_collision(const Point& point) const Compute first collision between bounding boxes and :cpp:class:`Point`. *Returns* unsigned int The local index for the first found entity contained in a (leaf) bounding box that collides with (intersects) the given point. If not found, std::numeric_limits::max() is returned. *Arguments* point (:cpp:class:`Point`) The point. .. cpp:function:: unsigned int compute_first_entity_collision(const Point& point) const Compute first collision between entities and :cpp:class:`Point`. *Returns* unsigned int The local index for the first found entity that collides with (intersects) the given point. If not found, std::numeric_limits::max() is returned. *Arguments* point (:cpp:class:`Point`) The point. .. cpp:function:: std::pair compute_closest_entity(const Point& point) const Compute closest entity to :cpp:class:`Point`. *Returns* unsigned int The local index for the entity that is closest to the point. If more than one entity is at the same distance (or point contained in entity), then the first entity is returned. double The distance to the closest entity. *Arguments* point (:cpp:class:`Point`) The point. .. cpp:function:: std::pair compute_closest_point(const Point& point) const Compute closest point to :cpp:class:`Point`. This function assumes that the tree has been built for a point cloud. Developer note: This function should not be confused with computing the closest point in all entities of a mesh. That function could be added with relative ease since we actually compute the closest points to get the distance in the above function (compute_closest_entity) inside the specialized implementations in TetrahedronCell.cpp etc. *Returns* unsigned int The local index for the point that is closest to the point. If more than one point is at the same distance (or point contained in entity), then the first point is returned. double The distance to the closest point. *Arguments* point (:cpp:class:`Point`) The point. .. cpp:function:: bool collides(const Point& point) const Check whether given point collides with the bounding box tree. This is equivalent to calling compute_first_collision and checking whether any collision was detected. *Returns* bool True iff the point is inside the tree. .. cpp:function:: bool collides_entity(const Point& point) const Check whether given point collides with any entity contained in the bounding box tree. This is equivalent to calling compute_first_entity_collision and checking whether any collision was detected. *Returns* bool True iff the point is inside the tree.