| [/============================================================================ |
| Boost.Geometry (aka GGL, Generic Geometry Library) |
| |
| Copyright (c) 2009-2012 Mateusz Loskot, London, UK. |
| Copyright (c) 2009-2012 Barend Gehrels, Amsterdam, the Netherlands. |
| Copyright (c) 2009-2012 Bruno Lalande, Paris, France. |
| |
| Use, modification and distribution is subject to the Boost Software License, |
| Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
| http://www.boost.org/LICENSE_1_0.txt) |
| =============================================================================/] |
| |
| [section:concept_box Box Concept] |
| |
| [heading Description] |
| [concept Box..box] |
| |
| A box is a geometry with (usually) two or three dimensions, having its axis aligned to the coordinate system. |
| |
| The box is not one of the basic types in Boost.Geometry (point, linestring, polygon) but it is a ['helper type]. |
| The main reasons for the box existance are its usefulness for indexing (a spatial index, or splitting a geometry |
| into monotonic sections) and it is the output of the [link geometry.reference.algorithms.envelope envelope] algorithm. |
| |
| Therefore, a box is axis aligned (the envelope is also called aabb, axis aligned bounding box). |
| |
| [heading Concept Definition] |
| |
| The Box Concept is defined as following: |
| |
| * there must be a specialization of `traits::tag`, defining `box_tag` as type |
| * there must be a specialization of `traits::point_type` to define the underlying point type |
| (even if it does not consist of points, it should define this type, to indicate the points it can work with) |
| * there must be a specialization of `traits::indexed_access`, per index (`min_corner`, `max_corner`) and per dimension, with two functions: |
| * `get` to get a coordinate value |
| * `set` to set a coordinate value (this one is not checked for ConstBox) |
| |
| |
| [heading Available Models] |
| * [link geometry.reference.models.model_box model::box] |
| |
| [endsect] |
| |
