ceph/src/boost/libs/geometry/doc/src/examples/geometries/register/point.cpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2 // QuickBook Example
   3
   4 // Copyright (c) 2011-2012 Barend Gehrels, Amsterdam, the Netherlands.
   5
   6 // Use, modification and distribution is subject to the Boost Software License,
   7 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   8 // http://www.boost.org/LICENSE_1_0.txt)
   9
  10 //[register_point_2d
  11 //` Show the use of the macro BOOST_GEOMETRY_REGISTER_POINT_2D
  12
  13 #include <iostream>
  14 #include <boost/geometry.hpp>
  15 #include <boost/geometry/geometries/register/point.hpp>
  16
  17 /*< Somewhere, any legacy point struct is defined >*/
  18 struct legacy_point
  19 {
  20     double x, y;
  21 };
  22
  23 BOOST_GEOMETRY_REGISTER_POINT_2D(legacy_point, double, cs::cartesian, x, y) /*< The magic: adapt it to Boost.Geometry Point Concept >*/
  24
  25 int main()
  26 {
  27     legacy_point p1, p2;
  28
  29     namespace bg = boost::geometry;
  30
  31     /*< Any Boost.Geometry function can be used for legacy point now. Here: assign_values and distance >*/
  32     bg::assign_values(p1, 1, 1);
  33     bg::assign_values(p2, 2, 2);
  34
  35     double d = bg::distance(p1, p2);
  36
  37     std::cout << "Distance: " << d << std::endl;
  38
  39     return 0;
  40 }
  41
  42 //]
  43
  44
  45 //[register_point_2d_output
  46 /*`
  47 Output:
  48 [pre
  49 Distance: 1.41421
  50 ]
  51 */
  52 //]