libs/geometry/doc/src/examples/algorithms/distance.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 //[distance
  11 //` Shows calculation of distance of point to some other geometries
  12
  13 #include <iostream>
  14 #include <list>
  15
  16 #include <boost/geometry.hpp>
  17 #include <boost/geometry/geometries/linestring.hpp>
  18 #include <boost/geometry/geometries/point_xy.hpp>
  19 #include <boost/geometry/geometries/polygon.hpp>
  20 #include <boost/geometry/multi/geometries/multi_point.hpp>
  21 #include <boost/geometry/multi/geometries/multi_polygon.hpp>
  22
  23 #include <boost/geometry/io/wkt/wkt.hpp>
  24
  25 #include <boost/foreach.hpp>
  26
  27 int main()
  28 {
  29     typedef boost::geometry::model::d2::point_xy<double> point_type;
  30     typedef boost::geometry::model::polygon<point_type> polygon_type;
  31     typedef boost::geometry::model::linestring<point_type> linestring_type;
  32     typedef boost::geometry::model::multi_point<point_type> multi_point_type;
  33
  34     point_type p(1,2);
  35     polygon_type poly;
  36     linestring_type line;
  37     multi_point_type mp;
  38
  39     boost::geometry::read_wkt(
  40         "POLYGON((2 1.3,2.4 1.7,2.8 1.8,3.4 1.2,3.7 1.6,3.4 2,4.1 3,5.3 2.6,5.4 1.2,4.9 0.8,2.9 0.7,2 1.3)"
  41             "(4.0 2.0, 4.2 1.4, 4.8 1.9, 4.4 2.2, 4.0 2.0))", poly);
  42     line.push_back(point_type(0,0));
  43     line.push_back(point_type(0,3));
  44     mp.push_back(point_type(0,0));
  45     mp.push_back(point_type(3,3));
  46
  47     std::cout
  48         << "Point-Poly: " << boost::geometry::distance(p, poly) << std::endl
  49         << "Point-Line: " << boost::geometry::distance(p, line) << std::endl
  50         << "Point-MultiPoint: " << boost::geometry::distance(p, mp) << std::endl;
  51
  52     return 0;
  53 }
  54
  55 //]
  56
  57
  58 //[distance_output
  59 /*`
  60 Output:
  61 [pre
  62 Point-Poly: 1.22066
  63 Point-Line: 1
  64 Point-MultiPoint: 2.23607
  65 ]
  66 */
  67 //]
  68