ceph/src/boost/libs/geometry/example/05_b_overlay_linestring_polygon_example.cpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
   4 // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
   5 // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
   6
   7 // Use, modification and distribution is subject to the Boost Software License,
   8 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   9 // http://www.boost.org/LICENSE_1_0.txt)
  10 //
  11 // Linestring Polygon Overlay Example
  12
  13 // NOTE: this example is obsolete. Boost.Geometry can now
  14 // overlay linestrings/polygons.
  15 // This sample will be removed in next version.
  16
  17 #include <fstream>
  18 #include <iostream>
  19 #include <string>
  20 #include <vector>
  21
  22 #include <boost/foreach.hpp>
  23
  24
  25 #include <boost/geometry/geometry.hpp>
  26 #include <boost/geometry/geometries/linestring.hpp>
  27 #include <boost/geometry/geometries/point_xy.hpp>
  28 #include <boost/geometry/geometries/polygon.hpp>
  29 #include <boost/geometry/geometries/adapted/c_array.hpp>
  30
  31 #if defined(HAVE_SVG)
  32 #  include <boost/geometry/io/svg/svg_mapper.hpp>
  33 #endif
  34
  35 BOOST_GEOMETRY_REGISTER_C_ARRAY_CS(cs::cartesian);
  36
  37
  38 int main(void)
  39 {
  40     namespace bg = boost::geometry;
  41
  42     typedef bg::model::d2::point_xy<double> point_2d;
  43
  44     bg::model::linestring<point_2d> ls;
  45     {
  46         const double c[][2] = { {0, 1}, {2, 5}, {5, 3} };
  47         bg::assign_points(ls, c);
  48     }
  49
  50     bg::model::polygon<point_2d> p;
  51     {
  52         const double c[][2] = { {3, 0}, {0, 3}, {4, 5}, {3, 0} };
  53         bg::assign_points(p, c);
  54     }
  55     bg::correct(p);
  56
  57 #if defined(HAVE_SVG)
  58     // Create SVG-mapper
  59     std::ofstream stream("05_b_overlay_linestring_polygon_example.svg");
  60     bg::svg_mapper<point_2d> svg(stream, 500, 500);
  61     // Determine extend by adding geometries
  62     svg.add(p);
  63     svg.add(ls);
  64     // Map geometries
  65     svg.map(ls, "opacity:0.6;stroke:rgb(255,0,0);stroke-width:2;");
  66     svg.map(p, "opacity:0.6;fill:rgb(0,0,255);");
  67 #endif
  68
  69     // Calculate intersection points (turn points)
  70     typedef bg::detail::segment_ratio_type<point_2d, bg::detail::no_rescale_policy>::type segment_ratio;
  71     typedef bg::detail::overlay::turn_info<point_2d, segment_ratio> turn_info;
  72     std::vector<turn_info> turns;
  73     bg::detail::get_turns::no_interrupt_policy policy;
  74     bg::detail::no_rescale_policy rescale_policy;
  75     bg::strategy::intersection::services::default_strategy<typename bg::cs_tag<point_2d>::type>::type intersection_strategy;
  76     bg::get_turns<false, false, bg::detail::overlay::assign_null_policy>(ls, p, intersection_strategy, rescale_policy, turns, policy);
  77
  78     std::cout << "Intersection of linestring/polygon" << std::endl;
  79     BOOST_FOREACH(turn_info const& turn, turns)
  80     {
  81         std::string action = "intersecting";
  82         if (turn.operations[0].operation
  83                 == bg::detail::overlay::operation_intersection)
  84         {
  85             action = "entering";
  86         }
  87         else if (turn.operations[0].operation
  88                 == bg::detail::overlay::operation_union)
  89         {
  90             action = "leaving";
  91
  92         }
  93         std::cout << action << " polygon at " << bg::dsv(turn.point) << std::endl;
  94 #if defined(HAVE_SVG)
  95         svg.map(turn.point, "fill:rgb(255,128,0);stroke:rgb(0,0,100);stroke-width:1");
  96         svg.text(turn.point, action, "fill:rgb(0,0,0);font-family:Arial;font-size:10px");
  97 #endif
  98     }
  99
 100     return 0;
 101 }