libs/geometry/example/ml02_distance_strategy.cpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
   4
   5 // Use, modification and distribution is subject to the Boost Software License,
   6 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   7 // http://www.boost.org/LICENSE_1_0.txt)
   8 //
   9 // Multipolygon DP simplification example from the mailing list discussion
  10 // about the DP algorithm issue:
  11 // http://lists.osgeo.org/pipermail/ggl/2011-September/001533.html
  12
  13 #include <boost/geometry.hpp>
  14 #include <boost/geometry/strategies/cartesian/distance_pythagoras.hpp>
  15 #include <boost/geometry/geometries/point_xy.hpp>
  16 using namespace boost::geometry;
  17
  18 int main()
  19 {
  20   typedef model::d2::point_xy<double> point_xy;
  21
  22   point_xy p1(0.0, 0.0);
  23   point_xy p2(5.0, 0.0);
  24
  25   // 1) This is direct call to Pythagoras algo
  26   typedef strategy::distance::pythagoras<point_xy, point_xy, double> strategy1_type;
  27   strategy1_type strategy1;
  28   strategy1_type ::calculation_type d1 = strategy1.apply(p1, p2);
  29
  30   // 2) This is what is effectively called by simplify
  31   typedef strategy::distance::comparable::pythagoras<point_xy, point_xy, double> strategy2_type;
  32   strategy2_type strategy2;
  33   strategy2_type::calculation_type d2 = strategy2.apply(p1, p2);
  34
  35   return 0;
  36 }