ceph/src/boost/libs/geometry/test/algorithms/distance/test_distance.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2 // Unit Test
   3
   4 // Copyright (c) 2010-2012 Barend Gehrels, Amsterdam, the Netherlands.
   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 #ifndef BOOST_GEOMETRY_TEST_DISTANCE_HPP
  10 #define BOOST_GEOMETRY_TEST_DISTANCE_HPP
  11
  12 #include <geometry_test_common.hpp>
  13
  14 #include <boost/geometry/algorithms/distance.hpp>
  15 #include <boost/geometry/io/wkt/read.hpp>
  16 #include <boost/geometry/strategies/strategies.hpp>
  17
  18 // Define a custom distance strategy
  19 // For this one, the "taxicab" distance,
  20 // see http://en.wikipedia.org/wiki/Taxicab_geometry
  21
  22 // For a point-point-distance operation, one typename Point is enough.
  23 // For a point-segment-distance operation, there is some magic inside
  24 // using another point type and casting if necessary. Therefore,
  25 // two point-types are necessary.
  26 struct taxicab_distance
  27 {
  28     template <typename P1, typename P2>
  29     static inline typename bg::coordinate_type<P1>::type apply(
  30                     P1 const& p1, P2 const& p2)
  31     {
  32         using bg::get;
  33         using bg::math::abs;
  34         return abs(get<0>(p1) - get<1>(p2))
  35             + abs(get<1>(p1) - get<1>(p2));
  36     }
  37 };
  38
  39
  40
  41 namespace boost { namespace geometry { namespace strategy { namespace distance { namespace services
  42 {
  43
  44 template <>
  45 struct tag<taxicab_distance>
  46 {
  47     typedef strategy_tag_distance_point_point type;
  48 };
  49
  50
  51 template <typename P1, typename P2>
  52 struct return_type<taxicab_distance, P1, P2>
  53 {
  54     typedef typename coordinate_type<P1>::type type;
  55 };
  56
  57
  58 template <>
  59 struct comparable_type<taxicab_distance>
  60 {
  61     typedef taxicab_distance type;
  62 };
  63
  64 template <>
  65 struct get_comparable<taxicab_distance>
  66 {
  67     static inline taxicab_distance apply(taxicab_distance const& input)
  68     {
  69         return input;
  70     }
  71 };
  72
  73 template <typename P1, typename P2>
  74 struct result_from_distance<taxicab_distance, P1, P2>
  75 {
  76     template <typename T>
  77     static inline typename coordinate_type<P1>::type apply(taxicab_distance const& , T const& value)
  78     {
  79         return value;
  80     }
  81 };
  82
  83
  84 }}}}} // namespace bg::strategy::distance::services
  85
  86
  87
  88
  89
  90 template <typename Geometry1, typename Geometry2>
  91 void test_distance(Geometry1 const& geometry1,
  92             Geometry2 const& geometry2,
  93             long double expected_distance)
  94 {
  95     typename bg::default_distance_result<Geometry1>::type distance = bg::distance(geometry1, geometry2);
  96
  97 #ifdef BOOST_GEOMETRY_TEST_DEBUG
  98     std::ostringstream out;
  99     out << typeid(typename bg::coordinate_type<Geometry1>::type).name()
 100         << std::endl
 101         << typeid(typename bg::default_distance_result<Geometry1>::type).name()
 102         << std::endl
 103         << "distance : " << bg::distance(geometry1, geometry2)
 104         << std::endl;
 105     std::cout << out.str();
 106 #endif
 107
 108     BOOST_CHECK_CLOSE(distance, expected_distance, 0.0001);
 109 }
 110
 111
 112 template <typename Geometry1, typename Geometry2>
 113 void test_geometry(std::string const& wkt1, std::string const& wkt2, double expected_distance)
 114 {
 115     Geometry1 geometry1;
 116     bg::read_wkt(wkt1, geometry1);
 117     Geometry2 geometry2;
 118     bg::read_wkt(wkt2, geometry2);
 119
 120     test_distance(geometry1, geometry2, expected_distance);
 121 }
 122
 123 template <typename Geometry1, typename Geometry2>
 124 void test_empty_input(Geometry1 const& geometry1, Geometry2 const& geometry2)
 125 {
 126     try
 127     {
 128         bg::distance(geometry1, geometry2);
 129     }
 130     catch(bg::empty_input_exception const& )
 131     {
 132         return;
 133     }
 134     BOOST_CHECK_MESSAGE(false, "A empty_input_exception should have been thrown" );
 135 }
 136
 137
 138 #endif