geometry/test/algorithms/distance.cpp
Barend Gehrels 8cf84e37b6 Added Point-Point strategy to default_strategy for Point-segment
Added some MPL assertions
Updated distance tests

[SVN r64087]
2010-07-17 10:46:25 +00:00

340 lines
9.7 KiB
C++

// Boost.Geometry (aka GGL, Generic Geometry Library) test file
//
// Copyright Barend Gehrels 2007-2009, Geodan, Amsterdam, the Netherlands
// Copyright Bruno Lalande 2008, 2009
// Use, modification and distribution is subject to the Boost Software License,
// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
#define TEST_ARRAY
#include <sstream>
#include <boost/mpl/if.hpp>
#include <geometry_test_common.hpp>
#include <boost/geometry/algorithms/distance.hpp>
#include <boost/geometry/strategies/strategies.hpp>
#ifndef TEST_ARRAY
#include <boost/geometry/algorithms/make.hpp>
#endif
#include <boost/geometry/geometries/geometries.hpp>
#include <boost/geometry/geometries/adapted/boost_array_as_linestring.hpp>
#include <boost/geometry/geometries/adapted/c_array_cartesian.hpp>
#include <boost/geometry/geometries/adapted/tuple_cartesian.hpp>
#include <test_common/test_point.hpp>
namespace bg = boost::geometry;
// Define a custom distance strategy
// For this one, the "taxicab" distance,
// see http://en.wikipedia.org/wiki/Taxicab_geometry
// For a point-point-distance operation, one typename Point is enough.
// For a point-segment-distance operation, there is some magic inside
// using another point type and casting if necessary. Therefore,
// two point-types are necessary.
template <typename P1, typename P2 = P1>
struct taxicab_distance
{
static inline typename boost::geometry::coordinate_type<P1>::type apply(
P1 const& p1, P2 const& p2)
{
using boost::geometry::get;
using boost::geometry::math::abs;
return abs(get<0>(p1) - get<1>(p2))
+ abs(get<1>(p1) - get<1>(p2));
}
};
namespace boost { namespace geometry { namespace strategy { namespace distance { namespace services
{
template <typename P1, typename P2>
struct tag<taxicab_distance<P1, P2> >
{
typedef strategy_tag_distance_point_point type;
};
template <typename P1, typename P2>
struct return_type<taxicab_distance<P1, P2> >
{
typedef typename coordinate_type<P1>::type type;
};
template<typename P1, typename P2, typename PN1, typename PN2>
struct similar_type<taxicab_distance<P1, P2>, PN1, PN2>
{
typedef taxicab_distance<PN1, PN2> type;
};
template<typename P1, typename P2, typename PN1, typename PN2>
struct get_similar<taxicab_distance<P1, P2>, PN1, PN2>
{
static inline typename similar_type
<
taxicab_distance<P1, P2>, PN1, PN2
>::type apply(taxicab_distance<P1, P2> const& )
{
return taxicab_distance<PN1, PN2>();
}
};
template <typename P1, typename P2>
struct comparable_type<taxicab_distance<P1, P2> >
{
typedef taxicab_distance<P1, P2> type;
};
template <typename P1, typename P2>
struct get_comparable<taxicab_distance<P1, P2> >
{
static inline taxicab_distance<P1, P2> apply(taxicab_distance<P1, P2> const& input)
{
return input;
}
};
template <typename P1, typename P2>
struct result_from_distance<taxicab_distance<P1, P2> >
{
template <typename T>
static inline typename coordinate_type<P1>::type apply(taxicab_distance<P1, P2> const& , T const& value)
{
return value;
}
};
}}}}} // namespace boost::geometry::strategy::distance::services
template <typename P>
void test_distance_point()
{
namespace services = bg::strategy::distance::services;
typedef typename bg::distance_result<P>::type return_type;
{
// Basic, trivial test
P p1;
bg::set<0>(p1, 1);
bg::set<1>(p1, 1);
P p2;
bg::set<0>(p2, 2);
bg::set<1>(p2, 2);
return_type d = bg::distance(p1, p2);
BOOST_CHECK_CLOSE(d, return_type(1.4142135), 0.001);
// Test specifying strategy manually
typename services::default_strategy<bg::point_tag, P>::type strategy;
d = bg::distance(p1, p2, strategy);
BOOST_CHECK_CLOSE(d, return_type(1.4142135), 0.001);
{
// Test custom strategy
BOOST_CONCEPT_ASSERT( (bg::concept::PointDistanceStrategy<taxicab_distance<P> >) );
typedef typename services::return_type<taxicab_distance<P> >::type cab_return_type;
BOOST_MPL_ASSERT((boost::is_same<cab_return_type, typename bg::coordinate_type<P>::type>));
taxicab_distance<P> tcd;
cab_return_type d = bg::distance(p1, p2, tcd);
BOOST_CHECK( bg::math::abs(d - cab_return_type(2)) <= cab_return_type(0.01) );
}
}
{
// 3-4-5 angle
P p1, p2, p3;
bg::set<0>(p1, 0); bg::set<1>(p1, 0);
bg::set<0>(p2, 3); bg::set<1>(p2, 0);
bg::set<0>(p3, 0); bg::set<1>(p3, 4);
return_type dr12 = bg::distance(p1, p2);
return_type dr13 = bg::distance(p1, p3);
return_type dr23 = bg::distance(p2, p3);
BOOST_CHECK_CLOSE(dr12, return_type(3), 0.001);
BOOST_CHECK_CLOSE(dr13, return_type(4), 0.001);
BOOST_CHECK_CLOSE(dr23, return_type(5), 0.001);
}
{
// test comparability
typedef typename services::default_strategy<bg::point_tag, P>::type strategy_type;
typedef typename services::comparable_type<strategy_type>::type comparable_strategy_type;
strategy_type strategy;
comparable_strategy_type comparable_strategy = services::get_comparable<strategy_type>::apply(strategy);
return_type comparable = services::result_from_distance<comparable_strategy_type>::apply(comparable_strategy, 3);
BOOST_CHECK_CLOSE(comparable, return_type(9), 0.001);
}
}
template <typename P>
void test_distance_segment()
{
typedef typename bg::distance_result<P>::type return_type;
typedef typename bg::coordinate_type<P>::type coordinate_type;
P s1; bg::set<0>(s1, 1); bg::set<1>(s1, 1);
P s2; bg::set<0>(s2, 4); bg::set<1>(s2, 4);
// Check points left, right, projected-left, projected-right, on segment
P p1; bg::set<0>(p1, 0); bg::set<1>(p1, 1);
P p2; bg::set<0>(p2, 1); bg::set<1>(p2, 0);
P p3; bg::set<0>(p3, 3); bg::set<1>(p3, 1);
P p4; bg::set<0>(p4, 1); bg::set<1>(p4, 3);
P p5; bg::set<0>(p5, 3); bg::set<1>(p5, 3);
bg::segment<P const> const seg(s1, s2);
return_type d1 = bg::distance(p1, seg);
return_type d2 = bg::distance(p2, seg);
return_type d3 = bg::distance(p3, seg);
return_type d4 = bg::distance(p4, seg);
return_type d5 = bg::distance(p5, seg);
BOOST_CHECK_CLOSE(d1, return_type(1), 0.001);
BOOST_CHECK_CLOSE(d2, return_type(1), 0.001);
BOOST_CHECK_CLOSE(d3, return_type(1.4142135), 0.001);
BOOST_CHECK_CLOSE(d4, return_type(1.4142135), 0.001);
BOOST_CHECK_CLOSE(d5, return_type(0), 0.001);
// Reverse case: segment/point instead of point/segment
return_type dr1 = bg::distance(seg, p1);
return_type dr2 = bg::distance(seg, p2);
BOOST_CHECK_CLOSE(dr1, d1, 0.001);
BOOST_CHECK_CLOSE(dr2, d2, 0.001);
// Test specifying strategy manually:
// 1) point-point-distance
typename bg::strategy::distance::services::default_strategy<bg::point_tag, P>::type pp_strategy;
d1 = bg::distance(p1, seg, pp_strategy);
BOOST_CHECK_CLOSE(d1, return_type(1), 0.001);
// 2) point-segment-distance
typename bg::strategy::distance::services::default_strategy<bg::segment_tag, P>::type ps_strategy;
d1 = bg::distance(p1, seg, ps_strategy);
BOOST_CHECK_CLOSE(d1, return_type(1), 0.001);
// 3) custom point strategy
taxicab_distance<P> tcd;
return_type d = bg::distance(p1, seg, tcd);
BOOST_CHECK_CLOSE(d1, return_type(1), 0.001);
}
template <typename P>
void test_distance_linestring()
{
typedef typename bg::distance_result<P>::type return_type;
boost::array<P, 2> points;
bg::set<0>(points[0], 1);
bg::set<1>(points[0], 1);
bg::set<0>(points[1], 3);
bg::set<1>(points[1], 3);
P p;
bg::set<0>(p, 2); bg::set<1>(p, 1);
return_type d = bg::distance(p, points);
BOOST_CHECK_CLOSE(d, return_type(0.70710678), 0.001);
bg::set<0>(p, 5); bg::set<1>(p, 5);
d = bg::distance(p, points);
BOOST_CHECK_CLOSE(d, return_type(2.828427), 0.001);
bg::linestring<P> line;
{
P lp;
bg::set<0>(lp, 1); bg::set<1>(lp, 1); line.push_back(lp);
bg::set<0>(lp, 2); bg::set<1>(lp, 2); line.push_back(lp);
bg::set<0>(lp, 3); bg::set<1>(lp, 3); line.push_back(lp);
}
bg::set<0>(p, 5); bg::set<1>(p, 5);
d = bg::distance(p, line);
BOOST_CHECK_CLOSE(d, return_type(2.828427), 0.001);
// Reverse case: line/point instead of point/line
d = bg::distance(line, p);
BOOST_CHECK_CLOSE(d, return_type(2.828427), 0.001);
}
template <typename P>
void test_distance_ring()
{
typedef typename bg::distance_result<P>::type return_type;
bg::linear_ring<P> ring;
{
P lp;
bg::set<0>(lp, 1); bg::set<1>(lp, 1); line.push_back(lp);
bg::set<0>(lp, 2); bg::set<1>(lp, 2); line.push_back(lp);
bg::set<0>(lp, 3); bg::set<1>(lp, 3); line.push_back(lp);
}
bg::set<0>(p, 5); bg::set<1>(p, 5);
d = bg::distance(p, line);
BOOST_CHECK_CLOSE(d, return_type(2.828427), 0.001);
// Reverse case: line/point instead of point/line
d = bg::distance(line, p);
BOOST_CHECK_CLOSE(d, return_type(2.828427), 0.001);
}
template <typename P>
void test_all()
{
test_distance_point<P>();
test_distance_segment<P>();
test_distance_linestring<P>();
}
int test_main(int, char* [])
{
#ifdef TEST_ARRAY
//test_all<int[2]>();
//test_all<float[2]>();
//test_all<double[2]>();
//test_all<test::test_point>(); // located here because of 3D
#endif
test_all<bg::point_xy<int> >();
test_all<boost::tuple<float, float> >();
test_all<bg::point_xy<float> >();
test_all<bg::point_xy<double> >();
return 0;
}