get_rescale_policy.hpp 9.02 KB
Newer Older
xuebingbing's avatar
xuebingbing committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290
// Boost.Geometry (aka GGL, Generic Geometry Library)

// Copyright (c) 2014 Barend Gehrels, Amsterdam, the Netherlands.
// Copyright (c) 2014 Bruno Lalande, Paris, France.
// Copyright (c) 2014 Mateusz Loskot, London, UK.
// Copyright (c) 2014 Adam Wulkiewicz, Lodz, Poland.

// 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)

#ifndef BOOST_GEOMETRY_POLICIES_ROBUSTNESS_GET_RESCALE_POLICY_HPP
#define BOOST_GEOMETRY_POLICIES_ROBUSTNESS_GET_RESCALE_POLICY_HPP


#include <cstddef>

#include <boost/type_traits.hpp>
#include <boost/mpl/assert.hpp>

#include <boost/geometry/core/tag_cast.hpp>

#include <boost/geometry/algorithms/envelope.hpp>
#include <boost/geometry/algorithms/expand.hpp>
#include <boost/geometry/algorithms/detail/recalculate.hpp>
#include <boost/geometry/algorithms/detail/get_max_size.hpp>
#include <boost/geometry/policies/robustness/robust_type.hpp>

#include <boost/geometry/geometries/point.hpp>
#include <boost/geometry/geometries/box.hpp>

#include <boost/geometry/policies/robustness/no_rescale_policy.hpp>
#include <boost/geometry/policies/robustness/rescale_policy.hpp>

#include <boost/geometry/util/promote_floating_point.hpp>

namespace boost { namespace geometry
{

#ifndef DOXYGEN_NO_DETAIL
namespace detail { namespace get_rescale_policy
{

template <typename Point, typename RobustPoint, typename Geometry, typename Factor>
static inline void init_rescale_policy(Geometry const& geometry,
        Point& min_point,
        RobustPoint& min_robust_point,
        Factor& factor)
{
    // Get bounding boxes
    model::box<Point> env = geometry::return_envelope<model::box<Point> >(geometry);

    // Scale this to integer-range
    typedef typename promote_floating_point
        <
            typename geometry::coordinate_type<Point>::type
        >::type num_type;
    num_type const diff = boost::numeric_cast<num_type>(detail::get_max_size(env));
    num_type const range = 10000000.0; // Define a large range to get precise integer coordinates
    num_type const half = 0.5;
    factor = math::equals(diff, num_type()) ? 1
        : boost::numeric_cast<num_type>(
            boost::numeric_cast<boost::long_long_type>(half + range / diff));

    // Assign input/output minimal points
    detail::assign_point_from_index<0>(env, min_point);
    num_type const two = 2;
    boost::long_long_type const min_coordinate
        = boost::numeric_cast<boost::long_long_type>(-range / two);
    assign_values(min_robust_point, min_coordinate, min_coordinate);
}

template <typename Point, typename RobustPoint, typename Geometry1, typename Geometry2, typename Factor>
static inline void init_rescale_policy(Geometry1 const& geometry1,
        Geometry2 const& geometry2,
        Point& min_point,
        RobustPoint& min_robust_point,
        Factor& factor)
{
    // Get bounding boxes
    model::box<Point> env = geometry::return_envelope<model::box<Point> >(geometry1);
    model::box<Point> env2 = geometry::return_envelope<model::box<Point> >(geometry2);
    geometry::expand(env, env2);

    // TODO: merge this with implementation above
    // Scale this to integer-range
    typedef typename promote_floating_point
        <
            typename geometry::coordinate_type<Point>::type
        >::type num_type;
    num_type const diff = boost::numeric_cast<num_type>(detail::get_max_size(env));
    num_type const range = 10000000.0; // Define a large range to get precise integer coordinates
    num_type const half = 0.5;
    factor = math::equals(diff, num_type()) ? 1
        : boost::numeric_cast<num_type>(
            boost::numeric_cast<boost::long_long_type>(half + range / diff));

    // Assign input/output minimal points
    detail::assign_point_from_index<0>(env, min_point);
    num_type const two = 2;
    boost::long_long_type const min_coordinate
        = boost::numeric_cast<boost::long_long_type>(-range / two);
    assign_values(min_robust_point, min_coordinate, min_coordinate);
}


template
<
    typename Point,
    bool IsFloatingPoint
>
struct rescale_policy_type
{
    typedef no_rescale_policy type;
};

// We rescale only all FP types
template
<
    typename Point
>
struct rescale_policy_type<Point, true>
{
    typedef typename geometry::coordinate_type<Point>::type coordinate_type;
    typedef model::point
    <
        typename detail::robust_type<coordinate_type>::type,
        geometry::dimension<Point>::value,
        typename geometry::coordinate_system<Point>::type
    > robust_point_type;
    typedef typename promote_floating_point<coordinate_type>::type factor_type;
    typedef detail::robust_policy<Point, robust_point_type, factor_type> type;
};

template <typename Policy>
struct get_rescale_policy
{
    template <typename Geometry>
    static inline Policy apply(Geometry const& geometry)
    {
        typedef typename point_type<Geometry>::type point_type;
        typedef typename geometry::coordinate_type<Geometry>::type coordinate_type;
        typedef typename promote_floating_point<coordinate_type>::type factor_type;
        typedef model::point
        <
            typename detail::robust_type<coordinate_type>::type,
            geometry::dimension<point_type>::value,
            typename geometry::coordinate_system<point_type>::type
        > robust_point_type;

        point_type min_point;
        robust_point_type min_robust_point;
        factor_type factor;
        init_rescale_policy(geometry, min_point, min_robust_point, factor);

        return Policy(min_point, min_robust_point, factor);
    }

    template <typename Geometry1, typename Geometry2>
    static inline Policy apply(Geometry1 const& geometry1, Geometry2 const& geometry2)
    {
        typedef typename point_type<Geometry1>::type point_type;
        typedef typename geometry::coordinate_type<Geometry1>::type coordinate_type;
        typedef typename promote_floating_point<coordinate_type>::type factor_type;
        typedef model::point
        <
            typename detail::robust_type<coordinate_type>::type,
            geometry::dimension<point_type>::value,
            typename geometry::coordinate_system<point_type>::type
        > robust_point_type;

        point_type min_point;
        robust_point_type min_robust_point;
        factor_type factor;
        init_rescale_policy(geometry1, geometry2, min_point, min_robust_point, factor);

        return Policy(min_point, min_robust_point, factor);
    }
};

// Specialization for no-rescaling
template <>
struct get_rescale_policy<no_rescale_policy>
{
    template <typename Geometry>
    static inline no_rescale_policy apply(Geometry const& )
    {
        return no_rescale_policy();
    }

    template <typename Geometry1, typename Geometry2>
    static inline no_rescale_policy apply(Geometry1 const& , Geometry2 const& )
    {
        return no_rescale_policy();
    }
};


}} // namespace detail::get_rescale_policy
#endif // DOXYGEN_NO_DETAIL

template<typename Point>
struct rescale_policy_type
    : public detail::get_rescale_policy::rescale_policy_type
    <
        Point,
#if defined(BOOST_GEOMETRY_NO_ROBUSTNESS)
        false
#else
        boost::is_floating_point
        <
            typename geometry::coordinate_type<Point>::type
        >::type::value
#endif
    >
{
    static const bool is_point
        = boost::is_same
            <
                typename geometry::tag<Point>::type,
                geometry::point_tag
            >::type::value;

    BOOST_MPL_ASSERT_MSG((is_point),
                         INVALID_INPUT_GEOMETRY,
                         (typename geometry::tag<Point>::type));
};


template
<
    typename Geometry1,
    typename Geometry2,
    typename Tag1 = typename tag_cast
    <
        typename tag<Geometry1>::type,
        box_tag,
        pointlike_tag,
        linear_tag,
        areal_tag
    >::type,
    typename Tag2 = typename tag_cast
    <
        typename tag<Geometry2>::type,
        box_tag,
        pointlike_tag,
        linear_tag,
        areal_tag
    >::type
>
struct rescale_overlay_policy_type
    // Default: no rescaling
    : public detail::get_rescale_policy::rescale_policy_type
        <
            typename geometry::point_type<Geometry1>::type,
            false
        >
{};

// Areal/areal: get rescale policy based on coordinate type
template
<
    typename Geometry1,
    typename Geometry2
>
struct rescale_overlay_policy_type<Geometry1, Geometry2, areal_tag, areal_tag>
    : public rescale_policy_type
        <
            typename geometry::point_type<Geometry1>::type
        >
{};


template <typename Policy, typename Geometry>
inline Policy get_rescale_policy(Geometry const& geometry)
{
    return detail::get_rescale_policy::get_rescale_policy<Policy>::apply(geometry);
}

template <typename Policy, typename Geometry1, typename Geometry2>
inline Policy get_rescale_policy(Geometry1 const& geometry1, Geometry2 const& geometry2)
{
    return detail::get_rescale_policy::get_rescale_policy<Policy>::apply(geometry1, geometry2);
}


}} // namespace boost::geometry


#endif // BOOST_GEOMETRY_POLICIES_ROBUSTNESS_GET_RESCALE_POLICY_HPP