boost/boost/geometry/policies/robustness/get_rescale_policy.hpp

// Boost.Geometry (aka GGL, Generic Geometry Library)

// Copyright (c) 2014-2015 Barend Gehrels, Amsterdam, the Netherlands.
// Copyright (c) 2014-2015 Bruno Lalande, Paris, France.
// Copyright (c) 2014-2015 Mateusz Loskot, London, UK.
// Copyright (c) 2014-2015 Adam Wulkiewicz, Lodz, Poland.

// This file was modified by Oracle on 2015.
// Modifications copyright (c) 2015, Oracle and/or its affiliates.

// Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle

// 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 Box,
    typename Point,
    typename RobustPoint,
    typename Factor
>
inline void scale_box_to_integer_range(Box const& box,
                                       Point& min_point,
                                       RobustPoint& min_robust_point,
                                       Factor& factor)
{
    // Scale box 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(box));
    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()) || diff >= range ? 1
        : boost::numeric_cast<num_type>(
            boost::numeric_cast<boost::long_long_type>(half + range / diff));

    BOOST_ASSERT(factor >= 1);

    // Assign input/output minimal points
    detail::assign_point_from_index<0>(box, 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 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_box_to_integer_range(env, min_point, min_robust_point, factor);
}

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);

    scale_box_to_integer_range(env, min_point, min_robust_point, factor);
}


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