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Filename : buffer_policies.hpp
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// Boost.Geometry (aka GGL, Generic Geometry Library)

// Copyright (c) 2012-2014 Barend Gehrels, Amsterdam, the Netherlands.

// This file was modified by Oracle on 2017, 2018.
// Modifications copyright (c) 2017-2018, Oracle and/or its affiliates.
// Contributed and/or modified by Adam Wulkiewicz, 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_ALGORITHMS_DETAIL_BUFFER_BUFFER_POLICIES_HPP
#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_BUFFER_BUFFER_POLICIES_HPP

#include <cstddef>

#include <boost/range.hpp>

#include <boost/geometry/core/coordinate_type.hpp>
#include <boost/geometry/core/point_type.hpp>

#include <boost/geometry/algorithms/detail/overlay/backtrack_check_si.hpp>
#include <boost/geometry/algorithms/detail/overlay/traversal_info.hpp>
#include <boost/geometry/algorithms/detail/overlay/turn_info.hpp>

#include <boost/geometry/strategies/buffer.hpp>


namespace boost { namespace geometry
{


#ifndef DOXYGEN_NO_DETAIL
namespace detail { namespace buffer
{

class backtrack_for_buffer
{
public :
    typedef detail::overlay::backtrack_state state_type;

    template
        <
            typename Operation,
            typename Rings,
            typename Turns,
            typename Geometry,
            typename Strategy,
            typename RobustPolicy,
            typename Visitor
        >
    static inline void apply(std::size_t size_at_start,
                Rings& rings, typename boost::range_value<Rings>::type& ring,
                Turns& turns,
                typename boost::range_value<Turns>::type const& /*turn*/,
                Operation& operation,
                detail::overlay::traverse_error_type /*traverse_error*/,
                Geometry const& ,
                Geometry const& ,
                Strategy const& ,
                RobustPolicy const& ,
                state_type& state,
                Visitor& /*visitor*/
                )
    {
#if defined(BOOST_GEOMETRY_COUNT_BACKTRACK_WARNINGS)
extern int g_backtrack_warning_count;
g_backtrack_warning_count++;
#endif
//std::cout << "!";
//std::cout << "WARNING " << traverse_error_string(traverse_error) << std::endl;

        state.m_good = false;

        // Make bad output clean
        rings.resize(size_at_start);
        ring.clear();

        // Reject this as a starting point
        operation.visited.set_rejected();

        // And clear all visit info
        clear_visit_info(turns);
    }
};

struct buffer_overlay_visitor
{
public :
    void print(char const* /*header*/)
    {
    }

    template <typename Turns>
    void print(char const* /*header*/, Turns const& /*turns*/, int /*turn_index*/)
    {
    }

    template <typename Turns>
    void print(char const* /*header*/, Turns const& /*turns*/, int /*turn_index*/, int /*op_index*/)
    {
    }

    template <typename Turns>
    void visit_turns(int , Turns const& ) {}

    template <typename Clusters, typename Turns>
    void visit_clusters(Clusters const& , Turns const& ) {}

    template <typename Turns, typename Turn, typename Operation>
    void visit_traverse(Turns const& /*turns*/, Turn const& /*turn*/, Operation const& /*op*/, const char* /*header*/)
    {
    }

    template <typename Turns, typename Turn, typename Operation>
    void visit_traverse_reject(Turns const& , Turn const& , Operation const& ,
            detail::overlay::traverse_error_type )
    {}

    template <typename Rings>
    void visit_generated_rings(Rings const& )
    {}
};


// Should follow traversal-turn-concept (enrichment, visit structure)
// and adds index in piece vector to find it back
template <typename Point, typename SegmentRatio>
struct buffer_turn_operation
    : public detail::overlay::traversal_turn_operation<Point, SegmentRatio>
{
    signed_size_type piece_index;
    signed_size_type index_in_robust_ring;

    inline buffer_turn_operation()
        : piece_index(-1)
        , index_in_robust_ring(-1)
    {}
};

// Version of turn_info for buffer with its turn index and other helper variables
template <typename Point, typename SegmentRatio>
struct buffer_turn_info
    : public detail::overlay::turn_info
        <
            Point,
            SegmentRatio,
            buffer_turn_operation<Point, SegmentRatio>
        >
{
    typedef Point point_type;

    std::size_t turn_index;

    // Information if turn can be used. It is not traversable if it is within
    // another piece, or within the original (depending on deflation),
    // or (for deflate) if there are not enough points to traverse it.
    bool is_turn_traversable;

    bool close_to_offset;
    bool is_linear_end_point;
    bool within_original;
    signed_size_type count_in_original; // increased by +1 for in ext.ring, -1 for int.ring

    inline buffer_turn_info()
        : turn_index(0)
        , is_turn_traversable(true)
        , close_to_offset(false)
        , is_linear_end_point(false)
        , within_original(false)
        , count_in_original(0)
    {}
};

struct buffer_less
{
    template <typename Indexed>
    inline bool operator()(Indexed const& left, Indexed const& right) const
    {
        if (! (left.subject->seg_id == right.subject->seg_id))
        {
            return left.subject->seg_id < right.subject->seg_id;
        }

        // Both left and right are located on the SAME segment.
        if (! (left.subject->fraction == right.subject->fraction))
        {
            return left.subject->fraction < right.subject->fraction;
        }

        return left.turn_index < right.turn_index;
    }
};

struct piece_get_box
{
    template <typename Box, typename Piece>
    static inline void apply(Box& total, Piece const& piece)
    {
        typedef typename strategy::expand::services::default_strategy
            <
                box_tag, typename cs_tag<Box>::type
            >::type expand_strategy_type;

        if (piece.m_piece_border.m_has_envelope)
        {
            geometry::expand(total, piece.m_piece_border.m_envelope,
                             expand_strategy_type());
        }
    }
};

template <typename DisjointBoxBoxStrategy>
struct piece_ovelaps_box
{
    template <typename Box, typename Piece>
    static inline bool apply(Box const& box, Piece const& piece)
    {
        if (piece.type == strategy::buffer::buffered_flat_end
            || piece.type == strategy::buffer::buffered_concave)
        {
            // Turns cannot be inside a flat end (though they can be on border)
            // Neither we need to check if they are inside concave helper pieces

            // Skip all pieces not used as soon as possible
            return false;
        }
        if (! piece.m_piece_border.m_has_envelope)
        {
            return false;
        }

        return ! geometry::detail::disjoint::disjoint_box_box(box, piece.m_piece_border.m_envelope,
                                                              DisjointBoxBoxStrategy());
    }
};

struct turn_get_box
{
    template <typename Box, typename Turn>
    static inline void apply(Box& total, Turn const& turn)
    {
        typedef typename strategy::expand::services::default_strategy
            <
                point_tag, typename cs_tag<Box>::type
            >::type expand_strategy_type;
        geometry::expand(total, turn.point, expand_strategy_type());
    }
};

template <typename DisjointPointBoxStrategy>
struct turn_ovelaps_box
{
    template <typename Box, typename Turn>
    static inline bool apply(Box const& box, Turn const& turn)
    {
        return ! geometry::detail::disjoint::disjoint_point_box(turn.point, box,
                                                                DisjointPointBoxStrategy());
    }
};

struct enriched_map_buffer_include_policy
{
    template <typename Operation>
    static inline bool include(Operation const& op)
    {
        return op != detail::overlay::operation_intersection
            && op != detail::overlay::operation_blocked;
    }
};

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


}} // namespace boost::geometry

#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_BUFFER_BUFFER_POLICIES_HPP