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// Boost.Geometry (aka GGL, Generic Geometry Library)
// Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
// 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_OVERLAY_ASSIGN_PARENTS_HPP
#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_ASSIGN_PARENTS_HPP
#include <boost/geometry/algorithms/area.hpp>
#include <boost/geometry/algorithms/envelope.hpp>
#include <boost/geometry/algorithms/expand.hpp>
#include <boost/geometry/algorithms/detail/partition.hpp>
#include <boost/geometry/algorithms/detail/overlay/get_ring.hpp>
#include <boost/geometry/algorithms/within.hpp>
#include <boost/geometry/geometries/box.hpp>
namespace boost { namespace geometry
{
#ifndef DOXYGEN_NO_DETAIL
namespace detail { namespace overlay
{
template
<
typename Item,
typename Geometry1, typename Geometry2,
typename RingCollection
>
static inline bool within_selected_input(Item const& item2, ring_identifier const& ring_id,
Geometry1 const& geometry1, Geometry2 const& geometry2,
RingCollection const& collection)
{
typedef typename geometry::tag<Geometry1>::type tag1;
typedef typename geometry::tag<Geometry2>::type tag2;
switch (ring_id.source_index)
{
case 0 :
return geometry::within(item2.point,
get_ring<tag1>::apply(ring_id, geometry1));
break;
case 1 :
return geometry::within(item2.point,
get_ring<tag2>::apply(ring_id, geometry2));
break;
case 2 :
return geometry::within(item2.point,
get_ring<void>::apply(ring_id, collection));
break;
}
return false;
}
template <typename Point>
struct ring_info_helper
{
typedef typename geometry::default_area_result<Point>::type area_type;
ring_identifier id;
area_type real_area;
area_type abs_area;
model::box<Point> envelope;
inline ring_info_helper()
: real_area(0), abs_area(0)
{}
inline ring_info_helper(ring_identifier i, area_type a)
: id(i), real_area(a), abs_area(geometry::math::abs(a))
{}
};
struct ring_info_helper_get_box
{
template <typename Box, typename InputItem>
static inline void apply(Box& total, InputItem const& item)
{
geometry::expand(total, item.envelope);
}
};
struct ring_info_helper_ovelaps_box
{
template <typename Box, typename InputItem>
static inline bool apply(Box const& box, InputItem const& item)
{
return ! geometry::detail::disjoint::disjoint_box_box(box, item.envelope);
}
};
template <typename Geometry1, typename Geometry2, typename Collection, typename RingMap>
struct assign_visitor
{
typedef typename RingMap::mapped_type ring_info_type;
Geometry1 const& m_geometry1;
Geometry2 const& m_geometry2;
Collection const& m_collection;
RingMap& m_ring_map;
bool m_check_for_orientation;
inline assign_visitor(Geometry1 const& g1, Geometry2 const& g2, Collection const& c,
RingMap& map, bool check)
: m_geometry1(g1)
, m_geometry2(g2)
, m_collection(c)
, m_ring_map(map)
, m_check_for_orientation(check)
{}
template <typename Item>
inline void apply(Item const& outer, Item const& inner, bool first = true)
{
if (first && outer.real_area < 0)
{
// Reverse arguments
apply(inner, outer, false);
return;
}
if (math::larger(outer.real_area, 0))
{
if (inner.real_area < 0 || m_check_for_orientation)
{
ring_info_type& inner_in_map = m_ring_map[inner.id];
if (geometry::within(inner_in_map.point, outer.envelope)
&& within_selected_input(inner_in_map, outer.id, m_geometry1, m_geometry2, m_collection)
)
{
// Only assign parent if that parent is smaller (or if it is the first)
if (inner_in_map.parent.source_index == -1
|| outer.abs_area < inner_in_map.parent_area)
{
inner_in_map.parent = outer.id;
inner_in_map.parent_area = outer.abs_area;
}
}
}
}
}
};
template
<
typename Geometry1, typename Geometry2,
typename RingCollection,
typename RingMap
>
inline void assign_parents(Geometry1 const& geometry1,
Geometry2 const& geometry2,
RingCollection const& collection,
RingMap& ring_map,
bool check_for_orientation = false)
{
typedef typename geometry::tag<Geometry1>::type tag1;
typedef typename geometry::tag<Geometry2>::type tag2;
typedef typename RingMap::mapped_type ring_info_type;
typedef typename ring_info_type::point_type point_type;
typedef model::box<point_type> box_type;
typedef typename RingMap::iterator map_iterator_type;
{
typedef ring_info_helper<point_type> helper;
typedef std::vector<helper> vector_type;
typedef typename boost::range_iterator<vector_type const>::type vector_iterator_type;
#ifdef BOOST_GEOMETRY_TIME_OVERLAY
boost::timer timer;
#endif
std::size_t count_total = ring_map.size();
std::size_t count_positive = 0;
std::size_t index_positive = 0; // only used if count_positive>0
std::size_t index = 0;
// Copy to vector (with new approach this might be obsolete as well, using the map directly)
vector_type vector(count_total);
for (map_iterator_type it = boost::begin(ring_map);
it != boost::end(ring_map); ++it, ++index)
{
vector[index] = helper(it->first, it->second.get_area());
helper& item = vector[index];
switch(it->first.source_index)
{
case 0 :
geometry::envelope(get_ring<tag1>::apply(it->first, geometry1),
item.envelope);
break;
case 1 :
geometry::envelope(get_ring<tag2>::apply(it->first, geometry2),
item.envelope);
break;
case 2 :
geometry::envelope(get_ring<void>::apply(it->first, collection),
item.envelope);
break;
}
if (item.real_area > 0)
{
count_positive++;
index_positive = index;
}
}
#ifdef BOOST_GEOMETRY_TIME_OVERLAY
std::cout << " ap: created helper vector: " << timer.elapsed() << std::endl;
#endif
if (! check_for_orientation)
{
if (count_positive == count_total)
{
// Optimization for only positive rings
// -> no assignment of parents or reversal necessary, ready here.
return;
}
if (count_positive == 1)
{
// Optimization for one outer ring
// -> assign this as parent to all others (all interior rings)
// In unions, this is probably the most occuring case and gives
// a dramatic improvement (factor 5 for star_comb testcase)
ring_identifier id_of_positive = vector[index_positive].id;
ring_info_type& outer = ring_map[id_of_positive];
std::size_t index = 0;
for (vector_iterator_type it = boost::begin(vector);
it != boost::end(vector); ++it, ++index)
{
if (index != index_positive)
{
ring_info_type& inner = ring_map[it->id];
inner.parent = id_of_positive;
outer.children.push_back(it->id);
}
}
return;
}
}
assign_visitor
<
Geometry1, Geometry2,
RingCollection, RingMap
> visitor(geometry1, geometry2, collection, ring_map, check_for_orientation);
geometry::partition
<
box_type, ring_info_helper_get_box, ring_info_helper_ovelaps_box
>::apply(vector, visitor);
#ifdef BOOST_GEOMETRY_TIME_OVERLAY
std::cout << " ap: quadradic loop: " << timer.elapsed() << std::endl;
std::cout << " ap: check_for_orientation " << check_for_orientation << std::endl;
#endif
}
if (check_for_orientation)
{
for (map_iterator_type it = boost::begin(ring_map);
it != boost::end(ring_map); ++it)
{
if (geometry::math::equals(it->second.get_area(), 0))
{
it->second.discarded = true;
}
else if (it->second.parent.source_index >= 0 && it->second.get_area() > 0)
{
// Discard positive inner ring with parent
it->second.discarded = true;
it->second.parent.source_index = -1;
}
else if (it->second.parent.source_index < 0 && it->second.get_area() < 0)
{
// Reverse negative ring without parent
it->second.reversed = true;
}
}
}
// Assign childlist
for (map_iterator_type it = boost::begin(ring_map);
it != boost::end(ring_map); ++it)
{
if (it->second.parent.source_index >= 0)
{
ring_map[it->second.parent].children.push_back(it->first);
}
}
}
template
<
typename Geometry,
typename RingCollection,
typename RingMap
>
inline void assign_parents(Geometry const& geometry,
RingCollection const& collection,
RingMap& ring_map,
bool check_for_orientation)
{
// Call it with an empty geometry
// (ring_map should be empty for source_id==1)
Geometry empty;
assign_parents(geometry, empty, collection, ring_map, check_for_orientation);
}
}} // namespace detail::overlay
#endif // DOXYGEN_NO_DETAIL
}} // namespace geometry
#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_ASSIGN_PARENTS_HPP