ceph/src/boost/libs/geometry/include/boost/geometry/algorithms/detail/overlay/append_no_dups_or_spikes.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
   4
   5 // This file was modified by Oracle on 2014.
   6 // Modifications copyright (c) 2014 Oracle and/or its affiliates.
   7
   8 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
   9
  10 // Use, modification and distribution is subject to the Boost Software License,
  11 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  12 // http://www.boost.org/LICENSE_1_0.txt)
  13
  14 #ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_APPEND_NO_DUPS_OR_SPIKES_HPP
  15 #define BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_APPEND_NO_DUPS_OR_SPIKES_HPP
  16
  17 #include <boost/range.hpp>
  18
  19 #include <boost/geometry/algorithms/append.hpp>
  20 #include <boost/geometry/algorithms/detail/point_is_spike_or_equal.hpp>
  21 #include <boost/geometry/algorithms/detail/equals/point_point.hpp>
  22
  23 #include <boost/geometry/util/condition.hpp>
  24 #include <boost/geometry/util/range.hpp>
  25
  26
  27 namespace boost { namespace geometry
  28 {
  29
  30
  31 #ifndef DOXYGEN_NO_DETAIL
  32 namespace detail { namespace overlay
  33 {
  34
  35 // TODO: move this / rename this
  36 template <typename Point1, typename Point2, typename RobustPolicy>
  37 inline bool points_equal_or_close(Point1 const& point1,
  38         Point2 const& point2,
  39         RobustPolicy const& robust_policy)
  40 {
  41     if (detail::equals::equals_point_point(point1, point2))
  42     {
  43         return true;
  44     }
  45
  46     if (BOOST_GEOMETRY_CONDITION(! RobustPolicy::enabled))
  47     {
  48         return false;
  49     }
  50
  51     // Try using specified robust policy
  52     typedef typename geometry::robust_point_type
  53     <
  54         Point1,
  55         RobustPolicy
  56     >::type robust_point_type;
  57
  58     robust_point_type point1_rob, point2_rob;
  59     geometry::recalculate(point1_rob, point1, robust_policy);
  60     geometry::recalculate(point2_rob, point2, robust_policy);
  61
  62     return detail::equals::equals_point_point(point1_rob, point2_rob);
  63 }
  64
  65
  66 template <typename Range, typename Point, typename RobustPolicy>
  67 inline void append_no_dups_or_spikes(Range& range, Point const& point,
  68         RobustPolicy const& robust_policy)
  69 {
  70 #ifdef BOOST_GEOMETRY_DEBUG_INTERSECTION
  71     std::cout << "  add: ("
  72         << geometry::get<0>(point) << ", " << geometry::get<1>(point) << ")"
  73         << std::endl;
  74 #endif
  75     // The code below this condition checks all spikes/dups
  76     // for geometries >= 3 points.
  77     // So we have to check the first potential duplicate differently
  78     if (boost::size(range) == 1
  79         && points_equal_or_close(*(boost::begin(range)), point, robust_policy))
  80     {
  81         return;
  82     }
  83
  84     traits::push_back<Range>::apply(range, point);
  85
  86     // If a point is equal, or forming a spike, remove the pen-ultimate point
  87     // because this one caused the spike.
  88     // If so, the now-new-pen-ultimate point can again cause a spike
  89     // (possibly at a corner). So keep doing this.
  90     // Besides spikes it will also avoid adding duplicates.
  91     while(boost::size(range) >= 3
  92             && point_is_spike_or_equal(point,
  93                 *(boost::end(range) - 3),
  94                 *(boost::end(range) - 2),
  95                 robust_policy))
  96     {
  97         // Use the Concept/traits, so resize and append again
  98         traits::resize<Range>::apply(range, boost::size(range) - 2);
  99         traits::push_back<Range>::apply(range, point);
 100     }
 101 }
 102
 103 template <typename Range, typename RobustPolicy>
 104 inline void clean_closing_dups_and_spikes(Range& range,
 105                 RobustPolicy const& robust_policy)
 106 {
 107     std::size_t const minsize
 108         = core_detail::closure::minimum_ring_size
 109             <
 110                 geometry::closure<Range>::value
 111             >::value;
 112
 113     if (boost::size(range) <= minsize)
 114     {
 115         return;
 116     }
 117
 118     typedef typename boost::range_iterator<Range>::type iterator_type;
 119     static bool const closed = geometry::closure<Range>::value == geometry::closed;
 120
 121 // TODO: the following algorithm could be rewritten to first look for spikes
 122 // and then erase some number of points from the beginning of the Range
 123
 124     bool found = false;
 125     do
 126     {
 127         found = false;
 128         iterator_type first = boost::begin(range);
 129         iterator_type second = first + 1;
 130         iterator_type ultimate = boost::end(range) - 1;
 131         if (BOOST_GEOMETRY_CONDITION(closed))
 132         {
 133             ultimate--;
 134         }
 135
 136         // Check if closing point is a spike (this is so if the second point is
 137         // considered as a spike w.r.t. the last segment)
 138         if (point_is_spike_or_equal(*second, *ultimate, *first, robust_policy))
 139         {
 140             range::erase(range, first);
 141             if (BOOST_GEOMETRY_CONDITION(closed))
 142             {
 143                 // Remove closing last point
 144                 range::resize(range, boost::size(range) - 1);
 145                 // Add new closing point
 146                 range::push_back(range, range::front(range));
 147             }
 148             found = true;
 149         }
 150     } while(found && boost::size(range) > minsize);
 151 }
 152
 153
 154 }} // namespace detail::overlay
 155 #endif // DOXYGEN_NO_DETAIL
 156
 157
 158 }} // namespace boost::geometry
 159
 160
 161 #endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_APPEND_NO_DUPS_OR_SPIKES_HPP