// Boost.Geometry (aka GGL, Generic Geometry Library)
// Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
// This file was modified by Oracle on 2017-2020.
// Modifications copyright (c) 2017-2020 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_OVERLAY_TRAVERSAL_HPP
#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_TRAVERSAL_HPP
#include <cstddef>
#include <set>
#include <boost/range/begin.hpp>
#include <boost/range/end.hpp>
#include <boost/range/value_type.hpp>
#include <boost/geometry/algorithms/detail/overlay/cluster_info.hpp>
#include <boost/geometry/algorithms/detail/overlay/cluster_exits.hpp>
#include <boost/geometry/algorithms/detail/overlay/is_self_turn.hpp>
#include <boost/geometry/algorithms/detail/overlay/sort_by_side.hpp>
#include <boost/geometry/algorithms/detail/overlay/turn_info.hpp>
#include <boost/geometry/core/access.hpp>
#include <boost/geometry/core/assert.hpp>
#include <boost/geometry/util/condition.hpp>
#if defined(BOOST_GEOMETRY_DEBUG_INTERSECTION) \
|| defined(BOOST_GEOMETRY_OVERLAY_REPORT_WKT) \
|| defined(BOOST_GEOMETRY_DEBUG_TRAVERSE)
# include <string>
# include <boost/geometry/algorithms/detail/overlay/debug_turn_info.hpp>
# include <boost/geometry/io/wkt/wkt.hpp>
#endif
namespace boost { namespace geometry
{
#ifndef DOXYGEN_NO_DETAIL
namespace detail { namespace overlay
{
template <typename Turn, typename Operation>
#ifdef BOOST_GEOMETRY_DEBUG_TRAVERSE
inline void debug_traverse(Turn const& turn, Operation op,
std::string const& header, bool condition = true)
{
if (! condition)
{
return;
}
std::cout << " " << header
<< " at " << op.seg_id
<< " meth: " << method_char(turn.method)
<< " op: " << operation_char(op.operation)
<< " vis: " << visited_char(op.visited)
<< " of: " << operation_char(turn.operations[0].operation)
<< operation_char(turn.operations[1].operation)
<< " " << geometry::wkt(turn.point)
<< std::endl;
if (boost::contains(header, "Finished"))
{
std::cout << std::endl;
}
}
#else
inline void debug_traverse(Turn const& , Operation, const char*, bool = true)
{
}
#endif
template
<
bool Reverse1,
bool Reverse2,
overlay_type OverlayType,
typename Geometry1,
typename Geometry2,
typename Turns,
typename Clusters,
typename RobustPolicy,
typename SideStrategy,
typename Visitor
>
struct traversal
{
private :
static const operation_type target_operation = operation_from_overlay<OverlayType>::value;
typedef typename sort_by_side::side_compare<target_operation>::type side_compare_type;
typedef typename boost::range_value<Turns>::type turn_type;
typedef typename turn_type::turn_operation_type turn_operation_type;
typedef typename geometry::point_type<Geometry1>::type point_type;
typedef sort_by_side::side_sorter
<
Reverse1, Reverse2, OverlayType,
point_type, SideStrategy, side_compare_type
> sbs_type;
public :
inline traversal(Geometry1 const& geometry1, Geometry2 const& geometry2,
Turns& turns, Clusters const& clusters,
RobustPolicy const& robust_policy, SideStrategy const& strategy,
Visitor& visitor)
: m_geometry1(geometry1)
, m_geometry2(geometry2)
, m_turns(turns)
, m_clusters(clusters)
, m_robust_policy(robust_policy)
, m_strategy(strategy)
, m_visitor(visitor)
{
}
template <typename TurnInfoMap>
inline void finalize_visit_info(TurnInfoMap& turn_info_map)
{
for (typename boost::range_iterator<Turns>::type
it = boost::begin(m_turns);
it != boost::end(m_turns);
++it)
{
turn_type& turn = *it;
for (int i = 0; i < 2; i++)
{
turn_operation_type& op = turn.operations[i];
if (op.visited.visited()
|| op.visited.started()
|| op.visited.finished() )
{
ring_identifier const ring_id = ring_id_by_seg_id(op.seg_id);
turn_info_map[ring_id].has_traversed_turn = true;
if (op.operation == operation_continue)
{
// Continue operations should mark the other operation
// as traversed too
turn_operation_type& other_op = turn.operations[1 - i];
ring_identifier const other_ring_id
= ring_id_by_seg_id(other_op.seg_id);
turn_info_map[other_ring_id].has_traversed_turn = true;
}
}
op.visited.finalize();
}
}
}
//! Sets visited for ALL turns traveling to the same turn
inline void set_visited_in_cluster(signed_size_type cluster_id,
signed_size_type rank)
{
typename Clusters::const_iterator mit = m_clusters.find(cluster_id);
BOOST_ASSERT(mit != m_clusters.end());
cluster_info const& cinfo = mit->second;
std::set<signed_size_type> const& ids = cinfo.turn_indices;
for (typename std::set<signed_size_type>::const_iterator it = ids.begin();
it != ids.end(); ++it)
{
signed_size_type const turn_index = *it;
turn_type& turn = m_turns[turn_index];
for (int i = 0; i < 2; i++)
{
turn_operation_type& op = turn.operations[i];
if (op.visited.none()
&& op.enriched.rank == rank)
{
op.visited.set_visited();
}
}
}
}
inline void set_visited(turn_type& turn, turn_operation_type& op)
{
if (op.operation == detail::overlay::operation_continue)
{
// On "continue", all go in same direction so set "visited" for ALL
for (int i = 0; i < 2; i++)
{
turn_operation_type& turn_op = turn.operations[i];
if (turn_op.visited.none())
{
turn_op.visited.set_visited();
}
}
}
else
{
op.visited.set_visited();
}
if (turn.is_clustered())
{
set_visited_in_cluster(turn.cluster_id, op.enriched.rank);
}
}
inline bool is_visited(turn_type const& , turn_operation_type const& op,
signed_size_type , int) const
{
return op.visited.visited();
}
template <signed_size_type segment_identifier::*Member>
inline bool select_source_generic(turn_type const& turn,
segment_identifier const& current,
segment_identifier const& previous) const
{
turn_operation_type const& op0 = turn.operations[0];
turn_operation_type const& op1 = turn.operations[1];
bool const switch_source = op0.enriched.region_id != -1
&& op0.enriched.region_id == op1.enriched.region_id;
#if defined(BOOST_GEOMETRY_DEBUG_TRAVERSAL_SWITCH_DETECTOR)
if (switch_source)
{
std::cout << "Switch source at " << &turn << std::endl;
}
else
{
std::cout << "DON'T SWITCH SOURCES at " << &turn << std::endl;
}
#endif
return switch_source
? current.*Member != previous.*Member
: current.*Member == previous.*Member;
}
inline bool select_source(turn_type const& turn,
segment_identifier const& candidate_seg_id,
segment_identifier const& previous_seg_id) const
{
// For uu/ii, only switch sources if indicated
if (BOOST_GEOMETRY_CONDITION(OverlayType == overlay_buffer))
{
// Buffer does not use source_index (always 0).
return select_source_generic<&segment_identifier::multi_index>(
turn, candidate_seg_id, previous_seg_id);
}
if (is_self_turn<OverlayType>(turn))
{
// Also, if it is a self-turn, stay on same ring (multi/ring)
return select_source_generic<&segment_identifier::multi_index>(
turn, candidate_seg_id, previous_seg_id);
}
// Use source_index
return select_source_generic<&segment_identifier::source_index>(
turn, candidate_seg_id, previous_seg_id);
}
inline bool traverse_possible(signed_size_type turn_index) const
{
if (turn_index == -1)
{
return false;
}
turn_type const& turn = m_turns[turn_index];
// It is not a dead end if there is an operation to continue, or of
// there is a cluster (assuming for now we can get out of the cluster)
return turn.is_clustered()
|| turn.has(target_operation)
|| turn.has(operation_continue);
}
inline std::size_t get_shortcut_level(turn_operation_type const& op,
signed_size_type start_turn_index,
signed_size_type origin_turn_index,
std::size_t level = 1) const
{
signed_size_type next_turn_index = op.enriched.get_next_turn_index();
if (next_turn_index == -1)
{
return 0;
}
if (next_turn_index == start_turn_index)
{
// This operation finishes the ring
return 0;
}
if (next_turn_index == origin_turn_index)
{
// This operation travels to itself
return level;
}
if (level > 10)
{
// Avoid infinite recursion
return 0;
}
turn_type const& next_turn = m_turns[next_turn_index];
for (int i = 0; i < 2; i++)
{
turn_operation_type const& next_op = next_turn.operations[i];
if (next_op.operation == target_operation
&& ! next_op.visited.finished()
&& ! next_op.visited.visited())
{
// Recursively continue verifying
if (get_shortcut_level(next_op, start_turn_index,
origin_turn_index, level + 1))
{
return level + 1;
}
}
}
return 0;
}
inline
bool select_cc_operation(turn_type const& turn,
signed_size_type start_turn_index,
int& selected_op_index) const
{
// For "cc", take either one, but if there is a starting one,
// take that one. If next is dead end, skip that one.
// If both are valid candidates, take the one with minimal remaining
// distance (important for #mysql_23023665 in buffer).
signed_size_type next[2] = {0};
bool possible[2] = {0};
bool close[2] = {0};
for (int i = 0; i < 2; i++)
{
next[i] = turn.operations[i].enriched.get_next_turn_index();
possible[i] = traverse_possible(next[i]);
close[i] = possible[i] && next[i] == start_turn_index;
}
if (close[0] != close[1])
{
// One of the operations will finish the ring. Take that one.
selected_op_index = close[0] ? 0 : 1;
debug_traverse(turn, turn.operations[selected_op_index], "Candidate cc closing");
return true;
}
if (BOOST_GEOMETRY_CONDITION(OverlayType == overlay_buffer)
&& possible[0] && possible[1])
{
// Buffers sometimes have multiple overlapping pieces, where remaining
// distance could lead to the wrong choice. Take the matching operation.
bool is_target[2] = {0};
for (int i = 0; i < 2; i++)
{
turn_operation_type const& next_op = m_turns[next[i]].operations[i];
is_target[i] = next_op.operation == target_operation;
}
if (is_target[0] != is_target[1])
{
// Take the matching operation
selected_op_index = is_target[0] ? 0 : 1;
debug_traverse(turn, turn.operations[selected_op_index], "Candidate cc target");
return true;
}
}
static bool const is_union = target_operation == operation_union;
typename turn_operation_type::comparable_distance_type
best_remaining_distance = 0;
bool result = false;
for (int i = 0; i < 2; i++)
{
if (!possible[i])
{
continue;
}
turn_operation_type const& op = turn.operations[i];
if (! result
|| (is_union && op.remaining_distance > best_remaining_distance)
|| (!is_union && op.remaining_distance < best_remaining_distance))
{
debug_traverse(turn, op, "First candidate cc", ! result);
debug_traverse(turn, op, "Candidate cc override (remaining)",
result && op.remaining_distance < best_remaining_distance);
selected_op_index = i;
best_remaining_distance = op.remaining_distance;
result = true;
}
}
return result;
}
inline
bool select_noncc_operation(turn_type const& turn,
segment_identifier const& previous_seg_id,
int& selected_op_index) const
{
bool result = false;
for (int i = 0; i < 2; i++)
{
turn_operation_type const& op = turn.operations[i];
if (op.operation == target_operation
&& ! op.visited.finished()
&& ! op.visited.visited()
&& (! result || select_source(turn, op.seg_id, previous_seg_id)))
{
selected_op_index = i;
debug_traverse(turn, op, "Candidate");
result = true;
}
}
return result;
}
inline
bool select_preferred_operation(turn_type const& turn,
signed_size_type turn_index,
signed_size_type start_turn_index,
int& selected_op_index) const
{
bool option[2] = {0};
bool finishing[2] = {0};
bool preferred[2] = {0};
std::size_t shortcut_level[2] = {0};
for (int i = 0; i < 2; i++)
{
turn_operation_type const& op = turn.operations[i];
if (op.operation == target_operation
&& ! op.visited.finished()
&& ! op.visited.visited())
{
option[i] = true;
if (op.enriched.get_next_turn_index() == start_turn_index)
{
finishing[i] = true;
}
else
{
shortcut_level[i] = get_shortcut_level(op, start_turn_index,
turn_index);
}
if (op.enriched.prefer_start)
{
preferred[i] = true;
}
}
}
if (option[0] != option[1])
{
// Only one operation is acceptable, take that one
selected_op_index = option[0] ? 0 : 1;
return true;
}
if (option[0] && option[1])
{
// Both operations are acceptable
if (finishing[0] != finishing[1])
{
// Prefer operation finishing the ring
selected_op_index = finishing[0] ? 0 : 1;
return true;
}
if (shortcut_level[0] != shortcut_level[1])
{
// If a turn can travel to itself again (without closing the
// ring), take the shortest one
selected_op_index = shortcut_level[0] < shortcut_level[1] ? 0 : 1;
return true;
}
if (preferred[0] != preferred[1])
{
// Only one operation is preferred (== was not intersection)
selected_op_index = preferred[0] ? 0 : 1;
return true;
}
}
for (int i = 0; i < 2; i++)
{
if (option[i])
{
selected_op_index = 0;
return true;
}
}
return false;
}
inline
bool select_operation(const turn_type& turn,
signed_size_type turn_index,
signed_size_type start_turn_index,
segment_identifier const& previous_seg_id,
int& selected_op_index) const
{
bool result = false;
selected_op_index = -1;
if (turn.both(operation_continue))
{
result = select_cc_operation(turn, start_turn_index,
selected_op_index);
}
else if (BOOST_GEOMETRY_CONDITION(OverlayType == overlay_dissolve))
{
result = select_preferred_operation(turn, turn_index,
start_turn_index, selected_op_index);
}
else
{
result = select_noncc_operation(turn, previous_seg_id,
selected_op_index);
}
if (result)
{
debug_traverse(turn, turn.operations[selected_op_index], "Accepted");
}
return result;
}
inline int starting_operation_index(const turn_type& turn) const
{
for (int i = 0; i < 2; i++)
{
if (turn.operations[i].visited.started())
{
return i;
}
}
return -1;
}
inline bool both_finished(const turn_type& turn) const
{
for (int i = 0; i < 2; i++)
{
if (! turn.operations[i].visited.finished())
{
return false;
}
}
return true;
}
inline int priority_of_turn_in_cluster_union(sort_by_side::rank_type selected_rank,
typename sbs_type::rp const& ranked_point,
std::set<signed_size_type> const& cluster_indices,
signed_size_type start_turn_index, int start_op_index) const
{
// Returns 0: not OK
// Returns 1: OK but next turn is in same cluster
// Returns 2: OK
// Returns 3: OK and start turn matches
// Returns 4: OK and start turn and start op both match
if (ranked_point.rank != selected_rank
|| ranked_point.direction != sort_by_side::dir_to)
{
return 0;
}
auto const& turn = m_turns[ranked_point.turn_index];
auto const& op = turn.operations[ranked_point.operation_index];
// Check finalized: TODO: this should be finetuned, it is not necessary
if (op.visited.finalized())
{
return 0;
}
if (BOOST_GEOMETRY_CONDITION(OverlayType != overlay_dissolve)
&& (op.enriched.count_left != 0 || op.enriched.count_right == 0))
{
// Check counts: in some cases interior rings might be generated with
// polygons on both sides. For dissolve it can be anything.
return 0;
}
bool const to_start = ranked_point.turn_index == start_turn_index;
bool const to_start_index = ranked_point.operation_index == start_op_index;
bool const next_in_same_cluster
= cluster_indices.count(op.enriched.get_next_turn_index()) > 0;
return to_start && to_start_index ? 4
: to_start ? 3
: next_in_same_cluster ? 1
: 2
;
}
template <typename RankedPoint>
inline turn_operation_type const& operation_from_rank(RankedPoint const& rp) const
{
return m_turns[rp.turn_index].operations[rp.operation_index];
}
inline sort_by_side::rank_type select_rank(sbs_type const& sbs) const
{
static bool const is_intersection
= target_operation == operation_intersection;
// Take the first outgoing rank corresponding to incoming region,
// or take another region if it is not isolated
auto const& in_op = operation_from_rank(sbs.m_ranked_points.front());
for (std::size_t i = 0; i < sbs.m_ranked_points.size(); i++)
{
auto const& rp = sbs.m_ranked_points[i];
if (rp.rank == 0 || rp.direction == sort_by_side::dir_from)
{
continue;
}
auto const& out_op = operation_from_rank(rp);
if (out_op.operation != target_operation
&& out_op.operation != operation_continue)
{
continue;
}
if (in_op.enriched.region_id == out_op.enriched.region_id
|| (is_intersection && ! out_op.enriched.isolated))
{
// Region corresponds to incoming region, or (for intersection)
// there is a non-isolated other region which should be taken
return rp.rank;
}
}
return -1;
}
inline bool select_from_cluster_union(signed_size_type& turn_index,
std::set<signed_size_type> const& cluster_indices,
int& op_index, sbs_type const& sbs,
signed_size_type start_turn_index, int start_op_index) const
{
sort_by_side::rank_type const selected_rank = select_rank(sbs);
int current_priority = 0;
for (std::size_t i = 1; i < sbs.m_ranked_points.size(); i++)
{
typename sbs_type::rp const& ranked_point = sbs.m_ranked_points[i];
if (ranked_point.rank > selected_rank)
{
break;
}
int const priority = priority_of_turn_in_cluster_union(selected_rank,
ranked_point, cluster_indices, start_turn_index, start_op_index);
if (priority > current_priority)
{
current_priority = priority;
turn_index = ranked_point.turn_index;
op_index = ranked_point.operation_index;
}
}
return current_priority > 0;
}
inline bool analyze_cluster_intersection(signed_size_type& turn_index,
int& op_index, sbs_type const& sbs) const
{
// Select the rank based on regions and isolation
sort_by_side::rank_type const selected_rank = select_rank(sbs);
if (selected_rank <= 0)
{
return false;
}
// From these ranks, select the index: the first, or the one with
// the smallest remaining distance
typename turn_operation_type::comparable_distance_type
min_remaining_distance = 0;
std::size_t selected_index = sbs.m_ranked_points.size();
for (std::size_t i = 0; i < sbs.m_ranked_points.size(); i++)
{
auto const& ranked_point = sbs.m_ranked_points[i];
if (ranked_point.rank > selected_rank)
{
break;
}
else if (ranked_point.rank == selected_rank)
{
auto const& op = operation_from_rank(ranked_point);
if (op.visited.finalized())
{
// This direction is already traveled,
// it cannot be traveled again
continue;
}
if (selected_index == sbs.m_ranked_points.size()
|| op.remaining_distance < min_remaining_distance)
{
// It was unassigned or it is better
selected_index = i;
min_remaining_distance = op.remaining_distance;
}
}
}
if (selected_index == sbs.m_ranked_points.size())
{
// Should not happen, there must be points with the selected rank
return false;
}
auto const& ranked_point = sbs.m_ranked_points[selected_index];
turn_index = ranked_point.turn_index;
op_index = ranked_point.operation_index;
return true;
}
inline bool fill_sbs(sbs_type& sbs,
signed_size_type turn_index,
std::set<signed_size_type> const& cluster_indices,
segment_identifier const& previous_seg_id) const
{
for (auto cluster_turn_index : cluster_indices)
{
turn_type const& cluster_turn = m_turns[cluster_turn_index];
if (cluster_turn.discarded)
{
// Defensive check, discarded turns should not be in cluster
continue;
}
for (int i = 0; i < 2; i++)
{
sbs.add(cluster_turn,
cluster_turn.operations[i],
cluster_turn_index, i, previous_seg_id,
m_geometry1, m_geometry2,
cluster_turn_index == turn_index);
}
}
if (! sbs.has_origin())
{
return false;
}
turn_type const& turn = m_turns[turn_index];
sbs.apply(turn.point);
return true;
}
inline bool select_turn_from_cluster(signed_size_type& turn_index,
int& op_index,
signed_size_type start_turn_index, int start_op_index,
segment_identifier const& previous_seg_id) const
{
bool const is_union = target_operation == operation_union;
turn_type const& turn = m_turns[turn_index];
BOOST_ASSERT(turn.is_clustered());
typename Clusters::const_iterator mit = m_clusters.find(turn.cluster_id);
BOOST_ASSERT(mit != m_clusters.end());
cluster_info const& cinfo = mit->second;
std::set<signed_size_type> const& cluster_indices = cinfo.turn_indices;
sbs_type sbs(m_strategy);
if (! fill_sbs(sbs, turn_index, cluster_indices, previous_seg_id))
{
return false;
}
cluster_exits<OverlayType, Turns, sbs_type> exits(m_turns, cluster_indices, sbs);
if (exits.apply(turn_index, op_index))
{
return true;
}
bool result = false;
if (is_union)
{
result = select_from_cluster_union(turn_index, cluster_indices,
op_index, sbs,
start_turn_index, start_op_index);
if (! result)
{
// There no way out found, try second pass in collected cluster exits
result = exits.apply(turn_index, op_index, false);
}
}
else
{
result = analyze_cluster_intersection(turn_index, op_index, sbs);
}
return result;
}
// Analyzes a non-clustered "ii" intersection, as if it is clustered.
inline bool analyze_ii_intersection(signed_size_type& turn_index, int& op_index,
turn_type const& current_turn,
segment_identifier const& previous_seg_id)
{
sbs_type sbs(m_strategy);
// Add this turn to the sort-by-side sorter
for (int i = 0; i < 2; i++)
{
sbs.add(current_turn,
current_turn.operations[i],
turn_index, i, previous_seg_id,
m_geometry1, m_geometry2,
true);
}
if (! sbs.has_origin())
{
return false;
}
sbs.apply(current_turn.point);
bool result = analyze_cluster_intersection(turn_index, op_index, sbs);
return result;
}
inline void change_index_for_self_turn(signed_size_type& to_vertex_index,
turn_type const& start_turn,
turn_operation_type const& start_op,
int start_op_index) const
{
if (BOOST_GEOMETRY_CONDITION(OverlayType != overlay_buffer
&& OverlayType != overlay_dissolve))
{
return;
}
const bool allow_uu = OverlayType != overlay_buffer;
// It travels to itself, can happen. If this is a buffer, it can
// sometimes travel to itself in the following configuration:
//
// +---->--+
// | |
// | +---*----+ *: one turn, with segment index 2/7
// | | | |
// | +---C | C: closing point (start/end)
// | |
// +------------+
//
// If it starts on segment 2 and travels to itself on segment 2, that
// should be corrected to 7 because that is the shortest path
//
// Also a uu turn (touching with another buffered ring) might have this
// apparent configuration, but there it should
// always travel the whole ring
turn_operation_type const& other_op
= start_turn.operations[1 - start_op_index];
bool const correct
= (allow_uu || ! start_turn.both(operation_union))
&& start_op.seg_id.source_index == other_op.seg_id.source_index
&& start_op.seg_id.multi_index == other_op.seg_id.multi_index
&& start_op.seg_id.ring_index == other_op.seg_id.ring_index
&& start_op.seg_id.segment_index == to_vertex_index;
#if defined(BOOST_GEOMETRY_DEBUG_TRAVERSE)
std::cout << " WARNING: self-buffer "
<< " correct=" << correct
<< " turn=" << operation_char(start_turn.operations[0].operation)
<< operation_char(start_turn.operations[1].operation)
<< " start=" << start_op.seg_id.segment_index
<< " from=" << to_vertex_index
<< " to=" << other_op.enriched.travels_to_vertex_index
<< std::endl;
#endif
if (correct)
{
to_vertex_index = other_op.enriched.travels_to_vertex_index;
}
}
bool select_turn_from_enriched(signed_size_type& turn_index,
segment_identifier& previous_seg_id,
signed_size_type& to_vertex_index,
signed_size_type start_turn_index,
int start_op_index,
turn_type const& previous_turn,
turn_operation_type const& previous_op,
bool is_start) const
{
to_vertex_index = -1;
if (previous_op.enriched.next_ip_index < 0)
{
// There is no next IP on this segment
if (previous_op.enriched.travels_to_vertex_index < 0
|| previous_op.enriched.travels_to_ip_index < 0)
{
return false;
}
to_vertex_index = previous_op.enriched.travels_to_vertex_index;
if (is_start &&
previous_op.enriched.travels_to_ip_index == start_turn_index)
{
change_index_for_self_turn(to_vertex_index, previous_turn,
previous_op, start_op_index);
}
turn_index = previous_op.enriched.travels_to_ip_index;
previous_seg_id = previous_op.seg_id;
}
else
{
// Take the next IP on this segment
turn_index = previous_op.enriched.next_ip_index;
previous_seg_id = previous_op.seg_id;
}
return true;
}
bool select_turn(signed_size_type start_turn_index, int start_op_index,
signed_size_type& turn_index,
int& op_index,
int previous_op_index,
signed_size_type previous_turn_index,
segment_identifier const& previous_seg_id,
bool is_start, bool has_points)
{
turn_type const& current_turn = m_turns[turn_index];
if (BOOST_GEOMETRY_CONDITION(target_operation == operation_intersection))
{
if (has_points)
{
bool const back_at_start_cluster
= current_turn.is_clustered()
&& m_turns[start_turn_index].cluster_id == current_turn.cluster_id;
if (turn_index == start_turn_index || back_at_start_cluster)
{
// Intersection can always be finished if returning
turn_index = start_turn_index;
op_index = start_op_index;
return true;
}
}
if (! current_turn.is_clustered()
&& current_turn.both(operation_intersection))
{
if (analyze_ii_intersection(turn_index, op_index,
current_turn, previous_seg_id))
{
return true;
}
}
}
if (current_turn.is_clustered())
{
if (! select_turn_from_cluster(turn_index, op_index,
start_turn_index, start_op_index, previous_seg_id))
{
return false;
}
if (is_start && turn_index == previous_turn_index)
{
op_index = previous_op_index;
}
}
else
{
op_index = starting_operation_index(current_turn);
if (op_index == -1)
{
if (both_finished(current_turn))
{
return false;
}
if (! select_operation(current_turn, turn_index,
start_turn_index,
previous_seg_id,
op_index))
{
return false;
}
}
}
return true;
}
private :
Geometry1 const& m_geometry1;
Geometry2 const& m_geometry2;
Turns& m_turns;
Clusters const& m_clusters;
RobustPolicy const& m_robust_policy;
SideStrategy m_strategy;
Visitor& m_visitor;
};
}} // namespace detail::overlay
#endif // DOXYGEN_NO_DETAIL
}} // namespace boost::geometry
#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_TRAVERSAL_HPP