[overlay] add handle_touch to examine u/u turns

First phase: check if a u/u turn should be traversed or discarded, including
unit test
This commit is contained in:
Barend Gehrels 2015-09-02 14:27:19 +02:00
parent 3dd8d1e689
commit 16967cc7f8
2 changed files with 690 additions and 0 deletions

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// Boost.Geometry (aka GGL, Generic Geometry Library)
// Copyright (c) 2015 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_HANDLE_TOUCH_HPP
#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_HANDLE_TOUCH_HPP
#include <cstddef>
#include <map>
#include <vector>
#include <boost/range.hpp>
#include <boost/geometry/algorithms/detail/overlay/turn_info.hpp>
#include <boost/geometry/geometries/concepts/check.hpp>
#include <boost/geometry/algorithms/detail/ring_identifier.hpp>
#include <boost/geometry/algorithms/detail/overlay/segment_identifier.hpp>
namespace boost { namespace geometry
{
#ifndef DOXYGEN_NO_DETAIL
namespace detail { namespace overlay
{
template <typename Turns>
class handle_touch_uu
{
private :
typedef typename boost::range_value<Turns>::type turn_type;
typedef typename boost::range_iterator<Turns>::type turn_iterator;
typedef typename boost::range_iterator<Turns const>::type turn_const_iterator;
typedef typename boost::range_iterator
<
typename turn_type::container_type const
>::type operation_const_iterator;
typedef std::map<ring_identifier, std::vector<int> > map_type;
public :
static inline void apply(detail::overlay::operation_type operation,
Turns& turns)
{
if (! has_uu(turns))
{
// Performance - if there is no u/u at all, nothing to be done
return;
}
map_type turns_per_ring;
create_ring_map(turns, turns_per_ring);
handle(turns, turns_per_ring);
}
private :
// Generic utility to be moved somewhere else
static inline
ring_identifier ring_id_from_seg_id(const segment_identifier& seg_id)
{
return ring_identifier(seg_id.source_index,
seg_id.multi_index,
seg_id.ring_index);
}
static inline
ring_identifier ring_id_from_op(const turn_type& turn,
int operation_index)
{
return ring_id_from_seg_id(turn.operations[operation_index].seg_id);
}
static inline bool has_uu(const Turns& turns)
{
for (turn_const_iterator it = boost::begin(turns);
it != boost::end(turns);
++it)
{
const turn_type& turn = *it;
if (turn.both(operation_union))
{
return true;
}
}
return false;
}
// Create a map of turns per ring (in both sources), excluding u/u turns
// and other discarded turns
static inline void create_ring_map(const Turns& turns, map_type& map)
{
int index = 0;
for (turn_const_iterator it = boost::begin(turns);
it != boost::end(turns);
++it, ++index)
{
const turn_type& turn = *it;
if (! turn.both(operation_union) && ! turn.discarded)
{
map[ring_id_from_op(turn, 0)].push_back(index);
map[ring_id_from_op(turn, 1)].push_back(index);
}
}
}
static inline void handle(Turns& turns, const map_type& map)
{
// Iterate through all u/u points
int index = 0;
for (turn_iterator it = boost::begin(turns);
it != boost::end(turns);
++it, ++index)
{
turn_type& turn = *it;
if (turn.both(operation_union))
{
bool traverse = turn_should_be_traversed(turns, turn, map);
#ifdef BOOST_GEOMETRY_DEBUG_HANDLE_TOUCH
std::cout << " " << index << " "
<< std::boolalpha << traverse
<< std::endl;
#endif
if (traverse)
{
// Remove the discarded flag
turn.discarded = false;
// TODO: insert into sequence
}
}
}
}
static inline bool turn_should_be_traversed(const Turns& turns,
const turn_type& uu_turn,
const map_type& map)
{
// Suppose this is a u/u turn between P and Q
// Examine all other turns on P and check if Q can be reached
ring_identifier const ring_id_p = ring_id_from_op(uu_turn, 0);
ring_identifier const ring_id_q = ring_id_from_op(uu_turn, 1);
// Use one of the operations and check if you can reach the other
map_type::const_iterator mit = map.find(ring_id_p);
if (mit == map.end())
{
// No other turns found
return false;
}
#ifdef BOOST_GEOMETRY_DEBUG_HANDLE_TOUCH
std::cout << " Check p: " << ring_id_p << " q: " << ring_id_q << std::endl;
#endif
for (std::vector<int>::const_iterator vit = mit->second.begin();
vit != mit->second.end();
++vit)
{
int const turn_index = *vit;
const turn_type& current_turn = turns[turn_index];
#ifdef BOOST_GEOMETRY_DEBUG_HANDLE_TOUCH
std::cout << "-> Examine " << turn_index << std::endl;
#endif
if (can_reach(turns, current_turn, ring_id_q, turn_index))
{
return true;
}
}
return false;
}
static inline bool can_reach(const Turns& turns,
const turn_type& turn,
const ring_identifier& target_ring_id,
signed_size_type original_turn_index,
std::size_t iteration = 0)
{
signed_size_type const turns_size =
static_cast<signed_size_type>(boost::size(turns));
// For any union operation in both operations, check if the specified
// ring can be reached again
for (operation_const_iterator it = boost::begin(turn.operations);
it != boost::end(turn.operations);
++it)
{
if (it->operation == operation_union)
{
signed_size_type index = it->enriched.travels_to_ip_index;
if (index == original_turn_index)
{
// Traveled through, not found
return false;
}
if (index >= 0 && index < turns_size)
{
#ifdef BOOST_GEOMETRY_DEBUG_HANDLE_TOUCH
std::cout << " Now to " << index << std::endl;
#endif
const turn_type& new_turn = turns[index];
ring_identifier const ring_id1 = ring_id_from_op(new_turn, 0);
ring_identifier const ring_id2 = ring_id_from_op(new_turn, 1);
if (ring_id1 == target_ring_id
|| ring_id2 == target_ring_id)
{
#ifdef BOOST_GEOMETRY_DEBUG_HANDLE_TOUCH
std::cout << " Found!" << std::endl;
#endif
return true;
}
if (iteration >= boost::size(turns))
{
// Defensive check to avoid infinite recursion
return false;
}
// Recursively check this turn
if (can_reach(turns, new_turn, target_ring_id,
original_turn_index, iteration + 1))
{
return true;
}
}
}
}
return false;
}
};
template <typename Turns>
inline void handle_touch(detail::overlay::operation_type operation,
Turns& turns)
{
handle_touch_uu<Turns>::apply(operation, turns);
}
}} // namespace detail::overlay
#endif // DOXYGEN_NO_DETAIL
}} // namespace boost::geometry
#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_HANDLE_TOUCH_HPP

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// Boost.Geometry (aka GGL, Generic Geometry Library)
// Unit Test
// Copyright (c) 2015 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)
#define BOOST_GEOMETRY_DEBUG_IDENTIFIER
#define BOOST_GEOMETRY_DEBUG_SEGMENT_IDENTIFIER
#define BOOST_GEOMETRY_DEBUG_HANDLE_TOUCH
#include <iostream>
#include <iomanip>
#include <fstream>
#include <sstream>
#include <string>
#include <geometry_test_common.hpp>
#include <boost/geometry/algorithms/detail/overlay/turn_info.hpp>
#include <boost/geometry/algorithms/detail/overlay/enrichment_info.hpp>
#include <boost/geometry/algorithms/detail/overlay/traversal_info.hpp>
#include <boost/geometry/algorithms/detail/overlay/get_turns.hpp>
#include <boost/geometry/algorithms/detail/overlay/enrich_intersection_points.hpp>
#include <boost/geometry/algorithms/detail/overlay/handle_touch.hpp>
#include <boost/geometry/algorithms/detail/overlay/debug_turn_info.hpp>
#include <boost/geometry/policies/robustness/get_rescale_policy.hpp>
#include <boost/geometry/strategies/strategies.hpp>
#include <boost/geometry/algorithms/area.hpp>
#include <boost/geometry/algorithms/correct.hpp>
#include <boost/geometry/geometries/geometries.hpp>
#include <boost/geometry/io/wkt/wkt.hpp>
#if defined(TEST_WITH_SVG)
# include <boost/geometry/io/svg/svg_mapper.hpp>
#endif
namespace detail
{
template
<
typename G1, typename G2,
bg::detail::overlay::operation_type Direction,
bool Reverse1, bool Reverse2
>
struct test_handle_touch
{
static void apply(std::string const& case_id,
std::size_t expected_traverse,
std::size_t expected_discarded,
G1 const& g1, G2 const& g2)
{
typedef typename bg::strategy::side::services::default_strategy
<
typename bg::cs_tag<G1>::type
>::type side_strategy_type;
typedef typename bg::point_type<G2>::type point_type;
typedef typename bg::rescale_policy_type<point_type>::type
rescale_policy_type;
rescale_policy_type rescale_policy
= bg::get_rescale_policy<rescale_policy_type>(g1, g2);
typedef bg::detail::overlay::traversal_turn_info
<
point_type,
typename bg::segment_ratio_type<point_type, rescale_policy_type>::type
> turn_info;
std::vector<turn_info> turns;
bg::detail::get_turns::no_interrupt_policy policy;
bg::get_turns<Reverse1, Reverse2, bg::detail::overlay::assign_null_policy>(g1, g2, rescale_policy, turns, policy);
bg::enrich_intersection_points<Reverse1, Reverse2>(turns,
Direction == 1 ? bg::detail::overlay::operation_union
: bg::detail::overlay::operation_intersection,
g1, g2, rescale_policy, side_strategy_type());
typedef bg::model::ring<typename bg::point_type<G2>::type> ring_type;
typedef std::vector<ring_type> out_vector;
std::cout << "*** Case: " << case_id << std::endl;
bg::detail::overlay::handle_touch(Direction, turns);
// Check number of resulting u/u turns
std::size_t uu_traverse = 0;
std::size_t uu_discarded = 0;
BOOST_FOREACH(turn_info const& turn, turns)
{
if (turn.both(bg::detail::overlay::operation_union))
{
if (turn.discarded)
{
uu_discarded++;
}
else
{
uu_traverse++;
}
}
}
BOOST_CHECK_MESSAGE(expected_traverse == uu_traverse,
"handle_touch: " << case_id
<< " traverse expected: " << expected_traverse
<< " detected: " << uu_traverse
<< " type: " << string_from_type
<typename bg::coordinate_type<G1>::type>::name());
BOOST_CHECK_MESSAGE(expected_discarded == uu_discarded,
"handle_touch: " << case_id
<< " discarded expected: " << expected_discarded
<< " detected: " << uu_discarded
<< " type: " << string_from_type
<typename bg::coordinate_type<G1>::type>::name());
#if defined(TEST_WITH_SVG)
{
std::ostringstream filename;
filename << "handle_touch"
<< "_" << case_id
<< "_" << string_from_type<typename bg::coordinate_type<G1>::type>::name()
<< ".svg";
std::ofstream svg(filename.str().c_str());
bg::svg_mapper<typename bg::point_type<G2>::type> mapper(svg, 500, 500);
mapper.add(g1);
mapper.add(g2);
// Input shapes in green/blue
mapper.map(g1, "fill-opacity:0.5;fill:rgb(153,204,0);"
"stroke:rgb(153,204,0);stroke-width:3");
mapper.map(g2, "fill-opacity:0.3;fill:rgb(51,51,153);"
"stroke:rgb(51,51,153);stroke-width:3");
// turn points in orange, + enrichment/traversal info
typedef typename bg::coordinate_type<G1>::type coordinate_type;
// Simple map to avoid two texts at same place (note that can still overlap!)
std::map<std::pair<int, int>, int> offsets;
int index = 0;
int const margin = 5;
BOOST_FOREACH(turn_info const& turn, turns)
{
int lineheight = 8;
mapper.map(turn.point, "fill:rgb(255,128,0);"
"stroke:rgb(0,0,0);stroke-width:1", 3);
{
coordinate_type half = 0.5;
coordinate_type ten = 10;
// Map characteristics
// Create a rounded off point
std::pair<int, int> p
= std::make_pair(
boost::numeric_cast<int>(half
+ ten * bg::get<0>(turn.point)),
boost::numeric_cast<int>(half
+ ten * bg::get<1>(turn.point))
);
std::string color = "fill:rgb(0,0,0);";
std::string fontsize = "font-size:8px;";
if (turn.both(bg::detail::overlay::operation_union))
{
// Adapt color to give visual feedback in SVG
if (turn.discarded)
{
color = "fill:rgb(255,0,0);"; // red
}
else
{
color = "fill:rgb(0,128,0);"; // green
}
}
else if (turn.discarded)
{
color = "fill:rgb(92,92,92);";
fontsize = "font-size:6px;";
lineheight = 6;
}
const std::string style = color + fontsize + "font-family:Arial;";
{
std::ostringstream out;
out << index
<< ": " << bg::method_char(turn.method)
<< std::endl
<< "op: " << bg::operation_char(turn.operations[0].operation)
<< " / " << bg::operation_char(turn.operations[1].operation)
//<< (turn.is_discarded() ? " (discarded) " : turn.blocked() ? " (blocked)" : "")
<< std::endl;
if (turn.operations[0].enriched.next_ip_index != -1)
{
out << "ip: " << turn.operations[0].enriched.next_ip_index;
}
else
{
out << "vx: " << turn.operations[0].enriched.travels_to_vertex_index
<< " -> ip: " << turn.operations[0].enriched.travels_to_ip_index;
}
out << " / ";
if (turn.operations[1].enriched.next_ip_index != -1)
{
out << "ip: " << turn.operations[1].enriched.next_ip_index;
}
else
{
out << "vx: " << turn.operations[1].enriched.travels_to_vertex_index
<< " -> ip: " << turn.operations[1].enriched.travels_to_ip_index;
}
out << std::endl;
offsets[p] += lineheight;
int offset = offsets[p];
offsets[p] += lineheight * 3;
mapper.text(turn.point, out.str(), style, margin, offset, lineheight);
}
index++;
}
}
}
#endif
}
};
}
template
<
typename G1, typename G2,
bg::detail::overlay::operation_type Direction,
bool Reverse1 = false,
bool Reverse2 = false
>
struct test_handle_touch
{
typedef detail::test_handle_touch
<
G1, G2, Direction, Reverse1, Reverse2
> detail_test_handle_touch;
inline static void apply(std::string const& case_id,
std::size_t expected_traverse,
std::size_t expected_discarded,
std::string const& wkt1, std::string const& wkt2)
{
if (wkt1.empty() || wkt2.empty())
{
return;
}
G1 g1;
bg::read_wkt(wkt1, g1);
G2 g2;
bg::read_wkt(wkt2, g2);
bg::correct(g1);
bg::correct(g2);
detail_test_handle_touch::apply(case_id,
expected_traverse, expected_discarded,
g1, g2);
}
};
template <typename MultiPolygon>
void test_geometries()
{
namespace ov = bg::detail::overlay;
typedef test_handle_touch
<
MultiPolygon, MultiPolygon,
ov::operation_intersection
> test_handle_touch_intersection;
typedef test_handle_touch
<
MultiPolygon, MultiPolygon,
ov::operation_union
> test_handle_touch_union;
test_handle_touch_union::apply
(
"case_36", 1, 0,
"MULTIPOLYGON(((1 0,0 3,4 2,1 0)))",
"MULTIPOLYGON(((1 5,5 5,4 2,3 3,2 1,1 2,1 5)))"
);
test_handle_touch_union::apply
(
"case_85", 1, 0,
"MULTIPOLYGON(((0 0,0 40,40 40,40 0,0 0),(10 10,30 10,30 30,10 30,10 10)))",
"MULTIPOLYGON(((5 15,5 30,30 15,5 15)))"
);
test_handle_touch_union::apply
(
"uu_case_1", 0, 1,
"MULTIPOLYGON(((4 0,2 2,4 4,6 2,4 0)))",
"MULTIPOLYGON(((4 4,2 6,4 8,6 6,4 4)))"
);
test_handle_touch_union::apply
(
"uu_case_2", 0, 2,
"MULTIPOLYGON(((0 0,0 2,2 4,4 2,6 4,8 2,8 0,0 0)))",
"MULTIPOLYGON(((0 8,8 8,8 6,6 4,4 6,2 4,0 6,0 8)))"
);
// Provided by Menelaos (1)
test_handle_touch_union::apply
(
"uu_case_3", 0, 2,
"MULTIPOLYGON(((0 0,0 10,10 10,10 0,0 0)),((15 5,15 10,20 10,20 5,15 5)))",
"MULTIPOLYGON(((10 0,15 5,15 0,10 0)),((10 5,10 10,15 10,15 5,10 5)))"
);
// Provided by Menelaos (2)
test_handle_touch_union::apply
(
"uu_case_4", 1, 0,
"MULTIPOLYGON(((0 0,0 10,10 10,10 0,0 0)),((15 5,15 10,20 10,20 5,15 5)))",
"MULTIPOLYGON(((10 0,15 5,20 5,20 0,10 0)),((10 5,10 10,15 10,15 5,10 5)))"
);
// Mailed by Barend
test_handle_touch_union::apply
(
"uu_case_5", 1, 0,
"MULTIPOLYGON(((4 0,2 2,4 4,6 2,4 0)),((4 6,6 8,8 6,6 4,4 6)))",
"MULTIPOLYGON(((4 4,2 6,4 8,6 6,4 4)),((4 2,7 6,8 3,4 2)))"
);
// Formerly referred to as a
test_handle_touch_union::apply
(
"uu_case_6", 2, 0,
"MULTIPOLYGON(((4 8,4 10,6 10,6 8,4 8)),((7 7,7 11,10 11,10 7,7 7)))",
"MULTIPOLYGON(((6 6,6 8,8 8,8 6,6 6)),((6 10,6 12,8 12,8 10,6 10)),((9 9,11 9,11 2,3 2,3 9,5 9,5 3,9 3,9 9)))"
);
// Should result in 1 polygon with 2 holes
// "POLYGON((4 9,4 10,6 10,6 12,8 12,8 11,10 11,10 9,11 9,11 2,3 2,3 9,4 9),(6 10,6 8,7 8,7 10,6 10),(6 8,5 8,5 3,9 3,9 7,8 7,8 6,6 6,6 8))"
// Formerly referred to as b
test_handle_touch_union::apply
(
"uu_case_7", 0, 2,
"MULTIPOLYGON(((4 8,4 10,6 10,6 8,4 8)),((7 7,7 11,10 11,10 7,7 7)))",
"MULTIPOLYGON(((6 6,6 8,8 8,8 6,6 6)),((6 10,6 12,8 12,8 10,6 10)))"
);
// Should result in 2 polygons
// "MULTIPOLYGON(((4 8,4 10,6 10,6 8,4 8)),((7 8,7 10,6 10,6 12,8 12,8 11,10 11,10 7,8 7,8 6,6 6,6 8,7 8)))"
// Formerly referred to as c
test_handle_touch_union::apply
(
"uu_case_8", 0, 4,
"MULTIPOLYGON(((4 8,4 10,6 10,6 8,4 8)),((8 8,8 10,10 10,10 8,8 8)),((7 11,7 13,13 13,13 5,7 5,7 7,11 7,11 11,7 11)))",
"MULTIPOLYGON(((6 6,6 8,8 8,8 6,6 6)),((6 10,6 12,8 12,8 10,6 10)))"
);
// Shoud result in 3 polygons:
// "MULTIPOLYGON(((4 8,4 10,6 10,6 8,4 8)),((8 8,8 10,10 10,10 8,8 8)),((7 12,7 13,13 13,13 5,7 5,7 6,6 6,6 8,8 8,8 7,11 7,11 11,8 11,8 10,6 10,6 12,7 12)))"
// Formerly referred to as d
test_handle_touch_union::apply
(
"uu_case_9", 0, 2,
"MULTIPOLYGON(((2 4,2 6,4 6,4 4,2 4)),((6 4,6 6,8 6,8 4,6 4)),((1 0,1 3,9 3,9 0,1 0)))",
"MULTIPOLYGON(((0 2,0 4,2 4,2 2,0 2)),((8 2,8 4,10 4,10 2,8 2)),((3 5,3 7,7 7,7 5,3 5)))"
);
// Should result in 2 polygons:
// "MULTIPOLYGON(((2 4,2 6,3 6,3 7,7 7,7 6,8 6,8 4,6 4,6 5,4 5,4 4,2 4)),((1 0,1 2,0 2,0 4,2 4,2 3,8 3,8 4,10 4,10 2,9 2,9 0,1 0)))"
}
template <typename T>
void test_all()
{
typedef bg::model::point<T, 2, bg::cs::cartesian> point_type;
typedef bg::model::multi_polygon
<
bg::model::polygon<point_type>
> multi_polygon;
typedef bg::model::multi_polygon
<
bg::model::polygon<point_type, false>
> multi_polygon_ccw;
test_geometries<multi_polygon>();
// test_geometries<multi_polygon_ccw, true>();
}
int test_main(int, char* [])
{
test_all<double>();
return 0;
}