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Merge pull request #966 from awulkiew/fix/simplify

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Fix simplify for open rings and improve it
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Adam Wulkiewicz 2022-01-20 00:37:41 +01:00 committed by GitHub
commit 6099339544
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2 changed files with 51 additions and 25 deletions
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55
include/boost/geometry/algorithms/simplify.hpp
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@ -4,8 +4,8 @@
// Copyright (c) 2008-2015 Bruno Lalande, Paris, France. // Copyright (c) 2008-2015 Bruno Lalande, Paris, France.
// Copyright (c) 2009-2015 Mateusz Loskot, London, UK. // Copyright (c) 2009-2015 Mateusz Loskot, London, UK.
// This file was modified by Oracle on 2018-2021. // This file was modified by Oracle on 2018-2022.
// Modifications copyright (c) 2018-2021 Oracle and/or its affiliates. // Modifications copyright (c) 2018-2022 Oracle and/or its affiliates.
// Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
// Parts of Boost.Geometry are redesigned from Geodan's Geographic Library // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
@ -56,6 +56,7 @@
#include <boost/geometry/strategies/concepts/simplify_concept.hpp> #include <boost/geometry/strategies/concepts/simplify_concept.hpp>
#include <boost/geometry/strategies/default_strategy.hpp> #include <boost/geometry/strategies/default_strategy.hpp>
#include <boost/geometry/strategies/detail.hpp> #include <boost/geometry/strategies/detail.hpp>
#include <boost/geometry/strategies/distance/comparable.hpp>
#include <boost/geometry/strategies/simplify/cartesian.hpp> #include <boost/geometry/strategies/simplify/cartesian.hpp>
#include <boost/geometry/strategies/simplify/geographic.hpp> #include <boost/geometry/strategies/simplify/geographic.hpp>
#include <boost/geometry/strategies/simplify/spherical.hpp> #include <boost/geometry/strategies/simplify/spherical.hpp>
@ -388,29 +389,27 @@ private :
static std::size_t get_opposite(std::size_t index, Ring const& ring, static std::size_t get_opposite(std::size_t index, Ring const& ring,
Strategies const& strategies) Strategies const& strategies)
{ {
// TODO: Use Pt-Pt distance strategy instead? // TODO: Instead of calling the strategy call geometry::comparable_distance() ?
// TODO: Use comparable distance strategy
auto distance_strategy = strategies.distance(detail::dummy_point(), detail::dummy_segment()); auto const cdistance_strategy = strategies::distance::detail::make_comparable(strategies)
.distance(detail::dummy_point(), detail::dummy_point());
typedef typename geometry::point_type<Ring>::type point_type; using point_type = typename geometry::point_type<Ring>::type;
typedef decltype(distance_strategy.apply(std::declval<point_type>(), using cdistance_type = decltype(cdistance_strategy.apply(
std::declval<point_type>(), std::declval<point_type>())) distance_type; std::declval<point_type>(), std::declval<point_type>()));
// Verify if it is NOT the case that all points are less than the // Verify if it is NOT the case that all points are less than the
// simplifying distance. If so, output is empty. // simplifying distance. If so, output is empty.
distance_type max_distance(-1); cdistance_type max_cdistance(-1);
point_type const& point = range::at(ring, index); point_type const& point = range::at(ring, index);
std::size_t i = 0; std::size_t i = 0;
for (auto it = boost::begin(ring); it != boost::end(ring); ++it, ++i) for (auto it = boost::begin(ring); it != boost::end(ring); ++it, ++i)
{ {
// This actually is point-segment distance but will result cdistance_type const cdistance = cdistance_strategy.apply(*it, point);
// in point-point distance if (cdistance > max_cdistance)
distance_type dist = distance_strategy.apply(*it, point, point);
if (dist > max_distance)
{ {
max_distance = dist; max_cdistance = cdistance;
index = i; index = i;
} }
} }
@ -428,6 +427,8 @@ public :
return; return;
} }
bool const is_closed = closure<Ring>::value == closed;
// TODO: instead of area() use calculate_point_order() ? // TODO: instead of area() use calculate_point_order() ?
int const input_sign = area_sign(geometry::area(ring, strategies)); int const input_sign = area_sign(geometry::area(ring, strategies));
@ -439,7 +440,8 @@ public :
// (duplicate end point will be simplified away) // (duplicate end point will be simplified away)
typedef typename geometry::point_type<Ring>::type point_type; typedef typename geometry::point_type<Ring>::type point_type;
std::vector<point_type> rotated(size); std::vector<point_type> rotated;
rotated.reserve(size + 1); // 1 because open rings are closed
// Closing point (but it will not start here) // Closing point (but it will not start here)
std::size_t index = 0; std::size_t index = 0;
@ -472,14 +474,29 @@ public :
continue; continue;
} }
std::rotate_copy(boost::begin(ring), range::pos(ring, index), // Do not duplicate the closing point
boost::end(ring), rotated.begin()); auto rot_end = boost::end(ring);
std::size_t rot_index = index;
if (is_closed && size > 1)
{
--rot_end;
if (rot_index == size - 1) { rot_index = 0; }
}
std::rotate_copy(boost::begin(ring), range::pos(ring, rot_index),
rot_end, std::back_inserter(rotated));
// Close the rotated copy // Close the rotated copy
rotated.push_back(range::at(ring, index)); rotated.push_back(range::at(ring, rot_index));
simplify_range<0>::apply(rotated, out, max_distance, impl, strategies); simplify_range<0>::apply(rotated, out, max_distance, impl, strategies);
// Open output if needed
if (! is_closed && boost::size(out) > 1)
{
range::pop_back(out);
}
// TODO: instead of area() use calculate_point_order() ? // TODO: instead of area() use calculate_point_order() ?
// Verify that what was positive, stays positive (or goes to 0) // Verify that what was positive, stays positive (or goes to 0)
@ -507,7 +524,7 @@ public :
// Prepare next try // Prepare next try
visited_indexes.insert(index); visited_indexes.insert(index);
rotated.resize(size); rotated.clear();
} }
} }
}; };

21
test/algorithms/simplify.cpp
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@ -5,8 +5,8 @@
// Copyright (c) 2008-2012 Bruno Lalande, Paris, France. // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
// Copyright (c) 2009-2012 Mateusz Loskot, London, UK. // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
// This file was modified by Oracle on 2021. // This file was modified by Oracle on 2021-2022.
// Modifications copyright (c) 2021 Oracle and/or its affiliates. // Modifications copyright (c) 2021-2022 Oracle and/or its affiliates.
// Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
// Parts of Boost.Geometry are redesigned from Geodan's Geographic Library // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
@ -200,10 +200,19 @@ void test_all()
"POLYGON((0 0,0 10,10 10,10 0,0 0),(5 5,6 6,5 6,5 5))", "POLYGON((0 0,0 10,10 10,10 0,0 0),(5 5,6 6,5 6,5 5))",
"POLYGON((0 0,0 10,10 10,10 0,0 0))", 5.0); "POLYGON((0 0,0 10,10 10,10 0,0 0))", 5.0);
// // Non-closed version // Non-closed version
// test_geometry<bg::model::polygon<P, true, false> >( test_geometry<bg::model::polygon<P, true, false> >(
// "POLYGON((1 0,0 0,0 4,4 4,4 0))", "POLYGON((1 0,0 0,0 4,4 4,4 0))",
// "POLYGON((0 0,0 4,4 4,4 0))", 0.1); "POLYGON((0 0,0 4,4 4,4 0))", 0.1);
test_geometry<bg::model::polygon<P, true, false> >(
"POLYGON((0 0,0 1,1 1,1 0))",
"POLYGON((0 0,0 1,1 1,1 0))", 0.1);
// Non-closed, ccw version
// https://github.com/boostorg/geometry/issues/956
test_geometry<bg::model::polygon<P, false, false> >(
"POLYGON((0 0,0.4 0,0.4 0.4))",
"POLYGON((0 0,0.4 0,0.4 0.4))", 0);
{ {