Fixed ExPolygon::overlaps(), which was not commutative.

Wrote unit tests for Clipper polyline clipping operations.
Rewrote ExPolygon unit tests from Perl to C++.
This commit is contained in:
Vojtech Bubnik 2022-11-15 15:32:16 +01:00
parent f1c0c61895
commit db3f696888
7 changed files with 187 additions and 90 deletions

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@ -154,14 +154,18 @@ bool ExPolygon::overlaps(const ExPolygon &other) const
svg.draw_outline(*this);
svg.draw_outline(other, "blue");
#endif
Polylines pl_out = intersection_pl(to_polylines(other), *this);
#if 0
svg.draw(pl_out, "red");
#endif
if (! pl_out.empty())
return true;
//FIXME ExPolygon::overlaps() shall be commutative, it is not!
return this->contains(other.contour.points.front());
// See unit test SCENARIO("Clipper diff with polyline", "[Clipper]")
// for in which case the intersection_pl produces any intersection.
return ! pl_out.empty() ||
// If *this is completely inside other, then pl_out is empty, but the expolygons overlap. Test for that situation.
other.contains(this->contour.points.front());
}
void ExPolygon::simplify_p(double tolerance, Polygons* polygons) const

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@ -60,6 +60,10 @@ public:
// Does this expolygon overlap another expolygon?
// Either the ExPolygons intersect, or one is fully inside the other,
// and it is not inside a hole of the other expolygon.
// The test may not be commutative if the two expolygons touch by a boundary only,
// see unit test SCENARIO("Clipper diff with polyline", "[Clipper]").
// Namely expolygons touching at a vertical boundary are considered overlapping, while expolygons touching
// at a horizontal boundary are NOT considered overlapping.
bool overlaps(const ExPolygon &other) const;
void simplify_p(double tolerance, Polygons* polygons) const;

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@ -84,8 +84,7 @@ public:
float overhangs_area = 0.f;
bool overlaps(const Structure &rhs) const {
//FIXME ExPolygon::overlaps() shall be commutative, it is not!
return this->bbox.overlap(rhs.bbox) && (this->polygon->overlaps(*rhs.polygon) || rhs.polygon->overlaps(*this->polygon));
return this->bbox.overlap(rhs.bbox) && this->polygon->overlaps(*rhs.polygon);
}
float overlap_area(const Structure &rhs) const {
double out = 0.;

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@ -2,25 +2,115 @@
#include "test_data.hpp"
#include "clipper/clipper_z.hpp"
#include "libslic3r/clipper.hpp"
using namespace Slic3r;
// Test case for an issue with duplicity vertices (same XY coordinates but differ in Z coordinates) in Clipper 6.2.9,
// (related to https://sourceforge.net/p/polyclipping/bugs/160/) that was fixed in Clipper 6.4.2.
// tests for ExPolygon::overlaps(const ExPolygon &other)
SCENARIO("Clipper intersection with polyline", "[Clipper]")
{
struct TestData {
ClipperLib::Path subject;
ClipperLib::Path clip;
ClipperLib::Paths result;
};
auto run_test = [](const TestData &data) {
ClipperLib::Clipper clipper;
clipper.AddPath(data.subject, ClipperLib::ptSubject, false);
clipper.AddPath(data.clip, ClipperLib::ptClip, true);
ClipperLib::PolyTree polytree;
ClipperLib::Paths paths;
clipper.Execute(ClipperLib::ctIntersection, polytree, ClipperLib::pftNonZero, ClipperLib::pftNonZero);
ClipperLib::PolyTreeToPaths(polytree, paths);
REQUIRE(paths == data.result);
};
WHEN("Open polyline completely inside stays inside") {
run_test({
{ { 10, 0 }, { 20, 0 } },
{ { -1000, -1000 }, { -1000, 1000 }, { 1000, 1000 }, { 1000, -1000 } },
{ { { 20, 0 }, { 10, 0 } } }
});
};
WHEN("Closed polyline completely inside stays inside") {
run_test({
{ { 10, 0 }, { 20, 0 }, { 20, 20 }, { 10, 20 }, { 10, 0 } },
{ { -1000, -1000 }, { -1000, 1000 }, { 1000, 1000 }, { 1000, -1000 } },
{ { { 10, 0 }, { 20, 0 }, { 20, 20 }, { 10, 20 }, { 10, 0 } } }
});
};
WHEN("Polyline which crosses right rectangle boundary is trimmed") {
run_test({
{ { 10, 0 }, { 2000, 0 } },
{ { -1000, -1000 }, { -1000, 1000 }, { 1000, 1000 }, { 1000, -1000 } },
{ { { 1000, 0 }, { 10, 0 } } }
});
};
WHEN("Polyline which is outside clipping region is removed") {
run_test({
{ { 1500, 0 }, { 2000, 0 } },
{ { -1000, -1000 }, { -1000, 1000 }, { 1000, 1000 }, { 1000, -1000 } },
{ }
});
};
WHEN("Polyline on left vertical boundary is kept") {
run_test({
{ { -1000, -1000 }, { -1000, 1000 } },
{ { -1000, -1000 }, { -1000, 1000 }, { 1000, 1000 }, { 1000, -1000 } },
{ { { -1000, -1000 }, { -1000, 1000 } } }
});
run_test({
{ { -1000, 1000 }, { -1000, -1000 } },
{ { -1000, -1000 }, { -1000, 1000 }, { 1000, 1000 }, { 1000, -1000 } },
{ { { -1000, 1000 }, { -1000, -1000 } } }
});
};
WHEN("Polyline on right vertical boundary is kept") {
run_test({
{ { 1000, -1000 }, { 1000, 1000 } },
{ { -1000, -1000 }, { -1000, 1000 }, { 1000, 1000 }, { 1000, -1000 } },
{ { { 1000, -1000 }, { 1000, 1000 } } }
});
run_test({
{ { 1000, 1000 }, { 1000, -1000 } },
{ { -1000, -1000 }, { -1000, 1000 }, { 1000, 1000 }, { 1000, -1000 } },
{ { { 1000, 1000 }, { 1000, -1000 } } }
});
};
WHEN("Polyline on bottom horizontal boundary is removed") {
run_test({
{ { -1000, -1000 }, { 1000, -1000 } },
{ { -1000, -1000 }, { -1000, 1000 }, { 1000, 1000 }, { 1000, -1000 } },
{ }
});
run_test({
{ { 1000, -1000 }, { -1000, -1000 } },
{ { -1000, -1000 }, { -1000, 1000 }, { 1000, 1000 }, { 1000, -1000 } },
{ }
});
};
WHEN("Polyline on top horizontal boundary is removed") {
run_test({
{ { -1000, 1000 }, { 1000, 1000 } },
{ { -1000, -1000 }, { -1000, 1000 }, { 1000, 1000 }, { 1000, -1000 } },
{ }
});
run_test({
{ { 1000, 1000 }, { -1000, 1000 } },
{ { -1000, -1000 }, { -1000, 1000 }, { 1000, 1000 }, { 1000, -1000 } },
{ }
});
};
}
SCENARIO("Clipper Z", "[ClipperZ]")
{
ClipperLib_Z::Path subject;
subject.emplace_back(-2000, -1000, 10);
subject.emplace_back(-2000, 1000, 10);
subject.emplace_back( 2000, 1000, 10);
subject.emplace_back( 2000, -1000, 10);
ClipperLib_Z::Path clip;
clip.emplace_back(-1000, -2000, -5);
clip.emplace_back(-1000, 2000, -5);
clip.emplace_back( 1000, 2000, -5);
clip.emplace_back( 1000, -2000, -5);
ClipperLib_Z::Path subject { { -2000, -1000, 10 }, { -2000, 1000, 10 }, { 2000, 1000, 10 }, { 2000, -1000, 10 } };
ClipperLib_Z::Path clip{ { -1000, -2000, -5 }, { -1000, 2000, -5 }, { 1000, 2000, -5 }, { 1000, -2000, -5 } };
ClipperLib_Z::Clipper clipper;
clipper.ZFillFunction([](const ClipperLib_Z::IntPoint &e1bot, const ClipperLib_Z::IntPoint &e1top, const ClipperLib_Z::IntPoint &e2bot,
@ -41,3 +131,4 @@ SCENARIO("Clipper Z", "[ClipperZ]")
for (const ClipperLib_Z::IntPoint &pt : paths.front())
REQUIRE(pt.z() == 1);
}

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@ -12,6 +12,7 @@ add_executable(${_TEST_NAME}_tests
test_config.cpp
test_curve_fitting.cpp
test_elephant_foot_compensation.cpp
test_expolygon.cpp
test_geometry.cpp
test_placeholder_parser.cpp
test_polygon.cpp

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@ -0,0 +1,67 @@
#include <catch2/catch.hpp>
#include "libslic3r/Point.hpp"
#include "libslic3r/Polygon.hpp"
#include "libslic3r/ExPolygon.hpp"
using namespace Slic3r;
static inline bool points_close(const Point &p1, const Point &p2)
{
return (p1 - p2).cast<double>().norm() < SCALED_EPSILON;
}
static bool polygons_close_permuted(const Polygon &poly1, const Polygon &poly2, const std::vector<int> &permutation2)
{
if (poly1.size() != poly2.size() || poly1.size() != permutation2.size())
return false;
for (size_t i = 0; i < poly1.size(); ++ i)
if (poly1[i] != poly2[permutation2[i]])
return false;
return true;
}
SCENARIO("Basics", "[ExPolygon]") {
GIVEN("ccw_square") {
Polygon ccw_square{ { 100, 100 }, { 200, 100 }, { 200, 200 }, { 100, 200 } };
Polygon cw_hole_in_square{ { 140, 140 }, { 140, 160 }, { 160, 160 }, { 160, 140 } };
ExPolygon expolygon { ccw_square, cw_hole_in_square };
THEN("expolygon is valid") {
REQUIRE(expolygon.is_valid());
}
THEN("expolygon area") {
REQUIRE(expolygon.area() == Approx(100*100-20*20));
}
WHEN("Expolygon scaled") {
ExPolygon expolygon2 = expolygon;
expolygon2.scale(2.5);
REQUIRE(expolygon.contour.size() == expolygon2.contour.size());
REQUIRE(expolygon.holes.size() == 1);
REQUIRE(expolygon2.holes.size() == 1);
for (size_t i = 0; i < expolygon.contour.size(); ++ i)
REQUIRE(points_close(expolygon.contour[i] * 2.5, expolygon2.contour[i]));
for (size_t i = 0; i < expolygon.holes.front().size(); ++ i)
REQUIRE(points_close(expolygon.holes.front()[i] * 2.5, expolygon2.holes.front()[i]));
}
WHEN("Expolygon translated") {
ExPolygon expolygon2 = expolygon;
expolygon2.translate(10, -5);
REQUIRE(expolygon.contour.size() == expolygon2.contour.size());
REQUIRE(expolygon.holes.size() == 1);
REQUIRE(expolygon2.holes.size() == 1);
for (size_t i = 0; i < expolygon.contour.size(); ++ i)
REQUIRE(points_close(expolygon.contour[i] + Point(10, -5), expolygon2.contour[i]));
for (size_t i = 0; i < expolygon.holes.front().size(); ++ i)
REQUIRE(points_close(expolygon.holes.front()[i] + Point(10, -5), expolygon2.holes.front()[i]));
}
WHEN("Expolygon rotated around point") {
ExPolygon expolygon2 = expolygon;
expolygon2.rotate(M_PI / 2, Point(150, 150));
REQUIRE(expolygon.contour.size() == expolygon2.contour.size());
REQUIRE(expolygon.holes.size() == 1);
REQUIRE(expolygon2.holes.size() == 1);
REQUIRE(polygons_close_permuted(expolygon2.contour, expolygon.contour, { 1, 2, 3, 0}));
REQUIRE(polygons_close_permuted(expolygon2.holes.front(), expolygon.holes.front(), { 3, 0, 1, 2}));
}
}
}

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@ -1,69 +0,0 @@
#!/usr/bin/perl
use strict;
use warnings;
use List::Util qw(first sum);
use Slic3r::XS;
use Test::More tests => 7;
use constant PI => 4 * atan2(1, 1);
my $square = [ # ccw
[100, 100],
[200, 100],
[200, 200],
[100, 200],
];
my $hole_in_square = [ # cw
[140, 140],
[140, 160],
[160, 160],
[160, 140],
];
my $expolygon = Slic3r::ExPolygon->new($square, $hole_in_square);
ok $expolygon->is_valid, 'is_valid';
is_deeply $expolygon->clone->pp, [$square, $hole_in_square], 'clone';
is $expolygon->area, 100*100-20*20, 'area';
{
my $expolygon2 = $expolygon->clone;
$expolygon2->scale(2.5);
is_deeply $expolygon2->pp, [
[map [ 2.5*$_->[0], 2.5*$_->[1] ], @$square],
[map [ 2.5*$_->[0], 2.5*$_->[1] ], @$hole_in_square]
], 'scale';
}
{
my $expolygon2 = $expolygon->clone;
$expolygon2->translate(10, -5);
is_deeply $expolygon2->pp, [
[map [ $_->[0]+10, $_->[1]-5 ], @$square],
[map [ $_->[0]+10, $_->[1]-5 ], @$hole_in_square]
], 'translate';
}
{
my $expolygon2 = $expolygon->clone;
$expolygon2->rotate(PI/2, Slic3r::Point->new(150,150));
is_deeply $expolygon2->pp, [
[ @$square[1,2,3,0] ],
[ @$hole_in_square[3,0,1,2] ]
], 'rotate around Point';
}
{
my $expolygon2 = $expolygon->clone;
$expolygon2->rotate(PI/2, [150,150]);
is_deeply $expolygon2->pp, [
[ @$square[1,2,3,0] ],
[ @$hole_in_square[3,0,1,2] ]
], 'rotate around pure-Perl Point';
}
__END__