[T/GL] Test line segment intersecting algorithm (2d).

Tests/GeoLib/TestLineSegmentIntersect2d.cpp

+/**
+ * \copyright
+ * Copyright (c) 2012-2016, OpenGeoSys Community (http://www.opengeosys.org)
+ *            Distributed under a Modified BSD License.
+ *              See accompanying file LICENSE.txt or
+ *              http://www.opengeosys.org/LICENSE.txt
+ */
+
+#include "gtest/gtest.h"
+#include <array>
+#include <ctime>
+#include <functional>
+#include <memory>
+#include <random>
+
+#include "Tests/GeoLib/AutoCheckGenerators.h"
+
+#include "MathLib/Point3d.h"
+#include "GeoLib/AnalyticalGeometry.h"
+
+namespace ac = autocheck;
+
+class LineSegmentIntersect2dTest : public testing::Test
+{
+public:
+	using PointGenerator = ac::RandomCirclePointGeneratorXY<ac::generator<double>>;
+	using SymmSegmentGenerator = ac::SymmSegmentGeneratorXY<PointGenerator>;
+	using PairSegmentGenerator = ac::PairSegmentGeneratorXY<SymmSegmentGenerator>;
+
+	PointGenerator point_generator1 = PointGenerator(
+	    MathLib::Point3d(std::array<double, 3>{{0.0, 0.0, 0.0}}), 1.0);
+	SymmSegmentGenerator segment_generator1 = SymmSegmentGenerator{point_generator1,
+		std::bind(ac::reflect, point_generator1.center, std::placeholders::_1)};
+
+	PointGenerator point_generator2 = PointGenerator(
+	    MathLib::Point3d(std::array<double, 3>{{2.0, 0.0, 0.0}}), 1.0);
+	SymmSegmentGenerator segment_generator2 = SymmSegmentGenerator{point_generator2,
+		std::bind(ac::reflect, point_generator2.center, std::placeholders::_1)};
+
+	MathLib::Vector3 const translation_vector1 = {2,2,0};
+	PairSegmentGenerator pair_segment_generator1 = PairSegmentGenerator{
+	    segment_generator1,
+	    std::bind(ac::translate, translation_vector1, std::placeholders::_1)};
+
+	MathLib::Vector3 const translation_vector2 = {0,0,0};
+	PairSegmentGenerator pair_segment_generator2 = PairSegmentGenerator{
+	    segment_generator1,
+	    std::bind(ac::translate, translation_vector2, std::placeholders::_1)};
+
+	ac::gtest_reporter gtest_reporter;
+};
+
+// Test the intersection of intersecting line segments. Line segments are chords
+// of the same circle that both contains the center of the circle. As a
+// consequence the center of the circle is the intersection point.
+TEST_F(LineSegmentIntersect2dTest, RandomSegmentOrientationIntersecting)
+{
+	auto intersect =
+	    [](GeoLib::LineSegment const& s0, GeoLib::LineSegment const& s1)
+	{
+		auto ipnts = GeoLib::lineSegmentIntersect2d(s0.a, s0.b, s1.a, s1.b);
+		if (ipnts.size() == 1) {
+			MathLib::Point3d const center{std::array<double, 3>{
+			    {(s0.a[0] + s0.b[0]) / 2, (s0.a[1] + s0.b[1]) / 2, 0.0}}};
+			const double sqr_dist(MathLib::sqrDist(ipnts[0], center));
+			if (sqr_dist < std::numeric_limits<double>::epsilon())
+				return true;
+			else
+				return false;
+		}
+		return ipnts.size() == 2;
+	};
+
+	ac::check<GeoLib::LineSegment, GeoLib::LineSegment>(
+	    intersect, 1000,
+	    ac::make_arbitrary(segment_generator1, segment_generator1),
+	    gtest_reporter);
+}
+
+// Test the intersection of non-intersecting line segments. Line segments are
+// chords of non-intersecting circles.
+TEST_F(LineSegmentIntersect2dTest, RandomSegmentOrientationNonIntersecting)
+{
+	auto intersect =
+	    [](GeoLib::LineSegment const& s0, GeoLib::LineSegment const& s1)
+	{
+		auto ipnts = GeoLib::lineSegmentIntersect2d(s0.a, s0.b, s1.a, s1.b);
+		return ipnts.empty();
+	};
+
+	// generate non-intersecting segments
+	ac::check<GeoLib::LineSegment, GeoLib::LineSegment>(
+	    intersect, 1000,
+	    ac::make_arbitrary(segment_generator1, segment_generator2),
+	    gtest_reporter);
+}
+
+// Test the intersection of non-intersecting, parallel line segments. The second
+// line segment is created by translating the first line segment.
+TEST_F(LineSegmentIntersect2dTest, ParallelNonIntersectingSegmentOrientation)
+{
+	auto intersect = [](
+	    std::pair<GeoLib::LineSegment const&, GeoLib::LineSegment const&> const&
+	        segment_pair)
+	{
+		auto ipnts = GeoLib::lineSegmentIntersect2d(
+		    segment_pair.first.a, segment_pair.first.b, segment_pair.second.a,
+		    segment_pair.second.b);
+		return ipnts.empty();
+	};
+
+	// generate non-intersecting segments
+	ac::check<std::pair<GeoLib::LineSegment, GeoLib::LineSegment>>(
+	    intersect, 1000,
+	    ac::make_arbitrary(pair_segment_generator1),
+	    gtest_reporter);
+}
+
+// Test the intersection of parallel, interfering line segments.
+TEST_F(LineSegmentIntersect2dTest, ParallelIntersectingSegmentOrientation)
+{
+	auto intersect = [](
+	    std::pair<GeoLib::LineSegment const&, GeoLib::LineSegment const&> const&
+	        segment_pair)
+	{
+		auto ipnts = GeoLib::lineSegmentIntersect2d(
+		    segment_pair.first.a, segment_pair.first.b, segment_pair.second.a,
+		    segment_pair.second.b);
+		return ipnts.size() == 2;
+	};
+
+	// generate non-intersecting segments
+	ac::check<std::pair<GeoLib::LineSegment, GeoLib::LineSegment>>(
+	    intersect, 1000,
+	    ac::make_arbitrary(pair_segment_generator2),
+	    gtest_reporter);
+}