geometry_unittest.cpp

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */

#include <mrpt/math/geometry.h>
#include <mrpt/math/CPolygon.h>
#include <gtest/gtest.h>
#include <algorithm>

using namespace mrpt;
using namespace mrpt::utils;
using namespace mrpt::math;
using namespace std;

TEST(Geometry, Line2DIntersect)
{
        // Two lines that should intersect at (0.5,0.5)
        const TLine2D l1(TPoint2D(0, 1), TPoint2D(1, 0));
        const TLine2D l2(TPoint2D(-1, 0.5), TPoint2D(4, 0.5));

        TObject2D inter;
        bool do_inter = intersect(l1, l2, inter);

        EXPECT_TRUE(do_inter);
        EXPECT_EQ(inter.getType(), GEOMETRIC_TYPE_POINT);

        TPoint2D i(0, 0);
        inter.getPoint(i);
        EXPECT_NEAR(i.x, 0.5, 1e-9);
        EXPECT_NEAR(i.y, 0.5, 1e-9);
}

TEST(Geometry, Segment2DIntersect)
{
        {
                // Two segments that should intersect at (0.5,0.5)
                const TSegment2D s1(TPoint2D(0, 1), TPoint2D(1, 0));
                const TSegment2D s2(TPoint2D(-1, 0.5), TPoint2D(4, 0.5));

                TObject2D inter;
                bool do_inter = intersect(s1, s2, inter);

                EXPECT_TRUE(do_inter);
                EXPECT_EQ(inter.getType(), GEOMETRIC_TYPE_POINT);

                TPoint2D i(0, 0);
                inter.getPoint(i);
                EXPECT_NEAR(i.x, 0.5, 1e-9);
                EXPECT_NEAR(i.y, 0.5, 1e-9);
        }

        {
                // Two segments that do NOT intersect
                const TSegment2D s1(TPoint2D(0, 1), TPoint2D(1, 0));
                const TSegment2D s2(TPoint2D(0.6, 0.5), TPoint2D(4, 0.5));

                TObject2D inter;
                bool do_inter = intersect(s1, s2, inter);

                EXPECT_FALSE(do_inter);
        }

#if 0
        {
                // Two parallel segments that do NOT intersect: result is a "segment in the middle".
                const TSegment2D s1(TPoint2D(-0.05,0.05), TPoint2D(-0.05,-0.05));
                const TSegment2D s2(TPoint2D(0,0.135), TPoint2D(0,-0.0149999));

                TObject2D inter;
                bool do_inter = intersect(s1, s2, inter);

                EXPECT_TRUE(do_inter && inter.getType()==GEOMETRIC_TYPE_SEGMENT);
        }
#endif
}

void myTestPolygonContainsPoint(std::vector<TPoint2D>& vs, bool convex)
{
        const mrpt::math::TPolygon2D poly(vs);

        EXPECT_EQ(poly.isConvex(), convex);

        EXPECT_TRUE(poly.contains(TPoint2D(0.0, 0.0)));
        EXPECT_TRUE(poly.contains(TPoint2D(0.0, 0.9)));
        EXPECT_TRUE(poly.contains(TPoint2D(-0.9, -0.9)));
        EXPECT_TRUE(poly.contains(TPoint2D(0.9, -0.9)));

        EXPECT_FALSE(poly.contains(TPoint2D(-4.0, -5.1)));
        EXPECT_FALSE(poly.contains(TPoint2D(-5.0, -0.1)));
        EXPECT_FALSE(poly.contains(TPoint2D(1.1, -6.1)));
        EXPECT_FALSE(poly.contains(TPoint2D(0, 5.1)));
        EXPECT_FALSE(poly.contains(TPoint2D(0, -1.1)));
}

TEST(Geometry, PolygonConvexContainsPoint)
{
        // Test with a polygon in one winding order:
        std::vector<TPoint2D> vs;
        vs.push_back(TPoint2D(-1.0, -1.0));
        vs.push_back(TPoint2D(0.0, 1.0));
        vs.push_back(TPoint2D(1.0, -1.0));
        myTestPolygonContainsPoint(vs, true);

        // and the other:
        std::reverse(vs.begin(), vs.end());
        myTestPolygonContainsPoint(vs, true);

        {
                mrpt::math::CPolygon p;
                p.AddVertex(0, -0.322);
                p.AddVertex(-0.644, -0.322);
                p.AddVertex(-0.210377, -0.324673);
                p.AddVertex(0.433623, -0.324673);

                EXPECT_FALSE(p.contains(TPoint2D(0.73175, -0.325796)));
        }
}

TEST(Geometry, PolygonConcaveContainsPoint)
{
        // Test with a polygon in one winding order:
        std::vector<TPoint2D> vs;
        vs.push_back(TPoint2D(-2.0, 3.0));
        vs.push_back(TPoint2D(2.0, 2.0));
        vs.push_back(TPoint2D(3.0, -4.0));
        vs.push_back(TPoint2D(0.1, -3.0));
        vs.push_back(TPoint2D(0.1, -0.1));
        vs.push_back(TPoint2D(-0.1, -0.1));
        vs.push_back(TPoint2D(-0.1, -3.0));
        vs.push_back(TPoint2D(-2.0, -2.0));

        myTestPolygonContainsPoint(vs, false);

        // and the other:
        std::reverse(vs.begin(), vs.end());
        myTestPolygonContainsPoint(vs, false);
}