test_intersect_line_alignedbox.cpp

// Description: Testing for line-alignedbox intersection
// DocumentationOf: intersect_line_alignedbox.h

#include "test/test_init.h"

#include "pastel/sys/rational.h"
#include "pastel/geometry/intersect/intersect_line_alignedbox.h"

#include <iostream>

namespace
{

    using Real = Rational<integer>;

}

TEST_CASE("Positive (intersect_line_alignedbox)")
{
    // Rays are inside the aligned box.
    // The rays are axis-aligned.
    // The aligned box is centered on origin.
    // Send rays from the origin and
    // make sure they intersect the aligned box
    // as they should.
    {
        AlignedBox<Real, 2> alignedBox(
            Vector<Real, 2>(-1),
            Vector<Real, 2>(1));

        Line<Real, 2> a(
            Vector<Real, 2>(0),
            Vector<Real, 2>(1, 0));

        Line<Real, 2> b(
            Vector<Real, 2>(0),
            Vector<Real, 2>(0, 1));

        Line<Real, 2> c(
            Vector<Real, 2>(0),
            Vector<Real, 2>(-1, 0));

        Line<Real, 2> d(
            Vector<Real, 2>(0),
            Vector<Real, 2>(0, -1));

        Vector<Real, 2> hitList;

        REQUIRE(intersect(a, alignedBox, hitList));
        REQUIRE(hitList[0] == -1);
        REQUIRE(hitList[1] == 1);

        REQUIRE(intersect(b, alignedBox, hitList));
        REQUIRE(hitList[0] == -1);
        REQUIRE(hitList[1] == 1);

        REQUIRE(intersect(c, alignedBox, hitList));
        REQUIRE(hitList[0] == -1);
        REQUIRE(hitList[1] == 1);

        REQUIRE(intersect(d, alignedBox, hitList));
        REQUIRE(hitList[0] == -1);
        REQUIRE(hitList[1] == 1);
    }
    // Rays are inside the aligned box.
    // The rays are diagonal.
    // The aligned box is centered on origin.
    // Send rays from the origin and
    // make sure they intersect the aligned box
    // as they should.
    {
        AlignedBox<Real, 2> alignedBox(
            Vector<Real, 2>(-1),
            Vector<Real, 2>(1));

        Line<Real, 2> a(
            Vector<Real, 2>(0),
            Vector<Real, 2>(Real(1, 1)));

        Line<Real, 2> b(
            Vector<Real, 2>(0),
            Vector<Real, 2>(Real(-1, 1)));

        Line<Real, 2> c(
            Vector<Real, 2>(0),
            Vector<Real, 2>(Real(-1, -1)));

        Line<Real, 2> d(
            Vector<Real, 2>(0),
            Vector<Real, 2>(Real(1, -1)));

        Vector<Real, 2> hitList;

        REQUIRE(intersect(a, alignedBox, hitList));
        REQUIRE(hitList[0] == -1);
        REQUIRE(hitList[1] == 1);

        REQUIRE(intersect(b, alignedBox, hitList));
        REQUIRE(hitList[0] == -1);
        REQUIRE(hitList[1] == 1);

        REQUIRE(intersect(c, alignedBox, hitList));
        REQUIRE(hitList[0] == -1);
        REQUIRE(hitList[1] == 1);

        REQUIRE(intersect(d, alignedBox, hitList));
        REQUIRE(hitList[0] == -1);
        REQUIRE(hitList[1] == 1);
    }

    // The aligned box is centered on origin.
    // The rays originate from the boundary
    // of the aligned box.
    // Make sure the rays
    // intersect the aligned box as they should.
    {
        AlignedBox<Real, 2> alignedBox(
            Vector<Real, 2>(-1),
            Vector<Real, 2>(1));

        Line<Real, 2> a(
            Vector<Real, 2>(
            1, Real(-1, 2)),
            Vector<Real, 2>(
            -2, 1));

        Line<Real, 2> b(
            Vector<Real, 2>(
            -1, Real(1, 2)),
            Vector<Real, 2>(
            2, -1));

        Line<Real, 2> c(
            Vector<Real, 2>(
            Real(-1, 2), -1),
            Vector<Real, 2>(
            Real(-1, 2), 1));

        Vector<Real, 2> hitList;

        REQUIRE(intersect(a, alignedBox, hitList));
        REQUIRE(hitList[0] == 0);
        REQUIRE(hitList[1] == 1);

        REQUIRE(intersect(b, alignedBox, hitList));
        REQUIRE(hitList[0] == 0);
        REQUIRE(hitList[1] == 1);

        REQUIRE(intersect(c, alignedBox, hitList));
        REQUIRE(hitList[0] == 0);
        REQUIRE(hitList[1] == 1);
    }
    // These rays have origin outside the aligned boxes,
    // but still intersect the aligned box.
    {
        AlignedBox<Real, 2> alignedBox(
            Vector<Real, 2>(-1),
            Vector<Real, 2>(1));

        Line<Real, 2> a(
            Vector<Real, 2>(
            0, -2),
            Vector<Real, 2>(
            1, 4));

        Line<Real, 2> b(
            Vector<Real, 2>(
            -2, 2),
            Vector<Real, 2>(
            1, -1));

        Vector<Real, 2> hitList;

        REQUIRE(intersect(a, alignedBox, hitList));
        REQUIRE(hitList[0] == Real(1, 4));
        REQUIRE(hitList[1] == Real(3, 4));

        REQUIRE(intersect(b, alignedBox, hitList));
        REQUIRE(hitList[0] == 1);
        REQUIRE(hitList[1] == 3);
    }
    // These rays just touch the aligned box corners.
    {
        AlignedBox<Real, 2> alignedBox(
            Vector<Real, 2>(-1),
            Vector<Real, 2>(1));

        Line<Real, 2> a(
            Vector<Real, 2>(
            0, 3),
            Vector<Real, 2>(
            -2, -4));

        Line<Real, 2> b(
            Vector<Real, 2>(
            -5, 0),
            Vector<Real, 2>(
            4, 1));

        Line<Real, 2> c(
            Vector<Real, 2>(
            -2, 1),
            Vector<Real, 2>(
            1, 0));

        Line<Real, 2> d(
            Vector<Real, 2>(
            -1, -2),
            Vector<Real, 2>(
            0, 1));

        Vector<Real, 2> hitList;

        REQUIRE(intersect(a, alignedBox, hitList));
        REQUIRE(hitList[0] == Real(1, 2));
        REQUIRE(hitList[1] == Real(1, 2));

        REQUIRE(intersect(b, alignedBox, hitList));
        REQUIRE(hitList[0] == 1);
        REQUIRE(hitList[1] == 1);

        REQUIRE(intersect(c, alignedBox, hitList));
        REQUIRE(hitList[0] == 1);
        REQUIRE(hitList[1] == 3);

        REQUIRE(intersect(d, alignedBox, hitList));
        REQUIRE(hitList[0] == 1);
        REQUIRE(hitList[1] == 3);
    }
}

TEST_CASE("Negative (intersect_line_alignedbox)")
{
    {
        AlignedBox<Real, 2> alignedBox(
            Vector<Real, 2>(-1),
            Vector<Real, 2>(1));

        Line<Real, 2> a(
            Vector<Real, 2>(
            0, -2),
            Vector<Real, 2>(
            2, 1));

        Line<Real, 2> b(
            Vector<Real, 2>(
            -2, 2),
            Vector<Real, 2>(
            1, 0));

        Line<Real, 2> c(
            Vector<Real, 2>(
            -1, -2),
            Vector<Real, 2>(
            -1, 3));

        Line<Real, 2> d(
            Vector<Real, 2>(
            0, -5),
            Vector<Real, 2>(
            2, 6));

        Vector<Real, 2> hitList;

        REQUIRE(!intersect(a, alignedBox, hitList));
        REQUIRE(!intersect(b, alignedBox, hitList));
        REQUIRE(!intersect(c, alignedBox, hitList));
        REQUIRE(!intersect(d, alignedBox, hitList));
    }
}