public void Test_R1Interval_TestBasic()
{
// Constructors and accessors.
R1Interval unit = new(0, 1);
R1Interval negunit = new(-1, 0);
Assert.Equal(0, unit.Lo);
Assert.Equal(1, unit.Hi);
Assert.Equal(-1, negunit[0]);
Assert.Equal(0, negunit[1]);
R1Interval ten = new(0, 10);
Assert.Equal(new R1Interval(0, 10), ten);
ten = new R1Interval(-10, ten.Hi);
Assert.Equal(new R1Interval(-10, 10), ten);
ten = new R1Interval(ten.Lo, 0);
Assert.True(new R1Interval(-10, 0) == ten);
ten = new R1Interval(0, 10);
Assert.Equal(new R1Interval(0, 10), ten);
// IsEmpty
R1Interval half = new(0.5, 0.5);
Assert.False(unit.IsEmpty());
Assert.False(half.IsEmpty());
R1Interval empty = R1Interval.Empty;
Assert.True(empty.IsEmpty());
// == and !=
Assert.True(empty == R1Interval.Empty);
Assert.True(unit == new R1Interval(0, 1));
Assert.True(unit != empty);
Assert.True(new R1Interval(1, 2) != new R1Interval(1, 3));
// Check that the default R1Interval is identical to Empty().
R1Interval default_empty = R1Interval.Empty;
Assert.True(default_empty.IsEmpty());
Assert.Equal(empty.Lo, default_empty.Lo);
Assert.Equal(empty.Hi, default_empty.Hi);
// GetCenter(), GetLength()
Assert.Equal(0.5, unit.GetCenter());
Assert.Equal(0.5, half.GetCenter());
Assert.Equal(1.0, negunit.GetLength());
Assert.Equal(0, half.GetLength());
Assert.True(empty.GetLength() < 0);
// Contains(double), InteriorContains(double)
Assert.True(unit.Contains(0.5));
Assert.True(unit.InteriorContains(0.5));
Assert.True(unit.Contains(0));
Assert.False(unit.InteriorContains(0));
Assert.True(unit.Contains(1));
Assert.False(unit.InteriorContains(1));
// Contains(R1Interval), InteriorContains(R1Interval)
// Intersects(R1Interval), InteriorIntersects(R1Interval)
TestIntervalOps(empty, empty, "TTFF");
TestIntervalOps(empty, unit, "FFFF");
TestIntervalOps(unit, half, "TTTT");
TestIntervalOps(unit, unit, "TFTT");
TestIntervalOps(unit, empty, "TTFF");
TestIntervalOps(unit, negunit, "FFTF");
TestIntervalOps(unit, new R1Interval(0, 0.5), "TFTT");
TestIntervalOps(half, new R1Interval(0, 0.5), "FFTF");
// AddPoint()
R1Interval r = empty;
r = R1Interval.AddPoint(r, 5);
Assert.Equal(5, r.Lo);
Assert.Equal(5, r.Hi);
r = R1Interval.AddPoint(r, -1);
Assert.Equal(-1, r.Lo);
Assert.Equal(5, r.Hi);
r = R1Interval.AddPoint(r, 0);
Assert.Equal(-1, r.Lo);
Assert.Equal(5, r.Hi);
// Project()
Assert.Equal(0.3, new R1Interval(0.1, 0.4).Project(0.3));
Assert.Equal(0.1, new R1Interval(0.1, 0.4).Project(-7.0));
Assert.Equal(0.4, new R1Interval(0.1, 0.4).Project(0.6));
// FromPointPair()
Assert.Equal(new R1Interval(4, 4), R1Interval.FromPointPair(4, 4));
Assert.Equal(new R1Interval(-2, -1), R1Interval.FromPointPair(-1, -2));
Assert.Equal(new R1Interval(-5, 3), R1Interval.FromPointPair(-5, 3));
// Expanded()
Assert.Equal(empty, empty.Expanded(0.45));
Assert.Equal(new R1Interval(-0.5, 1.5), unit.Expanded(0.5));
Assert.Equal(new R1Interval(0.5, 0.5), unit.Expanded(-0.5));
Assert.True(unit.Expanded(-0.51).IsEmpty());
Assert.True(unit.Expanded(-0.51).Expanded(0.51).IsEmpty());
// Union(), Intersection()
Assert.Equal(new R1Interval(99, 100), new R1Interval(99, 100).Union(empty));
Assert.Equal(new R1Interval(99, 100), empty.Union(new R1Interval(99, 100)));
Assert.True(new R1Interval(5, 3).Union(new R1Interval(0, -2)).IsEmpty());
Assert.True(new R1Interval(0, -2).Union(new R1Interval(5, 3)).IsEmpty());
Assert.Equal(unit, unit.Union(unit));
Assert.Equal(new R1Interval(-1, 1), unit.Union(negunit));
Assert.Equal(new R1Interval(-1, 1), negunit.Union(unit));
Assert.Equal(unit, half.Union(unit));
Assert.Equal(half, unit.Intersection(half));
Assert.Equal(new R1Interval(0, 0), unit.Intersection(negunit));
Assert.True(negunit.Intersection(half).IsEmpty());
Assert.True(unit.Intersection(empty).IsEmpty());
Assert.True(empty.Intersection(unit).IsEmpty());
}
