public LineSeg[] GetLineSegments()
{
LineSeg[] segs = new LineSeg[point.Length];
for (int i = 0; i < point.Length; i++)
{
segs[i] = new LineSeg(point[i], point[(i + 1) % point.Length]);
}
return(segs);
}
public void TestLineSegClass()
{
LineSeg l1 = new LineSeg(2, 2, 11, 5);
LineSeg l2 = new LineSeg(3, 7, 5, 3);
LineSeg l3 = new LineSeg(6, 0, 9, 6);
LineSeg l4 = new LineSeg(10, 2, 10, 8);
LineSeg l5 = new LineSeg(12, 1, 13, 3);
LineSeg l6 = new LineSeg(0, 7, 12, 7);
Point p;
Assert.IsTrue(Line.IsParallel(l3, l5));
Assert.IsFalse(Line.IsParallel(l2, l4));
Assert.IsTrue(Line.Intersect(l2, l6, out p));
Assert.IsTrue(p.Equals(new Point(3, 7)));
Assert.IsTrue(Line.Intersect(l3, l1, out p));
Assert.IsTrue(p.Equals(new Point(8, 4)));
Assert.IsTrue(Line.Intersect(l1, l4, out p));
Assert.IsNull(p);
Assert.IsTrue(Line.Intersect(l4, l6, out p));
Assert.IsTrue(p.Equals(new Point(10, 7)));
Assert.IsFalse(Line.Intersect(l5, l1));
Assert.IsFalse(Line.Intersect(l3, l5));
Assert.IsFalse(Line.Intersect(l3, l6));
Assert.IsFalse(Line.Intersect(l6, l3));
Assert.IsTrue(l2.LiesOn(new Point(4, 5)));
Assert.IsTrue(l5.LiesOn(new Point(12, 1)));
Assert.IsFalse(l1.LiesOn(new Point(-1, 1)));
Assert.IsFalse(l1.LiesOn(new Point(14, 6)));
Assert.IsTrue(l1.LiesOn(new Point(5, 3)));
Assert.IsFalse(l1.LiesOn(new Point(5, 2)));
double d1 = l1.Distance(new Point(4, 2));
Assert.IsTrue(Math.Abs(d1 - 0.63245553203367588) < 1e-10);
double d2 = l3.Distance(new Point(-23, -7));
Assert.IsTrue(Math.Abs(d2 - 29.832867780352597) < 1e-10);
double d3 = l6.Distance(new Point(14832, 7));
Assert.IsTrue(Math.Abs(d3 - 14820) < 1e-10);
Assert.IsTrue(Math.Abs(l5.Length - Math.Sqrt(5)) < 1e-10);
Assert.IsNull(LineSeg.Merge(l3, l5));
LineSeg l7 = new LineSeg(8, 4, 7, 2);
Assert.IsTrue(LineSeg.Merge(l3, l7).Equals(l3));
LineSeg l8 = new LineSeg(4, -4, 7, 2);
Assert.IsTrue(LineSeg.Merge(l8, l3).Equals(new LineSeg(9, 6, 4, -4)));
Assert.IsTrue(LineSeg.Merge(new LineSeg(9, 6, 10, 8), l3).Equals(new LineSeg(10, 8, 6, 0)));
}
// If a and b are parallel lines that share at least one point, return the merge of these lines.
// Otherwise return null. If a LineSeg is returned, it will be a new instance.
public static LineSeg Merge(LineSeg a, LineSeg b)
{
if (!IsParallel(a, b))
{
return(null);
}
if (!a.LiesOn(b.a) && !a.LiesOn(b.b) && !b.LiesOn(a.a) && !b.LiesOn(a.b))
{
return(null);
}
Point[] p = new Point[] { a.a, a.b, b.a, b.b };
Array.Sort(p);
return(new LineSeg(p[0], p[3]));
}
public void TestLineLineSegMix()
{
Line l1 = new Line(2, 3, 8, 9);
Line l2 = new Line(8, 9, 2, 3);
LineSeg ls1 = new LineSeg(2, 3, 8, 9);
LineSeg ls2 = new LineSeg(8, 9, 2, 3);
Assert.IsTrue(l1.Equals(l2));
Assert.IsTrue(l2.Equals(l1));
Assert.IsTrue(ls1.Equals(ls2));
Assert.IsTrue(ls2.Equals(ls1));
Assert.IsFalse(l1.Equals(ls2));
Assert.IsFalse(l2.Equals(ls1));
Assert.IsFalse(ls1.Equals(l2));
Assert.IsFalse(ls2.Equals(l1));
// TODO: Test Intersect
}
