public void TestExampleConvexHull()
{
var points = new List <Point>()
{
new Point(4, 21),
new Point(3, 15),
new Point(6, 9),
new Point(7, 7),
new Point(10, 5),
new Point(11, 29),
new Point(14, 29),
new Point(27, 14),
new Point(29, 18),
new Point(27, 22)
};
var hull = PointMath.ComputeConvexHull(points);
ExpectList(hull, new List <Point>()
{
new Point(3, 15),
new Point(4, 21),
new Point(11, 29),
new Point(14, 29),
new Point(27, 22),
new Point(29, 18),
new Point(27, 14),
new Point(10, 5),
new Point(7, 7)
});
}
public void TestConvexHull()
{
int seed = Environment.TickCount;
var r = new Random(55523173);
var pts = new List <Point> {
new Point(10, 22),
new Point(10, 10),
new Point(22, 20),
new Point(20, 10)
};
for (int i = 0; i < 20; i++)
{
pts.Insert(r.Next(pts.Count + 1), new Point(r.Next(10, 21), r.Next(10, 21)));
}
var results = PointMath.ComputeConvexHull(pts, true);
Assert.AreEqual(4, results.Count);
Assert.That(results.Contains(new Point(10, 22)));
Assert.That(results.Contains(new Point(10, 10)));
Assert.That(results.Contains(new Point(22, 20)));
Assert.That(results.Contains(new Point(20, 10)));
for (int trial = 0; trial < 20; trial++)
{
// For our second test we use random points plus a possible outlier,
// and check that all points are within or on the convex hull.
int Lim = 100, PtCount = 5 * (trial + 1);
pts.Clear();
for (int i = 0; i < PtCount; i++)
{
pts.Add(new Point(r.Next(-Lim, Lim), r.Next(-Lim, Lim)));
}
pts.Add(new Point(r.Next(Lim * -4, Lim * 4), r.Next(Lim * -4, Lim * 4)));
results = PointMath.ComputeConvexHull(pts, true);
for (int i = 0; i < pts.Count; i++)
{
Assert.That(PolygonMath.IsPointInPolygon(results, pts[i]) || results.Contains(pts[i]),
"Fail for seed {0}, trial {1}, pts[{2}]", seed, trial, i);
}
}
}
public void TestTrivialConvexHulls()
{
Point p = new Point(1, 2), q = new Point(2, 1);
ExpectList(PointMath.ComputeConvexHull(new List <Point>()));
ExpectList(PointMath.ComputeConvexHull(new List <Point>()
{
p
}), p);
ExpectList(PointMath.ComputeConvexHull(new List <Point>()
{
q
}), q);
ExpectList(PointMath.ComputeConvexHull(new List <Point>()
{
p, q
}), p, q);
ExpectList(PointMath.ComputeConvexHull(new List <Point>()
{
p, p, q
}), p, q);
ExpectList(PointMath.ComputeConvexHull(new List <Point>()
{
p, q, p
}), p, q);
// Ideally these would be the results, but it actually repeats p
//ExpectList(PointMath.ComputeConvexHull(new List<Point>() { p, p }), p);
//ExpectList(PointMath.ComputeConvexHull(new List<Point>() { p, p, p }), p);
ExpectList(PointMath.ComputeConvexHull(new List <Point>()
{
p, p
}), p, p);
ExpectList(PointMath.ComputeConvexHull(new List <Point>()
{
p, p, p
}), p, p);
}
