public void Sphere_IntersectDistance_gives_correct_distance()
{
Ray ray = new Ray(new Point(0.0f, -12.0f, 4.2f), new Vector(1.0f, 0.0f, 0.0f));
var centre = new Point(50.0f, -12.0f, 4.2f);
var radius = 10.0f;
var s = new Sphere(centre, radius);
var distance = s.IntersectDistance(ray);
Assert.AreEqual(40.0f, distance, EPSILON);
}
public void Sphere_IntersectDistance_negative_value_given_nonintersecting_ray()
{
Ray ray = new Ray(new Point(0.0f, 0.0f, 0.0f), new Vector(1.0f, 0.0f, 0.0f));
var centre = new Point(50.0f, -12.0f, 4.2f);
var radius = 10.0f;
var s = new Sphere(centre, radius);
var distance = s.IntersectDistance(ray);
Assert.IsTrue(distance < 0.0f);
}
public void Sphere_IntersectDistance_throws_given_null_ray()
{
Ray ray = null;
var centre = new Point(50.0f, -12.0f, 4.2f);
var radius = 10.0f;
var s = new Sphere(centre, radius);
s.IntersectDistance(ray);
}
