protected override Intersection[] LocalIntersect(Ray ray)
{
if (!Bounds().Intersects(ray))
{
return new Intersection[] { }
}
;
var sphereToRay = ray.Origin - Center;
var a = PointType.DotProduct(ray.Direction, ray.Direction);
var b = 2 * PointType.DotProduct(ray.Direction, sphereToRay);
var c = PointType.DotProduct(sphereToRay, sphereToRay) - 1;
var discriminant = Math.Pow(b, 2) - 4 * a * c;
if (discriminant < 0)
{
return new Intersection[] { }
}
;
var t1 = (-b - Math.Sqrt(discriminant)) / (2 * a);
var t2 = (-b + Math.Sqrt(discriminant)) / (2 * a);
return(new Intersection[]
{ new Intersection(t1, this), new Intersection(t2, this) });
}
public void DotProduct()
{
var v1 = PointType.Vector(1, 2, 3);
var v2 = PointType.Vector(2, 3, 4);
var expected = 20;
Assert.Equal(expected, PointType.DotProduct(v1, v2));
}