/// <summary>
/// Writes the given <see cref="Spherei"/> to an <see cref="Ibasa.IO.BinaryWriter">.
/// </summary>
public static void Write(this Ibasa.IO.BinaryWriter writer, Spherei sphere)
{
writer.Write(sphere.X);
writer.Write(sphere.Y);
writer.Write(sphere.Z);
writer.Write(sphere.Radius);
}
/// <summary>
/// Determines whether a ray intersects the specified sphere.
/// </summary>
/// <param name="ray">The ray which will be tested for intersection.</param>
/// <param name="sphere">A sphere that will be tested for intersection.</param>
/// <returns>Distance at which the ray intersects the sphere or null if there is no intersection.</returns>
public static double?Intersects(Rayd ray, Spherei sphere)
{
var distance = sphere.Center - ray.Position;
var pyth = Vector.AbsoluteSquared(distance);
var rr = sphere.Radius * sphere.Radius;
if (pyth <= rr)
{
return(0);
}
double dot = Vector.Dot(distance, ray.Direction);
if (dot < 0)
{
return(null);
}
var temp = pyth - (dot * dot);
if (temp > rr)
{
return(null);
}
return((double)(dot - Functions.Sqrt(rr - temp)));
}
public static bool Contains(Spherei sphere, Point3i point)
{
return(Vector.AbsoluteSquared(sphere.Center - point) <= sphere.Radius * sphere.Radius);
}
/// <summary>
/// Returns a value that indicates whether two spherees are equal.
/// </summary>
/// <param name="left">The first sphere to compare.</param>
/// <param name="right">The second sphere to compare.</param>
/// <returns>true if the left and right are equal; otherwise, false.</returns>
public static bool Equals(Spherei left, Spherei right)
{
return(left == right);
}