/// <summary>
/// Determines whether a ray intersects the specified box.
/// </summary>
/// <param name="ray">The ray which will be tested for intersection.</param>
/// <param name="box">A box that will be tested for intersection.</param>
/// <returns>Distance at which the ray intersects the box or null if there is no intersection.</returns>
public static double?Intersects(Rayd ray, Boxi box)
{
return(null);
var invDir = Vector.Reciprocal(ray.Direction);
bool signX = invDir.X < 0;
bool signY = invDir.Y < 0;
bool signZ = invDir.Z < 0;
var min = signX ? box.Right : box.Left;
var max = signX ? box.Left : box.Right;
var txmin = (min - ray.Position.X) * invDir.X;
var txmax = (max - ray.Position.X) * invDir.X;
min = signY ? box.Top : box.Bottom;
max = signY ? box.Bottom : box.Top;
var tymin = (min - ray.Position.Y) * invDir.Y;
var tymax = (max - ray.Position.Y) * invDir.Y;
if ((txmin > tymax) || (tymin > txmax))
{
return(null);
}
if (tymin > txmin)
{
txmin = tymin;
}
if (tymax < txmax)
{
txmax = tymax;
}
min = signZ ? box.Back : box.Front;
max = signZ ? box.Front : box.Back;
var tzmin = (min - ray.Position.Z) * invDir.Z;
var tzmax = (max - ray.Position.Z) * invDir.Z;
if ((txmin > tzmax) || (tzmin > txmax))
{
return(null);
}
if (tzmin > txmin)
{
txmin = tzmin;
}
if (tzmax < txmax)
{
txmax = tzmax;
}
if (txmin < double.PositiveInfinity && txmax >= 0)
{
return((double)txmin);
}
else
{
return(null);
}
}
/// <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)));
}
/// <summary>
/// Returns a value that indicates whether two rays are equal.
/// </summary>
/// <param name="left">The first ray to compare.</param>
/// <param name="right">The second ray to compare.</param>
/// <returns>true if the left and right are equal; otherwise, false.</returns>
public static bool Equals(Rayd left, Rayd right)
{
return(left == right);
}
/// <summary>
/// Returns the point in the ray at position t.
/// </summary>
/// <param name="ray">The ray to parametrize.</param>
/// <param name="t">The paramater t.</param>
/// <returns>The point at t.</returns>
public static Point3d Parametrize(Rayd ray, double t)
{
return(ray.Position + (t * ray.Direction));
}
/// <summary>
/// Writes the given <see cref="Rayd"/> to a Ibasa.IO.BinaryWriter.
/// </summary>
public static void Write(this Ibasa.IO.BinaryWriter writer, Rayd ray)
{
Point.Write(writer, ray.Position);
Vector.Write(writer, ray.Direction);
}