/// <summary>
/// Initializes a new instance of the <see cref="Ray"/> class using given ray.
/// </summary>
/// <param name="ray">A <see cref="Ray"/> instance to assign values from.</param>
public Ray(Ray ray)
{
_origin = ray.Origin;
_direction = ray.Direction;
}
/// <summary>
/// Calculates the distance between two rays.
/// </summary>
/// <param name="r0">A <see cref="Ray"/> instance.</param>
/// <param name="r1">A <see cref="Ray"/> instance.</param>
/// <returns>Returns the distance between two rays.</returns>
public static float Distance(Ray r0, Ray r1)
{
throw new NotImplementedException();
}
/// <summary>
/// Calculates the squared distance between a given point and a given ray.
/// </summary>
/// <param name="point">A <see cref="Vector2D"/> instance.</param>
/// <param name="ray">A <see cref="Ray"/> instance.</param>
/// <returns>The squared distance between the point and the ray.</returns>
public static double SquaredDistance(Vector2D point, Ray ray)
{
Vector2D diff = point - ray.Origin;
double t = Vector2D.DotProduct(diff, ray.Direction);
if (t <= 0.0f)
{
return diff.GetLengthSquared();
}
else
{
t = (t * t) / ray.Direction.GetLengthSquared();
return diff.GetLengthSquared() - t;
}
}
/// <summary>
/// Calculates the distance between a given point and a given ray.
/// </summary>
/// <param name="point">A <see cref="Vector2D"/> instance.</param>
/// <param name="ray">A <see cref="Ray"/> instance.</param>
/// <returns>The distance between the point and the ray.</returns>
public static float Distance(Vector2D point, Ray ray)
{
return (float)System.Math.Sqrt(SquaredDistance(point, ray));
}
public static bool Intersect(Segment seg, Ray ray, out Intersection2D interObj)
{
// (Ay-Cy)(Dx-Cx)-(Ax-Cx)(Dy-Cy)
//r = ----------------------------- (eqn 1)
// (Bx-Ax)(Dy-Cy)-(By-Ay)(Dx-Cx)
// (Ay-Cy)(Bx-Ax)-(Ax-Cx)(By-Ay)
//s = ----------------------------- (eqn 2)
// (Bx-Ax)(Dy-Cy)-(By-Ay)(Dx-Cx)
double den = (seg.P1.X - seg.P0.X) * ray.Direction.Y - (seg.P1.Y - seg.P0.Y) * ray.Direction.X;
double r = (seg.P0.Y - ray.Origin.Y) * ((ray.Origin + ray.Direction).X - ray.Origin.X) - (seg.P0.X - ray.Origin.X) * ((ray.Origin + ray.Direction).Y - ray.Origin.Y);
// If the denominator in eqn 1 is zero, AB & CD are parallel
if (System.Math.Abs(den) < MathFunctions.EpsilonF)
{
// If the numerator in eqn 1 is also zero, AB & CD are collinear.
if (System.Math.Abs(r) < MathFunctions.EpsilonF)
{
interObj = new Intersection2D(new Segment(seg));
return true;
}
else
{
interObj = new Intersection2D();
return false;
}
}
else
{
r /= den;
// Let P be the position vector of the intersection point, then
// P=A+r(B-A)
if (0 <= r && r <= 1)
{
interObj = new Intersection2D(new Vector2D(seg.P0 + r * (seg.P1 - seg.P0)));
return true;
}
}
interObj = new Intersection2D();
return false;
}
