/// <summary>
/// Calculates the intersection geometry between this segment and a ray.
/// </summary>
/// <param name="ray">The ray to find the intersection with.</param>
/// <returns>The intersection geometry or <c>null</c> for no intersection.</returns>
public IPlanarGeometry Intersection(Ray2 ray)
{
if (ray == null)
{
return(null);
}
return(ray.Intersection(this));
}
/// <summary>
/// Determines if this ray is geometrically equal to another.
/// </summary>
/// <param name="other">Another ray</param>
/// <returns><c>true</c> if the rays are spatially equal.</returns>
public bool SpatiallyEqual(Ray2 other)
{
return(!ReferenceEquals(null, other) &&
P.Equals(other.P) &&
(
Direction.Equals(other.Direction) ||
Direction.GetNormalized().Equals(other.Direction.GetNormalized())
));
}
/// <summary>
/// Determines if this ray intersect another <paramref name="ray"/>.
/// </summary>
/// <param name="ray">A ray.</param>
/// <returns><c>true</c> when another object intersects this object.</returns>
public bool Intersects(Ray2 ray)
{
if (ray == null)
{
return(false);
}
if (ray == this || P.Equals(ray.P) && Direction.Equals(ray.Direction))
{
return(true); // NOTE: requires ray to be immutable
}
Point2 a, c;
Vector2 d0, d1;
// next order the rays
var compareResult = P.CompareTo(ray.P);
if (0 < ((compareResult == 0) ? Direction.CompareTo(ray.Direction) : compareResult))
{
a = ray.P;
c = P;
d0 = ray.Direction;
d1 = Direction;
}
else
{
a = P;
c = ray.P;
d0 = Direction;
d1 = ray.Direction;
}
var e = c - a;
var tNumerator = (e.X * d0.Y) - (e.Y * d0.X);
var cross = (d0.X * d1.Y) - (d1.X * d0.Y);
if (cross == 0.0)
{
// parallel
return(tNumerator == 0.0 && IntersectsRayParallel(d0, d1, e, a, c));
}
// not parallel
var t = tNumerator / cross;
if (t < 0.0)
{
return(false); // not intersecting on other ray
}
var s = ((e.X * d1.Y) - (e.Y * d1.X)) / cross;
if (s < 0.0)
{
return(false); // not intersecting on this ray
}
return(true);
}
/// <summary>
/// Constructs a ray identical to the given <paramref name="ray"/>.
/// </summary>
/// <param name="ray">A ray.</param>
public Ray2(Ray2 ray)
{
if (null == ray)
{
throw new ArgumentNullException("ray");
}
Contract.EndContractBlock();
P = ray.P;
Direction = ray.Direction;
}
/// <inheritdoc/>
public IPlanarGeometry Intersection(Ray2 other)
{
if (ReferenceEquals(null, other) || Count == 0)
{
return(null);
}
var intersectedPoints = new MultiPoint2(this.Where(other.Intersects));
return(FixToProperPlanerGeometryResult(intersectedPoints));
}
/// <summary>
/// Calculates the intersection geometry between this ray and another.
/// </summary>
/// <param name="ray">The ray to find the intersection with.</param>
/// <returns>The intersection geometry or <c>null</c> for no intersection.</returns>
public IPlanarGeometry Intersection(Ray2 ray)
{
if (ray == null)
{
return(null);
}
if (ray == this || P.Equals(ray.P) && Direction.Equals(ray.Direction))
{
return(ray); // NOTE: requires ray to be immutable
}
Point2 a, c;
Vector2 d0, d1;
// next order the segments
var compareResult = P.CompareTo(ray.P);
if (0 < ((compareResult == 0) ? Direction.CompareTo(ray.Direction) : compareResult))
{
a = ray.P;
c = P;
d0 = ray.Direction;
d1 = Direction;
}
else
{
a = P;
c = ray.P;
d0 = Direction;
d1 = ray.Direction;
}
var e = c - a;
var tNumerator = (e.X * d0.Y) - (e.Y * d0.X);
var cross = (d0.X * d1.Y) - (d1.X * d0.Y);
if (cross == 0.0)
{
// parallel
return(tNumerator == 0.0
? IntersectionRayParallel(d0, d1, e, a, c)
: null); // no intersection
}
// not parallel
var t = tNumerator / cross;
if (t < 0.0)
{
return(null); // not intersecting on other ray
}
var s = ((e.X * d1.Y) - (e.Y * d1.X)) / cross;
if (s < 0.0)
{
return(null); // not intersecting on this ray
}
if (s == 0.0)
{
return(a);
}
if (t == 0.0)
{
return(c);
}
return(a + d0.GetScaled(s)); // it must intersect at a point, so find where
}
/// <summary>
/// Indicates whether the current object is equal to another object of the same type.
/// </summary>
/// <returns>
/// <c>true</c> if the current object is equal to the <paramref name="other"/> parameter; otherwise, <c>false</c>.
/// </returns>
/// <param name="other">An object to compare with this object.</param>
public bool Equals(Ray2 other)
{
return(!ReferenceEquals(null, other) &&
P.Equals(other.P) &&
Direction.Equals(other.Direction));
}
/// <summary>
/// Determines if this segment intersect another <paramref name="ray"/>.
/// </summary>
/// <param name="ray">A ray.</param>
/// <returns><c>true</c> when another object intersects this object.</returns>
public bool Intersects(Ray2 ray)
{
return(ray != null && ray.Intersects(this));
}
/// <inheritdoc/>
public bool Intersects(Ray2 other)
{
return(!ReferenceEquals(null, other) &&
Count > 0 &&
this.Any(other.Intersects));
}
