public void Intersects(ref BoundingSphereD sphere, out double?result)
{
// Find the vector between where the ray starts the the sphere's center.
Vector3D difference = sphere.Center - this.Position;
double differenceLengthSquared = difference.LengthSquared();
double sphereRadiusSquared = sphere.Radius * sphere.Radius;
double distanceAlongRay;
/* If the distance between the ray start and the sphere's center is less than
* the radius of the sphere, it means we've intersected. Checking the
* LengthSquared is faster.
*/
if (differenceLengthSquared < sphereRadiusSquared)
{
result = 0.0f;
return;
}
Vector3D.Dot(ref this.Direction, ref difference, out distanceAlongRay);
// If the ray is pointing away from the sphere then we don't ever intersect.
if (distanceAlongRay < 0)
{
result = null;
return;
}
/* Next we kinda use Pythagoras to check if we are within the bounds of the
* sphere.
* if x = radius of sphere
* if y = distance between ray position and sphere centre
* if z = the distance we've travelled along the ray
* if x^2 + z^2 - y^2 < 0, we do not intersect
*/
double dist = (
sphereRadiusSquared +
(distanceAlongRay * distanceAlongRay) -
differenceLengthSquared
);
result = (dist < 0) ? null : distanceAlongRay - (double?)Math.Sqrt(dist);
}
/// <summary>
/// Containment test between this <see cref="BoundingFrustumD"/> and specified <see cref="BoundingSphereD"/>.
/// </summary>
/// <param name="sphere">A <see cref="BoundingSphereD"/> for testing.</param>
/// <param name="result">Result of testing for containment between this <see cref="BoundingFrustumD"/> and specified <see cref="BoundingSphereD"/> as an output parameter.</param>
public void Contains(ref BoundingSphereD sphere, out ContainmentType result)
{
bool intersects = false;
for (int i = 0; i < PlaneCount; i += 1)
{
PlaneIntersectionTypeD planeIntersectionType = default(PlaneIntersectionTypeD);
// TODO: We might want to inline this for performance reasons.
sphere.Intersects(ref this.planes[i], out planeIntersectionType);
switch (planeIntersectionType)
{
case PlaneIntersectionTypeD.Front:
result = ContainmentType.Disjoint;
return;
case PlaneIntersectionTypeD.Intersecting:
intersects = true;
break;
}
}
result = intersects ? ContainmentType.Intersects : ContainmentType.Contains;
}
public void Contains(ref BoundingSphereD sphere, out ContainmentType result)
{
result = this.Contains(sphere);
}
public void Intersects(ref BoundingSphereD sphere, out bool result)
{
result = Intersects(sphere);
}
public ContainmentType Contains(BoundingSphereD sphere)
{
if (sphere.Center.X - Min.X >= sphere.Radius &&
sphere.Center.Y - Min.Y >= sphere.Radius &&
sphere.Center.Z - Min.Z >= sphere.Radius &&
Max.X - sphere.Center.X >= sphere.Radius &&
Max.Y - sphere.Center.Y >= sphere.Radius &&
Max.Z - sphere.Center.Z >= sphere.Radius)
{
return(ContainmentType.Contains);
}
double dmin = 0;
double e = sphere.Center.X - Min.X;
if (e < 0)
{
if (e < -sphere.Radius)
{
return(ContainmentType.Disjoint);
}
dmin += e * e;
}
else
{
e = sphere.Center.X - Max.X;
if (e > 0)
{
if (e > sphere.Radius)
{
return(ContainmentType.Disjoint);
}
dmin += e * e;
}
}
e = sphere.Center.Y - Min.Y;
if (e < 0)
{
if (e < -sphere.Radius)
{
return(ContainmentType.Disjoint);
}
dmin += e * e;
}
else
{
e = sphere.Center.Y - Max.Y;
if (e > 0)
{
if (e > sphere.Radius)
{
return(ContainmentType.Disjoint);
}
dmin += e * e;
}
}
e = sphere.Center.Z - Min.Z;
if (e < 0)
{
if (e < -sphere.Radius)
{
return(ContainmentType.Disjoint);
}
dmin += e * e;
}
else
{
e = sphere.Center.Z - Max.Z;
if (e > 0)
{
if (e > sphere.Radius)
{
return(ContainmentType.Disjoint);
}
dmin += e * e;
}
}
if (dmin <= sphere.Radius * sphere.Radius)
{
return(ContainmentType.Intersects);
}
return(ContainmentType.Disjoint);
}
public void Intersects(ref BoundingSphereD sphere, out PlaneIntersectionTypeD result)
{
sphere.Intersects(ref this, out result);
}
public PlaneIntersectionTypeD Intersects(BoundingSphereD sphere)
{
return(sphere.Intersects(this));
}
