/// <summary>
/// Test if a frustum is fully inside, outside, or just intersecting the sphere.
/// </summary>
/// <param name="frustum">The frustum for testing.</param>
/// <returns>The containment type.</returns>
public ContainmentType Contains(BoundingFrustum frustum)
{
//check if all corner is in sphere
bool inside = true;
Vector3[] corners = frustum.GetCorners();
foreach (Vector3 corner in corners)
{
if (this.Contains(corner) == ContainmentType.Disjoint)
{
inside = false;
break;
}
}
if (inside)
{
return(ContainmentType.Contains);
}
//check if the distance from sphere center to frustrum face < radius
double dmin = 0;
//TODO : calcul dmin
if (dmin <= Radius * Radius)
{
return(ContainmentType.Intersects);
}
//else disjoint
return(ContainmentType.Disjoint);
}
public ContainmentType Contains(BoundingFrustum frustum)
{
//TODO: bad done here need a fix.
//Because question is not frustum contain box but reverse and this is not the same
int i;
ContainmentType contained;
Vector3[] corners = frustum.GetCorners();
// First we check if frustum is in box
for (i = 0; i < corners.Length; i++)
{
this.Contains(ref corners[i], out contained);
if (contained == ContainmentType.Disjoint)
{
break;
}
}
if (i == corners.Length) // This means we checked all the corners and they were all contain or instersect
{
return(ContainmentType.Contains);
}
if (i != 0) // if i is not equal to zero, we can fastpath and say that this box intersects
{
return(ContainmentType.Intersects);
}
// If we get here, it means the first (and only) point we checked was actually contained in the frustum.
// So we assume that all other points will also be contained. If one of the points is disjoint, we can
// exit immediately saying that the result is Intersects
i++;
for (; i < corners.Length; i++)
{
this.Contains(ref corners[i], out contained);
if (contained != ContainmentType.Contains)
{
return(ContainmentType.Intersects);
}
}
// If we get here, then we know all the points were actually contained, therefore result is Contains
return(ContainmentType.Contains);
}
/// <summary>
/// Creates the smallest <see cref="BoundingSphere"/> that can contain a specified <see cref="BoundingFrustum"/>.
/// </summary>
/// <param name="frustum">The frustum to create the sphere from.</param>
/// <returns>The new <see cref="BoundingSphere"/>.</returns>
public static BoundingSphere CreateFromFrustum(BoundingFrustum frustum)
{
return(CreateFromPoints(frustum.GetCorners()));
}