/// <summary>
/// Returns the specified child octant instance, or instantiates a new octant if the specified child instance
/// is <c>null</c>. The newly constructed instance will then be returned.
/// </summary>
/// <param name="octants">
/// A reference to the <see cref="Octant"/> array from which to get the specified instance.
/// </param>
/// <param name="index">The index in the array whose held instance to get or set.</param>
/// <param name="newMidpoint">The midpoint of the new child instance, if necessary.</param>
/// <param name="newSideLength">The side length of the new child instance, if necessary.</param>
/// <returns>The instance held at the specified index, or the newly created instance.</returns>
private static Octant GetOrSetChildOctant(ref Octant[] octants, int index, Vector4 newMidpoint, double newSideLength)
{
if (octants != null && octants?[index] == null)
{
octants[index] = new Octant(newMidpoint, newSideLength);
}
return(octants?[index]);
}
/// <summary>
/// Returns the specified child octant tree instance, or instantiates a new octant tree if the specified child
/// instance is <c>null</c>. The newly constructed instance will then be returned.
/// </summary>
/// <param name="trees">
/// A reference to the <see cref="OctantTree"/> array from which to get the specified instance.
/// </param>
/// <param name="index">The index in the array whose held instance to get or set.</param>
/// <param name="newOctant">
/// The octant instance representing the space managed by the new child tree instance, if necessary.
/// </param>
/// <returns>The instance held at the specified index, or the newly created instance.</returns>
public static OctantTree GetOrSetSubTree(ref OctantTree[] trees, int index, Octant newOctant)
{
if (trees != null && trees?[index] == null)
{
trees[index] = new OctantTree(newOctant);
}
return(trees?[index]);
}
/// <summary>
/// Initialises a new instance of the <see cref="Octant"/> class.
/// </summary>
/// <param name="octant">The previous instance to make a copy of.</param>
public Octant(Octant octant)
{
midpoint = octant.Midpoint;
sideLength = octant.sideLength;
halfSideLength = octant.halfSideLength;
quarterSideLength = octant.quarterSideLength;
childOctants = new Octant[8];
octant.childOctants.CopyTo(childOctants, 0);
}
/// <summary>
/// Whether this instance is currently inside the bounds of the given <see cref="Octant"/> instance.
/// </summary>
/// <param name="octant">The octant to check.</param>
/// <returns>Whether this <see cref="Body"/> instance is inside the given <see cref="Octant"/> instance.</returns>
public bool IsInOctant(Octant octant)
{
return(octant.ContainsPoint(position));
}
/// <summary>
/// Initialises a new instance of the <see cref="OctantTree"/> class.
/// </summary>
/// <param name="octant">The <see cref="Octant"/> instance representing the space managed by this instance.</param>
public OctantTree(Octant octant)
{
this.octant = octant;
childTrees = new OctantTree[8];
}