/// <summary>
/// Splits a node based on bucket size, the chosen split dimension selector and chosen split location selector
/// </summary>
public void Split <T>(KdNode <T> target) where T : IVector
{
// Sanity check node
if (target.Intermediate)
{
throw new IntermediateNodeException();
}
if (target.Vectors.Count <= this.MaximumBucketSize)
{
throw new BucketSizeException();
}
// Find axis of split plane
int split_dim = _dim_selector.Select(target);
// Find location of split plane
double split_loc = _loc_selector.Select(target, split_dim);
// Possibly resolve a trivial split
ETrivialSplitType split_type = this.IsTrivialSplit(target, split_dim, split_loc);
if (split_type == ETrivialSplitType.EmptyLeft || split_type == ETrivialSplitType.EmptyRight)
{
split_loc = _trivial_resolver.Resolve(target, split_dim, split_loc, split_type);
}
// Pass over vectors, create leaves (one is possibly empty) and update parent
KdNode <T> left = target.SetLeftChild(new KdNode <T>());
KdNode <T> right = target.SetRightChild(new KdNode <T>());
// Assign vectors
left.Vectors = new List <T>();
right.Vectors = new List <T>();
// Classify each vector
foreach (T t in target.Vectors)
{
if (t[split_dim] <= split_loc)
{
left.Vectors.Add(t);
}
else
{
right.Vectors.Add(t);
}
}
// Update internal bounds
left.InternalBounds = new AABB(target.InternalBounds.Dimensions);
left.InternalBounds.Enlarge <T>(left.Vectors);
right.InternalBounds = new AABB(target.InternalBounds.Dimensions);
right.InternalBounds.Enlarge <T>(right.Vectors);
// Update target
target.SplitDimension = split_dim;
target.SplitLocation = split_loc;
}
public double Resolve <T> (KdNode <T> target, int split_dimension, double split_location, ETrivialSplitType tst) where T : IVector
{
if (tst == ETrivialSplitType.EmptyLeft)
{
return(ResolveLeftEmpty(target, split_dimension, split_location));
}
else if (tst == ETrivialSplitType.EmptyRight)
{
return(ResolveRightEmpty(target, split_dimension, split_location));
}
else
{
throw new SubdivisionException();
}
}
/// <summary>
/// Always keeps the trivial split.
/// </summary>
public double Resolve <T> (KdNode <T> target, int split_dimension, double split_location, ETrivialSplitType tst) where T : IVector
{
return(split_location);
}