S- Type of the space.
public static interface BSPTree.LeafMerger<S extends Space>
As explained in Bruce Naylor, John Amanatides and William
Thibault paper Merging
BSP Trees Yields Polyhedral Set Operations,
the operations on
BSP trees can be expressed as a
generic recursive merging operation where only the final part,
when one of the operand is a leaf, is specific to the real
operation semantics. For example, a tree representing a region
using a boolean attribute to identify inside cells and outside
cells would use four different objects to implement the final
merging phase of the four set operations union, intersection,
difference and symmetric difference (exclusive or).
BSPTree<S> merge(BSPTree<S> leaf, BSPTree<S> tree, BSPTree<S> parentTree, boolean isPlusChild, boolean leafFromInstance)
This method is called at the end of a recursive merging
resulting from a
call, when one of the sub-trees involved is a leaf (i.e. when
its cut-hyperplane is null). This is the only place where the
precise semantics of the operation are required. For all upper
level nodes in the tree, the merging operation is only a
generic partitioning algorithm.
Since the final operation may be non-commutative, it is
important to know if the leaf node comes from the instance tree
tree1) or the argument tree
tree2). The third argument of the method is
devoted to this. It can be ignored for commutative
may be useful to implement this method.
leaf- leaf node (its cut hyperplane is guaranteed to be null)
tree- tree node (its cut hyperplane may be null or not)
parentTree- parent tree to connect to (may be null)
isPlusChild- if true and if parentTree is not null, the resulting tree should be the plus child of its parent, ignored if parentTree is null
leafFromInstance- if true, the leaf node comes from the instance tree (
tree1) and the tree node comes from the argument tree (
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