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 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
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 * distributed under the License is distributed on an "AS IS" BASIS,
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package org.apache.commons.math3.geometry.partitioning;

import org.apache.commons.math3.geometry.Space;

Visitor building boundary shell tree.

The boundary shell is represented as boundary attributes at each internal node.

Type parameters:
  • <S> – Type of the space.
Since:3.4
/** Visitor building boundary shell tree. * <p> * The boundary shell is represented as {@link BoundaryAttribute boundary attributes} * at each internal node. * </p> * @param <S> Type of the space. * @since 3.4 */
class BoundaryBuilder<S extends Space> implements BSPTreeVisitor<S> {
{@inheritDoc}
/** {@inheritDoc} */
public Order visitOrder(BSPTree<S> node) { return Order.PLUS_MINUS_SUB; }
{@inheritDoc}
/** {@inheritDoc} */
public void visitInternalNode(BSPTree<S> node) { SubHyperplane<S> plusOutside = null; SubHyperplane<S> plusInside = null; NodesSet<S> splitters = null; // characterize the cut sub-hyperplane, // first with respect to the plus sub-tree final Characterization<S> plusChar = new Characterization<S>(node.getPlus(), node.getCut().copySelf()); if (plusChar.touchOutside()) { // plusChar.outsideTouching() corresponds to a subset of the cut sub-hyperplane // known to have outside cells on its plus side, we want to check if parts // of this subset do have inside cells on their minus side final Characterization<S> minusChar = new Characterization<S>(node.getMinus(), plusChar.outsideTouching()); if (minusChar.touchInside()) { // this part belongs to the boundary, // it has the outside on its plus side and the inside on its minus side plusOutside = minusChar.insideTouching(); splitters = new NodesSet<S>(); splitters.addAll(minusChar.getInsideSplitters()); splitters.addAll(plusChar.getOutsideSplitters()); } } if (plusChar.touchInside()) { // plusChar.insideTouching() corresponds to a subset of the cut sub-hyperplane // known to have inside cells on its plus side, we want to check if parts // of this subset do have outside cells on their minus side final Characterization<S> minusChar = new Characterization<S>(node.getMinus(), plusChar.insideTouching()); if (minusChar.touchOutside()) { // this part belongs to the boundary, // it has the inside on its plus side and the outside on its minus side plusInside = minusChar.outsideTouching(); if (splitters == null) { splitters = new NodesSet<S>(); } splitters.addAll(minusChar.getOutsideSplitters()); splitters.addAll(plusChar.getInsideSplitters()); } } if (splitters != null) { // the parent nodes are natural splitters for boundary sub-hyperplanes for (BSPTree<S> up = node.getParent(); up != null; up = up.getParent()) { splitters.add(up); } } // set the boundary attribute at non-leaf nodes node.setAttribute(new BoundaryAttribute<S>(plusOutside, plusInside, splitters)); }
{@inheritDoc}
/** {@inheritDoc} */
public void visitLeafNode(BSPTree<S> node) { } }