com.conversantmedia.util.collection.spatial.LinearSplitLeaf Maven / Gradle / Ivy

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package com.conversantmedia.util.collection.spatial;

/*
 * #%L
 * Conversant RTree
 * ~~
 * Conversantmedia.com © 2016, Conversant, Inc. Conversant® is a trademark of Conversant, Inc.
 * ~~
 * Licensed 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
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */

/**
 * Guttmann's Linear split
 *
 * Created by jcairns on 5/5/15.
 */
final class LinearSplitLeaf extends Leaf {

    protected LinearSplitLeaf(final RectBuilder builder, final int mMin, final int mMax) {
        super(builder, mMin, mMax, RTree.Split.LINEAR);
    }

    @Override
    protected Node split(final T t) {
        final Branch pNode = new Branch<>(builder, mMin, mMax, splitType);
        final Node l1Node = create(builder, mMin, mMax, splitType);
        final Node l2Node = create(builder, mMin, mMax, splitType);

        final int MIN = 0;
        final int MAX = 1;
        final int NRANGE = 2;
        final int nD = r[0].getNDim();
        final int[][][] rIndex = new int[nD][NRANGE][NRANGE];
        // separation between min and max extremes
        final double   [] separation = new double[nD];

        for(int d = 0; d < nD; d++) {

            rIndex[d][MIN][MIN] = 0;
            rIndex[d][MIN][MAX] = 0;
            rIndex[d][MAX][MIN] = 0;
            rIndex[d][MAX][MAX] = 0;

            for(int j = 1; j < size; j++) {
                if(r[rIndex[d][MIN][MIN]].getMin().getCoord(d).compareTo(r[j].getMin().getCoord(d)) > 0) {
                    rIndex[d][MIN][MIN] = j;
                }

                if(r[rIndex[d][MIN][MAX]].getMin().getCoord(d).compareTo(r[j].getMin().getCoord(d)) < 0) {
                    rIndex[d][MIN][MAX] = j;
                }

                if(r[rIndex[d][MAX][MIN]].getMax().getCoord(d).compareTo(r[j].getMax().getCoord(d)) > 0) {
                    rIndex[d][MAX][MIN] = j;
                }

                if(r[rIndex[d][MAX][MAX]].getMax().getCoord(d).compareTo(r[j].getMax().getCoord(d)) < 0) {
                    rIndex[d][MAX][MAX] = j;
                }
            }

            // highest max less lowest min
            final double width = r[rIndex[d][MAX][MAX]].getMax().distance(r[rIndex[d][MIN][MIN]].getMin(), d);

            // lowest max less highest min (normalized)
            separation[d] = r[rIndex[d][MAX][MIN]].getMax().distance(r[rIndex[d][MIN][MAX]].getMin(), d) / width;
        }

        int r1Ext = rIndex[0][MAX][MIN], r2Ext = rIndex[0][MIN][MAX];
        double highSep = separation[0];
        for(int d=1; d