/**
 * This file is part of CERMINE project.
 * Copyright (c) 2011-2018 ICM-UW
 *
 * CERMINE is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * CERMINE is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with CERMINE. If not, see <http://www.gnu.org/licenses/>.
 */
package pl.edu.icm.cermine.metadata.zoneclassification.features;

import pl.edu.icm.cermine.structure.model.BxPage;
import pl.edu.icm.cermine.structure.model.BxZone;
import pl.edu.icm.cermine.tools.classification.general.FeatureCalculator;

/**
 * @author Pawel Szostek
 */
public class EmptySpaceRelativeFeature extends FeatureCalculator<BxZone, BxPage> {

    @Override
    public double calculateFeatureValue(BxZone zone, BxPage page) {
        FeatureCalculator<BxZone, BxPage> emptySpaceCalc = new EmptySpaceFeature();
        if (zone.getArea() < 0.0005) {
            return 0.0;
        } else {
            double emptySpace = emptySpaceCalc.calculateFeatureValue(zone, page);
            return emptySpace / zone.getArea();
        }
    }
}
