    001/* ===========================================================
    002 * Orson Charts : a 3D chart library for the Java(tm) platform
    003 * ===========================================================
    004 *
    005 * (C)opyright 2013-2016, by Object Refinery Limited.  All rights reserved.
    006 *
    007 * http://www.object-refinery.com/orsoncharts/index.html
    008 *
    009 * This program is free software: you can redistribute it and/or modify
    010 * it under the terms of the GNU General Public License as published by
    011 * the Free Software Foundation, either version 3 of the License, or
    012 * (at your option) any later version.
    013 *
    014 * This program is distributed in the hope that it will be useful,
    015 * but WITHOUT ANY WARRANTY; without even the implied warranty of
    016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    017 * GNU General Public License for more details.
    018 *
    019 * You should have received a copy of the GNU General Public License
    020 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    021 *
    022 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
    023 * Other names may be trademarks of their respective owners.]
    024 *
    025 * If you do not wish to be bound by the terms of the GPL, an alternative
    026 * commercial license can be purchased.  For details, please see visit the
    027 * Orson Charts home page:
    028 *
    029 * http://www.object-refinery.com/orsoncharts/index.html
    030 *
    031 */
    032
    033package com.orsoncharts.graphics3d;
    034
    035import java.util.List;
    036
    037/**
    038 * An interface that must be implemented by objects that can sort faces prior
    039 * to rendering (the Painter's algorithm).
    040 *
    041 * @since 1.3
    042 */
    043public interface FaceSorter {
    044
    045    /**
    046     * Returns a list of faces in the order that they should be painted.
    047     *
    048     * @param faces  the faces before sorting ({@code null} not permitted).
    049     * @param eyePts  the points in 3D space relative to the viewing position.
    050     *
    051     * @return An ordered list (note that the result may be the same list
    052     *     passed in via the {@code faces} argument).
    053     */
    054    List<Face> sort(List<Face> faces, Point3D[] eyePts);
    055
    056}