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}