001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.geometry.io.euclidean.threed.obj;
018
019import java.nio.charset.Charset;
020import java.nio.charset.StandardCharsets;
021
022/** Class containing constants for use with OBJ files.
023 */
024public final class ObjConstants {
025
026    /** Default OBJ charset. */
027    public static final Charset DEFAULT_CHARSET = StandardCharsets.UTF_8;
028
029    /** Character used to indicate the start of a comment line. */
030    public static final char COMMENT_CHAR = '#';
031
032    /** Character placed before new line sequences to indicate a line continuation. */
033    public static final char LINE_CONTINUATION_CHAR = '\\';
034
035    /** Keyword used to indicate a vertex definition line. */
036    public static final String VERTEX_KEYWORD = "v";
037
038    /** Keyword used to indicate a vertex normal definition line. */
039    public static final String VERTEX_NORMAL_KEYWORD = "vn";
040
041    /** Keyword used to indicate a texture coordinate definition line. */
042    public static final String TEXTURE_COORDINATE_KEYWORD = "vt";
043
044    /** Keyword used to indicate a face definition line. */
045    public static final String FACE_KEYWORD = "f";
046
047    /** Character used to separate face vertex attribute indices. */
048    public static final char FACE_VERTEX_ATTRIBUTE_SEP_CHAR = '/';
049
050    /** Keyword used to indicate a geometry group. */
051    public static final String GROUP_KEYWORD = "g";
052
053    /** Keyword used to indicate a geometry group. */
054    public static final String SMOOTHING_GROUP_KEYWORD = "s";
055
056    /** Keyword used to associate a name with the following geometry. */
057    public static final String OBJECT_KEYWORD = "o";
058
059    /** Keyword used to reference a material library file. */
060    public static final String MATERIAL_LIBRARY_KEYWORD = "mtllib";
061
062    /** Keyword used to apply a named material to subsequent geometry. */
063    public static final String USE_MATERIAL_KEYWORD = "usemtl";
064
065    /** Utility class; no instantiation. */
066    private ObjConstants() {}
067}