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.io.Closeable;
020import java.io.Reader;
021
022import org.apache.commons.geometry.euclidean.threed.Vector3D;
023import org.apache.commons.geometry.io.core.internal.GeometryIOUtils;
024
025/** Abstract base class for types that read OBJ polygon content using
026 * {@link PolygonObjParser}.
027 */
028public abstract class AbstractObjPolygonReader implements Closeable {
029
030    /** Underlying reader. */
031    private final Reader reader;
032
033    /** OBJ polygon parser. */
034    private final PolygonObjParser parser;
035
036    /** Construct a new instance that reads OBJ content from the given reader.
037     * @param reader reader to read characters from
038     */
039    protected AbstractObjPolygonReader(final Reader reader) {
040        this.reader = reader;
041        this.parser = new PolygonObjParser(reader);
042    }
043
044    /** Get the flag indicating whether or not an {@link IllegalStateException} will be thrown
045     * if the OBJ content contains any keywords defining non-polygon geometric content
046     * (ex: {@code curv}). If false, non-polygon data is ignored.
047     * @return flag indicating whether or not an {@link IllegalStateException} will be thrown
048     *      if non-polygon content is encountered
049     * @see PolygonObjParser#isFailOnNonPolygonKeywords()
050     */
051    public boolean isFailOnNonPolygonKeywords() {
052        return parser.isFailOnNonPolygonKeywords();
053    }
054
055    /** Set the flag indicating whether or not an {@link IllegalStateException} will be thrown
056     * if the OBJ content contains any keywords defining non-polygon geometric content
057     * (ex: {@code curv}). If set to false, non-polygon data is ignored.
058     * @param fail flag indicating whether or not an {@link IllegalStateException} will be thrown
059     *      if non-polygon content is encountered
060     */
061    public void setFailOnNonPolygonKeywords(final boolean fail) {
062        parser.setFailOnNonPolygonKeywords(fail);
063    }
064
065    /** {@inheritDoc} */
066    @Override
067    public void close() {
068        GeometryIOUtils.closeUnchecked(reader);
069    }
070
071    /** Return the next face from the OBJ content or null if no face is found.
072     * @return the next face from the OBJ content or null if no face is found
073     * @throws IllegalStateException if a parsing error occurs
074     * @throws java.io.UncheckedIOException if an I/O error occurs
075     */
076    protected PolygonObjParser.Face readFace() {
077        while (parser.nextKeyword()) {
078            switch (parser.getCurrentKeyword()) {
079            case ObjConstants.VERTEX_KEYWORD:
080                handleVertex(parser.readVector());
081                break;
082            case ObjConstants.VERTEX_NORMAL_KEYWORD:
083                handleNormal(parser.readVector());
084                break;
085            case ObjConstants.FACE_KEYWORD:
086                return parser.readFace();
087            default:
088                break;
089            }
090        }
091
092        return null;
093    }
094
095    /** Method called when a vertex is found in the OBJ content.
096     * @param vertex vertex value
097     */
098    protected abstract void handleVertex(Vector3D vertex);
099
100    /** Method called when a normal is found in the OBJ content.
101     * @param normal normal value
102     */
103    protected abstract void handleNormal(Vector3D normal);
104}