Subversion Repositories mkgmap

/*
 * Copyright (C) 2007 Steve Ratcliffe
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 *
 *  This program 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 General Public License for more details.
 *
 *
 * Author: Steve Ratcliffe
 * Create date: Jan 5, 2008
 */
package uk.me.parabola.imgfmt.app.net;

import uk.me.parabola.imgfmt.ReadFailedException;
import uk.me.parabola.imgfmt.app.CommonHeader;
import uk.me.parabola.imgfmt.app.ImgFileReader;
import uk.me.parabola.imgfmt.app.ImgFileWriter;
import uk.me.parabola.imgfmt.app.Section;
import uk.me.parabola.imgfmt.app.SectionWriter;

/**
 * The header of the NET file.
 *
 * @author Steve Ratcliffe
 */
public class NETHeader extends CommonHeader {
        public static final int HEADER_LEN = 55; // Other lengths are possible

        private static final char SORTED_ROAD_RECSIZE = 3;

        private final Section roadDefinitions = new Section();
        private final Section segmentedRoads = new Section(roadDefinitions);
        private final Section sortedRoads = new Section(segmentedRoads, SORTED_ROAD_RECSIZE);

        private byte roadShift;
        private byte segmentShift;

        public NETHeader() {
                super(HEADER_LEN, "GARMIN NET");
        }

        /**
         * Read the rest of the header.  Specific to the given file.  It is guaranteed
         * that the file position will be set to the correct place before this is
         * called.
         *
         * @param reader The header is read from here.
         */
        protected void readFileHeader(ImgFileReader reader) throws ReadFailedException {
                roadDefinitions.readSectionInfo(reader, false);
                roadShift = reader.get();

                segmentedRoads.readSectionInfo(reader, false);
                segmentShift = reader.get();

                sortedRoads.readSectionInfo(reader, true);

                reader.getInt();
                reader.get();
                reader.get();
        }

        /**
         * Write the rest of the header.  It is guaranteed that the writer will be set
         * to the correct position before calling.
         *
         * @param writer The header is written here.
         */
        protected void writeFileHeader(ImgFileWriter writer) {
                roadDefinitions.writeSectionInfo(writer);

                writer.put(roadShift); // offset multiplier

                segmentedRoads.writeSectionInfo(writer);

                writer.put(segmentShift); // offset multiplier

                sortedRoads.writeSectionInfo(writer);

                writer.putInt(0);
                writer.put((byte) 1);
                writer.put((byte) 0);
        }

        ImgFileWriter makeRoadWriter(ImgFileWriter writer) {
                roadDefinitions.setPosition(writer.position());
                return new SectionWriter(writer, roadDefinitions);
        }

        ImgFileWriter makeSortedRoadWriter(ImgFileWriter writer) {
                sortedRoads.setPosition(writer.position());
                return new SectionWriter(writer, sortedRoads);
        }

        public int getRoadDefinitionsStart() {
                return roadDefinitions.getPosition();
        }

        public int getSortedRoadsStart() {
                return sortedRoads.getPosition();
        }

        public int getSortedRoadsEnd() {
                return sortedRoads.getEndPos();
        }

        public int getRoadShift() {
                return roadShift & 0xff;
        }
}