Subversion Repositories mkgmap

/*
 * Copyright (C) 2009.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3 or
 * 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.
 */
package uk.me.parabola.imgfmt.app.mdr;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import uk.me.parabola.imgfmt.app.srt.Sort;
import uk.me.parabola.imgfmt.app.srt.SortKey;

/**
 * A bunch of static routines for use in creating the MDR file.
 */
public class MdrUtils {

        public static final int STREET_INDEX_PREFIX_LEN = 4;
        public static final int POI_INDEX_PREFIX_LEN = 4;

        /**
         * Get the group number for the poi.  This is the first byte of the records
         * in mdr9.
         *
         * Not entirely sure about how this works yet.
         * @param fullType The primary type of the object.
         * @return The group number.  This is a number between 1 and 9 (and later
         * perhaps higher numbers such as 0x40, so do not assume there are no
         * gaps).
         */
        public static int getGroupForPoi(int fullType) {
                // We group pois based on their type.  This may not be the final thoughts on this.
                int type = MdrUtils.getTypeFromFullType(fullType);
                int group = 0;
                if (fullType < 0xf)
                        group = 1;
                else if (type >= 0x2a && type <= 0x30) {
                        group = type - 0x28;
                } else if (type == 0x28) {
                        group = 9;
                }
                return group;
        }

        public static boolean canBeIndexed(int fullType) {
                return getGroupForPoi(fullType) != 0;
        }

        private static int getTypeFromFullType(int fullType) {
                if ((fullType & 0xfff00) > 0)
                        return (fullType>>8) & 0xfff;
                else
                        return fullType & 0xff;
        }

        /**
         * Gets the subtype if there is one, else the type.
         * @param fullType The type in the so-called 'full' format.
         * @return If there is a subtype, then it is returned. Otherwise the type is returned.
         */
        public static int getSubtypeOrTypeFromFullType(int fullType) {
                return fullType & 0xff;
        }

        /**
         * Sort records that are sorted by a name.  They appropriate sort order will be used.
         * @param sort The sort to be applied.
         * @param list The list to be sorted.
         * @param <T> One of the Mdr?Record types that need to be sorted on a text field, eg street name.
         * @return A list of sort keys in the sorted order.  The original object is retrieved from the key
         * by calling getObject().
         */
        public static <T extends NamedRecord> List<SortKey<T>> sortList(Sort sort, List<T> list) {
                List<SortKey<T>> toSort = new ArrayList<SortKey<T>>(list.size());
                for (T m : list) {
                        SortKey<T> sortKey = sort.createSortKey(m, m.getName(), m.getMapIndex());
                        toSort.add(sortKey);
                }
                Collections.sort(toSort);
                return toSort;
        }

        /**
         * The 'natural' type is always a combination of the type and subtype with the type
         * shifted 5 bits and the sub type in the low 5 bits.
         *
         * For various reasons, we use 'fullType' in which the type is shifted up a full byte
         * or is in the lower byte.
         *
         * @param ftype The so-called full type of the object.
         * @return The natural type as defined above.
         */
        public static int fullTypeToNaturalType(int ftype) {
                int type = getTypeFromFullType(ftype);
                int sub = 0;
                if ((ftype & ~0xff) != 0)
                        sub = ftype & 0x1f;

                return type << 5 | sub;
        }
}