style.c

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/*
 * static char *rcsid_style_c =
 *   "$Id: style.c 11578 2009-02-23 22:02:27Z lalo $";
 */

/*
    CrossFire, A Multiplayer game for X-windows

    Copyright (C) 2002 Mark Wedel & Crossfire Development Team
    Copyright (C) 1992 Frank Tore Johansen

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    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.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

    The authors can be reached via e-mail at crossfire-devel@real-time.com
*/

#include <global.h>
#include <random_map.h>
#ifndef WIN32 /* ---win32 exclude headers */
#include <dirent.h>
#include <sys/stat.h>
#include <unistd.h>
#include "../include/autoconf.h"
#endif /* win32 */

static int pointer_strcmp(const void *p1, const void *p2) {
    const char *s1 = *(const char * const *)p1;
    const char *s2 = *(const char * const *)p2;

    return(strcmp(s1, s2));
}

int load_dir(const char *dir, char ***namelist, int skip_dirs) {
    DIR *dp;
    struct dirent *d;
    int entries = 0, entry_size = 0;
    char name[NAME_MAX+1], **rn = NULL;
    struct stat sb;

    dp = opendir(dir);
    if (dp == NULL)
        return -1;

    while ((d = readdir(dp)) != NULL) {
        if (skip_dirs) {
            snprintf(name, sizeof(name), "%s/%s", dir, d->d_name);
            stat(name, &sb);
            if (S_ISDIR(sb.st_mode)) {
                continue;
            }
        }

        if (entries == entry_size) {
            entry_size += 10;
            rn = realloc(rn, sizeof(char *)*entry_size);
        }
        rn[entries] = strdup_local(d->d_name);
        entries++;

    }
    (void)closedir(dp);

    qsort(rn, entries, sizeof(char *), pointer_strcmp);

    *namelist = rn;
    return entries;
}

mapstruct *styles = NULL;

mapstruct *load_style_map(char *style_name) {
    mapstruct *style_map;

    /* Given a file.  See if its in memory */
    for (style_map = styles; style_map != NULL; style_map = style_map->next) {
        if (!strcmp(style_name, style_map->path))
            return style_map;
    }
    style_map = load_original_map(style_name, MAP_STYLE);
    /* Remove it from global list, put it on our local list */
    if (style_map) {
        mapstruct *tmp;

        if (style_map == first_map)
            first_map = style_map->next;
        else {
            for (tmp = first_map; tmp && tmp->next != style_map; tmp = tmp->next)
                ;
            if (tmp)
                tmp->next = style_map->next;
        }
        style_map->next = styles;
        styles = style_map;
    }
    return style_map;
}

mapstruct *find_style(const char *dirname, const char *stylename, int difficulty) {
    char style_file_path[256];
    char style_file_full_path[256];
    mapstruct *style_map = NULL;
    struct stat file_stat;
    int i, only_subdirs = 0;

    /* if stylename exists, set style_file_path to that file.*/
    if (stylename && strlen(stylename) > 0)
        snprintf(style_file_path, sizeof(style_file_path), "%s/%s", dirname, stylename);
    else /* otherwise, just use the dirname.  We'll pick a random stylefile.*/
        snprintf(style_file_path, sizeof(style_file_path), "%s", dirname);

    /* is what we were given a directory, or a file? */
    snprintf(style_file_full_path, sizeof(style_file_full_path), "%s/maps%s", settings.datadir, style_file_path);
    if (stat(style_file_full_path, &file_stat) == 0
        && !S_ISDIR(file_stat.st_mode)) {
        style_map = load_style_map(style_file_path);
    }
    if (style_map == NULL) { /* maybe we were given a directory! */
        char **namelist;
        int n;
        char style_dir_full_path[256];

        /* get the names of all the files in that directory */
        snprintf(style_dir_full_path, sizeof(style_dir_full_path), "%s/maps%s", settings.datadir, style_file_path);

        /* First, skip subdirectories.  If we don't find anything, then try again
         * without skipping subdirs.
         */
        n = load_dir(style_dir_full_path, &namelist, 1);
        if (n <= 0) {
            n = load_dir(style_dir_full_path, &namelist, 0);
            only_subdirs = 1;
        }

        if (n <= 0)
            return NULL; /* nothing to load.  Bye. */

        /* Picks a random map.  Note that if this is all directories,
         * we know it won't be able to load, so save a few ticks.
         * the door handling checks for this failure and handles
         * it properly.
         */
        if (difficulty == -1) { /* pick a random style from this dir. */
            if (only_subdirs)
                style_map = NULL;
            else {
                strncat(style_file_path, "/", sizeof(style_file_path));
                strncat(style_file_path, namelist[RANDOM()%n], sizeof(style_file_path));
                style_map = load_style_map(style_file_path);
            }
        } else { /* find the map closest in difficulty */
            int min_dist = 32000, min_index = -1;

            for (i = 0; i < n; i++) {
                int dist;
                char *mfile_name = strrchr(namelist[i], '_')+1;

                if ((mfile_name-1) == NULL) { /* since there isn't a sequence, */
                    int q;

                    /*pick one at random to recurse */
                    style_map = find_style(style_file_path, namelist[RANDOM()%n], difficulty);
                    for (q = 0; q < n; q++)
                        free(namelist[q]);
                    free(namelist);
                    return style_map;
                } else {
                    dist = abs(difficulty-atoi(mfile_name));
                    if (dist < min_dist) {
                        min_dist = dist;
                        min_index = i;
                    }
                }
            }
            /* presumably now we've found the "best" match for the
               difficulty. */
            strncat(style_file_path, "/", sizeof(style_file_path));
            strncat(style_file_path, namelist[min_index], sizeof(style_file_path));
            style_map = load_style_map(style_file_path);
        }
        for (i = 0; i < n; i++)
            free(namelist[i]);
        free(namelist);
    }
    return style_map;
}

object *pick_random_object(mapstruct *style) {
    int x, y, limit = 0;
    object *new_obj;

    /* while returning a null object will result in a crash, that
     * is actually preferable to an infinite loop.  That is because
     * most servers will automatically restart in case of crash.
     * Change the logic on getting the random space - shouldn't make
     * any difference, but this seems clearer to me.
     */
    do {
        limit++;
        x = RANDOM()%MAP_WIDTH(style);
        y = RANDOM()%MAP_HEIGHT(style);
        new_obj = GET_MAP_OB(style, x, y);
    } while (new_obj == NULL && limit < 1000);
    if (new_obj->head)
        return new_obj->head;
    else
        return new_obj;
}

void free_style_maps(void) {
    mapstruct *next;
    int  style_maps = 0;

    /* delete_map will try to free it from the linked list,
     * but won't find it, so we need to do it ourselves
     */
    while (styles) {
        next = styles->next;
        delete_map(styles);
        styles = next;
        style_maps++;
    }
    LOG(llevDebug, "free_style_maps: Freed %d maps\n", style_maps);
}