libanvil Code

/*
 * region.h: Functions for parsing Minecraft region files.
 *
 * Copyright (c) 2013, Benjamin Johnson.
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the original developer nor the names of any
 *       contributors may be used to endorse or promote products derived from
 *       this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef LIBANVIL_REGION_H
#define LIBANVIL_REGION_H


#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */


#include <math.h>  /* for floorf() */

#include "cNBT/nbt.h"


/* The number of chunks in any dimension in a given region */
#define CHUNKS_PER_REGION 32


/*
 * Convert chunk to region coordinates.
 */
#define C2R(coord) ((int) floorf((coord) / (float)CHUNKS_PER_REGION))


/*
 * Open a file to read region data.
 * The x and z parameters are in region coordinates.
 */
FILE *region_open_read(const char *base_dir, int x, int z);

/*
 * Read the region header from an open file.
 */
char *region_read_header(FILE *fp);

/*
 * Return the parsed NBT data for the chunk at (x, z).
 * The x and z parameters are in region coordinates.
 */
nbt_node *region_get_chunk(FILE *region_file,
			   char *header, int x, int z);

/*
 * Open a file to write region data.
 * The x and z parameters are in region coordinates.
 */
FILE *region_open_write(const char *base_dir, int x, int z);

/*
 * Open a file to both read and write region data.
 * The x and z parameters are in region coordinates.
 */
FILE *region_open_read_write(const char *base_dir, int x, int z);

/*
 * Return a new, empty region header.
 */
char *region_create_header(void);

/*
 * Free a region header.
 */
void region_free_header(char *header);

/*
 * Write a chunk to the specified region file.
 * The x and z parameters are in chunk coordinates.
 *
 * Existing chunk data is NOT overwritten in place, to avoid corrupting
 * other chunks if the new data is larger than the existing data. Instead,
 * the region header is simply updated to point to the new data, which is
 * written to the end of the region file. This is harmless and will not
 * affect game performance, though repeated calls will result in gradually
 * increasing region file sizes.
 *
 * You can remove old chunk data from region files using the program mctrim.c
 * included in the libanvil distribution.
 */
bool region_write_chunk(FILE *region_file,
			char *header, nbt_node *chunk_data, int x, int z);

/*
 * Close an open region file.
 */
void region_close(FILE *region_file);


#ifdef __cplusplus
}
#endif /* __cplusplus */


#endif /* LIBANVIL_REGION_H */