/* The GIMP -- an image manipulation program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#ifndef __TILE_PRIVATE_H__
#define __TILE_PRIVATE_H__

#include "config.h"

#ifdef USE_PTHREADS
#include <pthread.h>
#endif

#include <sys/types.h>

#include <glib.h>


typedef struct _TileLink TileLink;

struct _TileLink
{
  TileLink    *next;
  gint         tile_num; /* the number of this tile within the drawable */
  TileManager *tm;       /* A pointer to the tile manager for this tile.
			  *  We need this in order to call the tile managers 
			  *  validate proc whenever the tile is referenced 
			  *  yet invalid.
			  */
};

struct _Tile
{
  gshort  ref_count;   /* reference count. when the reference count is
 		        *  non-zero then the "data" for this tile must
		        *  be valid. when the reference count for a tile
		        *  is 0 then the "data" for this tile must be
		        *  NULL.
		        */
  gshort  write_count; /* write count: number of references that are
			  for write access */ 
  gshort  share_count; /* share count: number of tile managers that
			  hold this tile */
  guint   dirty : 1;   /* is the tile dirty? has it been modified? */
  guint   valid : 1;   /* is the tile valid? */

  guchar  bpp;         /* the bytes per pixel (1, 2, 3 or 4) */
  gushort ewidth;      /* the effective width of the tile */
  gushort eheight;     /* the effective height of the tile
		        *  a tile's effective width and height may be smaller
		        *  (but not larger) than TILE_WIDTH and TILE_HEIGHT.
		        *  this is to handle edge tiles of a drawable.
		        */

  TileRowHint *rowhint;   /* An array of hints for rendering purposes */

  guchar *data;       /* the data for the tile. this may be NULL in which
		       *  case the tile data is on disk.
		       */

  gint swap_num;      /* the index into the file table of the file to be used
		       * for swapping. swap_num 1 is always the global
		       * swap file.
		       */
  off_t swap_offset;  /* the offset within the swap file of the tile data.
		       * if the tile data is in memory this will be set to -1.
		       */
  TileLink *tlink;

  Tile     *next;
  Tile     *prev;     /* List pointers for the tile cache lists */
  gpointer  listhead; /* Pointer to the head of the list this tile is on */

#ifdef USE_PTHREADS
  pthread_mutex_t mutex;
#endif
};

#ifdef USE_PTHREADS
#define TILE_MUTEX_LOCK(tile)   pthread_mutex_lock(&((tile)->mutex))
#define TILE_MUTEX_UNLOCK(tile) pthread_mutex_unlock(&((tile)->mutex))
#else
#define TILE_MUTEX_LOCK(tile) /* nothing */
#define TILE_MUTEX_UNLOCK(tile) /* nothing */
#endif


#endif /* __TILE_PRIVATE_H__ */