/* gif.h:
 *
 * gifin.h
 * kirk johnson
 * november 1989
 * external interface to gifin.c
 *
 * Copyright 1989 Kirk L. Johnson (see the included file
 * "kljcpyrght.h" for complete copyright information)
 */
#ifndef _KLJ_COPYRIGHT_

/****
  Copyright 1989, 1990 Kirk L. Johnson

  Permission to use, copy, modify, distribute, and sell this
  software and its documentation for any purpose is hereby granted
  without fee, provided that the above copyright notice appear in
  all copies and that both that copyright notice and this
  permission notice appear in supporting documentation. The
  author makes no representations about the suitability of this
  software for any purpose. It is provided "as is" without express
  or implied warranty.

  THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, INDIRECT
  OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
  NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
****/

#ifndef __SABER__
static char *KLJCopyright = "Copyright 1989, 1990 Kirk L. Johnson";
#endif
#define _KLJ_COPYRIGHT_
#endif

/*
	$Disclaimer: 
 * Permission to use, copy, modify, and distribute this software and its 
 * documentation for any purpose is hereby granted without fee, 
 * provided that the above copyright notice appear in all copies and that 
 * both that copyright notice, this permission notice, and the following 
 * disclaimer appear in supporting documentation, and that the names of 
 * IBM, Carnegie Mellon University, and other copyright holders, not be 
 * used in advertising or publicity pertaining to distribution of the software 
 * without specific, written prior permission.
 * 
 * IBM, CARNEGIE MELLON UNIVERSITY, AND THE OTHER COPYRIGHT HOLDERS 
 * DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING 
 * ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.  IN NO EVENT 
 * SHALL IBM, CARNEGIE MELLON UNIVERSITY, OR ANY OTHER COPYRIGHT HOLDER 
 * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY 
 * DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, 
 * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 
 * OF THIS SOFTWARE.
 *  $
*/


/*
 * gifin return codes
 */
#define GIFIN_SUCCESS       0   /* success */
#define GIFIN_DONE          1   /* no more images */

#define GIFIN_ERR_BAD_SD   -1   /* bad screen descriptor */
#define GIFIN_ERR_BAD_SEP  -2   /* bad image separator */
#define GIFIN_ERR_BAD_SIG  -3   /* bad signature */
#define GIFIN_ERR_EOD      -4   /* unexpected end of raster data */
#define GIFIN_ERR_EOF      -5   /* unexpected end of input stream */
#define GIFIN_ERR_FAO      -6   /* file already open */
#define GIFIN_ERR_IAO      -7   /* image already open */
#define GIFIN_ERR_NFO      -8   /* no file open */
#define GIFIN_ERR_NIO      -9   /* no image open */

/*
 * colormap indices 
 */

#define GIF_RED  0
#define GIF_GRN  1
#define GIF_BLU  2

/*
 * typedef BYTE for convenience
 */

typedef unsigned char BYTE;

static int gifin_open_file();
static int gifin_open_image();
static int gifin_get_pixel();
#if 0
static int gifin_close_image();
#endif
static int gifin_close_file();
static int gifin_load_cmap();
static int gifin_skip_extension();
static int gifin_read_data_block();
static int gifin_push_string();
static int gifin_add_string();
static int gifin_fatal();

/* #defines, typedefs, and such
 */

#define GIF_SIG      "GIF87a"
#define GIF_SIG_89   "GIF89a"
#define GIF_SIG_LEN  6          /* GIF signature length */
#define GIF_SD_SIZE  7          /* GIF screen descriptor size */
#define GIF_ID_SIZE  9          /* GIF image descriptor size */

#define GIF_SEPARATOR   ','     /* GIF image separator */
#define GIF_EXTENSION   '!'     /* GIF extension block marker */
#define GIF_TERMINATOR  ';'     /* GIF terminator */

#define STAB_SIZE  4096         /* string table size */
#define PSTK_SIZE  4096         /* pixel stack size */

#define NULL_CODE  -1           /* string table null code */