orle.h

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/** @addtogroup utahrle */
/*@{*/
/*

        Modified by :           Gary S. Moss
                                U. S. Army Ballistic Research Laboratory
                                Aberdeen Proving Ground
                                Maryland 21005-5066
                                (301)278-6647 or AV-283-6647
 *
 *  Note:  Users of this file will need to include "fb.h" first.
 */
/*
 * Runsv.h - Definitions for Run Length Encoding.
 *
 * Author:      Spencer W. Thomas
 *              Computer Science Dept.
 *              University of Utah
 * Date:        Mon Aug  9 1982
 * Copyright (c) 1982 Spencer W. Thomas
 */

#include "machine.h"            /* for BIG_ENDIAN definition */

#ifdef BIG_ENDIAN
#define SWAB(shrt)  (shrt = ((shrt >> 8) & 0xff) | ((shrt << 8) & 0xff00))
#else
#define SWAB(shrt)
#endif

/* Opcode definitions.                                                  */
#define RSkipLinesOp    1
#define RSetColorOp     2
#define RSkipPixelsOp   3
#define RByteDataOp     5
#define RRunDataOp      6

/* If this bit is set in inst.opcode, we have a long instruction.       */
#define LONG            0x40

/* Flags returned by 'rle_rhdr()'.                                      */
#define NO_BOX_SAVE     (1<<0)  /* Saved with backgr.== H_CLEARFIRST    */
#define NO_COLORMAP     (1<<1)  /* Color map not saved.                 */
#define NO_IMAGE        (1<<2)  /* Only color map saved.                */

typedef struct  /* Extended format RLE header.                          */
        {
        short   h_xpos, h_ypos; /* Lower-left corner of image.          */
        short   h_xlen, h_ylen; /* Size of saved box.                   */
        char    h_flags;        /* Some flags.                          */
#define H_CLEARFIRST    0x1     /* Clear the fb to background first.    */
#define H_BOXSAVE       0x0     /* Straight box save.                   */
        char    h_ncolors;      /* Number of color channels.            */
#define H_LD_CMAP_ONLY  0       /* Load only the color map (if present).*/
#define H_B_W           1       /* We have a black and white image.     */
#define H_RGB           3       /* We have a normal color image.        */
        char    h_pixelbits;    /* Bits per pixel per channel.          */
        char    h_ncmap;        /* Channels in color map (map present). */
        char    h_cmaplen;      /* Log base 2 of entries in color map.  */
        unsigned char  h_background[3]; /* Background color.            */
} Xtnd_Rle_Header;

typedef struct  /* Old format RLE header minus magic number field.      */
        {
/***    short   magic;  Read seperately ***/
        short   xpos, ypos;     /* Lower-left corner of image.          */
        short   xsize, ysize;   /* Size of saved box.                   */
        unsigned char   bg_r;   /* Background colors.                   */
        unsigned char   bg_g;
        unsigned char   bg_b;
        char    map;            /* Flag for map presence.               */
        } Old_Rle_Header;

typedef struct /* Old RLE format instruction.                           */
        {
#if __STDC__ || defined(__convexc__)
        /* XXX This won't match the file format, but will at least compile */
        /* ANSI insists that bit-field must be of type signed int, unsigned int or int */
        unsigned int datum:12, opcode:4;
#else
        unsigned short datum:12, opcode:4;
#endif
        } Old_Inst;

typedef struct /* Old RLE format instruction.                           */
        {
#if __STDC__ || defined(__convexc__)
        /* XXX This won't match the file format, but will at least compile */
        /* ANSI insists that bit-field must be of type signed int, unsigned int or int */
        int     opcode:8, datum:8;
#else
        short   opcode:8, datum:8;
#endif
        } Xtnd_Inst;

#define OPCODE(inst) (inst.opcode & ~LONG)
#define LONGP(inst) (inst.opcode & LONG)
#define DATUM(inst) (0x00ff & inst.datum)

/* Old RLE format magic numbers.                                        */
#define     RMAGIC      ('R' << 8)      /* Top half of magic number.    */
#define     WMAGIC      ('W' << 8)      /* Black&white rle image.       */

#define     XtndRMAGIC  ((short)0xcc52) /* Extended RLE magic number.   */

#define STRIDE (sizeof(RGBpixel))       /* Distance (bytes) to next pixel.      */

/* Global data intended mainly for internal (library) use.              */
extern int      _bg_flag;
extern int      _bw_flag;
extern int      _cm_flag;
extern RGBpixel _bg_pixel;

/* Global flags for general use.                                        */
extern int      rle_debug;
extern int      rle_verbose;

/* Entry points.                                                        */
void    rle_rlen(), rle_wlen(), rle_rpos(), rle_wpos();
int     rle_rhdr(), rle_whdr(), rle_rmap(), rle_wmap();
int     rle_decode_ln(), rle_encode_ln();

/*@}*/
/*
 * Local Variables:
 * mode: C
 * tab-width: 8
 * c-basic-offset: 4
 * indent-tabs-mode: t
 * End:
 * ex: shiftwidth=4 tabstop=8
 */

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