/* wrapeps.c - wrap an eps file for printing */

/*
 * Copyright (C) 1999 Roger Willcocks
 * rogerw@centipede.co.uk 28/05/99
 *
 * 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.
 */

/*
 * This is a minimal program to strip the PostScript portion out of an EPS
 * file, translate the origin according to the bounding box information, and
 * append a 'showpage' instruction. The resulting file should be printable.
 * Usage: wrapeps infile [outfile]; defaults to stdout.
 */

#include <stdio.h>
#include <fcntl.h>
#include <string.h>

#ifdef _WIN32
#define BinaryMode O_BINARY
#else
#define BinaryMode 0
#endif

#define BITE 2048

char buffer[BITE+1];
char temp[80];

long longval(unsigned char *p)
{
   return ((((((long)p[3] << 8) | (long)p[2]) << 8) | (long)p[1]) << 8) | (long)p[0];
}

int main(int argc, char *argv[])
{
    int infile, outfile, got;
    long length;
    int x, y, w, h;
    char *ptr;

    if (argc != 2 && argc != 3) {
	fprintf(stderr, "usage: wrapeps <filename> [ <outfile> ]\n");
	exit(4);
    }

    infile = open(argv[1], O_RDONLY|BinaryMode);
    outfile = 1; /* stdout */

    if (argc == 3)
	outfile = open(argv[2], O_RDWR|O_TRUNC|O_CREAT|BinaryMode, 0666);

    if (infile < 0 || outfile < 0)
	exit(3);

    got = read(infile, buffer, BITE);

    if (got > 2 && buffer[0] == '%' && buffer[1] == '!')
	length = 0x7fffffffL; /* the lot */
    else if (got > 30 && longval(buffer) == 0xc6d3d0c5L) { /* eps signature */
	long offset = longval(buffer + 4);
	length = longval(buffer + 8) + offset;
	lseek(infile, offset, 0);
	got = read(infile, buffer, (length > BITE) ? BITE : length);
    }
    else
	exit(2); /* not an eps file */

    buffer[BITE] = 0; /* sic */
    if ((ptr = strstr(buffer, "%%BoundingBox: ")) == 0 ||
	sscanf(ptr + 15, "%d %d %d %d", &x, &y, &w, &h) != 4)
	exit(1); /* no bounding box in 1st BITE characters */

    sprintf(temp, "%%!PS-Adobe-1.0\n%d %d translate\n%%%%BeginDocument\n", -x, -y);
    write(outfile, temp, strlen(temp));  /* move the origin */

    do { /* copy the code */
	write(outfile, buffer, got);
	length -= got;
    } while ((got = read(infile, buffer, (length > BITE) ? BITE : length)) > 0);

    sprintf(temp, "\n%%%%EndDocument\nshowpage\n");
    write(outfile, temp, strlen(temp));

    return 0;
}

/* end */