Current File : //data/old/usr/share/texlive/texmf-dist/doc/generic/xypic/support/pnmrawtopcropwhite.c
/* $Id: pnmrawtopcropwhite.c,v 3.10 2011/03/14 20:14:00 krisrose Exp $
**
** Crop off top white lines from raw PBM file (efficiently :)
** Copyright (c) 1991-1998 Kristoffer H. Rose <krisrose@tug.org>
**
** This file is part of the Xy-pic package for graphs and diagrams in TeX.
** Copyright (c) 1991-2011 Kristoffer H. Rose <krisrose@tug.org>
**
** The Xy-pic package 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.
**
** The Xy-pic package 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 package; if not, see http://www.gnu.org/licenses/.
*/
static const char Id[] =
"@(#)$Id: pnmrawtopcropwhite.c,v 3.10 2011/03/14 20:14:00 krisrose Exp $\n";
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
/* Globals */
#define PBMRAWMAGIC "P4" /* Portable BitMap magic cookie */
#define PGMRAWMAGIC "P5" /* Portable GrayMap magic cookie */
#define PPMRAWMAGIC "P6" /* Portable PixMap magic cookie */
#define MAGICSIZE 2
static char *me; /* program name */
/* Subroutines */
void oops(void) {
fprintf(stderr, "Usage: %s\n", me);
exit(1);
}
void panic(const char *mess) {
fprintf(stderr, "Error: %s\nUsage: %s\n", mess, me);
exit(2);
}
void skipcomment(void) {
int c;
while(1) {
switch (c = getchar()) {
case EOF: panic("premature EOF on input"); break;
case '\n': return;
default: break;
}
}
}
void skipwhite(void) {
int c;
while(1) {
switch (c = getc(stdin)) {
case EOF: panic("premature EOF on input"); break;
case ' ': case '\t': case '\r': case '\n': break;
case '#': skipcomment(); break;
default: ungetc(c, stdin); return;
}
}
}
int nextint(const char *what) {
int i;
skipwhite();
if (!scanf("%d", &i)) panic(what);
return i;
}
/* Program */
int main (int argc, char *argv[]) {
char magic[MAGICSIZE];
enum { PBM, PGM, PPM } which;
int width, height, newheight, pixelmax;
int linelength;
char *line, *whiteline;
/* establish identity and proper usage */
me = argv[0];
if (argc != 1) oops();
/* magic */
if (!fread(magic, 1, MAGICSIZE, stdin))
panic("no magic (nothing on standard input)");
if (!memcmp(magic, PBMRAWMAGIC, MAGICSIZE))
which = PBM;
else if (!memcmp(magic, PGMRAWMAGIC, MAGICSIZE))
which = PGM;
else if (!memcmp(magic, PPMRAWMAGIC, MAGICSIZE))
which = PPM;
else
panic("bad magic (standard input not a raw anymap)");
/* width and height */
width = nextint("pixelwidth integer");
height = nextint("pixelheight integer");
switch (which) {
case PBM: pixelmax = 0; break; /* hack (used by memset below) */
case PGM: case PPM:
pixelmax = nextint("pixelmax integer");
if (pixelmax > 255) panic("pixelmax larger than 255");
}
if (getchar() != '\n')
panic("something not a simple newline after width height [pixelmax]");
/* allocate pixel line */
switch (which) {
case PBM: linelength = (width + 7) / 8; break;
case PGM: linelength = width; break;
case PPM: linelength = width * 3; break;
}
line = (char*)malloc(linelength);
if (!line) panic("could not allocate pixel line");
whiteline = (char*)malloc(linelength);
if (!whiteline) panic("could not allocate white pixel line");
memset(whiteline, pixelmax, linelength);
/* skip white pixel lines */
newheight = height;
while (fread(line, linelength, 1, stdin)
&& !memcmp(line, whiteline, linelength)) {
newheight--;
if (newheight <= 0) panic("entire image blank");
}
/* output revised header */
if (newheight < height)
fprintf(stderr,"%s: cropping %d rows off the top\n", me, height-newheight);
printf("%.*s\n%d %d\n", MAGICSIZE, magic, width, newheight);
switch (which) {
case PBM: break;
case PGM: case PPM:
printf("%d\n", pixelmax); break;
}
/* output remainder of image */
do {
if (!fwrite(line, linelength, 1, stdout)) panic("could not write");
} while (fread(line, linelength, 1, stdin));
if (!feof(stdin)) panic("input not exhausted");
return(0);
}
/*
** $Log: pnmrawtopcropwhite.c,v $
** Revision 3.10 2011/03/14 20:14:00 krisrose
** Preparing for release 3.8.6.
**
** Revision 3.9 2010/06/10 18:45:49 krisrose
** Reference to GPL by URL.
**
** Revision 3.8 2010/04/16 06:06:51 krisrose
** Preparing for a new release...
**
** Revision 3.7 1999/02/16 15:12:50 krisrose
** Interim release (Y&Y fonts now free).
**
** Revision 1.3 1997/05/01 20:59:51 krisrose
** Works for all three raw formats now.
**
** Revision 1.2 1997/05/01 17:34:58 krisrose
** Extended to raw PGM and PPM in addition to PBM.
**
** Revision 1.1 1997/04/30 21:30:31 krisrose
** Initial revision
*/
Mini Shell