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#include "imager.h"
#include "log.h"
#include "iolayer.h"
#include "imageri.h"
#include <stdlib.h>
#include <errno.h>
/*
=head1 NAME
pnm.c - implements reading and writing ppm/pnm/pbm files, uses io layer.
=head1 SYNOPSIS
io_glue *ig = io_new_fd( fd );
i_img *im = i_readpnm_wiol(ig, -1); // no limit on how much is read
// or
io_glue *ig = io_new_fd( fd );
return_code = i_writepnm_wiol(im, ig);
=head1 DESCRIPTION
pnm.c implements the basic functions to read and write portable
anymap files. It uses the iolayer and needs either a seekable source
or an entire memory mapped buffer.
=head1 FUNCTION REFERENCE
Some of these functions are internal.
=over
=cut
*/
#define BSIZ 1024
#define misspace(x) (x==' ' || x=='\n' || x=='\r' || x=='\t' || x=='\f' || x=='\v')
#define misnumber(x) (x <= '9' && x>='0')
static char *typenames[]={"ascii pbm", "ascii pgm", "ascii ppm", "binary pbm", "binary pgm", "binary ppm"};
/*
* Type to encapsulate the local buffer
* management skipping over in a file
*/
typedef struct {
io_glue *ig;
int len;
int cp;
char buf[BSIZ];
} mbuf;
static
void init_buf(mbuf *mb, io_glue *ig) {
mb->len = 0;
mb->cp = 0;
mb->ig = ig;
}
/*
=item gnext(mbuf *mb)
Fetches a character and advances in stream by one character.
Returns a pointer to the byte or NULL on failure (internal).
mb - buffer object
=cut
*/
static
char *
gnext(mbuf *mb) {
io_glue *ig = mb->ig;
if (mb->cp == mb->len) {
mb->cp = 0;
mb->len = ig->readcb(ig, mb->buf, BSIZ);
if (mb->len == -1) {
i_push_error(errno, "file read error");
mm_log((1, "i_readpnm: read error\n"));
return NULL;
}
if (mb->len == 0) {
i_push_error(errno, "unexpected end of file");
mm_log((1, "i_readpnm: end of file\n"));
return NULL;
}
}
return &mb->buf[mb->cp++];
}
/*
=item gpeek(mbuf *mb)
Fetches a character but does NOT advance. Returns a pointer to
the byte or NULL on failure (internal).
mb - buffer object
=cut
*/
static
char *
gpeek(mbuf *mb) {
io_glue *ig = mb->ig;
if (mb->cp == mb->len) {
mb->cp = 0;
mb->len = ig->readcb(ig, mb->buf, BSIZ);
if (mb->len == -1) {
i_push_error(errno, "read error");
mm_log((1, "i_readpnm: read error\n"));
return NULL;
}
if (mb->len == 0) {
i_push_error(0, "unexpected end of file");
mm_log((1, "i_readpnm: end of file\n"));
return NULL;
}
}
return &mb->buf[mb->cp];
}
/*
=item skip_spaces(mb)
Advances in stream until it is positioned at a
non white space character. (internal)
mb - buffer object
=cut
*/
static
int
skip_spaces(mbuf *mb) {
char *cp;
while( (cp = gpeek(mb)) && misspace(*cp) ) if ( !gnext(mb) ) break;
if (!cp) return 0;
return 1;
}
/*
=item skip_comment(mb)
Advances in stream over whitespace and a comment if one is found. (internal)
mb - buffer object
=cut
*/
static
int
skip_comment(mbuf *mb) {
char *cp;
if (!skip_spaces(mb)) return 0;
if (!(cp = gpeek(mb))) return 0;
if (*cp == '#') {
while( (cp = gpeek(mb)) && (*cp != '\n' && *cp != '\r') ) {
if ( !gnext(mb) ) break;
}
}
if (!cp) return 0;
return 1;
}
/*
=item gnum(mb, i)
Fetches the next number from stream and stores in i, returns true
on success else false.
mb - buffer object
i - integer to store result in
=cut
*/
static
int
gnum(mbuf *mb, int *i) {
char *cp;
*i = 0;
if (!skip_spaces(mb)) return 0;
while( (cp = gpeek(mb)) && misnumber(*cp) ) {
*i = *i*10+(*cp-'0');
cp = gnext(mb);
}
return 1;
}
/*
=item i_readpnm_wiol(ig, length)
Retrieve an image and stores in the iolayer object. Returns NULL on fatal error.
ig - io_glue object
length - maximum length to read from data source, before closing it -1
signifies no limit.
=cut
*/
i_img *
i_readpnm_wiol(io_glue *ig, int length) {
i_img* im;
int type;
int x, y, ch;
int width, height, maxval, channels, pcount;
int rounder;
char *cp;
unsigned char *uc;
mbuf buf;
i_color val;
i_clear_error();
mm_log((1,"i_readpnm(ig %p, length %d)\n", ig, length));
io_glue_commit_types(ig);
init_buf(&buf, ig);
cp = gnext(&buf);
if (!cp || *cp != 'P') {
i_push_error(0, "bad header magic, not a PNM file");
mm_log((1, "i_readpnm: Could not read header of file\n"));
return NULL;
}
if ( !(cp = gnext(&buf)) ) {
mm_log((1, "i_readpnm: Could not read header of file\n"));
return NULL;
}
type = *cp-'0';
if (type < 1 || type > 6) {
i_push_error(0, "unknown PNM file type, not a PNM file");
mm_log((1, "i_readpnm: Not a pnm file\n"));
return NULL;
}
if ( !(cp = gnext(&buf)) ) {
mm_log((1, "i_readpnm: Could not read header of file\n"));
return NULL;
}
if ( !misspace(*cp) ) {
i_push_error(0, "unexpected character, not a PNM file");
mm_log((1, "i_readpnm: Not a pnm file\n"));
return NULL;
}
mm_log((1, "i_readpnm: image is a %s\n", typenames[type-1] ));
/* Read sizes and such */
if (!skip_comment(&buf)) {
i_push_error(0, "while skipping to width");
mm_log((1, "i_readpnm: error reading before width\n"));
return NULL;
}
if (!gnum(&buf, &width)) {
i_push_error(0, "could not read image width");
mm_log((1, "i_readpnm: error reading width\n"));
return NULL;
}
if (!skip_comment(&buf)) {
i_push_error(0, "while skipping to height");
mm_log((1, "i_readpnm: error reading before height\n"));
return NULL;
}
if (!gnum(&buf, &height)) {
i_push_error(0, "could not read image height");
mm_log((1, "i_readpnm: error reading height\n"));
return NULL;
}
if (!(type == 1 || type == 4)) {
if (!skip_comment(&buf)) {
i_push_error(0, "while skipping to maxval");
mm_log((1, "i_readpnm: error reading before maxval\n"));
return NULL;
}
if (!gnum(&buf, &maxval)) {
i_push_error(0, "could not read maxval");
mm_log((1, "i_readpnm: error reading maxval\n"));
return NULL;
}
if (maxval == 0) {
i_push_error(0, "maxval is zero - invalid pnm file");
mm_log((1, "i_readpnm: maxval is zero, invalid pnm file\n"));
return NULL;
}
else if (maxval > 65535) {
i_push_errorf(0, "maxval of %d is over 65535 - invalid pnm file",
maxval);
mm_log((1, "i_readpnm: maxval of %d is over 65535 - invalid pnm file\n"));
return NULL;
}
else if (type >= 4 && maxval > 255) {
i_push_errorf(0, "maxval of %d is over 255 - not currently supported by Imager for binary pnm", maxval);
mm_log((1, "i_readpnm: maxval of %d is over 255 - not currently supported by Imager for binary pnm\n", maxval));
return NULL;
}
} else maxval=1;
rounder = maxval / 2;
if (!(cp = gnext(&buf)) || !misspace(*cp)) {
i_push_error(0, "garbage in header, invalid PNM file");
mm_log((1, "i_readpnm: garbage in header\n"));
return NULL;
}
channels = (type == 3 || type == 6) ? 3:1;
pcount = width*height*channels;
if (!i_int_check_image_file_limits(width, height, channels, sizeof(i_sample_t))) {
mm_log((1, "i_readpnm: image size exceeds limits\n"));
return NULL;
}
mm_log((1, "i_readpnm: (%d x %d), channels = %d, maxval = %d\n", width, height, channels, maxval));
im = i_img_empty_ch(NULL, width, height, channels);
i_tags_add(&im->tags, "i_format", 0, "pnm", -1, 0);
switch (type) {
case 1: /* Ascii types */
case 2:
case 3:
for(y=0;y<height;y++) for(x=0; x<width; x++) {
for(ch=0; ch<channels; ch++) {
int t;
if (gnum(&buf, &t)) val.channel[ch] = (t * 255 + rounder) / maxval;
else {
mm_log((1,"i_readpnm: gnum() returned false in data\n"));
return im;
}
}
i_ppix(im, x, y, &val);
}
break;
case 4: /* binary pbm */
for(y=0;y<height;y++) for(x=0; x<width; x+=8) {
if ( (uc = (unsigned char*)gnext(&buf)) ) {
int xt;
int pc = width-x < 8 ? width-x : 8;
/* mm_log((1,"i_readpnm: y=%d x=%d pc=%d\n", y, x, pc)); */
for(xt = 0; xt<pc; xt++) {
val.channel[0] = (*uc & (128>>xt)) ? 0 : 255;
i_ppix(im, x+xt, y, &val);
}
} else {
mm_log((1,"i_readpnm: gnext() returned false in data\n"));
return im;
}
}
break;
case 5: /* binary pgm */
case 6: /* binary ppm */
for(y=0;y<height;y++) for(x=0; x<width; x++) {
for(ch=0; ch<channels; ch++) {
if ( (uc = (unsigned char*)gnext(&buf)) )
val.channel[ch] = (*uc * 255 + rounder) / maxval;
else {
mm_log((1,"i_readpnm: gnext() returned false in data\n"));
return im;
}
}
i_ppix(im, x, y, &val);
}
break;
default:
mm_log((1, "type %s [P%d] unsupported\n", typenames[type-1], type));
return NULL;
}
return im;
}
undef_int
i_writeppm_wiol(i_img *im, io_glue *ig) {
char header[255];
int rc;
mm_log((1,"i_writeppm(im %p, ig %p)\n", im, ig));
i_clear_error();
/* Add code to get the filename info from the iolayer */
/* Also add code to check for mmapped code */
io_glue_commit_types(ig);
if (im->channels == 3) {
sprintf(header,"P6\n#CREATOR: Imager\n%d %d\n255\n",im->xsize,im->ysize);
if (ig->writecb(ig,header,strlen(header))<0) {
i_push_error(errno, "could not write ppm header");
mm_log((1,"i_writeppm: unable to write ppm header.\n"));
return(0);
}
if (!im->virtual && im->bits == i_8_bits && im->type == i_direct_type) {
rc = ig->writecb(ig,im->idata,im->bytes);
}
else {
unsigned char *data = mymalloc(3 * im->xsize);
if (data != NULL) {
int y = 0;
static int rgb_chan[3] = { 0, 1, 2 };
rc = 0;
while (y < im->ysize && rc >= 0) {
i_gsamp(im, 0, im->xsize, y, data, rgb_chan, 3);
rc = ig->writecb(ig, data, im->xsize * 3);
++y;
}
myfree(data);
}
else {
i_push_error(0, "Out of memory");
return 0;
}
}
if (rc<0) {
i_push_error(errno, "could not write ppm data");
mm_log((1,"i_writeppm: unable to write ppm data.\n"));
return(0);
}
}
else if (im->channels == 1) {
sprintf(header, "P5\n#CREATOR: Imager\n%d %d\n255\n",
im->xsize, im->ysize);
if (ig->writecb(ig,header, strlen(header)) < 0) {
i_push_error(errno, "could not write pgm header");
mm_log((1,"i_writeppm: unable to write pgm header.\n"));
return(0);
}
if (!im->virtual && im->bits == i_8_bits && im->type == i_direct_type) {
rc=ig->writecb(ig,im->idata,im->bytes);
}
else {
unsigned char *data = mymalloc(im->xsize);
if (data != NULL) {
int y = 0;
int chan = 0;
rc = 0;
while (y < im->ysize && rc >= 0) {
i_gsamp(im, 0, im->xsize, y, data, &chan, 1);
rc = ig->writecb(ig, data, im->xsize);
++y;
}
myfree(data);
}
else {
i_push_error(0, "Out of memory");
return 0;
}
}
if (rc<0) {
i_push_error(errno, "could not write pgm data");
mm_log((1,"i_writeppm: unable to write pgm data.\n"));
return(0);
}
}
else {
i_push_error(0, "can only save 1 or 3 channel images to pnm");
mm_log((1,"i_writeppm: ppm/pgm is 1 or 3 channel only (current image is %d)\n",im->channels));
return(0);
}
ig->closecb(ig);
return(1);
}
/*
=back
=head1 AUTHOR
Arnar M. Hrafnkelsson <addi@umich.edu>
=head1 SEE ALSO
Imager(3)
=cut
*/
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