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tdegraphics/tdefile-plugins/ps/gscreator.cpp

620 lines
16 KiB

/* This file is part of the KDE libraries
Copyright (C) 2001 Malte Starostik <malte@kde.org>
Handling of EPS previews Copyright (C) 2003 Philipp Hullmann <phull@gmx.de>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
/* This function gets a path of a DVI, EPS, PS or PDF file and
produces a PNG-Thumbnail which is stored as a TQImage
The program works as follows
1. Test if file is a DVI file
2. Create a child process (1), in which the
file is to be changed into a PNG
3. Child-process (1) :
4. If file is DVI continue with 6
5. If file is no DVI continue with 9
6. Create another child process (2), in which the DVI is
turned into PS using dvips
7. Parent process (2) :
Turn the recently created PS file into a PNG file using gs
8. continue with 10
9. Turn the PS,PDF or EPS file into a PNG file using gs
10. Parent process (1)
store data in a TQImage
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <assert.h>
#include <ctype.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <signal.h>
#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif
#include <sys/time.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <errno.h>
#include <kdemacros.h>
#include <tqcolor.h>
#include <tqfile.h>
#include <tqimage.h>
#include <tqregexp.h>
#include "gscreator.h"
#include "dscparse_adapter.h"
#include "dscparse.h"
extern "C"
{
KDE_EXPORT ThumbCreator *new_creator()
{
return new GSCreator;
}
}
// This PS snippet will be prepended to the actual file so that only
// the first page is output.
static const char *psprolog =
"%!PS-Adobe-3.0\n"
"/.showpage.orig /showpage load def\n"
"/.showpage.firstonly {\n"
" .showpage.orig\n"
" quit\n"
"} def\n"
"/showpage { .showpage.firstonly } def\n";
// This is the code recommended by Adobe tech note 5002 for including
// EPS files.
static const char *epsprolog =
"%!PS-Adobe-3.0\n"
"userdict begin /pagelevel save def /showpage { } def\n"
"0 setgray 0 setlinecap 1 setlinewidth 0 setlinejoin 10 setmiterlimit\n"
"[ ] 0 setdash newpath false setoverprint false setstrokeadjust\n";
static const char * gsargs_ps[] = {
"gs",
"-sDEVICE=png16m",
"-sOutputFile=-",
"-dSAFER",
"-dPARANOIDSAFER",
"-dNOPAUSE",
"-dFirstPage=1",
"-dLastPage=1",
"-q",
"-",
0, // file name
"-c",
"showpage",
"-c",
"quit",
0
};
static const char * gsargs_eps[] = {
"gs",
"-sDEVICE=png16m",
"-sOutputFile=-",
"-dSAFER",
"-dPARANOIDSAFER",
"-dNOPAUSE",
0, // page size
0, // resolution
"-q",
"-",
0, // file name
"-c",
"pagelevel",
"-c",
"restore",
"-c",
"end",
"-c",
"showpage",
"-c",
"quit",
0
};
static const char *dvipsargs[] = {
"dvips",
"-n",
"1",
"-q",
"-o",
"-",
0, // file name
0
};
static bool correctDVI(const TQString& filename);
namespace {
bool got_sig_term = false;
void handle_sigterm( int ) {
got_sig_term = true;
}
}
bool GSCreator::create(const TQString &path, int width, int height, TQImage &img)
{
// The code in the loop (when testing whether got_sig_term got set)
// should read some variation of:
// parentJob()->wasKilled()
//
// Unfortunatelly, that's currently impossible without breaking BIC.
// So we need to catch the signal ourselves.
// Otherwise, on certain funny PS files (for example
// http://www.tjhsst.edu/~Eedanaher/pslife/life.ps )
// gs would run forever after we were dead.
// #### Reconsider for KDE 4 ###
// (24/12/03 - luis_pedro)
//
typedef void ( *sighandler_t )( int );
// according to linux's "man signal" the above typedef is a gnu extension
sighandler_t oldhandler = signal( SIGTERM, handle_sigterm );
int input[2];
int output[2];
int dvipipe[2];
TQByteArray data(1024);
bool ok = false;
// Test if file is DVI
bool no_dvi =!correctDVI(path);
if (pipe(input) == -1) {
return false;
}
if (pipe(output) == -1) {
close(input[0]);
close(input[1]);
return false;
}
KDSC dsc;
endComments = false;
dsc.setCommentHandler(this);
if (no_dvi)
{
FILE* fp = fopen(TQFile::encodeName(path), "r");
if (fp == 0) return false;
char buf[4096];
int count;
while ((count = fread(buf, sizeof(char), 4096, fp)) != 0
&& !endComments) {
dsc.scanData(buf, count);
}
fclose(fp);
if (dsc.pjl() || dsc.ctrld()) {
// this file is a mess.
return false;
}
}
const bool is_encapsulated = no_dvi &&
(path.find(TQRegExp("\\.epsi?$", false, false)) > 0) &&
(dsc.bbox()->width() > 0) && (dsc.bbox()->height() > 0) &&
(dsc.page_count() <= 1);
char translation[64] = "";
char pagesize[32] = "";
char resopt[32] = "";
std::unique_ptr<KDSCBBOX> bbox = dsc.bbox();
if (is_encapsulated) {
// GhostScript's rendering at the extremely low resolutions
// required for thumbnails leaves something to be desired. To
// get nicer images, we render to four times the required
// resolution and let TQImage scale the result.
const int hres = (width * 72) / bbox->width();
const int vres = (height * 72) / bbox->height();
const int resolution = (hres > vres ? vres : hres) * 4;
const int gswidth = ((bbox->urx() - bbox->llx()) * resolution) / 72;
const int gsheight = ((bbox->ury() - bbox->lly()) * resolution) / 72;
snprintf(pagesize, 31, "-g%ix%i", gswidth, gsheight);
snprintf(resopt, 31, "-r%i", resolution);
snprintf(translation, 63,
" 0 %i sub 0 %i sub translate\n", bbox->llx(),
bbox->lly());
}
const CDSC_PREVIEW_TYPE previewType =
static_cast<CDSC_PREVIEW_TYPE>(dsc.preview());
switch (previewType) {
case CDSC_TIFF:
case CDSC_WMF:
case CDSC_PICT:
// FIXME: these should take precedence, since they can hold
// color previews, which EPSI can't (or can it?).
break;
case CDSC_EPSI:
{
const int xscale = bbox->width() / width;
const int yscale = bbox->height() / height;
const int scale = xscale < yscale ? xscale : yscale;
if (getEPSIPreview(path,
dsc.beginpreview(),
dsc.endpreview(),
img,
bbox->width() / scale,
bbox->height() / scale))
return true;
// If the preview extraction routine fails, gs is used to
// create a thumbnail.
}
break;
case CDSC_NOPREVIEW:
default:
// need to run ghostscript in these cases
break;
}
pid_t pid = fork();
if (pid == 0) {
// Child process (1)
// close(STDERR_FILENO);
// find first zero entry in gsargs and put the filename
// or - (stdin) there, if DVI
const char **gsargs = gsargs_ps;
const char **arg = gsargs;
if (no_dvi && is_encapsulated) {
gsargs = gsargs_eps;
arg = gsargs;
// find first zero entry and put page size there
while (*arg) ++arg;
*arg = pagesize;
// find second zero entry and put resolution there
while (*arg) ++arg;
*arg = resopt;
}
// find next zero entry and put the filename there
TQCString fname = TQFile::encodeName( path );
while (*arg)
++arg;
if( no_dvi )
*arg = fname.data();
else
*arg = "-";
// find first zero entry in dvipsargs and put the filename there
arg = dvipsargs;
while (*arg)
++arg;
*arg = fname.data();
if( !no_dvi ){
pipe(dvipipe);
pid_t pid_two = fork();
if( pid_two == 0 ){
// Child process (2), reopen stdout on the pipe "dvipipe" and exec dvips
close(input[0]);
close(input[1]);
close(output[0]);
close(output[1]);
close(dvipipe[0]);
dup2( dvipipe[1], STDOUT_FILENO);
execvp(dvipsargs[0], const_cast<char *const *>(dvipsargs));
exit(1);
}
else if(pid_two != -1){
close(input[1]);
close(output[0]);
close(dvipipe[1]);
dup2( dvipipe[0], STDIN_FILENO);
dup2( output[1], STDOUT_FILENO);
execvp(gsargs[0], const_cast<char *const *>(gsargs));
exit(1);
}
else{
// fork() (2) failed, close these
close(dvipipe[0]);
close(dvipipe[1]);
}
}
else if( no_dvi ){
// Reopen stdin/stdout on the pipes and exec gs
close(input[1]);
close(output[0]);
dup2(input[0], STDIN_FILENO);
dup2(output[1], STDOUT_FILENO);
execvp(gsargs[0], const_cast<char *const *>(gsargs));
exit(1);
}
}
else if (pid != -1) {
// Parent process, write first-page-only-hack (the hack is not
// used if DVI) and read the png output
close(input[0]);
close(output[1]);
const char *prolog;
if (is_encapsulated)
prolog = epsprolog;
else
prolog = psprolog;
int count = write(input[1], prolog, strlen(prolog));
if (is_encapsulated)
write(input[1], translation, strlen(translation));
close(input[1]);
if (count == static_cast<int>(strlen(prolog))) {
int offset = 0;
while (!ok) {
fd_set fds;
FD_ZERO(&fds);
FD_SET(output[0], &fds);
struct timeval tv;
tv.tv_sec = 20;
tv.tv_usec = 0;
got_sig_term = false;
if (select(output[0] + 1, &fds, 0, 0, &tv) <= 0) {
if ( ( errno == EINTR || errno == EAGAIN ) && !got_sig_term ) continue;
break; // error, timeout or master wants us to quit (SIGTERM)
}
if (FD_ISSET(output[0], &fds)) {
count = read(output[0], data.data() + offset, 1024);
if (count == -1)
break;
else
if (count) // prepare for next block
{
offset += count;
data.resize(offset + 1024);
}
else // got all data
{
data.resize(offset);
ok = true;
}
}
}
}
if (!ok) // error or timeout, gs probably didn't exit yet
{
kill(pid, SIGTERM);
}
int status = 0;
if (waitpid(pid, &status, 0) != pid || (status != 0 && status != 256) )
ok = false;
}
else {
// fork() (1) failed, close these
close(input[0]);
close(input[1]);
close(output[1]);
}
close(output[0]);
int l = img.loadFromData( data );
if ( got_sig_term &&
oldhandler != SIG_ERR &&
oldhandler != SIG_DFL &&
oldhandler != SIG_IGN ) {
oldhandler( SIGTERM ); // propagate the signal. Other things might rely on it
}
if ( oldhandler != SIG_ERR ) signal( SIGTERM, oldhandler );
return ok && l;
}
ThumbCreator::Flags GSCreator::flags() const
{
return static_cast<Flags>(DrawFrame);
}
void GSCreator::comment(Name name)
{
switch (name) {
case EndPreview:
case BeginProlog:
case Page:
endComments = true;
break;
default:
break;
}
}
// Quick function to check if the filename corresponds to a valid DVI
// file. Returns true if <filename> is a DVI file, false otherwise.
static bool correctDVI(const TQString& filename)
{
TQFile f(filename);
if (!f.open(IO_ReadOnly))
return FALSE;
unsigned char test[4];
if ( f.readBlock( (char *)test,2)<2 || test[0] != 247 || test[1] != 2 )
return FALSE;
int n = f.size();
if ( n < 134 ) // Too short for a dvi file
return FALSE;
f.at( n-4 );
unsigned char trailer[4] = { 0xdf,0xdf,0xdf,0xdf };
if ( f.readBlock( (char *)test, 4 )<4 || strncmp( (char *)test, (char*) trailer, 4 ) )
return FALSE;
// We suppose now that the dvi file is complete and OK
return TRUE;
}
bool GSCreator::getEPSIPreview(const TQString &path, long start, long
end, TQImage &outimg, int imgwidth, int imgheight)
{
FILE *fp;
fp = fopen(TQFile::encodeName(path), "r");
if (fp == 0) return false;
const long previewsize = end - start + 1;
char *buf = (char *) malloc(previewsize);
fseek(fp, start, SEEK_SET);
int count = fread(buf, sizeof(char), previewsize - 1, fp);
fclose(fp);
buf[previewsize - 1] = 0;
if (count != previewsize - 1)
{
free(buf);
return false;
}
TQString previewstr = TQString::fromLatin1(buf);
free(buf);
int offset = 0;
while ((offset < previewsize) && !(previewstr[offset].isDigit())) offset++;
int digits = 0;
while ((offset + digits < previewsize) && previewstr[offset + digits].isDigit()) digits++;
int width = previewstr.mid(offset, digits).toInt();
offset += digits + 1;
while ((offset < previewsize) && !(previewstr[offset].isDigit())) offset++;
digits = 0;
while ((offset + digits < previewsize) && previewstr[offset + digits].isDigit()) digits++;
int height = previewstr.mid(offset, digits).toInt();
offset += digits + 1;
while ((offset < previewsize) && !(previewstr[offset].isDigit())) offset++;
digits = 0;
while ((offset + digits < previewsize) && previewstr[offset + digits].isDigit()) digits++;
int depth = previewstr.mid(offset, digits).toInt();
// skip over the rest of the BeginPreview comment
while ((offset < previewsize) &&
previewstr[offset] != '\n' &&
previewstr[offset] != '\r') offset++;
while ((offset < previewsize) && previewstr[offset] != '%') offset++;
unsigned int imagedepth;
switch (depth) {
case 1:
case 2:
case 4:
case 8:
imagedepth = 8;
break;
case 12: // valid, but not (yet) supported
default: // illegal value
return false;
}
unsigned int colors = (1U << depth);
TQImage img(width, height, imagedepth, colors);
img.setAlphaBuffer(false);
if (imagedepth <= 8) {
for (unsigned int gray = 0; gray < colors; gray++) {
unsigned int grayvalue = (255U * (colors - 1 - gray)) /
(colors - 1);
img.setColor(gray, tqRgb(grayvalue, grayvalue, grayvalue));
}
}
const unsigned int bits_per_scan_line = width * depth;
unsigned int bytes_per_scan_line = bits_per_scan_line / 8;
if (bits_per_scan_line % 8) bytes_per_scan_line++;
const unsigned int bindatabytes = height * bytes_per_scan_line;
TQMemArray<unsigned char> bindata(bindatabytes);
for (unsigned int i = 0; i < bindatabytes; i++) {
if (offset >= previewsize)
return false;
while (!isxdigit(previewstr[offset].latin1()) &&
offset < previewsize)
offset++;
bool ok = false;
bindata[i] = static_cast<unsigned char>(previewstr.mid(offset, 2).toUInt(&ok, 16));
if (!ok)
return false;
offset += 2;
}
for (int scanline = 0; scanline < height; scanline++) {
unsigned char *scanlineptr = img.scanLine(scanline);
for (int pixelindex = 0; pixelindex < width; pixelindex++) {
unsigned char pixelvalue = 0;
const unsigned int bitoffset =
scanline * bytes_per_scan_line * 8U + pixelindex * depth;
for (int depthindex = 0; depthindex < depth;
depthindex++) {
const unsigned int byteindex = (bitoffset + depthindex) / 8U;
const unsigned int bitindex =
7 - ((bitoffset + depthindex) % 8U);
const unsigned char bitvalue =
(bindata[byteindex] & static_cast<unsigned char>(1U << bitindex)) >> bitindex;
pixelvalue |= (bitvalue << depthindex);
}
scanlineptr[pixelindex] = pixelvalue;
}
}
outimg = img.convertDepth(32).smoothScale(imgwidth, imgheight);
return true;
}