3 # \file lyxpreview2ppm.sh
4 # Copyright 2002 the LyX Team
5 # Read the file COPYING
7 # \author Angus Leeming, leeming@lyx.org
8 # with much help from David Kastrup, david.kastrup@t-online.de.
10 # This script takes a LaTeX file and generates PPM files, one per page.
11 # The idea is to use it with preview.sty from the preview-latex project
12 # (http://preview-latex.sourceforge.net/) to create small bitmap previews of
13 # things like math equations.
15 # preview.sty can be obtained from CTAN/macros/latex/contrib/supported/preview.
17 # This script, lyxpreview2ppm.sh, takes three arguments:
18 # FILE: the name of the file to be converted.
19 # SCALEFACTOR: scale factor, used to ascertain the resolution of the
20 # generated imagewhich is then passed to gs.
21 # NDIGITS: the number of digits in the filenames generated by gs,
22 # ${BASE}%${NDIGITS}d.ppm
24 # If successful it will leave in dir ${DIR} a number of image files
25 # ${BASE}[0-9]\{${NDIGITS}\}.ppm and a file ${BASE}.metrics containing info
26 # needed by LyX to position the images correctly on the screen.
27 # All other files ${BASE}* will be deleted.
29 # Three helper functions.
31 which ${EXECUTABLE} > /dev/null
33 echo "Unable to find \"${EXECUTABLE}\". Please install."
39 # Remove everything except the original .tex file.
40 FILES=`ls ${BASE}* | sed -e "/${BASE}.tex/d"`
41 rm -f ${FILES} texput.log
46 echo "We require preview.sty version 0.73 or newer. You're using"
47 grep 'Package: preview' ${LOGFILE}
55 # We use latex, dvips and gs, so check that they're all there.
56 EXECUTABLE=latex; FIND_IT
57 EXECUTABLE=dvips; FIND_IT
58 EXECUTABLE=gs; FIND_IT
60 # Initialise some variables.
62 BASE=`basename $1 .tex`
71 METRICSFILE=${BASE}.metrics
77 echo "Failed: latex ${TEXFILE}"
81 # Parse ${LOGFILE} to obtain bounding box info to output to ${METRICSFILE}.
82 # This extracts lines starting "Preview: Tightpage" and "Preview: Snippet".
83 grep -E 'Preview: [ST]' ${LOGFILE} > ${METRICSFILE}
85 echo "Failed: grep -E 'Preview: [ST]' ${LOGFILE}"
90 # Parse ${LOGFILE} to obtain ${RESOLUTION} for the gs process to follow.
91 # 1. Extract font size from a line like "Preview: Fontsize 20.74pt"
92 # Use grep for speed and because it gives an error if the line is not found.
93 LINE=`grep 'Preview: Fontsize' ${LOGFILE}`
95 echo "Failed: grep 'Preview: Fontsize' ${LOGFILE}"
99 # Use "" quotes in the echo to preserve newlines (technically IFS separators).
100 # The sed script strips out everything that won't form a decimal number from the
101 # line. It bails out after the first match has been made in case there are
102 # multiple lines "Preview: Fontsize". (There shouldn't be.)
103 LATEXFONT=`echo "${LINE}" | sed 's/[^0-9\.]//g; 1q'`
105 # 2. Extract magnification from a line like "Preview: Magnification 2074"
106 # If no such line found, default to MAGNIFICATION=1000.
107 LINE=`grep 'Preview: Magnification' ${LOGFILE}`
108 if [ $? -ne 0 ]; then
111 # The sed script strips out everything that won't form an /integer/.
112 MAGNIFICATION=`echo "${LINE}" | sed 's/[^0-9]//g; 1q'`
115 # 3. Compute resolution.
116 # "bc" allows floating-point arithmetic, unlike "expr" or "dc".
117 RESOLUTION=`echo "scale=2; \
118 ${SCALEFACTOR} * (10/${LATEXFONT}) * (1000/${MAGNIFICATION})" \
122 dvips -o ${PSFILE} ${DVIFILE}
123 if [ $? -ne 0 ]; then
124 echo "Failed: dvips -o ${PSFILE} ${DVIFILE}"
128 # PostScript -> Bitmap files
129 # Older versions of gs have problems with a large degree of anti-aliasing
130 # at high resolutions
132 # test expects integer arguments. ${RESOLUTION} may be a float. Truncate it.
133 INT_RESOLUTION=`echo "${RESOLUTION} / 1" | bc`
136 if [ ${INT_RESOLUTION} -gt 150 ]; then
140 gs -q -dNOPAUSE -dBATCH -dSAFER \
141 -sDEVICE=pnmraw -sOutputFile=${BASE}%0${NDIGITS}d.ppm \
142 -dGraphicsAlphaBit=${ALPHA} -dTextAlphaBits=${ALPHA} -r${RESOLUTION} \
145 if [ $? -ne 0 ]; then
146 echo "Failed: gs ${PSFILE}"
150 # All has been successful, so remove everything except the bitmap files
151 # and the metrics file.
152 FILES=`ls ${BASE}* | \
153 sed -e "/${BASE}.metrics/d" -e "/${BASE}[0-9]\{${NDIGITS}\}.ppm/d"`