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 advice 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 takes three arguments:
18 # TEXFILE: the name of the .tex file to be converted.
19 # SCALEFACTOR: scale factor, used to ascertain the resolution of the
20 # generated image which is then passed to gs.
21 # NDIGITS: the number of digits in the filenames generated by gs,
22 # ${BASE}%0${NDIGITS}d.ppm.
24 # If successful, this script will leave in dir ${DIR}:
25 # ${BASE}[0-9]\{${NDIGITS}\}.ppm: a (possibly large) number of image files.
26 # ${BASE}.metrics: a file containing info needed by LyX to
27 # position the images correctly on the screen.
28 # All other files ${BASE}* will be deleted.
30 # Three helper functions.
32 which ${EXECUTABLE} > /dev/null
34 echo "Unable to find \"${EXECUTABLE}\". Please install."
40 # Remove everything except the original .tex file.
41 FILES=`ls ${BASE}* | sed -e "/${BASE}.tex/d"`
42 rm -f ${FILES} texput.log
47 echo "We require preview.sty version 0.73 or newer. You're using"
48 grep 'Package: preview' ${LOGFILE}
56 # We use latex, dvips and gs, so check that they're all there.
57 EXECUTABLE=latex; FIND_IT
58 EXECUTABLE=dvips; FIND_IT
59 EXECUTABLE=gs; FIND_IT
61 # Initialise some variables.
63 BASE=`basename $1 .tex`
72 METRICSFILE=${BASE}.metrics
78 echo "Failed: latex ${TEXFILE}"
82 # Parse ${LOGFILE} to obtain bounding box info to output to ${METRICSFILE}.
83 # This extracts lines starting "Preview: Tightpage" and "Preview: Snippet".
84 grep -E 'Preview: [ST]' ${LOGFILE} > ${METRICSFILE}
86 echo "Failed: grep -E 'Preview: [ST]' ${LOGFILE}"
91 # Parse ${LOGFILE} to obtain ${RESOLUTION} for the gs process to follow.
92 # 1. Extract font size from a line like "Preview: Fontsize 20.74pt"
93 # Use grep for speed and because it gives an error if the line is not found.
94 LINE=`grep 'Preview: Fontsize' ${LOGFILE}`
96 echo "Failed: grep 'Preview: Fontsize' ${LOGFILE}"
100 # Use "" quotes in the echo to preserve newlines (technically IFS separators).
101 # The sed script strips out everything that won't form a decimal number from the
102 # line. It bails out after the first match has been made in case there are
103 # multiple lines "Preview: Fontsize". (There shouldn't be.)
104 LATEXFONT=`echo "${LINE}" | sed 's/[^0-9\.]//g; 1q'`
106 # 2. Extract magnification from a line like "Preview: Magnification 2074"
107 # If no such line found, default to MAGNIFICATION=1000.
108 LINE=`grep 'Preview: Magnification' ${LOGFILE}`
109 if [ $? -ne 0 ]; then
112 # The sed script strips out everything that won't form an /integer/.
113 MAGNIFICATION=`echo "${LINE}" | sed 's/[^0-9]//g; 1q'`
116 # 3. Compute resolution.
117 # "bc" allows floating-point arithmetic, unlike "expr" or "dc".
118 RESOLUTION=`echo "scale=2; \
119 ${SCALEFACTOR} * (10/${LATEXFONT}) * (1000/${MAGNIFICATION})" \
123 dvips -o ${PSFILE} ${DVIFILE}
124 if [ $? -ne 0 ]; then
125 echo "Failed: dvips -o ${PSFILE} ${DVIFILE}"
129 # PostScript -> Bitmap files
130 # Older versions of gs have problems with a large degree of anti-aliasing
131 # at high resolutions
133 # test expects integer arguments. ${RESOLUTION} may be a float. Truncate it.
134 INT_RESOLUTION=`echo "${RESOLUTION} / 1" | bc`
137 if [ ${INT_RESOLUTION} -gt 150 ]; then
141 gs -q -dNOPAUSE -dBATCH -dSAFER \
142 -sDEVICE=pnmraw -sOutputFile=${BASE}%0${NDIGITS}d.ppm \
143 -dGraphicsAlphaBit=${ALPHA} -dTextAlphaBits=${ALPHA} -r${RESOLUTION} \
146 if [ $? -ne 0 ]; then
147 echo "Failed: gs ${PSFILE}"
151 # All has been successful, so remove everything except the bitmap files
152 # and the metrics file.
153 FILES=`ls ${BASE}* | \
154 sed -e "/${BASE}.metrics/d" -e "/${BASE}[0-9]\{${NDIGITS}\}.ppm/d"`