lyx_mirror/lib/scripts/lyxpreview2bitmap.py

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#! /usr/bin/env python
# -*- coding: iso-8859-1 -*-
# file lyxpreview2bitmap.py
# This file is part of LyX, the document processor.
# Licence details can be found in the file COPYING.
# author Angus Leeming
# with much advice from members of the preview-latex project:
# David Kastrup, dak@gnu.org and
# Jan-<2D>ke Larsson, jalar@mai.liu.se.
# Full author contact details are available in file CREDITS
# This script takes a LaTeX file and generates a collection of
# png or ppm image files, one per previewed snippet.
# Pre-requisites:
# * A latex executable;
# * preview.sty;
# * dvipng;
# * pngtoppm (if outputing ppm format images).
# preview.sty and dvipng are part of the preview-latex project
# http://preview-latex.sourceforge.net/
# preview.sty can alternatively be obtained from
# CTAN/support/preview-latex/
# Example usage:
# lyxpreview2bitmap.py png 0lyxpreview.tex 128 000000 faf0e6
# This script takes five arguments:
# FORMAT: The desired output format. Either 'png' or 'ppm'.
# TEXFILE: the name of the .tex file to be converted.
# DPI: a scale factor, used to ascertain the resolution of the
# generated image which is then passed to gs.
# FG_COLOR: the foreground color as a hexadecimal string, eg '000000'.
# BG_COLOR: the background color as a hexadecimal string, eg 'faf0e6'.
# Decomposing TEXFILE's name as DIR/BASE.tex, this script will,
# if executed successfully, leave in DIR:
# * a (possibly large) number of image files with names
# like BASE[0-9]+.png
# * a file BASE.metrics, containing info needed by LyX to position
# the images correctly on the screen.
import glob, os, re, string, sys
from legacy_lyxpreview2ppm import legacy_conversion
from lyxpreview_tools import error, find_exe, \
find_exe_or_terminate, run_command
# Pre-compiled regular expressions.
hexcolor_re = re.compile("^[0-9a-fA-F]{6}$")
latex_file_re = re.compile("\.tex$")
def usage(prog_name):
return "Usage: %s <format> <latex file> <dpi> <fg color> <bg color>\n"\
"\twhere the colors are hexadecimal strings, eg 'faf0e6'"\
% prog_name
def make_texcolor(hexcolor):
# Test that the input string contains 6 hexadecimal chars.
if not hexcolor_re.match(hexcolor):
error("Cannot convert color '%s'" % hexcolor)
red = float(string.atoi(hexcolor[0:2], 16)) / 255.0
green = float(string.atoi(hexcolor[2:4], 16)) / 255.0
blue = float(string.atoi(hexcolor[4:6], 16)) / 255.0
return "rgb %f %f %f" % (red, green, blue)
def extract_metrics_info(dvipng_stdout, metrics_file):
metrics = open(metrics_file, 'w')
# "\[[0-9]+" can match two kinds of numbers: page numbers from dvipng
# and glyph numbers from mktexpk. The glyph numbers always match
# "\[[0-9]+\]" while the page number never is followed by "\]". Thus:
page_re = re.compile("\[([0-9]+)[^]]");
metrics_re = re.compile("depth=(-?[0-9]+) height=(-?[0-9]+)")
success = 0
page = ""
pos = 0
while 1:
match = page_re.search(dvipng_stdout, pos)
if match == None:
break
page = match.group(1)
pos = match.end()
match = metrics_re.search(dvipng_stdout, pos)
if match == None:
break
success = 1
# Calculate the 'ascent fraction'.
descent = string.atof(match.group(1))
ascent = string.atof(match.group(2))
frac = 0.5
if ascent >= 0 or descent >= 0:
if abs(ascent + descent) > 0.1:
frac = ascent / (ascent + descent)
# Sanity check
if frac < 0:
frac = 0.5
metrics.write("Snippet %s %f\n" % (page, frac))
pos = match.end() + 2
return success
def convert_to_ppm_format(pngtopnm, basename):
png_file_re = re.compile("\.png$")
for png_file in glob.glob("%s*.png" % basename):
ppm_file = png_file_re.sub(".ppm", png_file)
p2p_cmd = '%s "%s"' % (pngtopnm, png_file)
p2p_status, p2p_stdout = run_command(p2p_cmd)
if p2p_status != None:
error("Unable to convert %s to ppm format" % png_file)
ppm = open(ppm_file, 'w')
ppm.write(p2p_stdout)
os.remove(png_file)
def main(argv):
# Parse and manipulate the command line arguments.
if len(argv) != 6:
error(usage(argv[0]))
output_format = string.lower(argv[1])
dir, latex_file = os.path.split(argv[2])
if len(dir) != 0:
os.chdir(dir)
dpi = string.atoi(argv[3])
fg_color = make_texcolor(argv[4])
bg_color = make_texcolor(argv[5])
# External programs used by the script.
path = string.split(os.environ["PATH"], os.pathsep)
latex = find_exe_or_terminate(["pplatex", "latex2e", "latex"], path)
# This can go once dvipng becomes widespread.
dvipng = find_exe(["dvipng"], path)
if dvipng == None:
if output_format == "ppm":
# The data is input to legacy_conversion in as similar
# as possible a manner to that input to the code used in
# LyX 1.3.x.
vec = [ argv[0], argv[2], argv[3], argv[1], argv[4], argv[5] ]
return legacy_conversion(vec)
else:
error("The old 'dvi->ps->ppm' conversion requires "
"ppm as the output format")
pngtopnm = ""
if output_format == "ppm":
pngtopnm = find_exe_or_terminate(["pngtopnm"], path)
# Compile the latex file.
latex_call = '%s "%s"' % (latex, latex_file)
latex_status, latex_stdout = run_command(latex_call)
if latex_status != None:
error("%s failed to compile %s" \
% (os.path.basename(latex), latex_file))
# Run the dvi file through dvipng.
dvi_file = latex_file_re.sub(".dvi", latex_file)
dvipng_call = '%s -Ttight -depth -height -D %d -fg "%s" -bg "%s" "%s"' \
% (dvipng, dpi, fg_color, bg_color, dvi_file)
dvipng_status, dvipng_stdout = run_command(dvipng_call)
if dvipng_status != None:
error("%s failed to generate images from %s" \
% (os.path.basename(dvipng), dvi_file))
# Extract metrics info from dvipng_stdout.
metrics_file = latex_file_re.sub(".metrics", latex_file)
if not extract_metrics_info(dvipng_stdout, metrics_file):
error("Failed to extract metrics info from dvipng")
# Convert images to ppm format if necessary.
if output_format == "ppm":
convert_to_ppm_format(pngtopnm, latex_file_re.sub("", latex_file))
return 0
if __name__ == "__main__":
main(sys.argv)