lyx_mirror/lib/scripts/lyxpreview2bitmap.py
Pavel Sanda f9f7c4a4bd Mostly documentation for the pythonic part of instant preview.
Patch from Ale.
http://www.mail-archive.com/lyx-devel@lists.lyx.org/msg167220.html


git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@38256 a592a061-630c-0410-9148-cb99ea01b6c8
2011-04-05 14:54:38 +00:00

393 lines
14 KiB
Python
Executable File

#! /usr/bin/env python
# -*- coding: utf-8 -*-
# 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-Åke 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;
# * dv2dt;
# * 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 six 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'.
# CONVERTER: the converter (optional). Default is latex.
# 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.
# What does this script do?
# 1) Call latex/pdflatex/xelatex/whatever (CONVERTER parameter)
# 2) If the output is a PDF fallback to legacy
# 3) Otherwise check each page of the DVI (with dv2dt) looking for
# PostScript literals, not well supported by dvipng. Pages
# containing them are passed to the legacy method in a new LaTeX file.
# 4) Call dvipng on the pages without PS literals
# 5) Join metrics info coming from both methods (legacy and dvipng)
# and write them to file
# dvipng is fast but gives problem in several cases, like with
# PSTricks, TikZ and other packages using PostScript literals
# for all these cases the legacy route is taken (step 3).
# Moreover dvipng can't work with PDF files, so, if the CONVERTER
# paramter is pdflatex we have to fallback to legacy route (step 2).
import glob, os, re, string, sys
from legacy_lyxpreview2ppm import legacy_conversion, \
legacy_conversion_step2, legacy_extract_metrics_info, filter_pages
from lyxpreview_tools import copyfileobj, error, find_exe, \
find_exe_or_terminate, make_texcolor, mkstemp, run_command, warning, \
write_metrics_info, join_metrics_and_rename
# Pre-compiled regular expressions.
latex_file_re = re.compile("\.tex$")
# PATH environment variable
path = string.split(os.environ["PATH"], os.pathsep)
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
# Returns a list of tuples containing page number and ascent fraction
# extracted from dvipng output.
# Use write_metrics_info to create the .metrics file with this info
def extract_metrics_info(dvipng_stdout):
# "\[[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
results = []
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
results.append((int(page), frac))
pos = match.end() + 2
if success == 0:
error("Failed to extract metrics info from dvipng")
return results
def color_pdf(latex_file, bg_color, fg_color):
use_preview_pdf_re = re.compile("(\s*\\\\usepackage\[[^]]+)((pdftex|xetex)\]{preview})")
tmp = mkstemp()
fg = ""
if fg_color != "0.000000,0.000000,0.000000":
fg = ' \\AtBeginDocument{\\let\\oldpreview\\preview\\renewcommand\\preview{\\oldpreview\\color[rgb]{%s}}}\n' % (fg_color)
success = 0
try:
for line in open(latex_file, 'r').readlines():
match = use_preview_pdf_re.match(line)
if match == None:
tmp.write(line)
continue
success = 1
tmp.write(" \\usepackage{color}\n" \
" \\pagecolor[rgb]{%s}\n" \
"%s" \
"%s\n" \
% (bg_color, fg, match.group()))
continue
except:
# Unable to open the file, but do nothing here because
# the calling function will act on the value of 'success'.
warning('Warning in color_pdf! Unable to open "%s"' % latex_file)
warning(`sys.exc_type` + ',' + `sys.exc_value`)
if success:
copyfileobj(tmp, open(latex_file,"wb"), 1)
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)
# Returns a tuple of:
# ps_pages: list of page indexes of pages containing PS literals
# page_count: total number of pages
# pages_parameter: parameter for dvipng to exclude pages with PostScript
def find_ps_pages(dvi_file):
# latex failed
# FIXME: try with pdflatex
if not os.path.isfile(dvi_file):
error("No DVI output.")
# Check for PostScript specials in the dvi, badly supported by dvipng
# This is required for correct rendering of PSTricks and TikZ
dv2dt = find_exe_or_terminate(["dv2dt"], path)
dv2dt_call = '%s "%s"' % (dv2dt, dvi_file)
# The output from dv2dt goes to stdout
dv2dt_status, dv2dt_output = run_command(dv2dt_call)
psliteral_re = re.compile("^special[1-4] [0-9]+ '(\"|ps:)")
# Parse the dtl file looking for PostScript specials.
# Pages using PostScript specials are recorded in ps_pages and then
# used to create a different LaTeX file for processing in legacy mode.
page_has_ps = False
page_index = 0
ps_pages = []
for line in dv2dt_output.split("\n"):
# New page
if line.startswith("bop"):
page_has_ps = False
page_index += 1
# End of page
if line.startswith("eop") and page_has_ps:
# We save in a list all the PostScript pages
ps_pages.append(page_index)
if psliteral_re.match(line) != None:
# Literal PostScript special detected!
page_has_ps = True
# Create the -pp parameter for dvipng
pages_parameter = ""
if len(ps_pages) > 0 and len(ps_pages) < page_index:
# Don't process Postscript pages with dvipng by selecting the
# wanted pages through the -pp parameter. E.g., dvipng -pp 4-12,14,64
pages_parameter = " -pp "
skip = True
last = -1
# Use page ranges, as a list of pages could exceed command line
# maximum length (especially under Win32)
for index in xrange(1, page_index + 1):
if (not index in ps_pages) and skip:
# We were skipping pages but current page shouldn't be skipped.
# Add this page to -pp, it could stay alone or become the
# start of a range.
pages_parameter += str(index)
# Save the starting index to avoid things such as "11-11"
last = index
# We're not skipping anymore
skip = False
elif (index in ps_pages) and (not skip):
# We weren't skipping but current page should be skipped
if last != index - 1:
# If the start index of the range is the previous page
# then it's not a range
pages_parameter += "-" + str(index - 1)
# Add a separator
pages_parameter += ","
# Now we're skipping
skip = True
# Remove the trailing separator
pages_parameter = pages_parameter.rstrip(",")
# We've to manage the case in which the last page is closing a range
if (not index in ps_pages) and (not skip) and (last != index):
pages_parameter += "-" + str(index)
return (ps_pages, page_index, pages_parameter)
def main(argv):
# Parse and manipulate the command line arguments.
if len(argv) != 6 and len(argv) != 7:
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], False)
bg_color = make_texcolor(argv[5], False)
fg_color_gr = make_texcolor(argv[4], True)
bg_color_gr = make_texcolor(argv[5], True)
# External programs used by the script.
if len(argv) == 7:
latex = argv[6]
else:
latex = find_exe_or_terminate(["latex", "pplatex", "platex", "latex2e"], path)
# This can go once dvipng becomes widespread.
dvipng = find_exe(["dvipng"], path)
if dvipng == None:
# 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], latex ]
return legacy_conversion(vec)
pngtopnm = ""
if output_format == "ppm":
pngtopnm = find_exe_or_terminate(["pngtopnm"], path)
# Move color information for PDF into the latex file.
if not color_pdf(latex_file, bg_color_gr, fg_color_gr):
error("Unable to move color info into the latex file")
# Compile the latex file.
latex_call = '%s "%s"' % (latex, latex_file)
latex_status, latex_stdout = run_command(latex_call)
if latex_status != None:
warning("%s had problems compiling %s" \
% (os.path.basename(latex), latex_file))
if latex == "xelatex":
warning("Using XeTeX")
# FIXME: skip unnecessary dvips trial in legacy_conversion_step2
return legacy_conversion_step2(latex_file, dpi, output_format)
# The dvi output file name
dvi_file = latex_file_re.sub(".dvi", latex_file)
# If there's no DVI output, look for PDF and go to legacy or fail
if not os.path.isfile(dvi_file):
# No DVI, is there a PDF?
pdf_file = latex_file_re.sub(".pdf", latex_file)
if os.path.isfile(pdf_file):
warning("%s produced a PDF output, fallback to legacy." % \
(os.path.basename(latex)))
return legacy_conversion_step2(latex_file, dpi, output_format)
else:
error("No DVI or PDF output. %s failed." \
% (os.path.basename(latex)))
# Look for PS literals in DVI pages
# ps_pages: list of page indexes of pages containing PS literals
# page_count: total number of pages
# pages_parameter: parameter for dvipng to exclude pages with PostScript
(ps_pages, page_count, pages_parameter) = find_ps_pages(dvi_file)
# If all pages need PostScript, directly use the legacy method.
if len(ps_pages) == page_count:
vec = [argv[0], argv[2], argv[3], argv[1], argv[4], argv[5], latex]
return legacy_conversion(vec)
# Run the dvi file through dvipng.
dvipng_call = '%s -Ttight -depth -height -D %d -fg "%s" -bg "%s" %s "%s"' \
% (dvipng, dpi, fg_color, bg_color, pages_parameter, dvi_file)
dvipng_status, dvipng_stdout = run_command(dvipng_call)
if dvipng_status != None:
warning("%s failed to generate images from %s... fallback to legacy method" \
% (os.path.basename(dvipng), dvi_file))
# FIXME: skip unnecessary dvips trial in legacy_conversion_step2
return legacy_conversion_step2(latex_file, dpi, output_format)
# Extract metrics info from dvipng_stdout.
metrics_file = latex_file_re.sub(".metrics", latex_file)
dvipng_metrics = extract_metrics_info(dvipng_stdout)
# If some pages require PostScript pass them to legacy method
if len(ps_pages) > 0:
# Create a new LaTeX file just for the snippets needing
# the legacy method
legacy_latex_file = latex_file_re.sub("_legacy.tex", latex_file)
filter_pages(latex_file, legacy_latex_file, ps_pages)
# Pass the new LaTeX file to the legacy method
vec = [ argv[0], latex_file_re.sub("_legacy.tex", argv[2]), \
argv[3], argv[1], argv[4], argv[5], latex ]
legacy_metrics = legacy_conversion(vec, True)[1]
# Now we need to mix metrics data from dvipng and the legacy method
original_bitmap = latex_file_re.sub("%d." + output_format, legacy_latex_file)
destination_bitmap = latex_file_re.sub("%d." + output_format, latex_file)
# Join metrics from dvipng and legacy, and rename legacy bitmaps
join_metrics_and_rename(dvipng_metrics, legacy_metrics, ps_pages,
original_bitmap, destination_bitmap)
# Convert images to ppm format if necessary.
if output_format == "ppm":
convert_to_ppm_format(pngtopnm, latex_file_re.sub("", latex_file))
# Actually create the .metrics file
write_metrics_info(dvipng_metrics, metrics_file)
return (0, dvipng_metrics)
if __name__ == "__main__":
exit(main(sys.argv)[0])