#! /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; # * 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)