Re-enable preview generation using dvips, gs and pnmcrop.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@8675 a592a061-630c-0410-9148-cb99ea01b6c8

lib/ChangeLog

@@ -1,3 +1,10 @@
+2004-04-19  Angus Leeming  <leeming@lyx.org>
+
+	* scripts/legacy_lyxpreview2ppm.py: new file. Called automatically
+	by lyxpreview2bitmap.py if dvipng is not found.
+
+	* scripts/lyxpreview2bitmap.py (main): changes to suit.
+
 2004-04-19  Angus Leeming  <leeming@lyx.org>
 
 	* scripts/lyxpreview2bitmap.py (extract_metrics_info): make the

lib/scripts/legacy_lyxpreview2ppm.py

@@ -0,0 +1,278 @@
+#! /usr/bin/env python
+
+# file legacy_lyxpreview2ppm.py
+# This file is part of LyX, the document processor.
+# Licence details can be found in the file COPYING.
+
+# author Angus Leeming
+
+# Full author contact details are available in file CREDITS
+
+# This script converts a LaTeX file to a bunch of ppm files using the
+# deprecated dvi->ps->ppm conversion route.
+
+# If possible, please grab 'dvipng'; it's faster and more robust.
+# This legacy support will be removed one day...
+
+import glob, os, re, string, sys
+import pipes, shutil, tempfile
+
+
+# Pre-compiled regular expressions.
+latex_file_re = re.compile("\.tex$")
+
+
+def usage(prog_name):
+    return "Usage: %s <latex file> <dpi> <fg color> <bg color>\n"\
+           "\twhere the colors are hexadecimal strings, eg 'faf0e6'"\
+           % prog_name
+
+
+def error(message):
+    sys.stderr.write(message + '\n')
+    sys.exit(1)
+
+
+def find_exe(candidates, path):
+    for prog in candidates:
+        for directory in path:
+            full_path = os.path.join(directory, prog)
+            if os.access(full_path, os.X_OK):
+                return full_path
+
+    return None
+
+
+def find_exe_or_terminate(candidates, path):
+    exe = find_exe(candidates, path)
+    if exe == None:
+        error("Unable to find executable from '%s'" % string.join(candidates))
+
+    return exe
+
+
+def run_command(cmd):
+    handle = os.popen(cmd, 'r')
+    cmd_stdout = handle.read()
+    cmd_status = handle.close()
+
+    return cmd_status, cmd_stdout
+
+
+def extract_metrics_info(log_file, metrics_file):
+    metrics = open(metrics_file, 'w')
+
+    log_re = re.compile("Preview: ([ST])")
+    data_re = re.compile("(-?[0-9]+) (-?[0-9]+) (-?[0-9]+) (-?[0-9]+)")
+
+    tp_ascent  = 0.0
+    tp_descent = 0.0
+
+    success = 0
+    for line in open(log_file, 'r').readlines():
+        match = log_re.match(line)
+        if match == None:
+            continue
+
+        snippet = (match.group(1) == 'S')
+        success = 1
+        match = data_re.search(line)
+        if match == None:
+            error("Unexpected data in %s\n%s" % (log_file, line))
+
+        if snippet:
+            ascent  = string.atof(match.group(2)) + tp_ascent
+            descent = string.atof(match.group(3)) - tp_descent
+
+            frac = 0.5
+            if abs(ascent + descent) > 0.1:
+                frac = ascent / (ascent + descent)
+
+                metrics.write("Snippet %s %f\n" % (match.group(1), frac))
+
+        else:
+            tp_descent = string.atof(match.group(2))
+            tp_ascent  = string.atof(match.group(4))
+
+    return success
+
+
+def extract_resolution(log_file, dpi):
+    fontsize_re = re.compile("Preview: Fontsize")
+    magnification_re = re.compile("Preview: Magnification")
+    extract_decimal_re = re.compile("([0-9\.]+)")
+    extract_integer_re = re.compile("([0-9]+)")
+
+    found_fontsize = 0
+    found_magnification = 0
+
+    # Default values
+    magnification = 1000.0
+    fontsize = 0.0
+
+    for line in open(log_file, 'r').readlines():
+        if found_fontsize and found_magnification:
+            break
+
+        if not found_fontsize:
+            match = fontsize_re.match(line)
+            if match != None:
+                match = extract_decimal_re.search(line)
+                if match == None:
+                    error("Unable to parse: %s" % line)
+                fontsize = string.atof(match.group(1))
+                found_fontsize = 1
+                continue
+
+        if not found_magnification:
+            match = magnification_re.match(line)
+            if match != None:
+                match = extract_integer_re.search(line)
+                if match == None:
+                    error("Unable to parse: %s" % line)
+                magnification = string.atof(match.group(1))
+                found_magnification = 1
+                continue
+
+    return dpi * (10.0 / fontsize) * (1000.0 / magnification)
+
+    
+def get_version_info():
+    version_re = re.compile("([0-9])\.([0-9])")
+
+    match = version_re.match(sys.version)
+    if match == None:
+        error("Unable to extract version info from 'sys.version'")
+
+    return string.atoi(match.group(1)), string.atoi(match.group(2))
+
+
+def mkstemp():
+    major, minor = get_version_info()
+
+    if major >= 2 and minor >= 3:
+        return tempfile.mkstemp()
+
+    tmp_name = tempfile.mktemp()
+    return open(tmp_name, 'w'), tmp_name
+
+
+def legacy_latex_file(latex_file, fg_color, bg_color):
+    use_preview_re = re.compile("(\\\\usepackage\[[^]]+)(\]{preview})")
+
+    tmp, tmp_name = mkstemp()
+
+    success = 0
+    for line in open(latex_file, 'r').readlines():
+        match = use_preview_re.match(line)
+        if match == None:
+            tmp.write(line)
+            continue
+
+        success = 1
+        tmp.write("%s,dvips,tightpage%s\n\n" \
+                  "\\AtBeginDocument{\\AtBeginDvi{%%\n" \
+                  "\\special{!userdict begin/bop-hook{//bop-hook exec\n" \
+                  "<%s%s>{255 div}forall setrgbcolor\n" \
+                  "clippath fill setrgbcolor}bind def end}}}\n" \
+                  % (match.group(1), match.group(2), fg_color, bg_color))
+
+    if success:
+        tmp.close()
+        shutil.copy(tmp_name, latex_file)
+    os.remove(tmp_name)
+
+    return success
+
+
+def crop_files(pnmcrop, basename):
+    t = pipes.Template()
+    t.append("%s -left $IN" % pnmcrop, 'f-')
+    t.append("%s -right > $OUT" % pnmcrop, '-f')
+
+    tmp, tmp_name = mkstemp()
+    tmp.close()
+    os.remove(tmp_name)
+
+    for file in glob.glob("%s*.ppm" % basename):
+        if t.copy(file, tmp_name):
+            shutil.copy(tmp_name, file)
+        os.remove(tmp_name)
+
+
+def legacy_conversion(argv):
+    # Parse and manipulate the command line arguments.
+    if len(argv) != 6:
+        error(usage(argv[0]))
+
+    # Ignore argv[1]
+
+    dir, latex_file = os.path.split(argv[2])
+    if len(dir) != 0:
+        os.chdir(dir)
+
+    dpi = string.atoi(argv[3])
+    fg_color = argv[4]
+    bg_color = argv[5]
+
+    # External programs used by the script.
+    path = string.split(os.getenv("PATH"), os.pathsep)
+    latex   = find_exe_or_terminate(["pplatex", "latex2e", "latex"], path)
+    dvips   = find_exe_or_terminate(["dvips"], path)
+    gs      = find_exe_or_terminate(["gs"], path)
+    pnmcrop = find_exe(["pnmcrop"], path)
+
+    # Move color information into the latex file.
+    if not legacy_latex_file(latex_file, fg_color, bg_color):
+        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:
+        error("%s failed to compile %s" \
+              % (os.path.basename(latex), latex_file))
+
+    # Run the dvi file through dvips.
+    dvi_file = latex_file_re.sub(".dvi", latex_file)
+    ps_file  = latex_file_re.sub(".ps",  latex_file)
+
+    dvips_call = "%s -o %s %s" % (dvips, ps_file, dvi_file)
+    
+    dvips_status, dvips_stdout = run_command(dvips_call)
+    if dvips_status != None:
+        error("Failed: %s %s" % (os.path.basename(dvips), dvi_file))
+
+    # Extract resolution data for gs from the log file.
+    log_file = latex_file_re.sub(".log", latex_file)
+    resolution = extract_resolution(log_file, dpi)
+
+    # Older versions of gs have problems with a large degree of
+    # anti-aliasing at high resolutions
+    alpha = 4
+    if resolution > 150:
+        alpha = 2
+
+    # Generate the bitmap images
+    gs_call = "%s -dNOPAUSE -dBATCH -dSAFER -sDEVICE=pnmraw " \
+              "-sOutputFile=%s%%d.ppm " \
+              "-dGraphicsAlphaBit=%d -dTextAlphaBits=%d " \
+              "-r%f %s" \
+              % (gs, latex_file_re.sub("", latex_file), \
+                 alpha, alpha, resolution, ps_file)
+
+    gs_status, gs_stdout = run_command(gs_call)
+    if gs_status != None:
+        error("Failed: %s %s" % (os.path.basename(gs), ps_file))
+
+    # Crop the images
+    if pnmcrop != None:
+        crop_files(pnmcrop, latex_file_re.sub("", latex_file))
+
+    # Extract metrics info from the log file.
+    metrics_file = latex_file_re.sub(".metrics", latex_file)
+    if not extract_metrics_info(log_file, metrics_file):
+        error("Failed to extract metrics info from %s" % log_file)
+
+    return 0

lib/scripts/lyxpreview2bitmap.py

@@ -44,6 +44,7 @@
 #   the images correctly on the screen.
 
 import glob, os, re, string, sys
+from legacy_lyxpreview2ppm import legacy_conversion
 
 
 # Pre-compiled regular expressions.
@@ -159,7 +160,16 @@ def main(argv):
     # External programs used by the script.
     path = string.split(os.getenv("PATH"), os.pathsep)
     latex = find_exe_or_terminate(["pplatex", "latex2e", "latex"], path)
-    dvipng = find_exe_or_terminate(["dvipng"], path)
+
+    # This can go once dvipng becomes widespread.
+    dvipng = find_exe(["dvipng"], path)
+    if dvipng == None:
+        if output_format == "ppm":
+            return legacy_conversion(argv)
+        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)
@@ -191,6 +201,7 @@ def main(argv):
     if output_format == "ppm":
         convert_to_ppm_format(pngtopnm, latex_file_re.sub("", latex_file))
 
+    return 0
 
 if __name__ == "__main__":
     main(sys.argv)