lisp/muse-latex2png.el

   1 ;; muse-latex2png.el --- generate PNG images from inline LaTeX code
   2
   3 ;; Copyright (C) 2004, 2005 Ganesh Swami
   4 ;; Copyright (C) 2005 Free Software Foundation, Inc.
   5
   6 ;; Author: Ganesh Swami <ganesh AT iamganesh DOT com>
   7 ;; Created: May 01 2004
   8
   9 ;; This file is part of Emacs Muse.  It is not part of GNU Emacs.
  10
  11 ;; Emacs Muse is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published
  13 ;; by the Free Software Foundation; either version 2, or (at your
  14 ;; option) any later version.
  15
  16 ;; Emacs Muse is distributed in the hope that it will be useful, but
  17 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19 ;; General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with Emacs Muse; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  24 ;; Boston, MA 02110-1301, USA.
  25
  26 ;;; Commentary:
  27
  28 ;; Read The Fine Documentation at
  29 ;; http://www.sfu.ca/~gswamina/EmacsWikiBlog.html
  30
  31 ;; Michael Olson adapted this for Muse.
  32
  33 ;;; To Do:
  34
  35 ;; If we are publishing a LaTeX-based style, the
  36 ;; muse-publish-latex-tag function should insert the LaTeX code as-is.
  37
  38 ;;; Code
  39
  40 (require 'muse-publish)
  41
  42 (defvar latex2png-scale-factor 2.5
  43   "The scale factor to be used for sizing the resulting latex.")
  44 (defvar latex2png-fg "Black"
  45   "The foreground color.")
  46 (defvar latex2png-bg "Transparent"
  47   "The background color.")
  48
  49 (defun latex2png-move2pubdir (file prefix pubdir)
  50   "Move FILE to the PUBDIR folder.
  51
  52 This is done so that the resulting images do not clutter your
  53 main publishing directory.
  54
  55 Old files with PREFIX in the name are deleted."
  56   (if (and (file-exists-p file)
  57            (file-directory-p pubdir))
  58       (progn
  59         (copy-file file (concat pubdir (file-name-nondirectory file)) t)
  60         (delete-file file)
  61         (concat "./latex/" (file-name-nondirectory file)))
  62     (message "The latex folder does not exist!")))
  63
  64 (defun muse-publish-latex-tag (beg end attrs)
  65   (let ((end-marker (set-marker (make-marker) (1+ end)))
  66         (pubdir (concat (file-name-directory
  67                          muse-publishing-current-output-path)
  68                         "/latex/")))
  69     (save-restriction
  70       (narrow-to-region beg end)
  71       (let* ((text (buffer-substring-no-properties beg end))
  72              ;; the prefix given to the image file.
  73              (prefix (cdr (assoc "prefix" attrs)))
  74              ;; preamble (for extra options)
  75              (preamble (cdr (assoc "preamble" attrs)))
  76              ;; display inline or as a block
  77              (display (car (assoc "inline" attrs))))
  78         (delete-region beg end)
  79         (goto-char (point-min))
  80         (unless (file-directory-p pubdir)
  81           (make-directory pubdir))
  82         (muse-insert-markup
  83          "<img src=\""
  84          (latex2png-move2pubdir (latex2png text prefix preamble)
  85                                 prefix pubdir)
  86          "\" alt=\"latex2png equation\" "
  87          (if display (concat "class=\"latex-inline\"")
  88            (concat "class=\"latex-display\""))
  89          " />")
  90         (muse-insert-markup "<!-- " text "-->")
  91         (goto-char (point-max))))))
  92
  93 (defun latex2png (math prefix preamble)
  94   "Convert the MATH code into a png with PREFIX."
  95   (unless preamble
  96     (setq preamble ""))
  97   (let ((texfile (expand-file-name
  98                   (concat prefix "_"  (format "%d" (abs (sxhash math))))
  99                   (cond ((boundp 'temporary-file-directory)
 100                          temporary-file-directory)
 101                         ((fboundp 'temp-directory)
 102                          (temp-directory)))))
 103         (oldcddir default-directory))
 104     (with-temp-file (concat texfile ".tex")
 105       (insert (concat "\\documentclass{article}
 106 \\usepackage{fullpage}
 107 \\usepackage{amssymb}
 108 \\usepackage[usenames]{color}
 109 \\usepackage{amsmath}
 110 \\usepackage{latexsym}
 111 \\usepackage[mathscr]{eucal}\n" preamble
 112 "\n\\pagestyle{empty}
 113 \\begin{document}"
 114 "{"
 115  math
 116 "}\n"
 117 "\n\\end{document}\n\n")))
 118     (cd "/tmp")
 119     (call-process "latex" nil nil nil texfile)
 120     (if (file-exists-p (concat texfile ".dvi"))
 121         (progn
 122           (shell-command-to-string
 123            (concat "dvipng " texfile ".dvi -E "
 124                    " -fg " latex2png-fg
 125                    " -bg " latex2png-bg " -T tight"
 126                    " -x " (format  "%s" (* latex2png-scale-factor 1000))
 127                    " -y " (format  "%s" (* latex2png-scale-factor 1000))
 128                    " -o " texfile ".png"))
 129           (if (file-exists-p (concat texfile ".png"))
 130               (progn
 131                 (delete-file (concat texfile ".dvi"))
 132                 (delete-file (concat texfile ".tex"))
 133                 (delete-file (concat texfile ".aux"))
 134                 (delete-file (concat texfile ".log"))
 135                 (cd oldcddir)
 136                 (concat texfile ".png"))
 137             (message "Failed to create png file")))
 138       (message (concat "Failed to create dvi file " texfile)))))
 139
 140 ;;; Insinuate with muse-publish
 141
 142 (add-to-list 'muse-publish-markup-tags
 143              '("latex" t t muse-publish-latex-tag)
 144              t)
 145
 146 (provide 'muse-latex2png)
 147 ;;; muse-latex2png.el ends here