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 is free software; you can redistribute it and/or modify it
  10 ;; under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation; either version 2, or (at your option)
  12 ;; any later version.
  13
  14 ;; this software is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17 ;; General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  21 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  22 ;; Boston, MA 02111-1307, USA.
  23
  24 ;;; Commentary:
  25
  26 ;; Read The Fine Documentation at
  27 ;; http://www.sfu.ca/~gswamina/EmacsWikiBlog.html
  28
  29 ;; Michael Olson adapted this for Muse.
  30
  31 ;;; To Do:
  32
  33 ;; If we are publishing a LaTeX-based style, the
  34 ;; muse-publish-latex-tag function should insert the LaTeX code as-is.
  35
  36 ;;; Code
  37
  38 (require 'muse-publish)
  39
  40 (defvar latex2png-scale-factor 2.5
  41   "The scale factor to be used for sizing the resulting latex.")
  42 (defvar latex2png-fg "Black"
  43   "The foreground color.")
  44 (defvar latex2png-bg "Transparent"
  45   "The background color.")
  46
  47 (defun latex2png-move2pubdir (file prefix pubdir)
  48   "Move FILE to the PUBDIR folder.
  49
  50 This is done so that the resulting images do not clutter your
  51 main publishing directory.
  52
  53 Old files with PREFIX in the name are deleted."
  54   (if (and (file-exists-p file)
  55            (file-directory-p pubdir))
  56       (progn
  57         (copy-file file (concat pubdir (file-name-nondirectory file)) t)
  58         (delete-file file)
  59         (concat "./latex/" (file-name-nondirectory file)))
  60     (message "The latex folder does not exist!")))
  61
  62 (defun muse-publish-latex-tag (beg end attrs)
  63   (let ((end-marker (set-marker (make-marker) (1+ end)))
  64         (pubdir (concat (file-name-directory
  65                          muse-publishing-current-output-path)
  66                         "/latex/")))
  67     (save-restriction
  68       (narrow-to-region beg end)
  69       (let* ((text (buffer-substring-no-properties beg end))
  70              ;; the prefix given to the image file.
  71              (prefix (cdr (assoc "prefix" attrs)))
  72              ;; preamble (for extra options)
  73              (preamble (cdr (assoc "preamble" attrs)))
  74              ;; display inline or as a block
  75              (display (car (assoc "inline" attrs))))
  76         (delete-region beg end)
  77         (goto-char (point-min))
  78         (unless (file-directory-p pubdir)
  79           (make-directory pubdir))
  80         (muse-insert-markup
  81          "<img src=\""
  82          (latex2png-move2pubdir (latex2png text prefix preamble)
  83                                 prefix pubdir)
  84          "\" alt=\"latex2png equation\" "
  85          (if display (concat "class=\"latex-inline\"")
  86            (concat "class=\"latex-display\""))
  87          " />")
  88         (muse-insert-markup "<!-- " text "-->")
  89         (goto-char (point-max))))))
  90
  91 (defun latex2png (math prefix preamble)
  92   "Convert the MATH code into a png with PREFIX."
  93   (unless preamble
  94     (setq preamble ""))
  95   (let ((texfile (expand-file-name
  96                   (concat prefix "_"  (format "%d" (abs (sxhash math))))
  97                   (cond ((boundp 'temporary-file-directory)
  98                          temporary-file-directory)
  99                         ((fboundp 'temp-directory)
 100                          (temp-directory)))))
 101         (oldcddir default-directory))
 102     (with-temp-file (concat texfile ".tex")
 103       (insert (concat "\\documentclass{article}
 104 \\usepackage{fullpage}
 105 \\usepackage{amssymb}
 106 \\usepackage[usenames]{color}
 107 \\usepackage{amsmath}
 108 \\usepackage{latexsym}
 109 \\usepackage[mathscr]{eucal}\n" preamble
 110 "\n\\pagestyle{empty}
 111 \\begin{document}"
 112 "{"
 113  math
 114 "}\n"
 115 "\n\\end{document}\n\n")))
 116     (cd "/tmp")
 117     (call-process "latex" nil nil nil texfile)
 118     (if (file-exists-p (concat texfile ".dvi"))
 119         (progn
 120           (shell-command-to-string
 121            (concat "dvipng " texfile ".dvi -E "
 122                    " -fg " latex2png-fg
 123                    " -bg " latex2png-bg " -T tight"
 124                    " -x " (format  "%s" (* latex2png-scale-factor 1000))
 125                    " -y " (format  "%s" (* latex2png-scale-factor 1000))
 126                    " -o " texfile ".png"))
 127           (if (file-exists-p (concat texfile ".png"))
 128               (progn
 129                 (delete-file (concat texfile ".dvi"))
 130                 (delete-file (concat texfile ".tex"))
 131                 (delete-file (concat texfile ".aux"))
 132                 (delete-file (concat texfile ".log"))
 133                 (cd oldcddir)
 134                 (concat texfile ".png"))
 135             (message "Failed to create png file")))
 136       (message (concat "Failed to create dvi file " texfile)))))
 137
 138 ;;; Insinuate with muse-publish
 139
 140 (add-to-list 'muse-publish-markup-tags
 141              '("latex" t t muse-publish-latex-tag)
 142              t)
 143
 144 (provide 'muse-latex2png)
 145 ;;; muse-latex2png.el ends here