lisp/gs.el

   1 ;;; gs.el --- interface to Ghostscript
   2
   3 ;; Copyright (C) 1998 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: FSF
   6 ;; Keywords: internal
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 ;; Boston, MA 02111-1307, USA.
  24
  25 ;;; Commentary:
  26
  27 ;; This code is experimental.  Don't use it.
  28
  29 ;;; Code:
  30
  31 (defvar gs-program "gs"
  32   "The name of the Ghostscript interpreter.")
  33
  34
  35 (defvar gs-device "x11"
  36   "The Ghostscript device to use to produce images.")
  37
  38
  39 (defvar gs-options
  40   '("-q"
  41     ;"-dNOPAUSE"
  42     "-dBATCH"
  43     "-sDEVICE=<device>"
  44     "<file>")
  45   "List of command line arguments to pass to Ghostscript.
  46 Arguments may contain place-holders `<file>' for the name of the
  47 input file, and `<device>' for the device to use.")
  48
  49
  50 (defun gs-replace-in-string (string find repl)
  51   "Return STRING with all occurrences of FIND replaced by REPL.
  52 FIND is a regular expression."
  53   (while (string-match find string)
  54     (setq string (replace-match repl nil t string)))
  55   string)
  56
  57
  58 (defun gs-options (device file)
  59   "Return a list of command line options with place-holders replaced.
  60 DEVICE is the value to substitute for the place-holder `<device>',
  61 FILE is the value to substitute for the place-holder `<file>'."
  62   (mapcar #'(lambda (option)
  63               (setq option (gs-replace-in-string option "<device>" device)
  64                     option (gs-replace-in-string option "<file>" file)))
  65           gs-options))
  66
  67
  68 ;; The GHOSTVIEW property (taken from gv 3.5.8).
  69 ;;
  70 ;; Type:
  71 ;;
  72 ;; STRING
  73 ;;
  74 ;; Parameters:
  75 ;;
  76 ;; BPIXMAP ORIENT LLX LLY URX URY XDPI YDPI [LEFT BOTTOM TOP RIGHT]
  77 ;;
  78 ;; Scanf format: "%d %d %d %d %d %d %f %f %d %d %d %d"
  79 ;;
  80 ;; Explanation of parameters:
  81 ;;
  82 ;; BPIXMAP: pixmap id of the backing pixmap for the window.  If no
  83 ;; pixmap is to be used, this parameter should be zero.  This
  84 ;; parameter must be zero when drawing on a pixmap.
  85 ;;
  86 ;; ORIENT: orientation of the page.  The number represents clockwise
  87 ;; rotation of the paper in degrees.  Permitted values are 0, 90, 180,
  88 ;; 270.
  89 ;;
  90 ;; LLX, LLY, URX, URY: Bounding box of the drawable.  The bounding box
  91 ;; is specified in PostScript points in default user coordinates.
  92 ;;
  93 ;; XDPI, YDPI: Resolution of window.  (This can be derived from the
  94 ;; other parameters, but not without roundoff error.  These values are
  95 ;; included to avoid this error.)
  96 ;;
  97 ;; LEFT, BOTTOM, TOP, RIGHT: (optional) Margins around the window.
  98 ;; The margins extend the imageable area beyond the boundaries of the
  99 ;; window.  This is primarily used for popup zoom windows.  I have
 100 ;; encountered several instances of PostScript programs that position
 101 ;; themselves with respect to the imageable area.  The margins are
 102 ;; specified in PostScript points.  If omitted, the margins are
 103 ;; assumed to be 0.
 104
 105 (defun gs-width-in-pt (frame pixel-width)
 106   "Return, on FRAME, pixel width PIXEL-WIDTH tranlated to pt."
 107   (let ((mm (* (float pixel-width)
 108                (/ (float (x-display-mm-width frame))
 109                   (float (x-display-pixel-width frame))))))
 110     (/ (* 25.4 mm) 72.0)))
 111
 112
 113 (defun gs-height-in-pt (frame pixel-height)
 114   "Return, on FRAME, pixel height PIXEL-HEIGHT tranlated to pt."
 115   (let ((mm (* (float pixel-height)
 116                (/ (float (x-display-mm-height frame))
 117                   (float (x-display-pixel-height frame))))))
 118     (/ (* 25.4 mm) 72.0)))
 119
 120
 121 (defun gs-set-ghostview-window-prop (frame spec img-width img-height)
 122   "Set the `GHOSTVIEW' window property of FRAME.
 123 SPEC is a GS image specification.  IMG-WIDTH is the width of the
 124 requested image, and IMG-HEIGHT is the height of the requested
 125 image in pixels."
 126   (let* ((box (plist-get (cdr spec) :bounding-box))
 127          (llx (nth 0 box))
 128          (lly (nth 1 box))
 129          (urx (nth 2 box))
 130          (ury (nth 3 box))
 131          (rotation (or (plist-get (cdr spec) :rotate) 0))
 132          ;; The pixel width IMG-WIDTH of the pixmap gives the
 133          ;; dots, URX - LLX give the inch.
 134          (in-width (/ (- urx llx) 72.0))
 135          (in-height (/ (- ury lly) 72.0))
 136          (xdpi (/ img-width in-width))
 137          (ydpi (/ img-height in-height)))
 138     (x-change-window-property "GHOSTVIEW"
 139                               (format "0 %d %d %d %d %d %g %g"
 140                                       rotation llx lly urx ury xdpi ydpi)
 141                               frame)))
 142
 143
 144 (defun gs-set-ghostview-colors-window-prop (frame pixel-colors)
 145   "Set the `GHOSTVIEW_COLORS' environment variable depending on FRAME."
 146   (let ((mode (cond ((x-display-color-p frame) "Color")
 147                     ((x-display-grayscale-p frame) "Grayscale")
 148                     (t "Monochrome"))))
 149     (x-change-window-property "GHOSTVIEW_COLORS"
 150                               (format "%s %s" mode pixel-colors))))
 151
 152
 153 ;
 154 ;;;###autoload
 155 (defun gs-load-image (frame spec img-width img-height window-and-pixmap-id
 156                             pixel-colors)
 157   "Load a PS image for display on FRAME.
 158 SPEC is an image specification, IMG-HEIGHT and IMG-WIDTH are width
 159 and height of the image in pixels.  WINDOW-AND-PIXMAP-ID is a string of
 160 the form \"WINDOW-ID PIXMAP-ID\".  Value is non-nil if successful."
 161   (unwind-protect
 162       (let ((file (plist-get (cdr spec) :file))
 163             gs)
 164         (gs-set-ghostview-window-prop frame spec img-width img-height)
 165         (gs-set-ghostview-colors-window-prop frame pixel-colors)
 166         (setenv "GHOSTVIEW" window-and-pixmap-id)
 167         (setq gs (apply 'start-process "gs" "*GS*" gs-program
 168                         (gs-options gs-device file)))
 169         (process-kill-without-query gs)
 170         gs)
 171     nil))
 172
 173
 174 ;(defun gs-put-tiger ()
 175 ;  (let* ((ps-file "/usr/local/share/ghostscript/5.10/examples/tiger.ps")
 176 ;         (spec `(image :type ghostscript
 177 ;                       :pt-width 200 :pt-height 200
 178 ;                       :bounding-box (22 171 567 738)
 179 ;                       :file ,ps-file)))
 180 ;    (put-text-property 1 2 'display spec)))
 181 ;
 182
 183 (provide 'gs)
 184
 185 ;; gs.el ends here.