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 (defun gs-options (device file)
  50   "Return a list of command line options with place-holders replaced.
  51 DEVICE is the value to substitute for the place-holder `<device>',
  52 FILE is the value to substitute for the place-holder `<file>'."
  53   (mapcar #'(lambda (option)
  54               (setq option (replace-regexp-in-string "<device>" device option)
  55                     option (replace-regexp-in-string "<file>" file option)))
  56           gs-options))
  57
  58
  59 ;; The GHOSTVIEW property (taken from gv 3.5.8).
  60 ;;
  61 ;; Type:
  62 ;;
  63 ;; STRING
  64 ;;
  65 ;; Parameters:
  66 ;;
  67 ;; BPIXMAP ORIENT LLX LLY URX URY XDPI YDPI [LEFT BOTTOM TOP RIGHT]
  68 ;;
  69 ;; Scanf format: "%d %d %d %d %d %d %f %f %d %d %d %d"
  70 ;;
  71 ;; Explanation of parameters:
  72 ;;
  73 ;; BPIXMAP: pixmap id of the backing pixmap for the window.  If no
  74 ;; pixmap is to be used, this parameter should be zero.  This
  75 ;; parameter must be zero when drawing on a pixmap.
  76 ;;
  77 ;; ORIENT: orientation of the page.  The number represents clockwise
  78 ;; rotation of the paper in degrees.  Permitted values are 0, 90, 180,
  79 ;; 270.
  80 ;;
  81 ;; LLX, LLY, URX, URY: Bounding box of the drawable.  The bounding box
  82 ;; is specified in PostScript points in default user coordinates.
  83 ;;
  84 ;; XDPI, YDPI: Resolution of window.  (This can be derived from the
  85 ;; other parameters, but not without roundoff error.  These values are
  86 ;; included to avoid this error.)
  87 ;;
  88 ;; LEFT, BOTTOM, TOP, RIGHT: (optional) Margins around the window.
  89 ;; The margins extend the imageable area beyond the boundaries of the
  90 ;; window.  This is primarily used for popup zoom windows.  I have
  91 ;; encountered several instances of PostScript programs that position
  92 ;; themselves with respect to the imageable area.  The margins are
  93 ;; specified in PostScript points.  If omitted, the margins are
  94 ;; assumed to be 0.
  95
  96 (defun gs-width-in-pt (frame pixel-width)
  97   "Return, on FRAME, pixel width PIXEL-WIDTH tranlated to pt."
  98   (let ((mm (* (float pixel-width)
  99                (/ (float (x-display-mm-width frame))
 100                   (float (x-display-pixel-width frame))))))
 101     (/ (* 25.4 mm) 72.0)))
 102
 103
 104 (defun gs-height-in-pt (frame pixel-height)
 105   "Return, on FRAME, pixel height PIXEL-HEIGHT tranlated to pt."
 106   (let ((mm (* (float pixel-height)
 107                (/ (float (x-display-mm-height frame))
 108                   (float (x-display-pixel-height frame))))))
 109     (/ (* 25.4 mm) 72.0)))
 110
 111
 112 (defun gs-set-ghostview-window-prop (frame spec img-width img-height)
 113   "Set the `GHOSTVIEW' window property of FRAME.
 114 SPEC is a GS image specification.  IMG-WIDTH is the width of the
 115 requested image, and IMG-HEIGHT is the height of the requested
 116 image in pixels."
 117   (let* ((box (plist-get (cdr spec) :bounding-box))
 118          (llx (nth 0 box))
 119          (lly (nth 1 box))
 120          (urx (nth 2 box))
 121          (ury (nth 3 box))
 122          (rotation (or (plist-get (cdr spec) :rotate) 0))
 123          ;; The pixel width IMG-WIDTH of the pixmap gives the
 124          ;; dots, URX - LLX give the inch.
 125          (in-width (/ (- urx llx) 72.0))
 126          (in-height (/ (- ury lly) 72.0))
 127          (xdpi (/ img-width in-width))
 128          (ydpi (/ img-height in-height)))
 129     (x-change-window-property "GHOSTVIEW"
 130                               (format "0 %d %d %d %d %d %g %g"
 131                                       rotation llx lly urx ury xdpi ydpi)
 132                               frame)))
 133
 134
 135 (defun gs-set-ghostview-colors-window-prop (frame pixel-colors)
 136   "Set the `GHOSTVIEW_COLORS' environment variable depending on FRAME."
 137   (let ((mode (cond ((x-display-color-p frame) "Color")
 138                     ((x-display-grayscale-p frame) "Grayscale")
 139                     (t "Monochrome"))))
 140     (x-change-window-property "GHOSTVIEW_COLORS"
 141                               (format "%s %s" mode pixel-colors))))
 142
 143
 144 ;
 145 ;;;###autoload
 146 (defun gs-load-image (frame spec img-width img-height window-and-pixmap-id
 147                             pixel-colors)
 148   "Load a PS image for display on FRAME.
 149 SPEC is an image specification, IMG-HEIGHT and IMG-WIDTH are width
 150 and height of the image in pixels.  WINDOW-AND-PIXMAP-ID is a string of
 151 the form \"WINDOW-ID PIXMAP-ID\".  Value is non-nil if successful."
 152   (unwind-protect
 153       (let ((file (plist-get (cdr spec) :file))
 154             gs)
 155         (gs-set-ghostview-window-prop frame spec img-width img-height)
 156         (gs-set-ghostview-colors-window-prop frame pixel-colors)
 157         (setenv "GHOSTVIEW" window-and-pixmap-id)
 158         (setq gs (apply 'start-process "gs" "*GS*" gs-program
 159                         (gs-options gs-device file)))
 160         (process-kill-without-query gs)
 161         gs)
 162     nil))
 163
 164
 165 ;(defun gs-put-tiger ()
 166 ;  (let* ((ps-file "/usr/local/share/ghostscript/5.10/examples/tiger.ps")
 167 ;         (spec `(image :type postscript
 168 ;                       :pt-width 200 :pt-height 200
 169 ;                       :bounding-box (22 171 567 738)
 170 ;                       :file ,ps-file)))
 171 ;    (put-text-property 1 2 'display spec)))
 172 ;
 173
 174 (provide 'gs)
 175
 176 ;; gs.el ends here.