;; Copyright (C) 2019 Tim Vaughan
-;; Author: Tim Vaughan <tgvaughan@gmail.com>
+;; Author: Tim Vaughan <plugd@thelambdalab.xyz>
;; Created: 19 May 2019
;; Version: 1.0.0
-;; Keywords:
-;; Homepage: https://github.com/tgvaughan/sixel
-;; Package-Requires: ((emacs "25"))
+;; Keywords:
+;; Homepage: gopher://thelambdalab.xyz/1/projects/sixel
+;; Package-Requires: ((emacs "26"))
;;; Commentary:
+;; This file is not part of GNU Emacs.
+
+;; This program is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this file. If not, see <http://www.gnu.org/licenses/>.
+
;;; Code:
(defvar test-string
- (concat "q"
+ (concat "\ePq"
"#0;2;0;0;0#1;2;100;100;0#2;2;0;100;0"
"#1~~@@vv@@~~@@~~$"
"#2??}}GG}}??}}??-"
- "#1!14@"))
+ "#1!14@\e\\"))
(defun sixel-get-params (string)
"Retrieve the sixel parameters."
- (car (split-string string "q")))
+ (car (split-string (substring string 2) "q")))
(defun sixel-get-data (string)
"Retrieve data string."
finished)
(while (not finished)
(cond
+ ;; Define colour:
((looking-at "#\\([0-9]+\\);\\([0-9]+\\);\\([0-9]+\\);\\([0-9]+\\);\\([0-9]+\\)")
(let ((tag (format "%02x" (string-to-number (match-string 1))))
(mode (match-string 2))
(g (string-to-number (match-string 4)))
(b (string-to-number (match-string 5))))
(push (list tag r g b) colour-map)))
-
+ ;; Set current colour:
((looking-at "#\\([0-9]+\\)")
(let ((tag (format "%02x" (string-to-number (match-string 1)))))
(setq current-colour tag)))
-
+ ;; Carriage return:
((looking-at "\\$")
(setq idx-out 0))
-
+ ;; New line:
((looking-at "-")
(push (reverse this-row) rows)
(setq this-row nil)
(setq idx-out 0))
-
+ ;; RLE sixel char sequence:
((looking-at "!\\([0-9]+\\)\\([?-~]\\)")
(let ((repeat-count (string-to-number (match-string 1)))
(char (elt (match-string 2) 0)))
(setq this-row
(sixel-tag-sixel-in-row this-row idx-out char current-colour))
(setq idx-out (1+ idx-out)))))
-
- ((looking-at "\\([?-~]\\)")
+ ;; Sixel char:
+ ((looking-at "\\([?-~]\\)") ; Sixel char
(let ((char (elt (match-string 1) 0)))
(setq this-row
(sixel-tag-sixel-in-row this-row idx-out char current-colour))
(setq idx-out (1+ idx-out))))
-
- (t (setq finished t)))
-
+ ;; Termination sequence:
+ ((looking-at "\e\\\\")
+ (setq finished t))
+ ;; Skip other char:
+ ((looking-at "[[:ascii:]]")))
(goto-char (match-end 0)))
(push (reverse this-row) rows)
(cons colour-map
(reverse rows)))))
+(defun sixel-pad-rows (sixel-image)
+ "Pad out contents of rows in SIXEL-IMAGE so that all rows are the same length."
+ (let ((width (car (sixel-image-dims sixel-image)))
+ (rows (cdr sixel-image)))
+ (dotimes (row-idx (length rows))
+ (let* ((row-cdr (nthcdr row-idx rows))
+ (row-width (length (car row-cdr))))
+ (if (< row-width width)
+ (setcar row-cdr (append (car row-cdr)
+ (make-list (- width row-width)
+ [nil nil nil nil nil nil])))))))
+ sixel-image)
+
(defun sixel-image-colour-map (sixel-image)
- "Extract colour map from SIXEL-DATA."
+ "Extract colour map from SIXEL-IMAGE."
(car sixel-image))
(defun sixel-image-sixels (sixel-image)
- "Extract sixels from SIXEL-DATA."
+ "Extract sixels from SIXEL-IMAGE."
(cdr sixel-image))
(defun sixel-image-dims (sixel-image)
- "Computes image width from SIXEL-DATA. Returns pair (width . height)."
+ "Compute image width from SIXEL-IMAGE. Return pair (width . height)."
(let ((sixels (sixel-image-sixels sixel-image)))
(cons
(apply #'max (mapcar (lambda (row) (length row)) sixels))
(* 6 (length sixels)))))
(defun sixel-image-to-xpm-values (sixel-image)
- "Produce string representing parameter values component of XPM
-representation of SIXEL-IMAGE."
+ "Produce parameter values component of XPM representation of SIXEL-IMAGE."
(let* ((dims (sixel-image-dims sixel-image))
(colour-map (sixel-image-colour-map sixel-image))
(n-colours (1+ (length colour-map))))
(number-to-string n-colours) " 2\"")))
(defun sixel-image-to-xpm-colours (sixel-image)
- "Produce string representing colour definitions component of XPM
-representation of SIXEL-IMAGE."
+ "Produce colour definitions component of XPM representation of SIXEL-IMAGE."
(let ((colour-map (sixel-image-colour-map sixel-image)))
(concat
(string-join
(elt colour 0) " "
"c #"
(format "%02x%02x%02x"
- (elt colour 1)
- (elt colour 2)
- (elt colour 3))
+ (/ (* 255 (elt colour 1)) 100)
+ (/ (* 255 (elt colour 2)) 100)
+ (/ (* 255 (elt colour 3)) 100))
"\""))
colour-map)
",\n")
"\"-- c #000000\"")))
(defun sixel-image-to-xpm-pixels (sixel-image)
- "Produce string representating pixels component of XPM representation
-of SIXEL-IMAGE."
+ "Produce pixels component of XPM representation of SIXEL-IMAGE."
(concat
"\""
(string-join
"\""))
(defun sixel-to-xpm (string)
- "Returns an XPM image representation of the SIXEL graphic encoded in STRING."
+ "Return an XPM image representation of the SIXEL graphic encoded in STRING."
(let* ((param-string (sixel-get-params string))
(data-string (sixel-get-data string))
- (sixel-image (sixel-process-data data-string)))
- (concat
- "/* XPM */"
- "static char * pixmap[] = {"
- (sixel-image-to-xpm-values sixel-image) ",\n"
- (sixel-image-to-xpm-colours sixel-image) ",\n"
- (sixel-image-to-xpm-pixels sixel-image) "};")))
-
-;; sixel.el ends here
+ (sixel-image (sixel-pad-rows (sixel-process-data data-string))))
+ (if (string-prefix-p "\eP" string)
+ (concat
+ "/* XPM */"
+ "static char * pixmap[] = {"
+ (sixel-image-to-xpm-values sixel-image) ",\n"
+ (sixel-image-to-xpm-colours sixel-image) ",\n"
+ (sixel-image-to-xpm-pixels sixel-image) "};")
+ (error "Incorrecly formatted sixel string"))))
+
+(defun sixel-render-images-in-buffer ()
+ "Find and render any sixel images in the current buffer."
+ (interactive)
+ (save-excursion
+ (goto-char (point-min))
+ (while (re-search-forward "\eP[[:ascii:]]*\e\\\\" nil t)
+ (let ((sixel-string (match-string 0))
+ (inhibit-read-only t))
+ (delete-region (match-beginning 0)
+ (match-end 0))
+ (insert-image
+ (create-image (sixel-to-xpm sixel-string) 'xpm t))
+ (insert "\n")))))
+
+(defgroup sixel nil
+ "Render sixel images."
+ :group 'multimedia)
+
+(define-minor-mode sixel-mode
+ "A minor mode which renders sixel graphics." nil "sixel" nil
+ (add-hook 'after-change-functions
+ (lambda (start end size)
+ (sixel-render-images-in-buffer)
+ (message "Render complete."))
+ nil t))
+
+;;; sixel.el ends here