X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?p=sixel.git;a=blobdiff_plain;f=sixel.el;h=87d387d728f317615747c1a904652ce36f2cc346;hp=6bcef4eb794d772bd816912cf3ab31fef9f4220d;hb=HEAD;hpb=d248b8db1153ba5b0139fb52812d0487c7f196c2 diff --git a/sixel.el b/sixel.el index 6bcef4e..87d387d 100644 --- a/sixel.el +++ b/sixel.el @@ -1,92 +1,238 @@ +;;; sixel.el --- minor mode for processing sixel graphics + +;; Copyright (C) 2019 Tim Vaughan + +;; Author: Tim Vaughan +;; Created: 19 May 2019 +;; Version: 1.0.0 +;; 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 . + +;;; Code: + (defvar test-string - (concat "q" + (concat "Pq" "#0;2;0;0;0#1;2;100;100;0#2;2;0;100;0" "#1~~@@vv@@~~@@~~$" - "#2??GG????-" - "#1!14@")) - + "#2??}}GG}}??}}??-" + "#1!14@\\")) (defun sixel-get-params (string) "Retrieve the sixel parameters." - (car (split-string string "q"))) + (car (split-string (substring string 2) "q"))) (defun sixel-get-data (string) "Retrieve data string." (substring string (1+ (string-match "q" string)))) -(defvar sixel-colour-map nil - "Map of two-character names to RGB colour triples.") - -(defvar sixel-current-colour nil - "Current colour.") - -(defun sixel-compute-row-length (string) - (apply 'max - (mapcar - (lambda (substr) - (apply 'max (mapcar - (lambda (subsubstr) - (length (subsubstr))) - (split-string substr "$")))) - (split-string string -)))) - -(defun sixel-tag-bits (n tag bit-count) - "Create a list of length BIT-COUNT with the elements corresponding to the -true bits of N set to TAG." - (if (= bit-count 0) - nil - (cons (if (= (% n 2) 1) - tag - nil) - (sixel-tag-bits (/ n 2) tag (1- bit-count))))) - -(defun sixel-make-sixel-from-char (char tag) - "Retrieve sequence of bits to be set." - (sixel-tag-bits (- char 63) tag 6)) - -(defun sixel-union (sixel1 sixel2) - "Returns a union of the two sixels, SIXEL1 and SIXEL2. -When both sixels specify a tag for the same pixel, the tag -from SIXEL2 wins." - (seq-mapn (lambda (tag1 tag2) - (or tag2 tag1)) - sixel1 sixel2)) - -(defun sixel-process-row (string) - (let ((idx-in 0) - (idx-out 0) - result) - (while (< idx-in (length string)) - (let (trunc-string (substring string index-in)) +(defun sixel-tag-bits (sixel n tag) + "Set bits of SIXEL corresponding to N with to the value TAG." + (dotimes (i 6) + (if (= (% n 2) 1) + (aset sixel i tag)) + (setq n (/ n 2)))) + +(defun sixel-tag-sixel-in-row (row index char tag) + "Tag the bits of the sixel at INDEX in the list identified by +the variable ROW-VARIABLE corresponding to input character CHAR +with TAG." + (while (not (< index (length row))) + (push (make-vector 6 nil) row)) + (let ((sixel (elt row (- (length row) 1 index)))) + (sixel-tag-bits sixel (- char 63) tag)) + row) + +(defun sixel-process-data (string) + "Convert STRING into a list of lists representing individual sixels. +Returns a sixel image object." + (with-temp-buffer + (insert string) + (goto-char (point-min)) + (let ((idx-out 0) + this-row rows + current-colour colour-map + finished) + (while (not finished) (cond - ((string-match "^#\\([0-9]+\\);\\([0-9]+\\);\\([0-9]+\\);\\([0-9]+\\);\\([0-9]+\\)" - trunc-string) - (let ((tag (intern (string-to (match-string 1 trunc-string)))) - (mode (match-string 2 trunc-string)) - (r (string-to-number (match-string 3 trunc-string))) - (g (string-to-number (match-string 4 trunc-string))) - (b (string-to-number (match-string 5 trunc-string)))) - (add-to-list 'sixel-colour-map (list (tag r g b))) - (setq idx-in (match-end 0)))) - ((string-match "^#\\([0-9]+\\)" trunc-string) - (let ((tag (intern (match-string 1 trunc-string)))) - (setq current-colour tag) - (setq idx-in (match-end 0)))) - ((string-match "^!\\([0-9]+\\)\\([?-~]\\)" trunc-string) - (let ((repeat-count (string-to-number (match-string 1 trunc-string))) - (char (elt (match-string 2 trunc-string) 0))) + ;; 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)) + (r (string-to-number (match-string 3))) + (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))) (dotimes (i repeat-count) - (unless (< idx-out (length result)) - (add-to-list result (make-vector 6 nil))) - (let ((sixel (elt result idx-out)))))))))))) - - + (setq this-row + (sixel-tag-sixel-in-row this-row idx-out char current-colour)) + (setq idx-out (1+ idx-out))))) + ;; 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)))) + ;; Termination sequence: + ((looking-at "\\\\") + (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-IMAGE." + (car sixel-image)) + +(defun sixel-image-sixels (sixel-image) + "Extract sixels from SIXEL-IMAGE." + (cdr sixel-image)) -(sixel-get-rows test-string) +(defun sixel-image-dims (sixel-image) + "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 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)))) + (concat "\"" + (number-to-string (car dims)) " " + (number-to-string (cdr dims)) " " + (number-to-string n-colours) " 2\""))) + +(defun sixel-image-to-xpm-colours (sixel-image) + "Produce colour definitions component of XPM representation of SIXEL-IMAGE." + (let ((colour-map (sixel-image-colour-map sixel-image))) + (concat + (string-join + (mapcar (lambda (colour) + (concat + "\"" + (elt colour 0) " " + "c #" + (format "%02x%02x%02x" + (/ (* 255 (elt colour 1)) 100) + (/ (* 255 (elt colour 2)) 100) + (/ (* 255 (elt colour 3)) 100)) + "\"")) + colour-map) + ",\n") + ",\n" + "\"-- c #000000\""))) + +(defun sixel-image-to-xpm-pixels (sixel-image) + "Produce pixels component of XPM representation of SIXEL-IMAGE." + (concat + "\"" + (string-join + (mapcar (lambda (sixel-row) + (string-join + (mapcar (lambda (i) + (string-join + (mapcar (lambda (sixel) + (let ((pixel (elt sixel i))) + (if pixel + pixel + "--"))) + sixel-row))) + (number-sequence 0 5)) + "\",\n\"")) + (sixel-image-sixels sixel-image)) + "\",\n\"") + "\"")) (defun sixel-to-xpm (string) - "Converts the given sixel string into an XPM image." + "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-pad-rows (sixel-process-data data-string)))) + (if (string-prefix-p "P" 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 "P[[:ascii:]]*\\\\" 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) - (let* ((sp (split-string string "q")) - (control-string (car sp)) - ()))) +(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