X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=sixel.el;h=f2532e56ba5796b28935e8b9f120c5ed4ff06f1f;hb=6b9058e99e890e33246c6e4e3cad2d4dc81dd951;hp=cd7fd316d81203339e5c0d9ed5f8b6ebab428e37;hpb=c4291595d24b1ca19db14a675268cd87d168983b;p=sixel.git

diff --git a/sixel.el b/sixel.el
index cd7fd31..f2532e5 100644
--- a/sixel.el
+++ b/sixel.el
@@ -1,3 +1,18 @@
+;;; sixel.el --- minor mode for processing sixel graphics
+
+;; Copyright (C) 2019 Tim Vaughan
+
+;; Author: Tim Vaughan <tgvaughan@gmail.com>
+;; Created: 19 May 2019
+;; Version: 1.0.0
+;; Keywords: 
+;; Homepage: https://github.com/tgvaughan/sixel
+;; Package-Requires: ((emacs "25"))
+
+;;; Commentary:
+
+;;; Code:
+
 (defvar test-string
   (concat "q"
           "#0;2;0;0;0#1;2;100;100;0#2;2;0;100;0"
@@ -5,7 +20,6 @@
           "#2??GG????-"
           "#1!14@"))
 
-
 (defun sixel-get-params (string)
   "Retrieve the sixel parameters."
   (car (split-string string "q")))
@@ -14,22 +28,6 @@
   "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 (sixel n tag)
   "Set bits of SIXEL corresponding to N with to the value TAG."
   (dotimes (i 6)
@@ -37,54 +35,122 @@
         (aset sixel i tag))
     (setq n (/ n 2))))
 
-(defun sixel-tag-sixel-in-row (row-variable index char tag)
+(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 (symbol-value row-variable))))
-    (add-to-list row-variable (make-vector 6 nil)))
-  (let ((sixel (elt (symbol-value row-variable) index)))
-    (sixel-tag-bits sixel (- char 63) tag)))
-
-(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))
+  (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 sixel-current-colour tag)
-            (setq idx-in (match-end 0))))
-         ((string-match "^$" trunc-string)
-          (setq idx-out 0)
-          (setq idx-in (match-end 0 trunc-string)))
-         ((string-match "^!\\([0-9]+\\)\\([?-~]\\)" trunc-string)
-          (let ((repeat-count (string-to-number (match-string 1 trunc-string)))
-                (char (elt (match-string 2 trunc-string) 0)))
+         ((looking-at "#\\([0-9]+\\);\\([0-9]+\\);\\([0-9]+\\);\\([0-9]+\\);\\([0-9]+\\)")
+          (let ((tag (format "%02x" (string-to-number (match-string 1))))
+                (mode (match-string 2))
+                (r (string-to-number (match-string 3)))
+                (g (string-to-number (match-string 4)))
+                (b (string-to-number (match-string 5))))
+            (push (list tag r g b) colour-map)))
+
+         ((looking-at "#\\([0-9]+\\)")
+          (let ((tag (format "%02x" (string-to-number (match-string 1)))))
+            (setq current-colour tag)))
+
+         ((looking-at "\\$")
+          (setq idx-out 0))
+
+         ((looking-at "-")
+          (push (reverse this-row) rows)
+          (setq this-row nil)
+          (setq idx-out 0))
+
+         ((looking-at "!\\([0-9]+\\)\\([?-~]\\)")
+          (let ((repeat-count (string-to-number (match-string 1)))
+                (char (elt (match-string 2) 0)))
             (dotimes (i repeat-count)
-              (sixel-tag-sixel-in-row 'result idx-out char sixel-current-colour)
-              (setq idx-out (+1 idx-out)))))
-         ((string-match "^\\([?-~]\\)" trunc-string)
-          (let ((char (elt (match-string 1 trunc-string) 0)))
-            (sixel-tag-sixel-in-row 'result idx-out char sixel-current-colour))
-          (setq idx-out (+1 idx-out))))))))
-              
-(sixel-get-rows test-string)
+              (setq this-row
+                    (sixel-tag-sixel-in-row this-row idx-out char current-colour))
+              (setq idx-out (1+ idx-out)))))
+
+         ((looking-at "\\([?-~]\\)")
+          (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)))
+
+        (goto-char (match-end 0)))
+      (push (reverse this-row) rows)
+      (cons colour-map
+            (reverse rows)))))
+
+(defun sixel-image-colour-map (sixel-image)
+  "Extract colour map from SIXEL-DATA."
+  (car sixel-image))
+
+(defun sixel-image-sixels (sixel-image)
+  "Extract sixels from SIXEL-DATA."
+  (cdr sixel-image))
+
+(defun sixel-image-dims (sixel-image)
+  "Computes image width from SIXEL-DATA. Returns pair (width . height)."
+  (let ((sixels (sixel-image-sixels sixel-image)))
+    (cons
+     (apply #'max (mapcar (lambda (row) (length row)) sixels))
+     (length sixels))))
+
+(defun sixel-image-to-xpm-values (sixel-image)
+  (let* ((dims (sixel-image-dims sixel-image))
+         (colour-map (sixel-image-colour-map sixel-image))
+         (n-colours (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)
+  (let ((colour-map (sixel-image-colour-map sixel-image)))
+    (string-join
+     (mapcar (lambda (colour)
+               (concat
+                "\""
+                (elt colour 0) " "
+                "c #"
+                (format "%02x%02x%02x"
+                        (elt colour 1)
+                        (elt colour 2)
+                        (elt colour 3))
+                "\""))
+             colour-map)
+     ",")))
 
 (defun sixel-to-xpm (string)
-  "Converts the given sixel string into an XPM image."
+  "Returns 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)
+     ;; (sixel-data-to-XPM-pixels data)
+     "};")))
+
+         
 
-  (let* ((sp (split-string string "q"))
-         (control-string (car sp))
-         ())))
+;; sixel.el ends here