Make fringe of the same width as a mono char

global.org

@@ -364,11 +364,54 @@
 ;    (hlinum-activate)
    #+END_SRC
    Add marker for current line in the fringe (see
-   [https://github.com/kyanagi/fringe-current-line])
+   [https://github.com/kyanagi/fringe-current-line] and
+   [https://github.com/nschum/fringe-helper.el])
    #+BEGIN_SRC emacs-lisp
-      (require 'fringe-current-line)
-      (global-fringe-current-line-mode 1)
-      (setq fcl-fringe-bitmap 'right-triangle)
+     (fringe-mode 10)
+     (require 'fringe-current-line)
+     (global-fringe-current-line-mode 1)
+
+     (defun +-fringe-helper-decimal (&rest strings)
+     "Convert STRINGS into a vector usable for `define-fringe-bitmap'.
+     Each string in STRINGS represents a line of the fringe bitmap.
+     Periods (.) are background-colored pixel; Xs are foreground-colored. The
+     fringe bitmap always is aligned to the right. If the fringe has half
+     width, only the left 4 pixels of an 8 pixel bitmap will be shown.
+     For example, the following code defines a diagonal line.
+     \(+-fringe-helper-decimal
+     \"XX......\"
+     \"..XX....\"
+     \"....XX..\"
+     \"......XX\"\)"
+       (unless (cdr strings)
+         (setq strings (split-string (car strings) "\n")))
+       (apply 'vector
+         (mapcar
+           (lambda (str)
+             (let ((num 0))
+               (dolist (c (string-to-list str))
+                 (setq num (+ (* num 2) (if (eq c ?.) 0 1))))
+               num))
+           strings)))
+     (define-fringe-bitmap '+-cursor-left-fringe-bitmap (+-fringe-helper-decimal
+       "x......."
+       "xx......"
+       "xxx....."
+       "xxxx...."
+       "xxxxx..."
+       "xxxxxx.."
+       "xxxxxxx."
+       "xxxxxxxx"
+       "xxxxxxx."
+       "xxxxxx.."
+       "xxxxx..."
+       "xxxx...."
+       "xxx....."
+       "xx......"
+       "x.......") nil nil 'center)
+
+
+     (setq fcl-fringe-bitmap '+-cursor-left-fringe-bitmap)
    #+END_SRC
 
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