Re: [off-topic] E-readers and Org-Mode

["Juan Manuel Macías" <maciaschain@posteo.net>]

Hi, Eric,

Fraga, Eric writes:

> Putting aside the org mode aspect for the moment, I highly recommend the
> reMarkable [1] tablet for reading PDF documents.  I have owned one for
> several years now and use it all the time (in particular for reading 300
> pages theses on the train...).  I do not use org mode on it, however.
>
> For Emacs, some people have hacked the reMarkable.  I have not tried any
> of the hacks but the Parabola initiative [2] seems the most advanced.
>
> HTH,
> eric
>
> Footnotes:
> [1]  https://remarkable.com/
>
> [2]  http://www.davisr.me/projects/parabola-rm/,

Thanks a lot for the pointers. I didn't know about it, but something
like reMarkable is what I'm looking for, a device that serves as a
substitute for printed paper in A4 and reading on a desktop screen. The
Parabola hack looks pretty cool (that's supposed to be equivalent to
being able to use Emacs with pdf-tools package). I have seen that the
Wi-Fi does not work (it is not essential for me) but the OTG does. I
will investigate about it... In that device line I had also seen the
Onyx Boox Note. But recently I read that this brand has a sad history of
violating the Linux kernel GPL license.

N.B.: I have to say that I have never used an e-ink device. The
''closest'' thing is this hack I wrote, for use especially on my old
Thinkpad in high light environments. It uses Picom compositor and
Redshift. And, after messing around with the parameters a lot, I found
these that I'm quite satisfied with. It also helps to apply a monochrome
theme in Emacs. Of course, it is nothing more than a simulation to try
to reduce the light emission as much as possible:

#+begin_src emacs-lisp

(setq picom-command "picom --backend glx --glx-fshader-win \"uniform sampler2D tex; uniform float opacity; void main() { vec4 color = texture2D(tex, gl_TexCoord[0].xy); gl_FragColor = vec4(vec3(0.2126 * color.r + 0.7152 * color.g + 0.0722 * color.b) * opacity, color.a * opacity); }\"")

(setq redshift-command "redshift -l 40.5914000:-4.1474000 -b 0.9:0.9 -t 4000k:4000k -g 0.5:0.5:0.8")

(defun my-poor-man-eink-toggle ()
  (interactive)
  (when (equal (process-status "picom") 'run)
    (kill-process "picom"))
  (if (and (not (equal (process-status "picom-g") 'run))
	   (not (equal (process-status "redshifg-g") 'run)))
      (progn
	(shell-command "killall picom") 
	(shell-command "killall redshift-gtk")
	(shell-command "redshift -x")
	(start-process-shell-command "redshift-g" nil redshift-command)
	(start-process-shell-command "picom-g" nil picom-command))
    (kill-process "picom-g")
    (kill-process "redshift-g")
    (shell-command "redshift -x")
    (start-process-shell-command "redshift" nil "redshift-gtk -c ~/.redshift.conf")))
#+end_src