Sixel image cut off horizontally

[Aonodensetsu]

Issue description

outside tmux:

inside tmux -f /dev/null:

The cutoff point seems to depend on the tmux pane width, the images are taken with one pane at 344 columns.
Weirdly, the wider the terminal, the less image is visible, at 64 columns it reaches the right side and is cut off "naturally", at 65 columns it does not even reach the right side.

Image link

Required information

• tmux version (tmux -V): tmux next-3.6 (master 35ad72e), configured with --enable-sixel
• Platform (uname -sp): Linux unknown (debian 6.1.140-1 x86_64)
• Terminal in use (xterm, rxvt, etc): Windows Terminal, ssh
• $TERM inside tmux (echo $TERM): tmux-256color
• $TERM outside tmux (echo $TERM): xterm-256color
• Logs from tmux (tmux kill-server; tmux -vv new): client, server, out

[nicm]

Hmm, tmux seems to want to crop to the right size but maybe it is not actually doing it...

Can you please give a copy of the exact SIXEL image you are using (so img2sixel tattoo.png >tattoo.sixel)?

Does this always happen or does it only happen when you only one pane? What if you have two panes, horizontally or vertically?

[Aonodensetsu]

I'll send a six when I get home. With more vertical splits the image gets proportionally even smaller. Did not test horizontal panes as I'm using Windows Terminal in _quake mode (the issue persists outside of _quake).

Adding -w $(tput cols) or the tmux display query for columns to img2sixel makes the whole image show, squashed into the space where the cutoff happens

[nicm]

Oh so it sounds like tmux isn't cutting off the image but instead img2sixel is getting the wrong idea of the width...

[nicm]

What do these show:

tput cols
echo $COLUMNS
resize
printf '\033[18t'; cat

[Aonodensetsu]

i don't have resize installed but the rest all report the correct number of columns, both outside tmux and inside it

however the cutoff happens only inside tmux

[nicm]

Maybe it is using TIOCSWINSZ to get the size but if that was wrong then all programs would be broken

You may have to ask the img2sixel developers why it is getting the wrong size by default because all the mechanisms available to it seem to be correct.

[Aonodensetsu]

ssh -t srv, exec bash --norc --noprofile
tput cols: 120, echo $COLUMNS: 120, printf '\033[18t': ^[[8;40;120t

by the img2sixel --help output, -w is given in pixels not columns, at font width 10 that gives 1200 pixels for a full width image, and behaves as expected outside tmux

img2sixel -w 1200 /var/www/dot/misc/tattoo.png >tattoo.six, tmux -f /dev/null, exec bash --norc --noprofile

tput cols: 120, echo $COLUMNS: 120, printf '\033[18t': ^[[8;39;120t

which is equivalent to running img2sixel in tmux, so the tmux environment does not influence sixel generation, note the empty lines below the image in tmux

at 80 cols, 24(-1 for tmux bar) rows, the cutoff seems to be at 640 pixels

at 100 cols, 30 rows, 600 pixels

at 120 cols, 40 rows, 600 pixels

at 240 cols, 40 rows, 500 pixels

at 344 cols, 40 rows, my maximum and the _quake width, the cutoff is around 350 pixels

accessing from my phone over termux, which does not support sixel, i get SIXEL IMAGE (75x5)+++... in landscape mode and SIXEL IMAGE (56x5)+++... in portrait mode (full screen width), outside of tmux it of course throws the escape sequences in plaintext

six image

[nicm]

I don't really know what you mean by all this. If you pipe the output from img2sixel to a file outside tmux, and then cat the file inside tmux, is it correct or is it incorrect?

[Aonodensetsu]

i showed my commands

• created then saved sixel to file outside tmux, image 1
• cat inside tmux, image 2
• changing the terminal width changes the cutoff point

[nicm]

You didn't say anything about cat in your comment. This file works fine for me both inside and outside tmux in WezTerm:

Do you only see this problem in Windows Terminal or do you also see it in, for example, xterm?

[Aonodensetsu]

the cat is in the image...

wezterm through x11forwarding shows correct output

[nicm]

Show me updated log files please using cat of the same file.

[Aonodensetsu]

on wez or wt?