This fixes the current implementation, which does not delete an image if
an application first erases the image and then spawns a new transparent
image in its place. The reason it didn't work before was because the two
operations were handled at different stages in the rendering pipeline.
Old images are automatically deleted if a new image is spawned over
them. This prevents them from piling up and choking the terminal when
viewing animated gifs.
Now if you use the latest version of Chafa to view the gifs, it
will set the transparency attribute (P2=1) to all sixel images
regardless of whether they are transparent or not. This prevents the
auto-delete from working because if the image is transparent, we can't
delete any images behind it.
The solution is that since Chafa fills the animation frames with an
opaque black background color, we treat the images as non-transparent if
they don't have any transparent pixels. This keeps the auto-delete
running with the new Chafa.
Although the solution works now, it may not be a long-term solution.
In the current implementation, when text is written over an image, we
have to cut the entire text line out of the image, regardless of how
long the text is. It doesn't look good, but it was a design choice for
the following reasons:
1) To keep the sixel engine as fast as possible
2) Most applications do not write text on the images anyway
To bring the st terminal in line with other terminals that support
sixels, I have now improved the sixel renderer so that the images can
now have gaps, which allows the text to be printed inside the images.
The changes should not affect performance in normal cases. Only when the
renderer has to deal with the text there might be some performance hits
depending on how many gaps there are in the images.
Patch by Mikhail Kot <to@myrrc.dev>
With some modifications to behave more like xterm (see note below).
Example:
printf '\033[48;2;255:0:0mtest\n'
https://invisible-island.net/xterm/ctlseqs/ctlseqs.html
Some notes:
"CSI Pm m Character Attributes (SGR).
[...]
o xterm allows either colons (standard) or semicolons
(legacy) to separate the subparameters (but after the
first colon, colons must be used).
P2 selects how the terminal draws the background color.
P2 Meaning
0 or 2 (default) Pixel positions specified as 0 are set to the
current background color.
1 Pixel positions specified as 0 remain at their
current color.
Both modes are now supported.
Ref. https://www.vt100.net/docs/vt3xx-gp/chapter14.html
With this patch, st will reset its window title when an empty string is
given as the terminal title. For example:
printf "\033]0;\007"
Some applications, like termdown, expect this functionality. xterm
implements it, but it seems that most other terminal emulators don't.
In any case, I don't see why there should ever be a case where the st
window doesn't have a title property.
Ref.
https://git.suckless.org/st/commit/497a75638291454875ba1ec8d484c7f3d6f41d66.html
* adds missing function prototype
* move xgetcolor() prototype to win.h (that's where all the other x.c
func prototype seems to be declared at)
* check for snprintf error/truncation
* reduces code duplication for osc 10/11/12
* unify osc_color_response() and osc4_color_response() into a single function
the latter two was suggested by Quentin Rameau in his patch review on
the hackers list.
ref.
https://git.suckless.org/st/commit/8629d9a1da72cc18568a8f146307b0e939b77ebf.html
The general reasoning is that the vim browse patch is very invasive,
has a high level of complexity, and is incompatible with a significant
number of other patches and it complicates further maintenance.
Additionally the patch has its own scrollback mechanism which seemingly
did not work properly - and nobody seems to have complained about this
since the patch was added back in May 2021.
If you want to try out the vim browse patch then I would recommend having
a play around with the patch author's own build that has this patch
integrated:
- https://github.com/juliusHuelsmann/st-history-vim
- https://github.com/juliusHuelsmann/st
Alternatively a tag has been added to this repository that refers to the
last commit that still has the vim browse patch:
- https://github.com/bakkeby/st-flexipatch/tree/VIM_BROWSE_PATCH
* sixel: remove black bars from sixel images
When the images don't fully cover the text cells, black bars are added
to them. This fix removes those bars, but if you need the old behavior,
you can restore it by setting 'sixelremovebars' to zero in config.h
* sixel: fix a potential memory leak
* sixel: improve behavior with text reflow
* sixel: prevent animated gifs from choking the terminal
Animated gifs constantly spawn new images that eventually choke the
terminal because the old animation frames are kept in the image buffer.
This fix removes overlapping images from the image buffer and prevents
them from piling up.
* sixel: add zooming and clipping
* sixel: copying bulk of changes
* sixel: move sixel_parser_parse() and add missing sequences and blocks (#113)
- Move sixel_parser_parse() from tputc() to twrite()
- Add missing 8452, DECSDM, XTSMGRAPHICS and XTWINOPS sequences
- Add more conditional blocks for the scrollback and sync patches
- Remove unused reflow_y from ImageList. It is only used for the
scrollback-reflow patch in st-sx.
* sixel: update vtiden to VT200 family
* sixel: fix scrolling issues inside tmux (#114)
tmux is using the scrolling region and sequence to clear the screen
below the shell prompt. This peculiar behavior caused the tscrollup()
function to be called, which always scrolled the images regardless of
whether they were inside the region or not. So the images moved out of
place whenever the bottom of the screen was cleared. This fix checks
that the images are inside the region before scrolling them.
* sixel: prevent images from being deleted when resizing (#115)
This fixes resizing issues outside of tmux not inside.
* Rewriting tresize logic based on veltza's proposed implementation in PR #115
* tresize: correction for tscrollup call when scrollback patch is used
---------
Co-authored-by: veltza <106755522+veltza@users.noreply.github.com>
The handler for 'S' final character does not check for a private
marker. This can cause a conflict with a sequence called 'XTSMGRAPHICS'
which also has an 'S' final character, but uses the private marker '?'.
Without checking for a private marker, st will perform a scroll up
operation when XTSMGRAPHICS is seen, which can cause unexpected display
artifacts.
ref.
https://git.suckless.org/st/commit/a3f7420310be0fd778ef9fe2abf20edc2d8dc81a.html
...support for transparency. Technically, the sixels do not have transparency,
but empty pixels are now rendered with the current background color instead
of black to make the them appear transparent. Same goes for the black bars.
The current background color makes them disappear.
There is one technical limitation with the alpha focus highlight patch.
The alpha value and background color is taken from the current background color,
so when the window is unfocused, images may have the wrong alpha and/or
background color. This can't be fixed easily.
