Re: Implementing image support for kitty terminal

[Akib Azmain Turja]

Jose A Ortega Ruiz <jao@gnu.org> writes:

> On Wed, Sep 07 2022, Tomas Hlavaty wrote:
>
>> On Wed 07 Sep 2022 at 21:11, Eli Zaretskii <eliz@gnu.org> wrote:
>>> In particular, the current model of image display
>>> in the Emacs display engine is that an image is basically considered a
>>> single very large character, from the screen layout POV.
>>
>> Are you talking about GUI emacs?
>> Is that not different in tty emacs?
>> I thought that the tty emacs has no concept of image (so far?).
>>
>>> I guess
>>> that's not what you have in mind for the above, so IMO it's important
>>> to come up with an alternative model that would somehow fit with the
>>> current display code with only minor changes, if we want this not to
>>> be too complex.
>>
>> For example, the tty based w3m web browser optionally supports images.
>> It reserves space w*h chars on the tty and then uses external program
>> to draw the image in the right place.
>>
>> I guess tty emacs would also need to reserve a w*h chars rectangle on
>> the tty and then send the right escape code to fill that gap with the
>> image.
>>
>> First, tty emacs would need to understand images instead of throwing
>> error.  At least their dimensions.  Maybe using some library or even in
>> elisp, for example like this
>> https://logand.com/sw/emacs-framebuffer/file/emacs-framebuffer.el.html#l286
>> I have not figured out, how to actually plug it into upstream emacs, as
>> this seems to require a lot of changes to C code.
>
> fwiw, in the kitty case, image libraries are going to be almost for sure
> available, it being an x11/wayland application.  so an emacs compiled
> with image support (but not necessarily linking against any x libs)
> doesn't seem like a strong requirement.  in that scenario, determining
> the size of an image wouldn't needed a lot of C code, would it? and, if
> those libraries are not available, a call to "file foo.png" is (at least
> in my system) telling me the size of foo.png... kind of hacky, of
> course, but as a first step maybe good enough.
>
>> Second, tty emacs would need to somehow reserve rectangle for the image.
>> This might be lots of work I guess.
>
> i was hoping this wouldn't be the case... at least when running inside
> terminal emulators, emacs nox seems pretty dexterous lying out windows
> and filly them with content, and i reckoned it must have a pretty good
> idea of their sizes.  but maybe i'm too optimistic :)
>
>> Third, there would have to be a piece of code which actually draws the
>> image.  In case of kitty terminal, the image path and coordinates would
>> be sent to the tty using the kitty terminal protocol.
>
> (as an aside, this would also work for other terminals like konsole or
> wayst, which support the protocol).
>
> cheers,
> jao

What?  You need to send the path of the image?  How would this work for
a SSH session?

-- 
Akib Azmain Turja

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