Request to scale image in image-viewer-mode to fit the buffer size

[Dima-369]

For instance, if you open a very large image, it is cut and not fully displayed:

In Emacs (by default, I think) the image is resized to fit the buffer's width and height for a good preview size.

I used this 3000x3000px image: https://fastly.picsum.photos/id/653/3000/3000.jpg?hmac=8ikcT_sejQ03UptLre2ZC6uV_QJIKk-6s_7-muUcem4

Here is how it looks like in Emacs for me:

[vindarel]

2 cents because I didn't know the keys before:

• image-zoom-[out/in] bound to C - - and C - +
• image-zoom-reset C - 0

[vindarel]

We added the keys +, - and 0 on the main branch.

[Dima-369]

I tested this and (fit-to-screen) does not work properly for the 3000x3000px image and my screen resolution. It triggers the (t nil) case in (cond). If I change (fit-to-screen buffer) to (fit-to-height buffer) in (open-image-buffer), it properly works for me.

So even with the current commit, I see the same state as in the issue description.

[vindarel]

ah damn! Thanks for testing. I'll need to test more with your input and send another PR.

[Sasanidas]

(ping @Dima-369 ) Did this PR https://github.com/lem-project/lem/pull/875 solved the issue?

[Dima-369]

Hmm, M-x image-fit-to-screen does not really work at all. See the video:

https://github.com/lem-project/lem/assets/15002298/f40f1be1-6446-4d50-ab52-57313de15803

[Sasanidas]

(ping @vindarel to maybe help)

[vindarel]

• does it work with your original 3000x3000 image?
• in this use case, is it the following:
  • small image, fit to screen does nothing (I wouldn't be surprised, might not be a bug but a feature : p )
  • fit to width and fit to height work
  • fit to screen again does nothing
  • rezise window, fit to screen does nothing
  • ?

(can't test right now, annoying breaking changes in my Lem)

[Dima-369]

does it work with your original 3000x3000 image?

Yeah, then it works just fine, but not for the smaller one.

in this use case, is it the following:

Yup, that's it. fit to screen does nothing when the image is already larger than the viewport.

[vindarel]

@Dima-369 It was a feature, there was a check that the image was smaller :p Should be good now.