Accessibility smooth zoom

[majstomphorst]

I hope I’ve posted this in the right place and that someone is willing and able to answer my question.

I am a visually impaired user, and my question regards the screen magnification accessibility settings. Specifically, in Pop!_OS: COSMIC Settings -> Accessibility -> Magnifier -> 'Enable mouse or touchpad zoom with Super + scroll'.

I recently installed the latest Pop!_OS 24.04 LTS on my old laptop (a 2014 MacBook Pro), and I was thrilled to see that smooth scrolling and zooming worked right out of the box with the trackpad.

However, when I connect a mouse (whether it's my Logitech MX Master 3 or a generic one), the behavior changes. The zoom level increases in steps based on the physical clicks of the scroll wheel and is no longer responsive; it jumps rather than zooming smoothly. Can anybody explain why there is a difference between the trackpad zoom (which is perfectly smooth, responsive, and exactly what I want) and the mouse wheel zoom?

macOS has this same feature, but it zooms smoothly with a mouse as well. This smooth zoom is something I cannot live without, and I would love to find a viable option outside of a Mac or expensive paid software.

I am more than willing to put time into this if someone could point me in the right direction. I'm a software developer by trade, so I'm happy to sink some hours into figuring out how to get it to work. In the meantime, if anybody could provide some information, I would be incredibly grateful!

The good stuff: .mp4 example trackpad
https://github.com/user-attachments/assets/6449ebda-946c-49cb-b0c5-d2c85ebcb6e8

The can be better stuff: .mp4 example mouse wheel
https://github.com/user-attachments/assets/d5a4e51d-1923-40ff-bf85-9fca2576f513

To be honest, while the smoothness is a "nice to have," the responsiveness is a "must-have" for me. If anyone knows how to achieve this outside of macOS, please let me know. I've been looking for a solution for years and haven't found a high-quality alternative yet.

With kind regards,

[tgrushka]

Hi @majstomphorst , I just now saw your discussion and noticed the same annoyance as a visually impaired user myself. I submitted a fix for this which was merged on May 20, so not sure when it will land in your release (it has landed for me on cachyOS, which is based on Arch).

The problem was that the animation easing function was set to EaseInOutCubic and "restarting" every click of the wheel, so every time you clicked the wheel, the zoom animation would "start over" from zero and then accelerate, causing an annoying lag. I ended up changing it to Linear and that seemed to fix it for me and the maintainers.

The issue was in the compositor. I am also working on a couple of other magnifier improvements.

Here is the issue: pop-os/cosmic-comp#2380

and the pull request: pop-os/cosmic-comp#2381