QUOTE(dnbdave @ Jul 23 2019, 18:40)

It boggles my mind how simple (for a desktop application anyway) this feature is, and that PicWalker's had it since 2004 at least, but I literally can't find another image viewer that will do the same thing period.
Now I get that Tenboro might not really want to implement this because of the likely resource strain it would place on the image servers or for other bandwith concerns. If it takes adding a hath perk or otherwise constraining the autoscroll so it's not unlimited that'd be fine too.
Just some ability to set it and forget it would be wonderful. MPV could use an update and this is a small ask I think far as feature additions go.
Tenb, whatcha think? Curious what your thoughts are.
Smooth scrolling is surprisingly hard. Even pixel-perfect "smooth" scrolling (which can look jerky) is quite hard. The human eyeball Mk1 is optimized to pick up exactly the kind of glitches it's hard to eliminate when you're working with pixels.
Add to that, HTML and Browsers try very hard to abstract away the tools you would use to write a smooth scroller in a native application because it's more valuable to have something that works the same everywhere than have something that's perfect in exactly one circumstance.
(There's also an argument against the use case, I for one can't read moving text. I hate scrolling marquees and having manga pages move when I try to read them seems like a terrible idea.)
All of that said, I did write this prototype:
[
hverse.gitlab.io]
https://hverse.gitlab.io/user-scripts/eh-mvp-plus.user.jsIt's built on the bones of Kutabe's MPVP and it's not feature complete, and I might have to revisit the MPV itself as at high scroll rates it exceeds the 5 requests/second limit of the API server and dies with a 503 (Service Unavailable).
There's a couple of lines at the top of the script (SCROLL_STRATEGY and SCROLL_FPS) you might have to edit. SCROLL_STRATEGY is either "auto" for instant-jump scrolling or "smooth" for trying to swoosh scrolling (using an easing function). In my experience, the "smooth" is actually quite juddery as it's expecting to accelerate and decelerate down the page to reach a specific point, not continually jump X times per second. SCROLL_FPS is how often it updates. Values under 10 are going to be noticeably jerky. Higher values will potentially lock up your browser as it hits 100% cpu utilization. (30 was about 40% cpu for me.)