I tried out Zen Browser recently, and one of the many good things about it that I noticed, is how smooth the scrolling feels.
I thought: “surely it's not zen-specific!” and turns out that its smoothness is due to about:config settings you can set in any firefox :D
The biggest / most important change, that will make your scrolling a lot smoother, is setting general.smoothScroll.msdPhysics.enabled to true.
Honestly, I'm not sure why it isn't true by default! (in non-zen firefoxi)
But of course, I didn't stop there. Let's take a look at the other relevant settings.
First of all, I'll point out that the other general.smoothScroll.* settings, that aren't in the msdPhysics section, no longer apply — so you can pretty much just ignore them.
Unsure if that's intentional or a bug honestly; I remember seeing some issue that claimed this to be a bug 👀
Anyway!
There are two quite core settings:
= 100
= 100
Pretty self-explanatory — these two multiply the horizontal / vertical scrolling speed.
The baseline (but not necessarily the default) is 100 — you can come back to these later to more directly express “please faster” and “please slower”.
I ended up sticking with 100 for both, however.
= 300
= 900
= 300
“Spring” is an animation type.
The constant here is somewhat of an arbitrary number, in not sure which range, but the main idea is that lower is more draggy / slow / smooth, and higher is more abrupt / fast / jumpy.
By setting the begin and slowdown springs to a lower number, 300, both starting and ending a scroll feels very smooth and gentle, without being too slow.
The regular constant, though, I have no clue does what!
At least, I wasn't able to find a notable difference in my experimentation.
But I set it to 900 for it to feel more “tight”
= 12
= 1.3
These two I never quite got do what, either.
= 3
This, as far as I understand, basically means “every how many milliseconds is the smooth scrolling logic calculated?”
It's 12 by default, so 3 is a lot more smooth! At least by an eye test.
Here's how all these settings applied look like!
Keep in mind, there might be some fps loss in the recording, so it likely looks even smoother irl.
The blog post I was scrolling.
mouse mode
I don't actually use my real mouse when scrolling, most of the time;
I have two keys in my mouse mode that send WheelUp and WheelDown, so that's how I scroll most of the time.
Did a bit of an optimization on the side of my mouse mode, to make scrolling even smoother.
o (mwheel-up 30 60)
i (mwheel-down 30 60)
w (mwheel-left 20 60)
r (mwheel-right 20 60)
The default “length” of a singular scroll (a nudge?) is 120 — it's noticeably more jumpy than the 60 I'm now using.
To account for the loss of speed, I send the nudges more frequently: 30 instead of whatever value I used to have prior.
This is what you're seeing me use in the recording, btw!
Kanata does warn me, though, that setting the length to something else than a multiple of 120 is error-prone — some programs might get utterly confused.
I already came across an example of that happening, with oculante; but it wouldn't be the last issue oculante has anyway :p
So I'll gladly optimize for the #1 place where I scroll — my browser 😌
acceleration
There are another two settings that are interesting to play with.
= 2
= 20
Start is “after how many nudges do we increase the scrolling speed?” and factor is “by how many times?”
Using these two, you can make it so you start to scroll faster after some amount of continuous scrolling.
Unfortunately factor has to be an integer :< so we can't speed up just slightly.
I ended up going without this feature (setting start to -1), but it might work for you 😼