Smooth Scrolling Targeted For X.Org Server 1.12

[RealNC]

Then I think it's because your system must be slow or something. Scrolling is very fast and does not slow you down. It's also the reverse of what you say: it *is* a good visual indication of where you land when you scroll the wheel.

Soft scrolling only feels slower on systems that perform this operating in a slow manner, where it feels like GUI lag.

[pingufunkybeat]

Even if it's fast, there is always a lag. Lag makes it feel sluggish. If you scroll a lot, you spend a significant amount of time waiting for the animation instead of doing what you want to do.

I scroll when I'm reading, and scrolling animation interferes with reading.

But I guess that the young generation who grew up with GUIs sees things differently and I might be showing my age.

[BlackStar]

@pingufunkybeat: these patches have nothing to do with what Firefox/IE call "smooth scrolling". Firefox/IE actually do scroll animation, where they render a fake animation for each scroll event that arrives. On top of that, they add some random acceleration/decceleration which make things really ugly (I also prefer disabling this so-called "smooth" scrolling).

These patches do something completely different: they enable continuous scrolling for high-resolution input devices. Imagine a touchpad with gesture support or a mouse with a non-indented scroll wheel that flows smoothly as you rotate it (newer apple/microsoft/logitech mice have such wheels).

The capabilities of these devices cannot be represented under core X. The problem stems from the fact that X11 has historically reported scroll events as discrete, zero-duration button events. This may have made sense originally, but these devices do not work like this: scrolling is a single, continuous motion, rather than multiple discrete events. In other words, if the mouse cursor moves on the x-y plane, scroll events should be mapped to a continuous z axis (or z+w for freely rotating wheels/balls).

Without these patches, the smallest scroll amount possible is 1 line multiplied by you scroll speed setting (typically ~3 lines per scroll event). With these patches, you can now scroll everywhere from 1 pixel to however far you wish.

There is no additional lag. The scrolling is still instantaneous but *extremely* more accurate, because your finger movement now corresponds one-to-one with the scrolling on screen. The result trully is amazing.

Looking forward to this!

[RealNC]

Even if it's fast, there is always a lag. Lag makes it feel sluggish. If you scroll a lot, you spend a significant amount of time waiting for the animation instead of doing what you want to do.

This doesn't happen on my system. Thus my assumption that your system might be slow.

If I scroll with the wheel, the animation stops at the same moment I stop scrolling the wheel. There's no lag, or "catch-up" animation. It's exactly the same speed as with soft scrolling disabled and takes the same amount of time to reach the document position (the slow-down effect at the destination only takes a few milliseconds.)

Thus, you're seeing a different effect than I am.

[pingufunkybeat]

Blackstar, that's a good explanation that makes sense. It's the "smooth scrolling" nonsense of IE that I can't stand. It only makes sense with input devices you describe, though, and not with discrete "clicking" wheels, IMHO.

RealNC, 12000 bogomips is powerful enough. In fact, I've never had any problems scrolling huge documents using the scrollbar. It's the slow animation that happens every time you press "page down" in some browsers that drives me mad. That is laggy and that distracts from the activity you're trying to do.

[BlackStar]

Blackstar, that's a good explanation that makes sense. It's the "smooth scrolling" nonsense of IE that I can't stand. It only makes sense with input devices you describe, though, and not with discrete "clicking" wheels, IMHO.

This is mostly a personal preference, but pretty much agreed.

I'm typing this in Chrome which doesn't have smooth animation but does have smooth scrolling (Windows/OSX-only, for now). When I scroll with a clicky mouse, I see discrete steps (3 lines per step); when I use my laptop's touchpad, I get perfectly smooth scrolling that corresponds perfectly to my hand movement - awesome!

Unfortunately, this smooth scrolling doesn't work on Linux right now: I scroll with a single smooth gesture on the touchpad, but I get multiple discrete jumps just as if I was using a clicky mouse. This is what's getting fixed (and the patches can't land soon enough - Windows have supported smooth scrolling since 2001!)

[bwat47]

Even if it's fast, there is always a lag. Lag makes it feel sluggish. If you scroll a lot, you spend a significant amount of time waiting for the animation instead of doing what you want to do.

I scroll when I'm reading, and scrolling animation interferes with reading.

But I guess that the young generation who grew up with GUIs sees things differently and I might be showing my age.

I can't stand not using smooth scrolling, especially if I am slowly scrolling down a page to read. Regular scrolling is too jarring and it distracts me. Smooth scrolling is the best thing ever for me whether I'm using a mouse or touch or whatever.

Smooth scrolling in linux has been very spotty for me. For example firefox or opera with smooth scrolling enabled is terrible compared to in windows.

[BlackStar]

Smooth scrolling in linux has been very spotty for me. For example firefox or opera with smooth scrolling enabled is terrible compared to in windows.

That's mostly due to the fact that 2d acceleration on Linux sucks, compared to Windows. There's little you can do about that, other than use a different compositing/non-compositing manager, video card and/or drivers.

[RealNC]

RealNC, 12000 bogomips is powerful enough.

Nope, it isn't. It's the graphics driver that matters. You can have a billion bogomips and still have scrolling lag If you don't, pressing pagedown is just as fast as with scrolling disabled. When I press pageup/down, the animation is *extremely* fast.

[pingufunkybeat]

If I press PgUp, it should be instantaneous. I don't want it animated.