More than ten years ago now, on my first laptop, the touchpad had pointer momentum.
When you moved the pointer, using the touchpad, and then released, it would continue moving at the speed it had at the moment you lifted your finger from the pad, then slowing down gradually, until it came to a stop.
This is an amazing feature. A game changer. It lifts touchpads to a completely new level, and you cannot know just how much difference it makes until you’ve tried it.
Touchpads without this are lifeless, stilted affairs - it is night and day.
Sounds really interesting! I’d want to try it!
It sounds more like a software thing though, might be worth looking for if someone created a program for something similar!
I’ve only ever found it mentioned in reference to Synaptics touchpads (which I had on the Sony). I would imagine it could be done in software - indeed, it must be, because the user no longer has their finger on the touchpad…
But I can find no mention of it for Linux, or on arbitrary touchpads.
Not the same thing. Acceleration is just sensitivity based on how fast you move your finger. The momentum feature means the cursor will continue to move after removing your finger from the trackpad. The cursor will continue to move in the direction the finger was tracked before taking it off the trackpad.
The momentum feature would be pretty nice for scrolling or panning and should have a threshold and velosity setting so that it doesn´t annoyingly move the cursor away from elements you actually want to stop on. And of cource, different people prefer different settings. There could also be a setting that limited momentum for certain gestures (like two-finger swipe so that it only applies to scrolling and panning, if the user doesn´t want it to affect normal cursor movement).
Coasting
Coasting is enabled by setting the CoastingSpeed parameter to a non-zero value. Coasting comes in two flavors: conventional (finger off) coasting, and corner (finger on) coasting.
Conventional coasting is enabled when coasting is enabled, and CornerCoasting is set to false. When conventional coasting is enabled, horizontal/vertical scrolling can continue after the finger is released from the lower/right edge of the touchpad. The driver computes the scrolling speed corresponding to the finger speed immediately before the finger leaves the touchpad. If this scrolling speed is larger than the CoastingSpeed parameter (measured in scroll events per second), the scrolling will continue with the same speed in the same direction until the finger touches the touchpad again.
Corner coasting is enabled when coasting is enabled, and CornerCoasting is set to true. When corner coasting is enabled, edge scrolling can continue as long as the finger stays in a corner. Coasting begins when the finger enters the corner, and continues until the finger leaves the corner. CornerCoasting takes precedence over the seamless switch from edge scrolling to circular scrolling. That is, if CornerCoasting is active, scrolling will stop, and circular scrolling will not start, when the finger leaves the corner.