Adds a dedicated scroll movement type to the custom acceleration profile.
Supported by physical mouse and touchpad.
Other profiles remain the same by using the same unaccelerated filter for the scroll filter.
Signed-off-by: Yinon Burgansky <51504-Yinon@users.noreply.gitlab.freedesktop.org>
The `speed_factor()` formula is unnecessarily complex, The behavior that is described in the comment can be achieved with a simple power function.
And adjust the comment to explicitly state that 0.05 is the minimum.
This is a leftover from when some of the filter code was shared between
pointer acceleration methods (pre v1.11 or so). Now these functions are
duplicated across files, so both the names and what they do isn't
necessarily reflective anymore.
Let's drop one layer of indirection to make the code a bit easier to
understand.
No functional changes.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
See d6e5313497 for confirmation that the
threshold is intended to be in mm/s, the comment here is simply a leftover from
earlier times when the acceleration method was using device-units only.
Fixes#585
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Scrolling and gestures use unaccelerated motion. The idea behind it was that
at least for the default speed setting of 0, the accelerated speed and
unaccelerated speed are identical where meaningful.
The touchpad speed curve has a plateau for 'normal' speeds (i.e. not very slow
and not very fast) where the acceleration factor is constant. This is the
reference factor that the unaccelerated motion should use as well.
Since the touchpad acceleration rework in d6e5313497 the reference factor is
0.9 * TP_MAGIC_SLOWDOWN (previously the factor was 1.0 * TP_MAGIC_SLOWDOWN)
and scroll motion is thus 10% faster than the pointer movement at the default
speeds. Let's fix this and let the two match up.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
libinput applies averaging to the velocity of most pointer devices. Averaging
the velocity makes the motion look smooth and may be of benefit to bad input
devices. For good devices, however, it comes at the unfortunate price of
decreased accuaracy.
This change turns velocity averaging off by default (sets ntrackers to 2 instead
of 16) and allows for it to be turned back on via a quirk, for bad devices which
require it.
This seems to give me roughly the same behaviour as macos does on the default
0 speed setting.
* Default speed is lower than before by around 30% [1]
* Acceleration kicks in much sooner (130mm/s vs 250mm/s before)
* Acceleration kicks in slower at lower speeds, so the change from 130mm/s to
150mm/s is less than that of 320mm/s to 350mm/s
* The effect of the speed setting is a wide-range constant (de|ac)celeration
[2], which means:
* The unaccelerated baseline up until the threshold now changes with the
speed setting
* The threshold is now the same for all speeds
* The range of the speed setting should now easily cover all desired device
speeds.
* Acceleration is steeper at higher speeds
* Deceleration was left as-is.
[1] This may or may not fix the jumping pointer issues caused by the previous
high defaults. When you have high default acceleration you move the finger
slower. This slow movement caused some touchpads (mostly seen on Lenovos) to
create pointer jumps. These weren't seen on synaptics previously because of a
combination of higher user finger speed (thus not triggering the bug) or just
not being as obvious (2px jump vs 10 px jump).
[2] The speed setting is actually a curve, the closer you get to 1.0 the more
difference you see between two different values. The curve's points are:
-1/0, 0/1, 1/5, so the resolution is closer for slow speeds. We still have
double resolution on the setting though so you'll find what you want.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Yeah, it's duplication. But this way it's also separation and we can't
accidentally use the wrong struct.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
