Configurable constant scale factor
There is currently no proper way to simply scale the pointer speed by a constant factor, something which seems quite basic and very useful. There are several workarounds, each of which has their drawbacks:
Accel Speedworks if the "flat" acceleration profile is used. Under any other profile, 'Accel Speed' does not simply scale the resulting pointer movement; it alters the shape of the acceleration curve as shown here. I like my mouse acceleration the way it is, but the speed is too fast.
CoordinateTransformationMatrixcan be used to achieve the desired effect, but it is not meant for relative devices like mouse pointers and so causes other problems. Additionally, it is my understanding that this would not be available under Wayland, where Libinput is the default (and only?) option.
This feature would introduce a new option, called something like
Constant Scale Factor, which would be a floating point value ranging from
0 to positive infinity. The acceleration factor for each pointer movement, after all other acceleration calculations, would be multiplied by this value.
Alternatively, call the value
Constant Deceleration and divide each acceleration factor by this value. This provides equivalent capability.
This would affect all relative pointing devices (mice, touchpads, and maybe trackpoints). The option would default to
1, so existing configurations would remain the same.
Implementation in Other Systems
Xorg has an option
Device Accel Constant Deceleration which does exactly what I want. Xorg divides each component of the pointer movement delta by this configurable constant value, after all other acceleration calculations.
Other relevant links
#224 (closed) would have brought this back, but Kim Kröger wanted to use the flat profile anyway, where
Accel Speed does the job. (I want to use the
adaptive profile, and so
Accel Speed does not do what I want.)
This forum thread and this StackExchange post should serve to illustrate that I am not the only one who would benefit from this feature, and that the currently accepted workaround is to use Xorg's
Thank you very much.