Use mouse scale instead of acceleration

[khokm]

To disable acceleration and set a mouse scale with Coordinate Transformation Matrix i used this code under X:

export SCALE=0.5
xinput set-prop <mouse device> 'libinput Accel Speed' -1
xinput set-prop <mouse device> 'Coordinate Transformation Matrix' 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, $SCALE

In wayfire.ini, i can set mouse_cursor_speed = -1 in [input] section to disable acceleration. But i haven't found any options to set a scale. Is there any way to do this (also through wlroots or libinput maybe)?

[ammen99]

Such options go through libinput usually, though I do not know them all. If you could point me to the libinput device settings you want to change, I'll add options.

[khokm]

Such options go through libinput usually, though I do not know them all. If you could point me to the libinput device settings you want to change, I'll add options.

There is a screenshot of all options. But Transformation Matrix seems like it's not a libinput option.

[ammen99]

Then I am not sure how to help you, because I do not know how this matrix works. We also have non-libinput options, for ex. here (if you're familiar with C/C++): https://github.com/WayfireWM/wayfire/blob/master/src/core/seat/cursor.cpp#L257

Perhaps this particular option needs similar manual handling.

[khokm]

(accidentally close)
It looks like callbacks.size() is not zero for mouse X and Y axes.
Think I'll try to do something with this, and submit PR then.

[ammen99]

I don't understand, when are those not empty?

[HactarCE]

The simplest way to use CoordianteTransformationMatrix is to set the last number of the reciprocal
of the mouse speed you want. So if you want the mouse to move twice as fast, set the last number to 0.5. But seriously, do not use Coordinate Transformation Matrix for pointers.

If acceleration is disabled, you can use libinput Accel Speed to control mouse speed. But if you do want acceleration (as I do), libinput Accel Speed modifies the acceleration curve, and there is no way other than the transformation matrix to apply a constant multiplier on the speed (relevant issue).