libinput pointer precision at different sensitivity levels

Josh Simmons simmons.44 at
Thu Aug 2 06:20:38 UTC 2018

On Thu, Aug 2, 2018 at 7:49 AM, Peter Hutterer <peter.hutterer at> wrote:
> and since devices don't give you anything < 1 unit delta, subpixel isn't
> really a thing unless you lower the speed setting.

So perhaps I'm missing something, but the raw events as reported by
libinput debug-events do in fact have sub-unit precision?

     event8   POINTER_MOTION    +7.14s   0.00/ -0.94
     event8   POINTER_MOTION    +7.20s   0.94/  0.00
     event8   POINTER_MOTION    +7.21s   0.57/  0.00
     event8   POINTER_MOTION    +7.21s   0.67/  0.00
     event8   POINTER_MOTION    +7.22s   0.74/  0.00
     event8   POINTER_MOTION    +7.34s   0.00/ -0.64

But I'm not really sure where the accumulation into singular device
units is coming from? Because it doesn't seem like it _should_ be
necessary - my mouse is capable of reporting at a much higher
resolution than integer device coordinates - regardless of the
sensitivity. At least it seems it should be that way?


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