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Commit 52ea8996 authored by Peter Hutterer's avatar Peter Hutterer Committed by Benjamin Tissoires
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Input: add `REL_WHEEL_HI_RES` and `REL_HWHEEL_HI_RES`

This event code represents scroll reports from high-resolution wheels and
is modelled after the approach Windows uses. The value 120 is one detent
(wheel click) of movement. Mice with higher-resolution scrolling can send
fractions of 120 which must be accumulated in userspace. Userspace can either
wait for a full 120 to accumulate or scroll by fractions of one logical scroll
movement as the events come in. 120 was picked as magic number because it has
a high number of integer fractions that can be used by high-resolution wheels.

For more information see
https://docs.microsoft.com/en-us/previous-versions/windows/hardware/design/dn613912(v=vs.85)



These new axes obsolete REL_WHEEL and REL_HWHEEL. The legacy axes are emulated
by the kernel but the most accurate (and most granular) data is available
through the new axes.

Signed-off-by: default avatarPeter Hutterer <peter.hutterer@who-t.net>
Acked-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
Verified-by: default avatarHarry Cutts <hcutts@chromium.org>
Signed-off-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
parent e195ca6c
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