OpenLogi0x2120 · highResolutionScrolling
较早的高分辨率滚轮功能，可查询并启用细粒度滚轮上报，是 0x2121 hiResWheel 的前身，不支持棘轮模式切换。
An older HID++ 2.0 scrolling feature that enables high-resolution wheel reporting
on mice and similar pointing devices. It predates the more capable 0x2121 hiResWheel
feature and is found on earlier Logitech wireless and wired mice. Devices that
advertise 0x2121 will typically not advertise 0x2120; where both are absent,
the OS receives only coarse low-resolution wheel ticks via the standard HID path.
Not implemented in OpenLogi
OpenLogi's vendored hidpp crate does not provide a typed wrapper for this feature yet. The notes below summarise the HID++ feature in general terms, not OpenLogi behaviour. OpenLogi instead relies on 0x2121 hiResWheel where applicable.
What it does
0x2120 highResolutionScrolling allows a host to query and configure the
high-resolution reporting mode of the device's scroll wheel. In general terms it
provides:
- A way to read whether the device supports and is currently using high-resolution scroll reporting, where each physical ratchet step is broken into multiple finer increments rather than reported as a single coarse wheel tick.
- A means to enable or disable high-resolution mode, routing the fine-grained scroll data either through the standard HID wheel axis or as diverted HID++ notifications.
- Optionally, the ability to invert the scroll direction at the device level.
Because it is a predecessor to 0x2121, the feature set is narrower: it does not
expose ratchet-mode switching (free-spin vs. ratchet) or the richer capability
metadata that 0x2121 provides.
Status: Not implemented · Feature ID:
0x2120· See also: 0x2121 hiResWheel