fastmouse

Fastmouse is a kernel patch (and collection of tiny bash scripts) which provide the ability to rotate and slow your mouse. Inspired by the leetmouse kernel module, Fastmouse aims to provide a more robust means of modifying your mouse inputs through direct modification of the HID driver in the Linux kernel. Additionally, as we only operate in integer space, we provide higher precision and avoid kernel floating-point pitfalls.

Usage

Fastmouse currently exposes three parameters in the /sys/module/hid/parameters directory.

division: A positive integer representing the amount of inputs to buffer before emitting an event. Useful for reducing mouse sensitivity - essentially the same as dividing DPI. '1' does nothing, '2' omits one event for every two, and so on.
rise: An integer describing the vertical component of the triangle used to calculate mouse rotation.
run: An integer describing the horizontal component of the triangle used to calculate mouse rotation.

fastmouse

Wraps the arguments specified after -- with an input division - also computes and sets a KDE-specific calculation for keeping the mouse moving at the same speed on the desktop. Effectively, this seamlessly drops the DPI of the mouse, and then restores the original configuration once the program exits. With fastmouse in your path, usage would look like this:

    $ fastmouse 10 -- my_program_which_doesnt_work_with_high_dpi_mice_or_doesnt_allow_me_to_lower_sens

set_rotation

set_rotation computes and sets optimal values for the exposed rise and run parameters of any desired mouse rotation angle. It is recommended to use this script over manually calculated values as set_rotation produces values which describe the desired angle with the greatest precision available. Usage is simply:

    $ set_rotation my_angle_in_degrees

Installation

Installation is dependent on your OS configuration - it requires that you build the Linux kernel with the patch fastmouse.patch applied. Installation has succeeded when the following command prints 1.

    $ cat /sys/module/hid/parameters/division

Building from Source

To download the latest available release, clone this repository.

    $ git clone https://git.nj3.xyz/fastmouse --recurse-submodules
    $ cd ./fastmouse

First, you need to setup the kernel build in kernel/ to whatever suits your needs. If you don't know what to do here, just save the defaults of menuconfig via:

    $ cd ./linux
    $ make menuconfig
    $ cd ../

We use cmake to as our build system, which consists of three steps. First, cmake will attempt to build fastmouse with a test runner via googletest. If this succeeds, cmake will make sure that all tests pass before moving on to the second step: attempting to build with whatever linux kernel is present in linux/. If this build succeeds, fastmouse should be usable as a patch (in theory). You can build the project by running:

    $ cmake ./ && make

If everything went well, leetmouse.patch will be in the placed in the topmost directory.