.. _trackpoint_configuration: ============================================================================== Trackpoint configuration ============================================================================== The sections below describe the trackpoint magic multiplier and how to apply it to your local device. See :ref:`trackpoint_range` for an explanation on why this multiplier is needed. .. note:: The magic trackpoint multiplier **is not user visible configuration**. It is part of the :ref:`device-quirks` system and provided once per device. User-specific preferences can be adjusted with the :ref:`config_pointer_acceleration` setting. .. _trackpoint_multiplier: ------------------------------------------------------------------------------ The magic trackpoint multiplier ------------------------------------------------------------------------------ To accomodate for the wildly different input data on trackpoint, libinput uses a multiplier that is applied to input deltas. Trackpoints that send comparatively high deltas can be "slowed down", trackpoints that send low deltas can be "sped up" to match the expected range. The actual acceleration profile is applied to these pre-multiplied deltas. Given a trackpoint delta ``(dx, dy)``, a multiplier ``M`` and a pointer acceleration function ``f(dx, dy) → (dx', dy')``, the algorithm is effectively: :: f(M * dx, M * dy) → (dx', dy') .. _trackpoint_multiplier_adjustment: .............................................................................. Adjusting the magic trackpoint multiplier .............................................................................. This section only applies if: - the trackpoint default speed (speed setting 0) is unusably slow or unusably fast, **and** - the lowest speed setting (-1) is still too fast **or** the highest speed setting is still too slow, **and** - the :ref:`device-quirks` for this device do not list a trackpoint multiplier (see :ref:`device-quirks-debugging`) If the only satisfactory speed settings are less than -0.75 or greater than 0.75, a multiplier *may* be required. A specific multiplier will apply to **all users with the same laptop model**, so proceed with caution. You must be capable/willing to adjust device quirks, build libinput from source and restart the session frequently to adjust the multiplier. If this does not apply, wait for someone else with the same hardware to do this. Finding the correct multiplier is difficult and requires some trial and error. The default multiplier is always 1.0. A value between 0.0 and 1.0 slows the trackpoint down, a value above 1.0 speeds the trackpoint up. Values below zero are invalid. .. warning:: The multiplier is not a configuration to adjust to personal preferences. The multiplier normalizes the input data into a range that can then be configured with the speed setting. To adjust the local multiplier, first :ref:`build libinput from git master `. It is not required to install libinput from git. The below assumes that all :ref:`building_dependencies` are already installed. :: $ cd path/to/libinput.git # Use an approximate multiplier in the quirks file $ cat > quirks/99-trackpont-override.quirks <` with the contents of the file. Alternatively, file a merge request with the data added. .. _trackpoint_range_measure: ------------------------------------------------------------------------------ Measuring the trackpoint range ------------------------------------------------------------------------------ This section only applied to libinput version 1.9.x, 1.10.x, and 1.11.x and has been removed. See :ref:`trackpoint_multiplier` for versions 1.12.x and later. If using libinput version 1.11.x or earlier, please see `the 1.11.0 documentation `_