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Diffstat (limited to 'backends/evdev.md')
| -rw-r--r-- | backends/evdev.md | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/backends/evdev.md b/backends/evdev.md index d750f1e..995b44c 100644 --- a/backends/evdev.md +++ b/backends/evdev.md @@ -7,7 +7,9 @@ This functionality may require elevated privileges (such as special group member #### Global configuration -This backend does not take any global configuration. +| Option | Example value | Default value | Description | +|---------------|-----------------------|-----------------------|-----------------------| +| `detect` | `on` | `off` | Output the channel specification for all events coming in on configured instances to help with configuration. | #### Instance configuration @@ -18,7 +20,8 @@ This backend does not take any global configuration. | `output` | `My Input Device` | none | Output device presentation name. Setting this option enables the instance for output | | `exclusive` | `1` | `0` | Prevent other processes from using the device | | `id` | `0x1 0x2 0x3` | none | Set output device bus identification (Vendor, Product and Version), optional | -| `axis.AXISNAME`| `34300 0 65536 255 4095` | none | Specify absolute axis details (see below) for output. This is required for any absolute axis to be output. +| `axis.AXISNAME`| `34300 0 65536 255 4095` | none | Specify absolute axis details (see below) for output. This is required for any absolute axis to be output. | +| `relaxis.AXISNAME`| `65534 32767` | none | Specify relative axis details (extent and optional initial value) for output and input (see below). | The absolute axis details configuration (e.g. `axis.ABS_X`) is required for any absolute axis on output-enabled instances. The configuration value contains, space-separated, the following values: @@ -34,6 +37,13 @@ If an axis is not used for output, this configuration can be omitted. For real devices, all of these parameters for every axis can be found by running `evtest` on the device. +To use the input from relative axes in absolute-value based protocols, the backend needs a reference frame to +convert the relative movements to absolute values. + +If relative axes are used without specifying their extents, the channel will generate normalized values +of `0`, `0.5` and `1` for any input less than, equal to and greater than `0`, respectively. As for output, only +the values `-1`, `0` and `1` are generated for the same interval. + #### Channel specification A channel is specified by its event type and event code, separated by `.`. For a complete list of event types and codes @@ -64,10 +74,6 @@ Input devices may synchronize logically connected event types (for example, X an events. The MIDIMonster also generates these events after processing channel events, but may not keep the original event grouping. -Relative axes (`EV_REL`-type events), such as generated by mouses, are currently handled in a very basic fashion, -generating only the normalized channel values of `0`, `0.5` and `1` for any input less than, equal to and greater -than `0`, respectively. As for output, only the values `-1`, `0` and `1` are generated for the same interval. - `EV_KEY` key-down events are sent for normalized channel values over `0.9`. Extended event type values such as `EV_LED`, `EV_SND`, etc are recognized in the MIDIMonster configuration file |