pen-steer

Use a drawing tablet, or something similar, as a steering wheel.

Available for Linux and Windows (WIP).

Notice: somewhat useable but unpolished. Read on for more info.

Why?

Mouse steering is alright (Euro Truck Simulator 2, etc.), but I wanted to see if it would be practical to use a drawing tablet. Surprisingly, it's not that bad; it does take a bit of practice to draw a circle at the centre. I would still use an actual wheel if I could afford one, though.

As far as I know, there isn't anything else like this (or I didn't search enough), so I made this. Though, I am probably not the first person to try something like this.

This Rust application is not my first attempt, I wrote the initial prototype in C and a cursed bunch of ioctl()s.

Features

• Draw circles to turn the wheel.
• Press the centre to activate the horn.
• Configurable range.
• Configurable physics settings. (inertia, friction, etc.)
• Adjustable area mapping. (needs more work)
• Run without the GUI via --headless. (quite limited at the moment)
• Save/load configuration. (needs more work)
• Force-feedback! Allows the wheel to i.e. centre itself in a realistic-ish way:

Not all output devices support force-feedback.

---

Pen input can be collected from a few sources:

• Dummy - does nothing
• Net - reads input via UDP socket
• Wintab - [WIP] uses Wacom Wintab API (Windows only)
• Evdev - reads input from /dev/input/eventX. (Linux only)

There are a few methods to fake a virtual controller:

• Dummy - no output at all
• uinput - uses Linux's uinput module. (Linux only)
• ViGEm - uses ViGEm (Windows only)

TODO

This thing works okay, but needs more work.

• Wintab support for Windows.
• Less clunky control panel.

Building

Clone the repository and compile with the command:

cargo build --release

or run it with:

cargo run --release

To use this application without a GUI, simply use the --headless option:

./pen-steer --headless

Net Source

Listens for pen input via UDP.

By default, it will listen on 127.0.0.1:16027.

As an example, an OpenTabletDriver plugin can be used to send pen positions over UDP.

See OtdReport.cs for a (messy) code example.

Packet Format

+-------------------------------------------------------+
|                 Pen Packet (13 bytes)                 |
+------------+------------+---------------+-------------+
| pos_X: f32 | pos_Y: f32 | pressure: u32 | buttons: u8 |
+------------+------------+---------------+-------------+

Fields are expected to be in little-endian.

pos_X and pos_Y are expected to be normalised [-1.0, 1.0].

buttons is a bitfield.

Evdev Source

Reads from a /dev/input/event* file. You may need to either run as the root user (not ideal), or add your user to the input group (less worse).

uinput Device

Currently the only device available for Linux. It uses Linux's uinput API.

You may need to either run as the root user (not ideal), or add your user to the input group (less worse).

ViGEmBus Device

Currently the only device available for Windows. It uses the ViGEmBus driver, which is no longer being updated, to emulate a virtual joystick.

Force-feedback is not supported.

You will need to install the driver for this output method to work.