FFFSake

Through this document, FFB is used as an acronym for Force Feedback.

FFFSake, or For Force Feedback’s Sake, is:

• Technically, a library that can bridge FFB commands received by vJoy to a DirectInput-compatible device.
• Practically, a plugin to get FFB effects on your physical device while your game is actually being played with a vJoy virtual joystick, which is in turn being fed with inputs by an application like Joystick Gremlin.

What is this for?

tl;dr if you’re having a wheel/joystick binding, input, or FFB problem, Joystick Gremlin with FFFSake can usually help you work around that.

In a perfect world, your game controller (typically a racing wheel or joystick/HOTAS, plus additional hardware like pedals, H-shifter etc.) would allow configuring inputs in ways that work for everyone. They would also correctly implement outputs i.e., the FFB specification for DirectInput devices completely and correctly, so that the player gets the game developers’ intended experience.

Meanwhile, the game you’re playing would have a nice configurable control scheme. It would allow you to tune your FFB experience based on your preferences and your specific hardware.

In the real world, both hardware and software can fall short or fail at these for a variety of reasons. This is where third-party tools like Joystick Gremlin and vJoy come in. You configure your game to use the vJoy virtual joystick as a FFB capable input device, and use Joystick Gremlin to read control inputs from various sources (say, your physical steering wheel), and “feed” them into the vJoy virtual joystick. This allows you to fix a broad range of input-related issues, such as:

1. Setting response curves for analog axes, usually pedals.
2. Configuring buttons and switches as toggle or sticky.
3. Converting split pedals to combined or vice versa (for using modern racing pedals with flight sims or older racing games)
4. Macro playback
5. Combination inputs
6. Mode switches

FFFSake handles the output i.e. FFB side of things, taking these commands from the vJoy device (coming from the game) and writing them to your physical FFB capable device. In this process, it can also fix various force feedback issues and allow some amount of tweaking; see the Features section later.

Why Joystick Gremlin?

While there are other applications with similar functionality, feeding vJoy with inputs from DirectInput devices, none of them appear to be maintained by the time of this writing. Joystick Gremlin is actively being developed; we will be using the older but stable R13 version.

Support could be added for other vJoy feeders, especially if someone is willing to help integrate FFFSake as a DLL or Python module into the feeder. Please get in touch via GitHub Discussions.

Setup

Budget about 15-45 minutes for the one-time setup.

Usage

Once you’ve completed the above one-time setup, future usage involves (do all these BEFORE starting your game):

1. Launching HidHide and ensuring the filter is enabled.
2. Launch Joystick Gremlin and load your desired profile.
3. Options:
   1. Set gain percentages for hardware force feedback effects. Games typically use a subset of these, so changing them may not have an effect. The game guides have recommended settings for some games. The default value is 100%. See the game issues guide for why you might want to change these.
   2. Set spring coefficient for games that use the spring force and it feels weak when centered but strong at the edges of the steering range.
4. Click on Activate. FFFSake will activate if it’s a plugin loaded for this profile.
   1. With the profile active, you can use the button you bound earlier to toggle muting. FFFSake. Tools > Log Display > User will show a message when FFFSake is turned on or off.

At this point you can launch your game and configure it for vJoy. You should be able to select and configure it inside the game as you would a physical controller.

FFFSake Features

FFFSake has two “engines” that connect the FFB commands received by the vJoy device to your physical FFB-capable controller. They do this in rather different ways, as described below.

Forwarder Engine

The forwarder engine takes FFB commands received from vJoy (coming from the game or from Windows) and writes them to the physical device using DirectInput. In this process, the common compatibility fixes, described later, are also applied. This engine has relatively lower CPU usage but cannot fix all compatibility issues.

This engine supports force feedback joysticks (X and Y axes are force feedback).

Reducer Engine

The reducer engine takes FFB commands received from vJoy (coming from the game or from Windows) and “reduces” them to a stream of constant forces, which are written to the physical device using DirectInput. This way the above common and following additional compatibility issues can be fixed:

1. Incorrect hardware effects in the physical device. See also types of FFB issues.
2. More accurate “slip” if the application command rate exceeds what the device can handle.

Common Features

Both engines have the following features:

1. Rotate effects if input and output FFB axes counts mismatch (but see also: vJoy configuration to configure vJoy correctly)
2. “Slip” FFB commands when they are issued faster than the device can handle them, usually leading to a drop in FPS in game when using a FFB device.
3. Setting gain for individual hardware effects (requires re-Activate in Gremlin).

Limitations and Known Issues

The following limitations exist because I don’t know of any gamers who are affected by them; if you are, please in touch via GitHub Discussions

1. Only one vJoy device is currently supported.
2. Only single FFB axis devices are supported in the reducer engine. In other words, it’s only expected to be used for racing wheels. I don’t know of any FFB joysticks that have mistakes in their hardware effects implementation.

The following known issues may be addressed in a future release but are low severity:

1. Decrease CPU usage, especially for the reducer engine.
2. Some effects (friction and inertia, mainly) in the reducer engine could be refined. These effects are not commonly used.

Troubleshooting

General

The plugin publishes some messages via the Joystick Gremlin logging system, which you can view in the latter by going to Tools > Log Display > User.

FFFSake generates an error log file in the directory where Joystick Gremlin is running from. If you run into an issue and the file contains errors or warnings, please open a GitHub issue attaching the log file.

If force feedback cuts out or you seem to suddenly be missing effects, try Alt-tabbing out of the game and then getting back into it, this should generally fix the problem. Please check the FFFSake log for errors and send feedback via GitHub.

ImportError: DLL Load failed: The specified procedure could not be found

See the Setup section above, and follow the steps to replace the vJoyInterface.dll packaged with Joystick Gremlin with the latest one you downloaded from GitHub earlier.

(Section to be filled out based on user experience. Please share yours via the GitHub Discussions page!)