The Arcade Box

This repository contains some simple demo code to show you how to make use of the arcade box at Carnegie Mellon University in Qatar. At present, the arcade box only supports the cmu_graphics library. Other libraries are not supported at this time. (But they likely could be supported in the future.)

This documentation is a work in progress.

--Ryan Riley (rileyrd@cmu.edu)

Porting Your Game

If you are considering porting your game to the arcade box, there are two things you should do first:

1. Set your game's resolution to 800x600 by doing runApp(width=800, height=600). (This is resolution of the arcade box.) Other resolutions won't look quite right.
2. I recommend that you make your initial designs using keyboard input. The reason for this is simple: The arcade box is a fun way to play a game, but it isn't a great way to test/debug. You'll want to be able to do that on your local machine. After you have a basic game working (such as MVP), then make arcade box support one of your post-MVP features.

Once you are ready to add arcade box support to your game, simply copy joystick.py from this repository into your project, and import joystick at the top of your file. Look into (main.py) in this repository to see how it works.

In short, there are new callback functions that get called automatically when buttons are pressed. You can distinguish which joystick and which button on that joystick was pressed. (So, a 2-player game is possible.)

Before testing on the actual arcade box, it is very important that you have a way to quit the game. The easiest way to do that is by making sure your onJoyPress function starts out as follows:

def onJoyPress(app, button, joystick):
    if button == '5':
        sys.exit(0)

This will cause your game to quit if someone presses the P1 button on the arcade box.

Key-Map info:

Checkout Key-Map.md to know which physical button correspond to what number (which is registered in the button argument of your onJoyPress function).

Getting Your Code onto the Arcade Box

So, you have your fancy game, you've added some basic joystick support (and a quit key!) and you want to run it on the arcade box. How do we make that happen?

Use Git

Right now, the only supported method of loading your code onto the box is via git. You need a git repository somewhere (most likely GitHub). You will send me a link to your repository and I'll add it to the arcade box. Your repository can be public or private. If it is private, I'll show you how to add a deployment key on GitHub so that the box can fetch your code.

What Happens When You Run Your Game

When you select your game from the menu, the following happens:

1. The latest copy of your repository is pulled. (So any changes you've pushed can be tested immediately.)
2. Any Python libraries listed in requirements.txt are downloaded and installed
3. The file main.py is run.

Format of requirements.txt

Just list the packages you need, each on their own line. For example:

cmu-graphics
urllib3

If you need a specific version of a package, that is also possible:

cmu-graphics
urllib3==1.26.5

(This is just a pip requirements file)

The Reset Button

The proper way to quit your program is just to call sys.exit(0). Please make sure that you have a button input that triggers this. The easiest way is to just do something like:

def onJoyPress(app, button, joystick):
    if button == '5':
        sys.exit(0)

Which uses the P1 button to quit.

If things go horrible wrong, and you can't quit your program, there is a reset button on the front of the box that does a hard reset of the machine. Please use this sparingly, as frequent hard resets increase the chances of filesystem corruption.

Security

This box is not secured. You could do all sorts of horrible things to it. Please don't.

Random Things

Things that I don't want to forget, but need to be better organized later.

• The joystick library (joystick.py) supports more than just the arcade box. It also works with various gamepads. For example, I've tested it with both PS4 and Nintendo Switch controllers connected to a PC via USB or Bluetooth.
• I've never tested sound. Maybe it works?
• The cmu_graphics library is not very efficient, and the CPU inside of the arcade box is not super high powered. You'll need to be careful not to have too much complication in redrawAll or onStep.