Compiler and runtime for the QG language. QG is designed for creating games that can be compiled to a QR code. These QR codes can be executed using the Android app QR Game. The language focuses on small byte code footprint, ease of use and basic type safety.
Link to the Android app QR Game
Requires Java 8 to run. Also requires maven to compile.
Download the latest release and add it to the PATH.
mkdir /etc/qrgame
cd /etc/qrgame
latest=$(curl --silent "https://api.github.com/repos/SiXoS/qr-game/releases/latest" | grep '"tag_name":' | sed -E 's/.*"([^"]+)".*/\1/')
wget -q https://github.com/SiXoS/qr-game/releases/download/$latest/qgc.sh
wget -q https://github.com/SiXoS/qr-game/releases/download/$latest/qr-game-core-jar-with-dependencies.jar
chmod +x qgc.sh
ln -s /etc/qrgame/qgc.sh /usr/bin/qgc
You can then use it with:
qgc --help
qgc compile code.qg output.png
Download the latest jar from Releases.
Run it with java:
java -jar <path_to_jar> --help
java -jar <path_to_jar> compile code.qg output.png
The runtime is executed in Java and is therefore slower than Java, about 10-15 times slower. This might sound a lot but as this language is designed for simple, tiny 2D games it should not pose a big issue.
Since this enables running code directly from a QR-code, security is a concern. The language is purposely built to have no knowledge of the outside world.
The only "input" that the language has is provided actively by the running device. This includes execution of the input block and the time since the last frame executed. The program has a concept of time but "epoch" is at the launch of the game.
The only "output" that the language can produce is a list of objects that should be drawn. These are polled by the running device.
The only malicious use of this language is hogging resources. The running device should add some logic to detect this. i.e. if an iteration takes too long to run or if it's using too much memory.
There are more complex samples in qr-game-samples.
Example UI and code for a small "game". It with a square in the center. When you hit a d-pad button the square will move.
This is an image of the game UI. The buttons are static for all games but the behavior is controlled through code.
init {
position = -1
}
run {
coords = when(position) {
0 -> new pos(490, 390)
1 -> new pos(590, 490)
2 -> new pos(490, 590)
3 -> new pos(390, 490)
default -> new pos(490, 490)
}
draw(createRectangle(coords.x, coords.y, 20, 20))
}
input(button, pressedElseReleased) {
if (pressedElseReleased) {
position = button % 4
}
}
struct pos {
x: number
y: number
}
The compiled bytecode is 64 bytes and is stored in the below QR code. The maximum number of bytes in a QR is 2952.
