gb.ts

    interface Window {
        emulator: GameboyEmulator;
        panic: (message: string) => void;
        speedCallback: (speed: GameBoySpeed) => void;
        loggerCallback: (data: Uint8Array) => void;
        printerCallback: (imageBuffer: Uint8Array) => void;
        rumbleCallback: (active: boolean) => void;
    }

    interface Console {
        image(url: string, size?: number): void;
    }
}

window.panic = (message: string) => {
    console.error(message);
};

window.speedCallback = (speed: GameBoySpeed) => {
    window.emulator.onSpeedSwitch(speed);
};

window.loggerCallback = (data: Uint8Array) => {
    window.emulator.onLoggerDevice(data);
};

window.printerCallback = (imageBuffer: Uint8Array) => {
    window.emulator.onPrinterDevice(imageBuffer);
};

window.rumbleCallback = (active: boolean) => {
    if (!active) return;

    // runs the vibration actuator on the current window
    // this will probably affect only mobile devices
    window?.navigator?.vibrate?.(250);

    // iterates over all the available gamepads to run
    // the vibration actuator on each of them
    let gamepadIndex = 0;
    while (true) {
        const gamepad = navigator.getGamepads()[gamepadIndex];
        if (!gamepad) break;
        gamepad?.vibrationActuator?.playEffect?.("dual-rumble", {
            startDelay: 0,
            duration: 150,
            weakMagnitude: 0.8,
            strongMagnitude: 0.0
        });
        gamepadIndex++;
    }
};

console.image = (url: string, size = 80) => {
    const style = `font-size: ${size}px; background-image: url("${url}"); background-size: contain; background-repeat: no-repeat;`;
    console.log("%c     ", style);
};

const wasm = async (setHook = true) => {
    await _wasm();

    // in case the set hook flag is set, then tries to
    // set the panic hook for the WASM module, this call
    // may fail in some versions of wasm-bindgen as the
    // thread is still marked as "panicking", so we need to
    // wrap the call around try/catch
    if (setHook) {
        try {
            GameBoy.set_panic_hook_wa();
        } catch (err) {
            console.error(err);
        }
    }
};