float get_brightness()
{
    return [UIScreen mainScreen].brightness;
}

void set_brightness(float val)
{
    val = val < 0.0f ? 0.0f : val;
    val = val > 1.0f ? 1.0f : val;
    
    [UIScreen mainScreen].brightness = val;
}

// c interface
extern "C"
{
    float get_screen_brightness()
    {
        return get_brightness();
    }
    
    void set_screen_brightness(float val)
    {
        set_brightness(val);
    }
}