Pixonic grew engagement by 25% on ChromeOS by optimizing for large screens

Keyboard and mouse support

In third-person PvP games like War Robots, moving and aiming is a lot easier using a keyboard and mouse, especially on larger-screen devices. So, the next step was to rewrite the code for keyboard and mouse support for the game’s battle mode while retaining touchscreen controls.

To provide the right controls at the right time, Pixonic’s team wrote new code to check the user’s current gameplay mode:

@Override
public void onConfigurationChanged(Configuration newConfig) {
    boolean hasQwertyKeyboard = newConfig.keyboard == Configuration.KEYBOARD_QWERTY && newConfig.hardKeyboardHidden == Configuration.HARDKEYBOARDHIDDEN_NO;
    try {
        UnityPlayer.UnitySendMessage("Receiver", "ConfigChange", new JSONObject().put("keyboard", hasQwertyKeyboard).toString());
    } catch (JSONException e) {
        e.printStackTrace();
    }
}

If a QWERTY keyboard is detected, the game adapts to desktop mode. The movement joystick in the bottom-left corner disappears, and all available actions (such as sorting through weapons, abilities, and menus) are labeled with keyboard shortcuts.

If a keyboard isn’t detected, the movement joystick appears in the bottom-left corner, and the keyboard shortcuts are hidden on the bottom-right menu buttons.

Next, Pixonic wanted to make sure the cursor stays hidden when a player uses their mouse to rotate the camera. By targeting Android 7.0 (API level 24) or higher, the team could set any pointer icon. In this case, the team used a transparent bitmap to make the cursor invisible during gameplay:

public boolean setPointerVisibility(boolean visible) {
    View = activity.findViewById(android.R.id.content);
    view.setPointerIcon(PointerIcon.getSystemIcon(activity, visible ? PointerIcon.TYPE_DEFAULT : PointerIcon.TYPE_NULL));
}

This ensured the cursor would be disabled and invisible when all other windows are closed and a battle is in progress. If any pop-up windows appear, such as the pause menu, Pixonic made the cursor visible, displaying its default icon.

Adapting gameplay tutorials and mechanics

For a better user experience, Pixonic also wrote new code to display different gameplay tutorials based on a user’s current device mode. If a player switches between tablet and laptop gameplay during battle and they haven’t yet seen a tutorial for the different mode, the tutorial is shown before gameplay resumes.

When players are in laptop mode, Pixonic also disables touchscreen camera control (since players will control the camera with a mouse) while all the gameplay buttons work as usual. To differentiate touches from mouse movements, the team uses the Input.touchCount property (in Unity scripts):

if (Input.touchCount > 0) {
  // this is screen touch event
} else {
  // this is mouse (touchpad) event
}

Multi-window support

For the final step, Pixonic wanted to make sure the game didn’t lock itself in fullscreen mode when launched. Enabling windowed gameplay in ChromeOS allows users to simultaneously watch their favorite streamers while playing, upgrade their robots while reading about new abilities on the game’s website⁠, or spectate a battle in passive mode while watching a separate video.

To do this, Pixonic marked UnityPlayerActivity as resizable:

<activity android:name="com.unity3d.player.UnityPlayerActivity" ....
android:resizeableActivity="true">

Keeping in mind that the game interface only looks playable in a certain dimension range, the team set minimum supported window sizes:

<activity … >
    <layout android:gravity="center" android:minHeight="800dp" android:minWidth="1200dp" />
</activity>

For the most immersive gameplay, Pixonic used meta tags to set fullscreen mode as default and landscape orientation as desirable.

<application>
    <meta-data android:name="WindowManagerPreference:FreeformWindowSize" android:value="maximize" />
    <meta-data android:name="WindowManagerPreference:FreeformWindowOrientation" android:value="landscape" />
    ….
</application>

These optimizations also ensured that the game didn’t pause and that the battle HUD scales accordingly as players expand and shrink their gameplay windows.