The television screen presents a number of considerations that may be new to mobile game developers. These areas include its large size, its control scheme, and the fact that all players are viewing it simultaneously.
Display
The two main things to keep in mind when developing games for the TV screen are designing your your game for a landscape orientation and providing support for low latency.
Support landscape display
A TV is always sideways: You can’t turn it, and there is no portrait orientation. Always design your TV games to be displayed in landscape mode.
Auto low latency mode
Certain displays can perform graphics post-processing. This post-processing improves graphics quality but can increase latency. Newer displays that support HDMI 2.1 have an auto low latency mode (ALLM), which minimizes latency by switching off this post-processing. For more details on ALLM, refer to the HDMI 2.1 specification. Other displays may support a game mode with similar behavior.
In Android 11 and later, a window can request that auto low latency mode or game mode be used, if available, by requesting minimal post-processing. This is particularly useful for game and videoconferencing applications, where low latency is more important than having the best possible graphics.
To enable or disable minimal post-processing, call
Window.setPreferMinimalPostProcessing(),
or set the window's
preferMinimalPostProcessing
attribute to true. Not all displays support minimal post-processing; to find out if a
particular display does support it, call the
Display.isMinimalPostProcessingSupported() method.
Input devices
TVs don't have touch interfaces, so it's even more important to get your controls right and make sure players find them intuitive and fun to use. Handling controllers also introduces some other issues to pay attention to, like keeping track of multiple controllers, and handling disconnects gracefully. All TV apps, including games, should handle controllers consistently. Read Manage TV controllers for more information about using TV controllers and Handle controllers for games for specific information about using TV controllers for games.
Keyboard layouts
In Android 13 (API level 33) and higher, you can determine keyboard layouts using
getKeyCodeForKeyLocation().
For example, your game supports movement using the WASD keys, but this may not work correctly on
an AZERTY keyboard which has the A and W keys in different locations. You can get the keycodes
for the keys you expect at certain positions:
Kotlin
val inputManager: InputManager? = requireActivity().getSystemService()
inputManager?.inputDeviceIds?.map { inputManager.getInputDevice(it) }
?.firstOrNull { it.keyboardType == InputDevice.KEYBOARD_TYPE_ALPHABETIC }
?.let { inputDevice ->
keyUp = inputDevice.getKeyCodeForKeyLocation(KeyEvent.KEYCODE_W)
keyLeft = inputDevice.getKeyCodeForKeyLocation(KeyEvent.KEYCODE_A)
keyDown = inputDevice.getKeyCodeForKeyLocation(KeyEvent.KEYCODE_S)
keyRight = inputDevice.getKeyCodeForKeyLocation(KeyEvent.KEYCODE_D)
}
Java
InputManager inputManager = requireActivity().getSystemService(InputManager.class);
InputDevice inputDevice = Arrays.stream(inputManager.getInputDeviceIds())
.mapToObj(inputManager::getInputDevice)
.filter( device -> device.getKeyboardType() == InputDevice.KEYBOARD_TYPE_ALPHABETIC)
.filter(Objects::nonNull)
.findFirst()
.orElse(null);
if (inputDevice != null) {
keyUp = inputDevice.getKeyCodeForKeyLocation(KeyEvent.KEYCODE_W);
keyLeft = inputDevice.getKeyCodeForKeyLocation(KeyEvent.KEYCODE_A);
keyDown = inputDevice.getKeyCodeForKeyLocation(KeyEvent.KEYCODE_S);
keyRight = inputDevice.getKeyCodeForKeyLocation(KeyEvent.KEYCODE_D);
}
In this example, with an AZERTY keyboard, keyUp is set to
KeyEvent.KEYCODE_Z, keyLeft is set to KeyEvent.KEYCODE_Q,
while keyDown and keyRight are set to KeyEvent.KEYCODE_S
and KeyEvent.KEYCODE_D respectively. You can now create key event handlers for these
key codes and implement the expected behavior.
Manifest
There are some special things games should include in the Android manifest.
Show your game on the home screen
The Android TV home screen displays games in a separate row from regular apps.
To make your game appear in the list of games, set the
android:isGame attribute to "true" in your app manifest's
<application>
tag. For example:
<application
...
android:isGame="true"
...
>
Declare support for game controllers
Games controllers may not be available or active for users of a TV device. In order to properly inform users that your game supports a game controller, you must include the following entry in your app manifest:
<uses-feature android:name="android.hardware.gamepad" android:required="false"/>
Note: When specifying android:hardware:gamepad support, do not set the
android:required attribute to "true". If you do this, users won’t be able to
install your app on TV devices.
For more information about manifest entries, see App manifest.
Google Play games services
If your game integrates Google Play games services, you should keep in mind a number of considerations pertaining to achievements, sign-in, and saving games.
Achievements
Your game should include at least five (earnable) achievements. Only a user controlling gameplay from a supported input device should be able to earn achievements. For more information about achievements and how to implement them, see Achievements in Android.
Sign-in
Your game should attempt to sign the user in on launch. If the player declines sign-in several times in a row, your game should stop asking. Learn more about sign-in at Implementing sign-in on Android.
Saving
Use Google Play Services Saved Games to store your game save. Your game should bind game saves to a specific Google account, so as to be uniquely identifiable even across devices: Whether the player is using a handset or a TV, the game should be able to pull the game-save information from the same user account.
You should also provide an option in your game's UI to allow the player to delete locally and
cloud-stored data. You might put the option in the game's Settings screen. For
specifics on implementing saved games using Play Services, see Saved Games in Android.
Exit
Provide a consistent and obvious UI element that lets the user exit the game gracefully. This element should be accessible with the D-pad navigation buttons. Do this instead of relying on the Home button to provide an exit, as that is not consistent nor reliable across different controllers.
Web
Do not enable web browsing in games for Android TV. Android TV does not support a web browser.
Note: You can use the WebView class for logins to
social media services.
Networking
Games frequently need greater bandwidth to provide optimum performance, and many users prefer ethernet to WiFi to provide that performance. Your app should check for both WiFi and ethernet connections. If your app is for TV only, you do not need to check for 3G/LTE service as you would for a mobile app.