How to handle AssetManager in multiple screens - java

public static AssetManager assets = new AssetManager(); should be avoided, however how do I handle an AssetManager in multiple screens? Is this a good solution?
public class myGame {
assetMananger manager = new AssetManager();
...
public assetManager getAssetMananger(){
return manager;
}
}
public class GameScreen implements Screen{
private AssetManager manager;
public GameScreen(myGame game){
manager = game.getManager();
}
public void render(){
manager.load(...);
}

Gdx.app.getApplicationListener() return ApplicationListener instance. You can typecast to your implemented class and then easily access any method or data member of that class.
In this way :
((GdxTest)Gdx.app.getApplicationListener()).assets // <-- You can use from where you want in your project.
ApplicationListener implemented class :
public class GdxTest extends ApplicationAdapter {
public Assets assets;
#Override
public void create() {
assets= new Assets();
}
....
#Override
public void dispose() {
assets.dispose();
}
}
Assets class that handle all assets/resources of Game
public class Assets implements Disposable {
public AssetManager assetManager;
public Assets(){
assetManager=new AssetManager();
}
...
#Override
public void dispose() {
assetManager.dispose();
}
}
Either load all resources in create() method and show splash screen while all your data are loading to AssetManager. (best way for small project)
else for big projects having lots of resources unload unnecessary resources -> load new resources, while loading show loading screen to user.

My approach is always like this:-
Create my own manager class that receive instance if AssetsManager and load all game assets when game is initially loaded
public class Assets implements Disposable{
public static final Assets instance = new Assets();
private AssetManager manager;
// Individual assets
public PlayerAssets playerAssets;
private Assets(){}
public void init(AssetManager manager){
this.manager = manager;
manager.load(..);
manager.finishLoading();
TextureAtlas atlas = manager.get(..);
playerAssets = new PlayerAssets(atlas);
}
public void dispose(){
manager.dispose();
}
/** Sample Inner class for catching loaded game assets */
public PlayerAssets{
public final AtlasRegion legs;
PlayerAssets(TextureAtlas atlas){
legs = atlas.find(..);
}
}
}
On your game class you load all game assets.
public class MyGame extends Game {
#Override
public void create(){
Assets.instance.init(new AssetManager()); // loading your resources
setScreen(new GameScreen());
}
}
Update from the comment below
Disposing your assets. You might want to create an abstract class for all your screen as follows
public abstract class AbstractScreen implements Screen{
protected Game game;
public AbstractScreen(Game game){
this.game = game;
}
}
. . . . . .
public void dispose(){
Assets.instance.dispose();
}
Then all of your Screens will extend this class. eg
public class MenuScreen extends AbstractScreen {
public MenuScreen(Game game){
super(game);
}
}
Calling screen instance dispose method will dispose all of the resources,
you can override it for places where you might prefer different behaviour
eg
#everride
public void dispose(){
// super.dispose();
// Release other screen resources
}
Where to call screen dispose is definitely up to you.
Also you might want to show loading screen when you load the assets to avoid blank screen due to loading delays
If you override dispose as above disposing a screen wont dispose the assets

Related

JavaFX - drawing (snake) in a loop

Currently, I'm playing around with JavaFX as I'm writing a Snake game for my Java Fundamentals class final project. I'm not that new to creating simple games with animations as I've made a bit of them using PyGame module and SDL in C. Anyway, now I'm quite struggling with understanding the correlations of some objects in JavaFX, especially when combined with SceneBuilder's FXMLs.
I just can't understand how to create an equivalent of gameloop I used to implement in PyGame or SDL. What I want to do with the code below is to enter the gameloop as soon as a new Game object is created and draw the state of the game continuously on the gameCanvas created in the SceneBuilder. I think I can easily manage all the stuff later, but I just can't sort it out how to create a legit bond between the FXML canvas and the gameloop I want to run.
GameController.java
public class GameController implements Initializable, ControlledScreen {
#FXML
private Canvas gameCanvas;
#Override
public void setScreenParent(ScreensController screenPage) {
// THIS IS FOR SCENE MANAGEMENT CONCEPT
}
Game.java
public class Game implements Runnable {
public static final int EASY = 1,
MEDIUM = 2,
HARD = 3;
int difficultyLevel, score = 0;
Snake snake;
Food food;
boolean isRunning = true;
public void setLevelEasy() {
difficultyLevel = EASY;
}
public void setLevelMedium() {
difficultyLevel = MEDIUM;
}
public void setLevelHard() {
difficultyLevel = HARD;
}
#Override
public void run() {
while (isRunning) {
}
}
}
#Override
public void initialize(URL location, ResourceBundle resources) {
// TODO Auto-generated method stub
}
}
You cant use FXML file to create new scene. Use this instead
public class Screen extends Application implements Runnable
{
#Override
public void start ( Stage primaryStage )
{
Pane pane = new Pane ();
Scene scene = new Scene(pane,500,300);
primaryStage.setScene ( scene );
primaryStage.show ();
}
#Override
public void run ()
{
launch ();
}
}
anything you want to add goes to pane element your canvas etc.
and by the way make dificulty enum not int like
enum {easy,medium,hard}
that way nobody can set dificulty level to something does not exist.

Android Libgdx assetManager: asset not loaded

I am having a weird issue with just loading my assets, using the assetManager. My assetManager is a separate class I made to make everything shorter and more neat. My Asset class isn't static. I have all the assets loaded in a non static assetDescriptor.
I load my splash screen which in tern loads all my assets while that is displaying. when I call the other screen the assets I have loaded can not be loaded and causes my game to crash. The splash screen does load but when it assigns a new screen it crashes.
I have spent 2 days on this issue. trying more then 15 variations. To no prevail.
My error message is:
com.badlogic.gdx.utils.GdxRuntimeException: Asset not loaded: stuff.png
at com.badlogic.gdx.assets.AssetManager.get(AssetManager.java:144)
at com.badlogic.gdx.assets.AssetManager.get(AssetManager.java:167)
at com.nectar.pewdybird.mainMenu.<init>(mainMenu.java:71)
at com.nectar.pewdybird.pewdyBird.render(pewdyBird.java:68)
at com.badlogic.gdx.backends.android.AndroidGraphics.onDrawFrame(AndroidGraphics.java:459)
at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1523)
at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1240)
Splash.class:
public Assets assets;
public void create(){
assets = new Assets();
assets.load();
}
public void render(){
if(assets.update()) {
setScreen(new mainMenu(this));
dispose();
} else {
//Splash Screen
gl.glClearColor(0,0,0,1);
gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
batch.begin();
//Draws SplashScreen
batch.end();
}
}
public void dispose(){
this.screen.dispose();
this.batch.dispose();
}
mainMenu.class
public Assets assets;
private Texture Stuff;
public mainMenu(Splash game){
assets = game.assets;
Stuff = game.assets.manager.get(game.assets.stuff);
}
Asset.class
public AssetManager manager = new AssetManager(new InternalFileHandleResolver());
public final AssetDescriptor<Texture> stuff =
new AssetDescriptor<Texture>("stuff.png", Texture.class);
public void load(){
manager.load(stuff);
//12 More loads
manager.finishLoading();
}
public boolean update(){
return manager.update();
}
Thank you for reading and possibly helping with my maybe simple issue.
Look at your mainMenu class. You're creating a new Assets object, that don't have any asset so instead of creating a new Assets object use Assets object of Splash because you loaded assets on that object.
public Assets assets;
public Texture Stuff;
public mainMenu(){
assets = new Assets(); // why are you creating new Assets here
Stuff = assets.manager.get(assets.stuff);
}
Actually you're creating object of mainMenu by using parameterised constructor in Splash class
public mainMenu(Splash splash){
assets = splash.assets; // instead of creating new take reference of Splash class assets
Stuff = assets.manager.get(assets.stuff);
}

Disposing Asset Manager in LibGDX

Here is my OOP setup:
Class MainGame extends Game:
...
public void create () {
assets = new Assets(); // my custom Assets object (constructor creates manager and AssetDescriptors
assets.load(); // loads Asset Descriptors into manager
assets.getManager().finishLoading();
batch = new SpriteBatch();
setScreen(new PlayScreen(this, assets));
}
...
public void dispose () {
assets.dispose(); // disposes asset manager
super.dispose();
batch.dispose();
}
Class PlayScreen implements Screen:
public PlayScreen(MainGame game, Assets assets) {
this.assets = assets;
this.game = game;
background = assets.getManager().get(assets.getBackground());
hero = new HeroSprite(290, 1100, this, assets);
// Create Game camera and Hub also
}
public void render(float delta) {
// Clear screen
// Use game batch to draw to screen
}
public void dispose() {
assets.dispose();
}
Class HeroSprite:
public HeroSprite(int x, int y, PlayScreen screen, Assets assets){
this.assets = assets;
this.screen = screen;
// Animation Textures
heroWalking = assets.getManager().get(assets.getWalking()); // This is an Asset Descriptor
walkAnime = new Animation(heroWalking) // my own custom animation class which takes the spritesheet and returns the appropriate frames
...
}
// This does not contain a dispose method
Sorr if there's a lot of code there I tried to minimize as much as possible. My main question is if I am disposing correctly?
It seems ok, my game runs fine. But when I quit the game and re-enter a black screen shows. This happens both on Desktop and Android.
A solution that works is to clear the memory on Android using Super Cleaner App. Since it's a memory issue I figures it has something to do with me disposing incorrectly.
EDIT : Revealing my Assets Class
public class Assets {
private AssetManager manager;
private AssetDescriptor<Texture> background;
private AssetDescriptor<Texture> wood;
public AssetManager getManager() {
return manager;
}
public AssetDescriptor<Texture> getBackground() {
return background;
}
public AssetDescriptor<Texture> getWood() {
return hero;
}
public Assets(){
manager = new AssetManager();
background = new AssetDescriptor<Texture>("textures/static/bg.png", Texture.class);
hero = new AssetDescriptor<Texture>("textures/static/hero.png", Texture.class);
...
}
public void load(){
manager.load(background);
manager.load(hero);
...
}
public void dispose(){
manager.dispose();
}
}
Screen.dispose() does not get called automatically, you should manually call dispose when you exit a screen and not needing the assets anymore. But obviously when you need them again you need to load them again and you need a new AssetManager for that. So if your assets won't take up that much you should just keep it in memory.
On exit however you need to dispose. Game.dispose() does get called automatically. Here you should call getScreen().dispose() and have everything needing disposing in the dispose() method of the effective Screen.
Since currently it does not look like you are disposing between screens it might be because you have a static AssetManager, you should show your Assets() class.

Error on Java libgdx with AssetsManager

So I start to try to do some game in java with libgdx, and I am trying to use the AssetsManager. but it keeps giving an error. I will put the code (I will try to resume the code) and the output.
The game goes through the loading screen fine but when it reaches the game screen it stops and gives an error, I do believe it's because the assets.
If someone knows why I am getting this error.
DesktopLauncher.java
public class DesktopLauncher {
public static void main (String[] arg) {
LwjglApplicationConfiguration config = new LwjglApplicationConfiguration();
new LwjglApplication(new pressme(), config);
}
}
pressme.java
public class pressme extends Game {
LoadingScreen loadingscreen;
AssetsManager assetsmanager;
Assets assets;
#Override
public void create() {
assets = new Assets();
assetsmanager = new AssetsManager();
assetsmanager.load();
assets.other();
loadingscreen = new LoadingScreen(this);
setScreen(loadingscreen);
}
}
LoadingScreen.java
public class LoadingScreen implements Screen {
Assets assets;
AssetsManager assetsmanager;
private final pressme game;
public GameScreen game_screen;
public LoadingScreen(final pressme game){
assets = new Assets();
assetsmanager = new AssetsManager();
this.game = game;
}
#Override
public void show() {
assetsmanager.load();
}
private void update(float delta){
System.out.println(progress);
if(assetsmanager.manager.update()) {
game.setScreen(new GameScreen(game));
}
progress = assetsmanager.manager.getProgress();
}
}
GameScreen.java
public class GameScreen implements Screen {
pressme game;
Assets assets;
AssetsManager assetsmanager;
public GameScreen(pressme game){
this.game = game;
assets = new Assets();
assetsmanager = new AssetsManager();
}
#Override
public void render(float delta) {
Gdx.gl.glClearColor( 0.5F, 0.5F, 0.5F, 0.5F);
Gdx.gl.glClear( GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT );
camera.update();
generalUpdate(touch, camera);
batch.setProjectionMatrix(camera.combined);
assets.load();
batch.begin();
batch.draw(assets.back, 0, 0);
batch.end();
}
}
Assets.java
public class Assets {
AssetsManager assetsmanager;
public Sprite back;
public void load(){
assetsmanager = new AssetsManager();
assetsmanager.load();
back = new Sprite(assetsmanager.manager.get(assetsmanager.back, Texture.class));
}
}
AssetsManager.java
public class AssetsManager {
public AssetManager manager = new AssetManager();
public String back = "back.png";
public void load(){
manager.load(back, Texture.class);
}
}
Output
LOADINGGG
0.0
0.0
0.015151516
0.015151516
0.030303031
.
.
.
0.969697
0.9848485
0.9848485
Exception in thread "LWJGL Application" java.lang.NullPointerException
at com.badlogic.gdx.graphics.g2d.SpriteBatch.draw(SpriteBatch.java:586)
at com.david.pressme.GameScreen.render(GameScreen.java:244)
at com.badlogic.gdx.Game.render(Game.java:46)
at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:223)
at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:124)
EDIT
RC Thank you for the tip
So After I put the "assets.load()" still with some error. I dont know if the "assets.load()" it is on the right place
LOADINGGG
0.0
0.0
0.015151516
0.015151516
0.030303031
.
.
.
0.969697
0.969697
0.9848485
0.9848485
Exception in thread "LWJGL Application" com.badlogic.gdx.utils.GdxRuntimeException: Asset not loaded: back.png
at com.badlogic.gdx.assets.AssetManager.get(AssetManager.java:144)
at com.david.pressme.Assets.load(Assets.java:254)
at com.david.pressme.GameScreen.render(GameScreen.java:172)
at com.badlogic.gdx.Game.render(Game.java:46)
at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:223)
at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:124)
EDIT2
RC, Spylot ty for the tips, it was what you said
So its resolved, i puting
"assets.load" on "public void show()"
this way when the screen its load he loads the assest on the begin, and i take it off from the
"public void render(){"
because he was always loading the assests because its a loop (I think so), then on
"Assets.java public load(){" i put "assetsmanager.load();"
Thanks Rc for the tips. Then on the same place I put the
"assetsmanager.manager.finishLoading();"
so it loads all assets before do something. Thank you spylot for the tip.
Thank you all who help or try to help much appreciate.
You should be aware that when you're loading assets, you cannot use them until you call finishLoading. finishLoading blocks all calls trying to grab onto the asset until they are fully loaded in the memory.
I highly suggest you to read the AssetManager API.
So in short, after each time you use load() call, you should finish it off using manager.finishLoading()

Assets wont get rendered after disposing and reloading them

In my game I have currently two screens. The MenuScreen and the GameScreen. Through the Play option in the menu the player can switch to the GameScreen and start the Gameplay and with Escape he can get back to the MenuScreen. I dispose the used Assets when I switch to the other Screen in the hide() method and load the needed Assets for the new Screen in the constructor of the Screen I switch to. The problem is that the Textures and Sound Effects aren't rendered/played when I switch back.
For example when I start the game in the MenuScreen, then switch to the GameScreen everything is fine. But when I switch back to the MenuScreen the MenuScreen is just a black window. When I then switch to the GameScreen again it's black too except for the BitmapFont.
Maybe there is a fundemental flaw in the way I handle this. I tried to leave out as much unnecessary things as I can from the code I post here, but I fear that it's still too much.
RessourceLoader Class:
public class RessourceLoader {
public static AssetManager manager;
public static void create() {
manager = new AssetManager();
}
public static void loadMenuScreen() {
manager.load("gfx/menuBackground.png", Texture.class);
}
public static void getMenuScreen() {
menuBackground = manager.get("gfx/menuBackground.png", Texture.class);
}
public static void disposeMenuScreen() {
menuBackground.dispose();
}
public static void loadGameScreen() {
// load GameScreen Assets through AssetManager
}
public static void getGameScreen() {
// get GameScreen Assets through AssetManager
}
public static void disposeGameScreen() {
// dispose all GameScreen Assets
}
public static void dispose() {
manager.dispose();
}
}
MenuScreen Class:
public class MenuScreen implements Screen {
// Game starts in the MenuScreen
// Instance of game
private PHGame game;
// Orthographic camera
private OrthographicCamera cam;
public MenuScreen(PHGame phGame) {
game = phGame;
RessourceLoader.loadMenuScreen();
RessourceLoader.manager.finishLoading();
RessourceLoader.getMenuScreen();
cam = new OrthographicCamera();
cam.setToOrtho(true, 640, 480);
game.batcher.setProjectionMatrix(cam.combined);
}
#Override
public void render(float delta) {
// Fills background with black to avoid flickering
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
// Begin Drawing
game.batcher.begin();
// Draw Menu
// Stop drawing
game.batcher.end();
// Pressing Space confirms currently selected menu item
if (GameKeys.isPressed(GameKeys.SPACE)) {
game.setScreen(new GameScreen(game));
}
// Update Key Presses
GameKeys.update();
}
#Override
public void hide() {
dispose();
}
#Override
public void dispose() {
RessourceLoader.disposeMenuScreen();
}
}
GameScreen Class:
public class GameScreen implements Screen {
// Instance of game
private PHGame game;
private GameWorld world;
private GameRenderer renderer;
private float runTime;
public GameScreen(PHGame phGame) {
game = phGame;
RessourceLoader.loadGameScreen();
RessourceLoader.manager.finishLoading();
RessourceLoader.getGameScreen();
world = new GameWorld(game, this);
renderer = new GameRenderer(world, game);
}
#Override
public void render(float delta) {
// runTime is the amount of time the game is running
runTime += delta;
// Updates the Game World
world.update(delta);
// Renders everything
renderer.render(runTime);
// Update Key Presses
GameKeys.update();
}
#Override
public void hide() {
dispose();
}
#Override
public void dispose() {
RessourceLoader.disposeGameScreen();
}
}
GameRenderer Class:
public class GameRenderer {
// Instance of PHGame
PHGame game;
// Instance of Game World
private GameWorld world;
// Orthographic Camera
private OrthographicCamera cam;
// If true hitbox's will be shown
private boolean showHitbox;
// Game Objects
private Player player;
public GameRenderer(GameWorld world, PHGame game) {
this.game = game;
this.world = world;
player = world.getPlayer();
cam = new OrthographicCamera();
cam.setToOrtho(true, 640, 480);
showHitbox = false;
game.batcher.setProjectionMatrix(cam.combined);
}
public void render(float runTime) {
// draw objects and hud
}
}
If there are any questions regarding my problem I'll try to answer then as good as I can.
Refer to the github article 'managing your assets'. AssetManagers should not be static. 'This typically would cause black/missing textures or incorrect assets.'
After you dispose your asset manager it can no londer be used. Instead use manager.unload to unload assets. manager.unload("gfx/menuBackground.png");
EDIT:
I also didn't see any overriden show() methods. If you want your assets back you will need to load your assets in the screen's show method every time.

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