Develop Reference

Having issues loading an image from a sprite sheet, am i loading the sprite sheet correctly? [duplicate]

I've been making a 2D game with my buddy and I've been learning a lot about some basic game dev concepts through some Youtube tutorials. One of the things I was learning about is sprites (for those that don't know, 2D images to render to the screen) and how to use them in my game. I've been using ImageIO.read(this.class.getResource(pathToMySprite)) but it seems that getResource() is returning null for some reason.
I've been screwing around with the path a little, adding "/" in front of it, removing "/", putting the user.dir property to see if it needed the whole path, and I'm still getting the same error.
TILE_TEXTURES(System.getProperty("user.dir") + "/textures/tile.png");
//ENTITY_TEXTURES("/textures/entity.png");
private BufferedImage img;
private SpriteSheet(String path) {
System.out.println(System.getProperty("user.dir"));
try {
//TODO: Fix this error, don't know what's wrong.
img = ImageIO.read(SpriteSheet.class.getResource(path)); // error here!!!
} catch (IOException e) {
e.printStackTrace();
}
}
public BufferedImage getImage() {
return img;
}
Any and all help is appreciated.
I haven't been commenting the code (I usually do that when I get to place where I can sit back and be happy with what I've finished) but it's a pretty small class so I think you guys will be able to understand what's going on just fine.
The folder that holds the image IS in the class path of my project.
I've also included the error:
Exception in thread "Thread-2" java.lang.ExceptionInInitializerError
at com.brickbattle.client.src.gui.Sprite.<clinit>(Sprite.java:7)
at com.brickbattle.client.src.objs.Tile.<init>(Tile.java:67)
at com.brickbattle.client.src.objs.Player.initPlayerNum(Player.java:19)
at com.brickbattle.client.src.util.BrickBattle.init(BrickBattle.java:114)
at com.brickbattle.client.src.util.BrickBattle.run(BrickBattle.java:85)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.IllegalArgumentException: input == null! //HERE IS ERROR
at javax.imageio.ImageIO.read(Unknown Source)
at com.brickbattle.client.src.gui.SpriteSheet.<init>(SpriteSheet.java:17)
at com.brickbattle.client.src.gui.SpriteSheet.<clinit>(SpriteSheet.java:8)
Thanks again!

This problem is basically unrelated to ImageIO, but rather how Class/ClassLoader.getResource or getResourceAsStream works.
For an explanation, see this answer.
In any case, these ways of obtaining a resource will only be able to read from classpath (ie. user.dir will never help here).
This should work:
ImageIO.read(getClass().getResource("/path/to/resource"));
Where the path is relative to the root of the classpath (specified by the leading /).
If your resources are not on the classpath, simply use:
ImageIO.read(new File("path/to/resource");
Where the path is relative to the directory your application was launched from.

How do I get a VLC Media Player in Java without a Displayable Component?

I'm working with the VLCJ Bindings and have finally been able to get several roadblocks. Now I am here.
I have no need (at this time), nor desire for, a visible Media Player component (the EmbeddedMediaPlayerComponent). All I need (for now) is to play Audio Files.
I have the following method in place to handle that for me:
public static void Play(File AudioFile){
if (!LibVLCLoader.Loaded) LibVLCLoader.loadLibVLC();
EmbeddedMediaPlayerComponent EMPC = new EmbeddedMediaPlayerComponent();
if (EMPC.getMediaPlayer().prepareMedia(AudioFile.getAbsolutePath())){
EMPC.getMediaPlayer().addMediaPlayerEventListener(new MediaPlayerEventAdapter(){
#Override public void subItemFinished(MediaPlayer p, int i){
EMPC.release(true);
}
});
Platform.runLater(() -> EMPC.getMediaPlayer().play());
}
}
But I keep getting this exception:
Exception in thread "JavaFX Application Thread" java.lang.IllegalStateException: The video surface component must be displayable
Which I understand. It makes sense. But I don't NEED it visible. I just need the sound. How can I make that happen?

EmbeddedMediaPlayer is only for the case where you want to literally embed a video surface inside your application.
If you just need audio, there's an AudioMediaPlayerComponent for expressly this purpose.
To create such a component, simply:
AudioMediaPlayerComponent audioMediaPlayerComponent =
new AudioMediaPlayerComponent();
You can subclass it, for example to customise behaviour and easily implement event handlers.
Using the so-called "component" media players gives you a slightly nicer/easier API than using the non-"component" media players that are created via the MediaPlayerFactory.
This works just fine if your media is an audio file.
If your media is actually video, but you only want to play the audio track, then even if you use the AudioMediaPlayerComponent by default VLC will open a video window. In this case you still need to actually disable the video output - the simplest way to do this is to tell VLC to use vcodec=dummy.
I really don't agree with tricks like creating a window and moving it off-screen, or sizing it down to 1x1, it's just not necessary.
In the code posted in the original question there is an unrelated problem. The EMPC and EMP variable will go out-of-scope when the Play() method terminates, making the media player eligible for garbage collection. What will happen is that some random time later your application will likely crash because the native hooks that vlcj uses will call back into a Java object that no longer exists. You need to keep your media player references alive via hard references.

Okay so it turns out you can create your own MediaPlayer object outside of the EmbeddedMediaPlayerComponent like so:
public static void Play(File AudioFile){
if (!LibVLCLoader.Loaded) LibVLCLoader.loadLibVLC();
MediaPlayerFactory MPF = new MediaPlayerFactory(
"--video-title=vlcj video output",
"--no-snapshot-preview",
"--quiet",
"--quiet-synchro",
"--sub-filter=logo:marq",
"--intf=dummy"
);
EmbeddedMediaPlayer EMP = MPF.newEmbeddedMediaPlayer();
if (EMP.prepareMedia(AudioFile.getAbsolutePath())){
EMP.addMediaPlayerEventListener(new MediaPlayerEventAdapter(){
#Override public void subItemFinished(MediaPlayer p, int i){
EMP.release();
MPF.release();
}
});
Platform.runLater(() -> EMP.play());
} else{
EMP.release();
MPF.release();
}
}

Unit-testing of libgdx-using classes

I'm writing a game over libgdx; I'm using the junit framework to simplify unit-testing my code.
Now there's part of the code (a map generator, a class converting my own map format into TiledMap...) which I need to test thoroughly, but it uses libgdx code: from file handling to asset loading.
I'm not planning to test the actual graphical output, or the game itself, in this way: but I want to test the single components (calculation, asset access...) to avoid blatant errors.
I've tried to do something like this in the "setUpBeforeClass" method:
LwjglApplicationConfiguration cfg = new LwjglApplicationConfiguration();
cfg.useGL20 = true;
cfg.width = 480;
cfg.height = 320;
cfg.resizable = true;
LwjglApplication app = new LwjglApplication( new TestApplicationListener(), cfg);
And calling within tearDownAfterClass():
Gfx.app.exit()
But it does create a window I do not need, and seems overkill when all I need is the file handling initialized. Is there a better way to initialize the libGDX components without creating an entire application object?
Thanks.
EDIT
Going back over it (thanks to Sam in the comments), I realize GL access is needed (loading assets requires it), but this approach does not seem to work: the graphic library does not seem to be initialized. GDX documentation hasn't helped. Any clue?

This question hasn't been answered and I am surprised nobody has pointed out the headless backend, which is ideal for this situation. Combine this with your favorite mocking library and you should be good to go.
public class HeadlessLauncher {
public static void main(final String[] args) {
final HeadlessApplicationConfiguration config = new HeadlessApplicationConfiguration();
config.renderInterval = Globals.TICK_RATE; // Likely want 1f/60 for 60 fps
new HeadlessApplication(new MyApplication(), config);
}
}

As already showed there is a HeadlessApplication backend which gives you an initialized libGDX but has no OpenGL context. For working with OpenGL you indeed need the LwjglApplication backend which creates an OpenGL window.
If you have problems writing tests which rely on the OpenGL context keep in mind that OpenGL is only attached to the thread of your LwjglApplication which is not the tread of your tests. Your tests have to call Gdx.app.postRunnable(Runnable r) to access the thread with the OpenGl context.
You may want to use synchronized and CountDownLatch to pause the test while waiting for your application to execute the command.

YouTubeEmbededPlayer GWT HowTo stop videos?

I am trying to use the youtube video gwt api.
The youtube-player works but how can I stop videos? I didnt find a command for that...
I created my player following:
protected YouTubeEmbeddedPlayer _youTubeEmbeddedPlayer;
_youTubeEmbeddedPlayer = new YouTubeEmbeddedPlayer(youTubeVideoID);
That´s the YouTube Player:
https://code.google.com/p/gwt-youtube-api/wiki/EmbededPlayer

By using YouTubePlayerWrapper.
You can stop video by calling the method
youTubePlayerWrapper.stopVideo();

This answer may not resolve the problem mentioned with the same library. In fact I tried multiple different library with every library having some issues. So end up creating my own wrapper. I have made it public check it if you can use it https://github.com/pandurangpatil/gwt-youtube

How to play sound in JavaFX?

I'm experimenting with JavaFX making a small game.
I want to add sound.
How?
I tried MediaPlayer with media defined with relative source attribute like:
attribute media = Media{
source: "{__FILE__}/sound/hormpipe.mp3"
}
attribute player = MediaPlayer{
autoPlay:true
media:media
}
It doesn't play.
I get
FX Media Object caught Exception com.sun.media.jmc.MediaUnavailableException: Media unavailable: file: ... Sound.class/sound/hormpipe.mp3

Just a guess, but is that file "hornpipe.mp3" and not "hormpipe.mp3" (with an m)?

var player = javafx.scene.media.MediaPlayer {
repeatCount: javafx.scene.media.MediaPlayer.REPEAT_FOREVER
media: Media { source: "{\_\_DIR\_\_}clip.wav"
};
};
player.play();
You have to incluye the audio file in the build/compiled directory so Netbeans can pack it into the jar file.

Just a guess, but I think your {__FILE__} will expand to the name of your file. Try replacing it with {__DIR__}.

Also note that {__DIR__} includes the trailing /, so try this instead:
attribute media = Media{
source: "{__DIR__}sound/hormpipe.mp3"}
EDIT: I did some digging, and apparently, the source of a Media object has to be either a remote URL, or an absolute file path, since media files aren't allowed in JARs (something I hope gets changed with future releases, since I really like JavaFX and want to be able to make desktop apps with it). See: JavaFX FAQs.

This worked for me:
MediaPlayer audio = new MediaPlayer(
new Media(
new File("file.mp3").toURI().toString()));
Source file should be in project's root directory (not src, not dist).

OK, having used this question to get MP3 audio working (kinda), I've learned the following (not much).
1) Audio for compressed formats is very platform dependent. My continually upgraded Mint 17.1->18 machine plays mp3 fine using Media and MediaPlayer. Fresh installs of Mint 18 won't (with the dev tools).
So use .wav files.
Media sound=new Media(new File("noises/roll.wav").toURI().toString());
MediaPlayer mediaPlayer=new MediaPlayer(sound);
mediaPlayer.play();
2) One of the things you need to be aware of with Media/MediaPlayer is that in order to play multiple times (repeatedly or all at once ie, on a button press/whatever in a game) you have to spawn N number of MediaPlayer objects, and each one will play once and then stop.
So use javafx.scene.media.AudioClip
AudioClip soundMyNoise = new AudioClip(new File("noises/roll.wav").toURI().toString());
soundMyNoise.play();
AudioClip also has its issues, which include storing the raw audio data in RAM all at once instead of buffering. So there is the possibility of excessive memory use.
No matter which method you end up going with, one thing to be critically aware of was mentioned by daevon earlier - the path issue. With NetBeans, you have NetBeansProjects/yourproject/src/yourproject/foo.java. The sounds in the example above go in NetBeansProjects/yourproject/noises/roll.wav