Develop Reference

LibGdx Understanding the viewports and associtate it with a Scene2D

Whenever I try to set my viewport to a Stage, the actors, that I puting into the Scene are blured and very large. I want to set my Game world size as a rectangle of 50x100 units and then scale everything (Sprites, actors, labels, fonts) according that units. Every state inharitate form a class State which provides render function etc.
public abstract class State {
public static final float GAME_SIZE_WIDTH = 50 ;
public static final float GAME_SIZE_HEIGHT = 100 ;
protected OrthographicCamera camera;
protected GameStateManager gsm;
protected Viewport viewport;
public State(GameStateManager gsm) {
this.gsm = gsm;
camera = new OrthographicCamera();
viewport = new ExtendViewport(GAME_SIZE_WIDTH, GAME_SIZE_HEIGHT, camera);
viewport.apply();
camera.position.set(GAME_SIZE_WIDTH / 2, GAME_SIZE_HEIGHT / 2, 0);
}
public abstract void handleInput();
public abstract void update(float dt);
public abstract void render (SpriteBatch sb);
public abstract void dispose();
public abstract void resize(int width, int height) ;
}
In every State I want to add the Stage and pass the viewPort for my State class according to keep the GAME_SIZE_WIDTH /GAME_SIZE_HEIGHT dimension, but Ive got unadjusted backgrounds (even if its full HD picture the white border on the left) and the Buttons are blured with unadjusted text on it.
public class MenuState extends State implements InputProcessor {
private Skin skin;
private Stage stage;
private Sprite background;
private Table table;
private TextButton startButton,quitButton;
private Sprite flappyButton;
private Sprite chodzenieButton;
private Sprite memoryButton;
private Sprite rememberSquare;
private static final String TAG = "kamil";
private Vector3 touchPoint;
public MenuState(GameStateManager gsm) {
super(gsm);
skin = new Skin(Gdx.files.internal("button/uiskin.json"));
stage = new Stage(viewport);
table = new Table();
table.setWidth(stage.getWidth());
table.align(Align.center | Align.top);
table.setPosition(0,GAME_SIZE_HEIGHT);
startButton = new TextButton("New Game",skin);
quitButton = new TextButton("Quit Game",skin);
startButton.addListener(new ClickListener() {
#Override
public void clicked(InputEvent event, float x, float y) {
Gdx.app.log("Clicked button","Yep, you did");
event.stop();
}
});
table.padTop(5);
table.add(startButton).padBottom(5).size(20,10);
table.row();
table.add(quitButton).size(20,10);
stage.addActor(table);
background =new Sprite(new Texture(Gdx.files.internal("backgrounds/bg.jpg")));
background.setSize(GAME_SIZE_WIDTH,GAME_SIZE_HEIGHT);
background.setPosition(0,0);
touchPoint= new Vector3();
InputMultiplexer im = new InputMultiplexer(stage,this);
Gdx.input.setInputProcessor(im);
flappyButton=new Sprite(new Texture("menuButton/floopyBirdButtonTexture.png"));
chodzenieButton =new Sprite(new Texture("menuButton/swipeMovementsButtonTexture.png"));
memoryButton =new Sprite(new Texture("menuButton/memory.png"));
rememberSquare = new Sprite(new Texture("menuButton/rememberSquare.png"));
rememberSquare.setSize(20,10);
flappyButton.setSize(20,10);
chodzenieButton.setSize(20,10);
memoryButton.setSize(20,10);
flappyButton.setPosition(GAME_SIZE_WIDTH/2-flappyButton.getWidth()/2,GAME_SIZE_HEIGHT/2-flappyButton.getHeight()/2);
chodzenieButton.setPosition(GAME_SIZE_WIDTH/2-flappyButton.getWidth()/2,flappyButton.getY()- chodzenieButton.getHeight() -2);
memoryButton.setPosition(chodzenieButton.getX(),chodzenieButton.getY()- flappyButton.getHeight() -2);
rememberSquare.setPosition(flappyButton.getX(),flappyButton.getY()+flappyButton.getHeight()+2);
}
#Override
public void render(SpriteBatch sb) {
sb.setProjectionMatrix(camera.combined);
sb.begin();
background.draw(sb);
flappyButton.draw(sb);
chodzenieButton.draw(sb);
memoryButton.draw(sb);
rememberSquare.draw(sb);
sb.end();
stage.act(Gdx.graphics.getDeltaTime());
stage.draw();
}
#Override
public void dispose() {
flappyButton.getTexture().dispose();
chodzenieButton.getTexture().dispose();
background.getTexture().dispose();
}
#Override
public void resize(int width, int height) {
Gdx.app.log("kamil","Resize");
viewport.update(width,height);
}
#Override
public void handleInput() {
if(Gdx.input.justTouched())
{
//
viewport.unproject(touchPoint.set(Gdx.input.getX(),Gdx.input.getY(),0));
if(flappyButton.getBoundingRectangle().contains(touchPoint.x,touchPoint.y)) {
gsm.set(new FlopyBirdState(gsm));
}
else if (chodzenieButton.getBoundingRectangle().contains(touchPoint.x,touchPoint.y)){
gsm.set(new ChodzenieState(gsm));
}
else if (memoryButton.getBoundingRectangle().contains(touchPoint.x,touchPoint.y)){
gsm.set(new MemoryState(gsm));
}
else if (rememberSquare.getBoundingRectangle().contains(touchPoint.x,touchPoint.y)){
gsm.set(new FoodEaterState(gsm));
}}
}

blured and very large : This is due to font size you're using.
Blured when some font scaled in appropriate manner, doesn't matter it is by you or by viewport.
You're using 50 and 100 as world width and height of viewport, and you're using BitmapFont from skin that having greater size as compare to 50 and 100. so when you update viewport by screenwidth and height then BitmapFont also scale up so look very large and blurry too.
Solution:
Use some greater world width and height of viewport by comparing your BitmapFont that you're using.
Use small size of your BitmapFont or you can scale down so that not scaled too much and look ugly.
skin.get("font-name",BitmapFont.class).getData().setScale(.25f);
you're using Table so you may need to check where your Actor is in cell/Table. You can enable debugging by this flag stage.setDebugAll(true);
EDIT
You're using ExtendViewport, from wiki
The ExtendViewport keeps the world aspect ratio without black bars by extending the world in one direction. The world is first scaled to fit within the viewport, then the shorter dimension is lengthened to fill the viewport.
Let's suppose you're device width and height is 400 and 640, then what happen when you update viewport by 400 and 640. First your background Sprite scaled in height and set his height to 640(because viewport worldheight is equal to background height) done, now it's time for width of background Sprite because you set width is half of height so scaled and set size 640/2 = 320. done
Your problem arrive, my device width is 400 but my background sprite size is only 320 rest (40*2 unit is white from both side).
Use 48*80(most of devices is in this ratio) instead of 50*100

libGDX: size of object in FitViewport is distorted

My goal is to create a game that is always displayed with an aspect ratio of 9:16 (basically 16:9, but upright) using FitViewport; it should be independet of a target device's resolution. In order to test this setup, I created the following minimal working example. A small green square indicates the origin of the coordinate system:
MyGame.java
public class MyGame extends ApplicationAdapter {
final int WORLD_WIDTH = 900;
final int WORLD_HEIGHT = 1600;
Stage stage;
Viewport vp;
public void create() {
stage = new Stage();
vp = new FitViewport(WORLD_WIDTH, WORLD_HEIGHT, stage.getCamera());
stage.setViewport(vp);
stage.addActor(new MySquare());
}
public void render() {
stage.act();
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
stage.draw();
}
public void resize(int width, int height) {
stage.getViewport().update(width, height, true);
}
// dispose...
}
MySquare.java
public class MySquare extends Actor {
ShapeRenderer renderer = new ShapeRenderer();
#Override
public void draw(Batch batch, float alpha){
batch.end();
renderer.begin(ShapeRenderer.ShapeType.Filled);
renderer.setColor(Color.GREEN);
renderer.rect(0, 0, 50, 50);
renderer.end();
batch.begin();
}
}
Unfortunately, the result is not as expected: As you can see, the green square is actually not a square. This behavior is the same for both Windows and Android (in landscape mode):
However, when setting the size of the window programmatically and explicitly via LwjglApplicationConfiguration in DesktopLauncher.java to a valid 9:16 resolution, the green square is displayed correctly. Why is that and how can I avoid this workaround (which does not work for Android anyway)?

Your problem is that your shape renderer is ignoring the camera. Update it like this:
public void draw(Batch batch, float alpha){
batch.end();
renderer.setProjectionMatrix(batch.getProjectionMatrix()); // <<<<< Add this
renderer.begin(ShapeRenderer.ShapeType.Filled);
renderer.setColor(Color.GREEN);
renderer.rect(0, 0, 50, 50);
renderer.end();
batch.begin();
}
If you are planning to eventually use sprites, and you're simply wanting rectangle placeholders for your actors, you don't need a custom actor for this. You can use a generic Actor and call setDebug(true) on it, and Stage will automatically draw its outline using an internal ShapeRenderer. Of course, you must first set a size and position on the Actor.

Fit Viewport Black Bars

I'm currently developing a game where you have to avoid Asteroids. To make the Game look same on every device I use the FitViewport. Unfortunately I somehow get White Bars on the top and on the Bottom instead of Black ones. My Game Background is also white, so it looks a bit weird.
GameScreen:
#Override
public void create()
{
float aspectRatio = (float)Gdx.graphics.getWidth() / (float)Gdx.graphics.getHeight();
cam = new OrthographicCamera();
viewport = new FitViewport(MyGdxGame.WIDTH * aspectRatio, MyGdxGame.HEIGHT, cam);
[...]
}
#Override
public void render(SpriteBatch batch)
{
cam.update();
batch.setProjectionMatrix(cam.combined);
batch.begin();
em.render(batch); //render Ship and Asteroids
[...]
}
#Override
public void resize(int width, int height)
{
viewport.update(width, height);
cam.position.set(MyGdxGame.WIDTH / 2, MyGdxGame.HEIGHT /2, 0);
}
I dragged the Ship into the white Bar.

LibGDX provides viewports as a more convenient way of dealing with different aspect ratios. You don't have to multiply MyGdxGame.WIDTH with aspectRatio. Just initialize it with MyGdxGame.WIDTH and MyGdxGame.HEIGHT.
Also, in resize function, you can change the cam position using viewport values (instead of using constants):
cam.position.set(cam.viewportWidth / 2, cam.viewportHeight / 2, 0);

I found some issues in your code. for best practice while handling with the different screen ratio just try with the fill viewPort. Here is simply editing your code with the fill viewport . Just try it once.
#Override
public void create()
{
float aspectRatio = (float)Gdx.graphics.getWidth() / (float)Gdx.graphics.getHeight();
camera = new OrthographicCamera();
camera.position.set(0, 0, 0);
camera.update();
//1280 is the screen width and 800 is screen height
camera.setToOrtho(false, 1280, 800);
viewPort = new FillViewport(1280, 800, camera);
}
#Override
public void render(SpriteBatch batch)
{
batch.setProjectionMatrix(camera.combined);
batch.begin();
em.render(batch); //render Ship and Asteroids
[...]
}
#Override
public void resize(int width, int height)
{
viewPort.update(width, height);
}
just try with the above code . it will definitely work

libGDX - Drawing Texture via SpriteBatch Result Flip

When I tried draw a Texture using SpriteBatch it was result flip like this:
Here what I do:
I create MyRect object which draw bounding rectangle and an image.
Here MyRect class preview:
public class MyRect {
private Vector2 position;
private int width;
private float height;
private Texture img;
private Sprite sprite;
public MyRect(int x, int y, int width, int height){
img = new Texture("badlogic.jpg");
sprite = new Sprite(img);
position = new Vector2(x,y);
this.width = width;
this.height = height;
}
public void draw(ShapeRenderer shapeRenderer, SpriteBatch batch){
// Gdx.gl.glClearColor(0, 0, 0, 1);
// Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
shapeRenderer.begin(ShapeType.Line);
// Draw Background color
shapeRenderer.setColor(55 / 255.0f, 80 / 255.0f, 100 / 255.0f, 1);
shapeRenderer.rect(position.x, position.y, width, height);
shapeRenderer.end();
batch.begin();
// batch.disableBlending();
batch.draw(img, position.x, position.y,
width, height);
batch.end();
}
}
Parameters ShapeRenderer and SpriteBatch pass by GameScreen class.
GameScreen preview:
public class GameScreen implements Screen{
private MyRect myRect;
private ShapeRenderer shapeRenderer;
private SpriteBatch batch;
private OrthographicCamera cam;
public GameScreen(){
myRect = new MyRect(10,10,50,50);
int gameHeight=100;
cam = new OrthographicCamera();
cam.setToOrtho(true, 136, gameHeight);
batch = new SpriteBatch();
batch.setProjectionMatrix(cam.combined);
shapeRenderer = new ShapeRenderer();
shapeRenderer.setProjectionMatrix(cam.combined);
}
#Override
public void render(float delta) {
// TODO Auto-generated method stub
myRect.draw(shapeRenderer, batch);
}
}
Why is this happen? Am I doing it wrong?

Your camera is upside down because you called setToOrtho(true, ...) on it instead of setToOrtho(false, ...)
It is valid to use an upside-down camera (which might be more comfortable if you've used Flash or some other Y-down system before), but then you need to flip all your TextureRegions (aka Sprites): sprite.flip(false, true). Alternatively, you can create a TextureAtlas using TexturePacker (look it up in libgdx documentation) and set the flipY option, so it flips them ahead of time for you. Eventually, for performance you will need to use a TextureAtlas anyway.
By the way, when you start drawing multiple instances of MyRect, you are going to need to move the spriteBatch.begin() and end() and shapeRenderer.begin() and end() out of the individual MyRect's draw method or you will run into a performance problem. And as such, there will need to be two draw methods (one for sprite batch and one for shape renderer).

apparently, the only thing I see different than how I would do, is try to change:
this meybe if it works"for test"
cam.setToOrtho(false, 136, gameHeight);
this is how I use the camera.
I do not know whether to use true, you have to do some different way, to draw the batch, in anyway. if the camera false, it looks good, I think it has to flip the image before to draw uv

Texture size with Libgdx

It may be a dumb question but I need a little help / explanations. I can't manage to resize correctly my textures when I resize the window in libgdx. I want to keep the aspect of my textures or have them at least reduced on a lower screen size, like on a mobile device. Here is a sample of my code, my original window size is 600*700 I tried a lot of things but nothing works :\
Can you help me ? Thanks in advance.
public class GameScreen implements Screen {
private World world;
private int ppxX, ppxY;
private SpriteBatch batch;
private OrthographicCamera camera;
private float cameraX, cameraY;
public GameScreen(World world) {
this.world = world;
camera = new OrthographicCamera();
}
public void show() {
batch = new SpriteBatch();
}
#Override
public void render(float delta) {
world.update(delta);
updateCamera();
ppxX = Gdx.graphics.getWidth() / 600;
ppxY = Gdx.graphics.getHeight() / 700;
Gdx.gl.glClearColor(0f, 0f, 0f, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
batch.setProjectionMatrix(camera.combined);
batch.begin();
batch.draw(world.getTexture(), 0, 0, ppxX, ppxY);
for (GameElement e : world.getListElements()) {
e.update(delta);
batch.draw(e.getTexture(), e.getPositionX()*ppxX, e.getPositionY()*ppxY, e.getWidth()*ppxX , e.getHeight()*ppxY );
}
batch.end();
}

You are on the right track, but there is couple of things you have to change.
Use ViewPorts
this.camera = new OrthographicCamera();
this.viewport = new FitViewport(WORLD_SIZE_X, WORLD_SIZE_Y, this.camera);
this.batch = new SpriteBatch();
this.batch.setProjectionMatrix(this.camera.combined);
Resize correctly.
#Override
public void resize(int width, int height) {
this.viewport.update(width, height);
}
Update the camera and render using World Units. Do not make the mistake of thinking in Screen Pixels.
public void render(float delta) {
this.camera.update();
this.batch.setProjectionMatrix(this.camera.combined);
this.batch.begin();
// draw using WORLD_SIZE
this.batch.end();
}