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LibGdx update with deltatime is not precise

I'm new in creating game.
I have several boxes that move from top to bottom of screen and i need to make 1 unit distance between them.
Every thing works fine except the distance is not precise and i think the deltatime cause this problem
This is how i move the boxes :
objX -= deltatime * speed;
Update
time += deltatime :if(time >= 3.0f) spawn
Im using libgdx

You can schedule your task in this way :
Array<Sprite> sprites;
Texture texture;
SpriteBatch batch;
float speed=35;
#Override
public void create() {
sprites=new Array<Sprite>();
texture=new Texture("badlogic.jpg");
batch=new SpriteBatch();
Timer.instance().scheduleTask(new Timer.Task() {
#Override
public void run() {
spawn();
}
},1,2);
}
private void spawn(){
Sprite sprite=new Sprite(texture);
sprite.setSize(50,50);
sprite.setPosition(Gdx.graphics.getWidth()/2,0);
sprites.add(sprite);
}
#Override
public void render() {
Gdx.gl.glClearColor(1,1,1,1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
float delta=Gdx.graphics.getDeltaTime();
batch.begin();
for (Sprite sprite:sprites){
sprite.setY(sprite.getY()+delta*speed);
sprite.draw(batch);
}
batch.end();
}

After a lot of struggling i came up with an idea which is
instead of moving boxes and spawning them by deltatime , make boxes static and move camera over them!
So i just move camera here
public void render(float delta) {
posCameraDesired.y += 2000.0f * Gdx.graphics.getDeltaTime();
guiCam.position.lerp(posCameraDesired, 0.1f);
SemiRender();
}
and i have static Y that i'll update after each spawn
lastY = 10 + lastY + ((width / 4) / 2) * 3;
and some other logic to recycle them when they passed the viewport.
and every one is happy!

Spritebatch not drawing anything LibGDX

This is one of the oddest things that has ever occured in LibGDX for me. I have used these exact specifications for all my other States in my game, but under different names and they all work fine, except for my ShopState, which won't render ANYTHING at all! Here's my code for the class:
public class ShopState extends State{
private Texture bg;
private Sprite shopLayout;
private OrthographicCamera shopCam;
Viewport viewport;
public ShopState(GameStateManager gsm) {
super(gsm);
shopLayout = new Sprite(new Texture(Gdx.files.internal("shopLayout.png")));
bg = new Texture("bg2.png");
shopCam = new OrthographicCamera();
viewport = new StretchViewport(720, 1280, shopCam);
viewport.apply();
shopCam.position.set(shopCam.viewportWidth / 2, shopCam.viewportHeight / 2, 0);
shopLayout.setPosition(shopCam.viewportWidth / 2 - shopLayout.getWidth() / 2, shopCam.viewportHeight / 2 - shopLayout.getHeight() / 2);
shopLayout.setSize(650, 1100);
}
#Override
public void handleInput() {
}
#Override
public void update(float dt) {
handleInput();
}
#Override
public void resize(int width, int height){
viewport.update(width, height);
shopCam.position.set(shopCam.viewportWidth / 2, shopCam.viewportHeight / 2, 0);
}
#Override
public void render(SpriteBatch sb) {
shopCam.update();
sb.setProjectionMatrix(shopCam.combined);
sb.begin();
sb.draw(bg, 0 , 0, shopCam.viewportWidth, shopCam.viewportHeight);
shopLayout.draw(sb);
sb.end();
}
#Override
public void dispose() {
bg.dispose();
shopLayout.getTexture().dispose();
}
}
What am I doing wrong? Everything seems fine, but all I get when I click on the Shop button, it gives me a black screen!

Ok, found a solution, but I have no idea why this fixes it. All I had to do was add a stage that uses the current viewport.
stage = Stage(viewport);
And that was it! It is now working properly, for some reason...

LibGDX text not rendering properly on larger screens

On my 854 x 480 LG Leon it renders fine, but on a larger screen resolution (2560 x 1440) this happens: http://imgur.com/a/rcbJK.
The code for processing the text is: http://imgur.com/a/c316e.
I've tried expanding the bounds of the Label because I thought that it might be constricting the text, but it still won't display properly.
What could be causing this?

The different mobile phone has the different aspect ratio in their screen size . that is the reason it shows different different screen. to avoid this problem you must use the viewPort. So you will be able to handle the different screen size. for more details, you must read the libgdx documentation. here I'm posting a sample code which can help you to handle the different screen size. there are three kinds of viewports mainly using
1) fillviewport
2) fitviewPort
3)stretchviewport
here is the documentation in detail.
https://libgdx.badlogicgames.com/nightlies/docs/api/com/badlogic/gdx/utils/viewport/FillViewport.html
public class myGame extends ApplicationAdapter {
public OrthographicCamera camera;
public Viewport viewPort;
private SpriteBatch batch;
public myGame() {
}
#Override
public void create() {
float w = Gdx.graphics.getWidth();
float h = Gdx.graphics.getHeight();
camera = new OrthographicCamera();
camera.position.set(0, 0, 0);
camera.update();
camera.setToOrtho(false, 1280, 800);
viewPort = new FillViewport(1280, 800, camera);
}
#Override
public void dispose() {
batch.dispose();
}
#Override
public void render() {
Gdx.gl.glClearColor(1, 1, 1, 1);
Gdx.gl.glClear(GL30.GL_COLOR_BUFFER_BIT);
float deltaTime = Gdx.graphics.getDeltaTime();
batch.setProjectionMatrix(camera.combined);
batch.begin();
batch.draw(sprie,0,0)
batch.end();
}
#Override
public void resize(int width, int height) {
viewPort.update(width, height);
}
#Override
public void pause() {
}
#Override
public void resume() {
}
}
// don't copy paste it . just try to understand and implement it.

You should use Scene2D and ViewPort.
Also , be careful to use coordinates (i.e : x: 64 , y:32 changes in every different screen size)

This is the common issue when your running your game in multiple devices. Because your game is running in different aspect ratios in different screens . it's generally called the multi screen issue. To solve this problem the libgdx is providing it's on class called the viewPort. Mainly you can see three viewpors.
1)Fill viewPort.
2)Fit viewPort.
3)stretch viewport.
For more details you can go through the libgdx documentation. Here im posting some example code which can solve your multi screen issues.
public class myGame extends ApplicationAdapter {
public OrthographicCamera camera;
public Viewport viewPort;
private SpriteBatch batch;
private BitmapFont myScoreFont;
//General screen resolution
public int APP_WIDTH=1280;
public int APP_HEIGHT=800;
public int fontPositionIn_X=600;
public int fontPositionIn_Y=400;
public myGame() {
}
#Override
public void create() {
myScoreFont = new BitmapFont(Gdx.files.internal(Constants.PATH_TO_MY_SCORE_FONT), true);
batch = new SpriteBatch();
float w = Gdx.graphics.getWidth();
float h = Gdx.graphics.getHeight();
camera = new OrthographicCamera();
camera.position.set(0, 0, 0);
camera.update();
camera.setToOrtho(false, APP_WIDTH, APP_HEIGHT);
viewPort = new fillViewPort(1280, 800, camera);
}
#Override
public void dispose() {
batch.dispose();
}
#Override
public void render() {
Gdx.gl.glClearColor(1, 1, 1, 1);
Gdx.gl.glClear(GL30.GL_COLOR_BUFFER_BIT);
float deltaTime = Gdx.graphics.getDeltaTime();
batch.setProjectionMatrix(camera.combined);
batch.begin();
myScoreFont.draw(batch,"any texts", fontPositionIn_X, fontPositionIn_Y)
batch.end();
}
#Override
public void resize(int width, int height) {
viewPort.update(width, height);
}
#Override
public void pause() {
}
#Override
public void resume() {
}
}
so by using the viewPort you can be able to play your game in all the different screens.

Atlas does not render images in order[libGDX]

I am using the following class to render an atlas on screen:
public class AnimationDemo implements ApplicationListener {
private SpriteBatch batch;
private TextureAtlas textureAtlas;
private Animation animation;
private float elapsedTime = 0;
#Override
public void create() {
batch = new SpriteBatch();
textureAtlas = new TextureAtlas(Gdx.files.internal("data/packOne.atlas"));
animation = new Animation(1 / 1f, textureAtlas.getRegions());
}
#Override
public void dispose() {
batch.dispose();
textureAtlas.dispose();
}
#Override
public void render() {
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
batch.begin();
//sprite.draw(batch);
elapsedTime += Gdx.graphics.getDeltaTime();
batch.draw(animation.getKeyFrame(elapsedTime, true), 0, 0);
batch.end();
}
#Override
public void resize(int width, int height) {
}
#Override
public void pause() {
}
#Override
public void resume() {
}
}
I am a beginner with libGDX, however with the above program my images are not rendered in order as random images appear. I was earlier using the following with the same . atlas file and it was working properly:
public class MyGdxGame implements ApplicationListener {
private SpriteBatch batch;
private TextureAtlas textureAtlas;
private Sprite sprite;
private int currentFrame = 1;
private String currentAtlasKey = new String("0001");
#Override
public void create() {
batch = new SpriteBatch();
textureAtlas = new TextureAtlas(Gdx.files.internal("data/packOne.atlas"));
TextureAtlas.AtlasRegion region = textureAtlas.findRegion("0001");
sprite = new Sprite(region);
sprite.setPosition(Gdx.graphics.getWidth() / 2 - sprite.getWidth() / 2, Gdx.graphics.getHeight() / 2 - sprite.getHeight() / 2);
sprite.scale(4.5f);
Timer.schedule(new Timer.Task() {
#Override
public void run() {
currentFrame++;
if (currentFrame > 393)
currentFrame = 1;
// ATTENTION! String.format() doesnt work under GWT for god knows why...
currentAtlasKey = String.format("%04d", currentFrame);
sprite.setRegion(textureAtlas.findRegion(currentAtlasKey));
}
}
, 0, 1 / 30.0f);
}
#Override
public void dispose() {
batch.dispose();
textureAtlas.dispose();
}
#Override
public void render() {
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
batch.begin();
sprite.draw(batch);
batch.end();
}
#Override
public void resize(int width, int height) {
}
#Override
public void pause() {
}
#Override
public void resume() {
}
}
Any hints about what might be wrong here?
I am also trying to adapt my program with Screen Viewport any headings as in how to implement this would also be welcome.
Edit: The .atlas file is located here

Your atlas file isn't ordered. If you call the code below, it will be ordered.
regions.sort(new Comparator<AtlasRegion>() {
#Override
public int compare(AtlasRegion o1, AtlasRegion o2) {
return Integer.parseInt(o1.name) > Integer.parseInt(o2.name) ? 1 : -1;
}
});
But I'm still checking why your atlas regions isn't ordered.

you should create array with frames ordered alphabetically instead of using textureAtlas.getRegions() which just gives you an array without caring of order.
The example for atlas with regions named like: region1, region2 and so on would be:
AtlasRegion[] frames = new AtlasRegion[framesCount];
for(int i = 0; i < framesCount; i++)
{
frames[i] = atlas.findRegion("region" + i);
}
so you can adjust it to your regions names.
If you want to get all frames from textureAtlas you can also do it like this:
Array<String> names = new Array<String>();
for(AtlasRegion region : textureAtlas.getRegions())
{
names.add( region.name );
}
names.sort();
Array<AtlasRegion> frames = new Array<AtlasRegion>();
for(String s : names)
{
frames.add( textureAtlas.findRegion(s) );
}
and then after get frames array just create animation object:
animation = new Animation(1/1f, frames.items); //or just frames depending on which type frames is

TexturePacker will index the images for you as long as you follow the naming scheme set forth here https://github.com/libgdx/libgdx/wiki/Texture-packer#image-indexes.
so your frames would be named something like
anim1_001.png
anim1_002.png
...
anim1_100.png
and a separate animation would simply be
anim2_001.png
....
anim2_100.png
EDIT:
additionally you can get the regions only related to certain animations. So instead of
animation = new Animation(1 / 1f, textureAtlas.getRegions());
you could use (yes it's findRegions() not findRegion()):
animation1 = new Animation(1 / 1f, textureAtlas.findRegions("anim1"));
animation2 = new Animation(1 / 1f, textureAtlas.findRegions("anim2"));
EDIT2:
If you're are using a stage it is quite easy to implement a screen viewport. I do it like this, (stage is a field and this step is in the show/create method):
stage = new Stage(new ScreenViewport());
Then in the resize method:
stage.getViewport().update(width, height, true);
Without a stage it's only slightly more complex
camera = new WhateverCamera();
viewport = new ScreenViewport(camera);
Then in the resize method:
viewport.update(width, height, true);
Use whatever camera you want, WhateverCamera is a placeholder and can be OrthographicCamera or PerspectiveCamera.
The last argument true centers the camera, if you don't want to do this set it to false or leave it out, it assumes false.

Draw a sprite onto the map not to the screen

I'm using libgdx and I have a tiled map which i want to draw the sprite onto. However the sprite is drawn onto the actual window so when I move the camera, the sprite stays in the same place. ?I want to the sprite to move on the map.
This is how i currently render my objects
#Override
public void render(float delta) {
translateCamera();
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL10.GL_COLOR_BUFFER_BIT);
camera.update();
renderer.setView(camera);
renderer.render(bgLayers);
batch.begin();
batch.draw(splayerSprite, Gdx.graphics.getWidth() / 2,
Gdx.graphics.getHeight() / 2);
batch.end();
renderer.render(fgLayers);
}
It always end up being in the middle of the screen, however I want to be able to move them seperatly like for example the camera with (W,A,S,D) and move my player with the direction keys. Then if I want the camera locks onto the player but other wise its free.
I'm new to libgdx so please bear with me, Thanks

The problem is the SpriteBatch projection matrix isn't being set to the Camera projection matrix. This means the Sprite is not being rendered relative to the Camera. This is why the camera is moving, but the sprite is not; the correct matrix is not being used.
Also the sprite is being rendered always at half the screen's width, and half the screen's height. To fix this Call sprite.draw. This will use the Sprite's internal position.
Set the SpriteBatch projection matrix via batch.setProjectionMatrix(camera.combined). This will cause the sprite to be rendered relative to the camera.
#Override
public void render(float delta) {
translateCamera();
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL10.GL_COLOR_BUFFER_BIT);
camera.update();
renderer.setView(camera);
renderer.render(bgLayers);
//here's the line that was missing.
batch.setProjectionMatrix(camera.combined);
batch.begin();
//be sure to call this instead of specifying position yourself!
splayerSprite.draw(batch);
batch.end();
renderer.render(fgLayers);
}
You'll still need to handle snapping the camera's position to the sprite's position whenever WASD is pressed, but that's trivial.
//snap the camera to the sprite's center.
if(wasd_isDown){
float centerX = sprite.getX()+sprite.getWidth()/2;
float centerY = sprite.getY()+sprite.getHeight()/2;
camera.position.set(x,y, 0);
}
If direction keys are pressed, just translate the camera's position vector via Vector3.add like so:
if(!wasd_isDown){
float deltaX = 0;
float deltaY = 0;
float MOVE_DIST = 10;//or whatever you need.
if(leftPressed) deltaX = -MOVE_DIST;
else if(rightPressed) deltaX = MOVE_DIST;
if(upPressed)deltaY = MOVE_DIST;
else if(downPressed)deltaY = -MOVE_DIST;
camera.position.add(deltaX, deltaY, 0);
}
This will allow the camera to move independently only when the player uses directional keys, and will allow the sprite be be rendered in relation to the camera's orientation. It will also snap the camera immediately back to the sprite when WASD is pressed.

batch.draw(splayerSprite, Gdx.graphics.getWidth() / 2, Gdx.graphics.getHeight() / 2);
You are telling the code to draw it to the center of your screen every time. You need to change Gdx.graphics.getWidth() / 2 and Gdx.graphics.getHeight() / 2 to actual values that change based on your input.
Edit #2: The line batch.setProjectionmatrix(camera.combined); is needed in addition to everything I have mentioned, I both did not notice that specific line was already in my code (it is included in the default libGDX project), and did not try running my demo with that line removed. I hope that clears up any confusion I may have caused.
Edit: Since apparently nobody really liked my answer, I went and wrote a demo using the controls specified in a clean libGDX game. Regardless of where the camera is aimed at (since it is being translated), the sprite was always being rendered in the center of the global screen. It is very much necessary to use the sprite's position in the batch.draw() instead of a static position, otherwise it will not move.
package com.me.mygdxgame;
import com.badlogic.gdx.ApplicationListener;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Input.Keys;
import com.badlogic.gdx.graphics.GL10;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.Texture.TextureFilter;
import com.badlogic.gdx.graphics.g2d.Sprite;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.graphics.g2d.TextureRegion;
import com.badlogic.gdx.math.Vector2;
public class MyGdxGame implements ApplicationListener {
private OrthographicCamera camera;
private SpriteBatch batch;
private Texture texture;
private Sprite sprite;
private Sprite background;
private boolean lockToSprite;
private Vector2 vecCamera;
private Vector2 vecSprite;
#Override
public void create() {
float w = Gdx.graphics.getWidth();
float h = Gdx.graphics.getHeight();
camera = new OrthographicCamera(w, h);
batch = new SpriteBatch();
lockToSprite = true;
vecCamera = new Vector2();
vecSprite = new Vector2();
texture = new Texture(Gdx.files.internal("data/libgdx.png"));
texture.setFilter(TextureFilter.Linear, TextureFilter.Linear);
TextureRegion region = new TextureRegion(texture, 0, 0, 512, 275);
sprite = new Sprite(region);
sprite.setSize(0.1f * sprite.getWidth(), 0.1f * sprite.getHeight());
sprite.setOrigin(sprite.getWidth()/2, sprite.getHeight()/2);
sprite.setPosition(-sprite.getWidth()/2, -sprite.getHeight()/2);
background = new Sprite(region);
background.setOrigin(background.getWidth() / 2, background.getHeight() / 2);
System.out.println(background.getOriginX());
background.setPosition(-background.getWidth() / 2, -background.getHeight() / 2);
}
#Override
public void dispose() {
batch.dispose();
texture.dispose();
}
#Override
public void render() {
camera.translate(vecCamera);
Gdx.gl.glClearColor(1, 1, 1, 1);
Gdx.gl.glClear(GL10.GL_COLOR_BUFFER_BIT);
camera.update();
camera.translate(vecCamera.cpy().mul(-1));
float moveSensitivity = 0.9f;
Vector2 vecInputSprite = new Vector2();
if (Gdx.input.isKeyPressed(Keys.UP))
vecInputSprite.y += moveSensitivity;
if (Gdx.input.isKeyPressed(Keys.DOWN))
vecInputSprite.y -= moveSensitivity;
if (Gdx.input.isKeyPressed(Keys.LEFT))
vecInputSprite.x -= moveSensitivity;
if (Gdx.input.isKeyPressed(Keys.RIGHT))
vecInputSprite.x += moveSensitivity;
if (Gdx.input.isKeyPressed(Keys.N))
vecSprite.set(new Vector2());
Vector2 vecInputCamera = new Vector2();
if (Gdx.input.isKeyPressed(Keys.W))
vecInputCamera.y += moveSensitivity;
if (Gdx.input.isKeyPressed(Keys.S))
vecInputCamera.y -= moveSensitivity;
if (Gdx.input.isKeyPressed(Keys.A))
vecInputCamera.x -= moveSensitivity;
if (Gdx.input.isKeyPressed(Keys.D))
vecInputCamera.x += moveSensitivity;
if (Gdx.input.isKeyPressed(Keys.R)) {
vecCamera.set(new Vector2());
lockToSprite = false;
}
if (vecInputCamera.len2() != 0)
lockToSprite = false;
else if (Gdx.input.isKeyPressed(Keys.L))
lockToSprite = true;
if (lockToSprite) {
vecCamera.set(vecSprite);
} else {
vecCamera.add(vecInputCamera);
}
vecSprite.add(vecInputSprite);
batch.setProjectionMatrix(camera.combined);
batch.begin();
background.draw(batch);
sprite.setPosition(vecSprite.x, vecSprite.y);
sprite.draw(batch);
//batch.draw(sprite, vecSprite.x, vecSprite.y);
batch.end();
}
#Override
public void resize(int width, int height) {
}
#Override
public void pause() {
}
#Override
public void resume() {
}
}