I am following a tutorial on creating a game with LibGdx from some ebook. the tutorial has steps for creating a game called "Canyon Bunny". Its a simple 2D game. but i keep getting this annoying error! (i also used to get the error on a different tutorial of the same genre)
i am in the early stages of the development for this game. and i am doing some test (of which i follow to the letter from the tutorial). I use a MAC and a i have tried many solutions with no luck at all.
Exception in thread "LWJGL Application" java.lang.NullPointerException
at com.Adel.CanyonBunny.game.WorldUpdater.updateTestObjects(WorldUpdater.java:83)
at com.Adel.CanyonBunny.game.WorldUpdater.update(WorldUpdater.java:76)
at com.Adel.CanyonBunny.CanyonBunnyMain.render(CanyonBunnyMain.java:39)
at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:207)
at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:114)
It is truly one of the most frustrating things a striving programmer can face.
ill get the code of all the classes in case that's related somehow...
This is CanyonBunnyMain in the general program:
package com.Adel.CanyonBunny;
import com.badlogic.gdx.ApplicationListener;
import com.badlogic.gdx.Gdx;
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.Adel.CanyonBunny.game.*;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.GL10;
import com.badlogic.gdx.Application;
public class CanyonBunnyMain implements ApplicationListener {
private static final String TAG = CanyonBunnyMain.class.getName();
private WorldUpdater worldUpdater;
private WorldRenderer worldRenderer ;
private boolean paused ;
public void create() {
//I'll set the log to debug for the developing process
Gdx.app.setLogLevel(Application.LOG_DEBUG) ;
worldUpdater = new WorldUpdater();
worldRenderer = new WorldRenderer() ;
// since, upon creation, the game is not paused, then:
paused = false ;
}
public void render() {
if (paused = true) {
//update the game by the time passed since the last update
worldUpdater.update(Gdx.graphics.getDeltaTime()) ;
}
//sets the screen color to: CornFlower Blue
Gdx.gl.glClearColor(0x64 / 255.0f, 0x95 / 255.0f, 0xed / 255.0f, 0xff / 255.0f);
//clears the screen to prevent flickering
Gdx.gl.glClear(GL10.GL_COLOR_BUFFER_BIT) ;
//Render the game to the screen
worldRenderer.render();
}
public void resize (int w, int h) {
worldRenderer.resize(w, h) ;
}
public void pause () {
paused = true ;
}
public void resume() {
paused = false ;
}
public void dispose() {
worldRenderer.dispose() ;
} }
this is the WorldRenderer (general program too) :
package com.Adel.CanyonBunny.game;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.Pixmap;
import com.badlogic.gdx.graphics.Pixmap.Format;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.Sprite;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.math.MathUtils;
public class WorldRenderer {
private OrthographicCamera cam;
private SpriteBatch batch ;
private WorldUpdater updater;
public void WorldRenderer(WorldUpdater worldUpdater) { }
public void init() { }
public void render() { }
public void resize(int w, int h) { }
public void dispose() { }
}
this is the main class (from the desktop project: the one that i run on my MAC) :
package com.Adel.CanyonBunny;
import com.badlogic.gdx.backends.lwjgl.LwjglApplication;
import com.badlogic.gdx.backends.lwjgl.LwjglApplicationConfiguration;
public class Main {
public static void main(String[] args) {
LwjglApplicationConfiguration cfg = new LwjglApplicationConfiguration();
cfg.title = "CanyonBunny";
cfg.useGL20 = false;
cfg.width = 800;
cfg.height = 480;
new LwjglApplication(new CanyonBunnyMain(), cfg);
}
}
Any help will be wonderful.
tell me should you need extra data
this is the WorldUpdater class for those who asked:
package com.Adel.CanyonBunny.game;
import com.badlogic.gdx.graphics.Pixmap;
import com.badlogic.gdx.graphics.Pixmap.Format;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.Sprite;
import com.badlogic.gdx.math.MathUtils;
public class WorldUpdater {
private final String TAG = WorldUpdater.class.getName();
public Sprite[] testSprites;
public int selectedSprite;
public WorldRenderer worldRenderer;
public void worldUpdater() {
init() ;
}
public void init() {
initTestObjects() ;
}
private void initTestObjects() {
// create new array of 5 sprites
testSprites = new Sprite[5] ;
// Create empty POT-sized Pixmap with 8 bit RGBA pixel data
int w = 32;
int h = 32;
Pixmap pixmap = createProceduralPixmap(w, h) ;
//create a new texture from Pixmap data
Texture texture = new Texture(pixmap) ;
//create sprites using the just created texture
for (int i = 0; i < testSprites.length; i++) {
Sprite spr = new Sprite(texture) ;
spr.setSize(1,1) ;
//set origin to sprite's center
spr.setOrigin(spr.getWidth() / 2.0f, spr.getHeight() / 2.0f) ;
float randomX = MathUtils.random(-2.0f, 2.0f) ;
float randomY = MathUtils.random(-2.0f, 2.0f) ;
spr.setPosition(randomX, randomY) ;
//put new sprite into array
testSprites[i] = spr ;
}
//set first sprite as the selected one
selectedSprite = 0 ;
}
private Pixmap createProceduralPixmap(int width, int height) {
Pixmap pixmap = new Pixmap(width, height , Format.RGBA8888) ;
//fill the square with red color at 50% opacity
pixmap.setColor(1, 0, 0, 0.5f) ;
pixmap.fill() ;
//draw a yellow X in the pixmap
pixmap.setColor(1, 1, 0 , 1) ;
pixmap.drawLine(0, 0, width, height) ;
pixmap.drawLine(width, 0, 0, height);
//draw a cyan-colored border around the square
pixmap.setColor(0, 1, 1, 1) ;
pixmap.drawRectangle(0, 0, width, height) ;
return pixmap;
}
public void update(float deltaTime) {
updateTestObjects(deltaTime);
}
private void updateTestObjects(float deltaTime) {
//get current rotation from the selected sprite
float rotation = testSprites[selectedSprite].getRotation();
//rotate sprite by 90 degrees per second
rotation += 90 * deltaTime;
//wrap around at 360 degrees
rotation %= 360 ;
testSprites[selectedSprite].setRotation(rotation);
}
}
Also, when i check this line out in Debugging mode:
testSprites = new Sprite[5] ;
"testSprites" keeps showing null.
i hope this clears up some details!
thanks again.