Hello I am currently programming a LibGDX game based on physics with a ball that must stay on a platform, I have set up the physics components for the ball, but when I try updating the sprite for the ball based on the physic body's position it is giving me a null pointer exception.
I have spent 1 whole day trying to fix the problem through researching and looking at other peoples' code but cannot find my error. Thank you for your time and any input that you can give. Below I have typed the code from my Render class, Ball GameObject class, Asset class, and Exception.
Ball GameObject Class:
public class Ball {
public static World physicsWorld;
public static BodyDef ballBodyDef;
public static Body ballBody;
public static CircleShape ballShape;
public static FixtureDef ballFixtureDef;
public static Fixture ballFixture;
public Ball() {
physicsWorld = new World(new Vector2(0, -9.8f), true);
ballBodyDef = new BodyDef();
ballBodyDef.position.set(Assets.ballSprite.getX(),
Assets.ballSprite.getY());
ballBodyDef.type = BodyDef.BodyType.DynamicBody;
ballBody = physicsWorld.createBody(ballBodyDef);
ballShape = new CircleShape();
ballShape.setRadius(6f);
ballFixtureDef = new FixtureDef();
ballFixtureDef.density = 1.0f;
ballFixtureDef.friction = 0.2f;
ballFixtureDef.restitution = 0.4f;
ballFixture = ballBody.createFixture(ballFixtureDef);
}
public void dispose() {
physicsWorld.dispose();
ballShape.dispose();
}
public BodyDef getBallBodyDef() {
return ballBodyDef;
}
public void setBallBodyDef(BodyDef ballBodyDef) {
this.ballBodyDef = ballBodyDef;
}
public Body getBallBody() {
return ballBody;
}
public void setBallBody(Body ballBody) {
this.ballBody = ballBody;
}
public CircleShape getBallShape() {
return ballShape;
}
public void setBallShape(CircleShape ballShape) {
this.ballShape = ballShape;
}
public FixtureDef getBallFixtureDef() {
return ballFixtureDef;
}
public void setBallFixtureDef(FixtureDef ballFixtureDef) {
this.ballFixtureDef = ballFixtureDef;
}
public Fixture getBallFixture() {
return ballFixture;
}
public void setBallFixture(Fixture ballFixture) {
this.ballFixture = ballFixture;
}
}
Render Class:
public class GameRenderer {
private GameWorld myWorld;
private OrthographicCamera cam;
int width = Gdx.graphics.getWidth();
int height = Gdx.graphics.getHeight();
private SpriteBatch batch;
public GameRenderer(GameWorld world, int gameHeight, int midPointY) {
myWorld = world;
cam = new OrthographicCamera();
cam.setToOrtho(true, width, height);
batch = new SpriteBatch();
batch.setProjectionMatrix(cam.combined);
}
public void render(float delta) {
Gdx.app.log("GameRenderer", "render");
Gdx.gl.glClearColor(0, 0, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
Ball.physicsWorld.step(Gdx.graphics.getDeltaTime(), 6, 2);
Assets.ballSprite.setPosition(Ball.ballBody.getPosition().x,
Ball.ballBody.getPosition().y);
batch.begin();
batch.draw(Assets.skySprite, 0, 0, 1920, 1080);
batch.draw(Assets.ballSprite, Assets.ballSprite.getX(),
Assets.ballSprite.getY());
batch.draw(Assets.platformSprite, Assets.platformSprite.getX(),
Assets.platformSprite.getY());
batch.end();
}
}
Lastly my Assets Class:
public class Assets {
public static Texture skyTexture;
public static Sprite skySprite;
public static Texture ballTexture;
public static Sprite ballSprite;
public static Texture platformTexture;
public static Sprite platformSprite;
public static Button rightTiltButton;
public static TextureAtlas rightButtonAtlas;
public static TextButtonStyle rightButtonStyle;
public static Skin rightButtonSkin;
public static void Load() {
skyTexture = new Texture(Gdx.files.internal("Assets/skybackground.png"));
skyTexture.setFilter(TextureFilter.Linear, TextureFilter.Linear);
skySprite = new Sprite(skyTexture);
skySprite.flip(false, true);
ballTexture = new Texture(
Gdx.files.internal("Assets/ballcharacter.png"));
ballTexture.setFilter(TextureFilter.Linear, TextureFilter.Linear);
ballSprite = new Sprite(ballTexture);
ballSprite.flip(false, true);
ballSprite.setPosition(
Gdx.graphics.getWidth() / 2 - ballSprite.getWidth()/2,
Gdx.graphics.getHeight() / 2 - ballSprite.getHeight()-4);
platformTexture = new Texture(Gdx.files.internal("Assets/platform.png"));
platformTexture.setFilter(TextureFilter.Linear, TextureFilter.Linear);
platformSprite = new Sprite(platformTexture);
platformSprite.flip(false, true);
platformSprite.setPosition(
Gdx.graphics.getWidth() / 2 - platformSprite.getWidth()/2,
Gdx.graphics.getHeight() / 2 - platformSprite.getHeight()/2);
rightButtonSkin = new Skin();
rightButtonAtlas = new TextureAtlas(
Gdx.files.internal("Assets/right_tilt_button.pack"));
rightButtonSkin.addRegions(rightButtonAtlas);
rightButtonStyle = new TextButtonStyle();
rightButtonStyle.up = rightButtonSkin.getDrawable("right_tilt_button");
rightButtonStyle.up = rightButtonSkin
.getDrawable("right_tilt_button_pressed");
rightButtonStyle.up = rightButtonSkin.getDrawable("right_tilt_button");
rightButtonStyle.over = rightButtonSkin
.getDrawable("right_tilt_button_pressed");
rightButtonStyle.down = rightButtonSkin
.getDrawable("right_tilt_button_pressed");
rightTiltButton = new Button(rightButtonStyle);
}
public static void dispose() {
skyTexture.dispose();
rightButtonAtlas.dispose();
rightButtonSkin.dispose();
ballTexture.dispose();
}
}
NullPointerException:
Exception in thread "LWJGL Application" java.lang.NullPointerException at com.manumade.tiltr.tiltrhelpers.GameRenderer.render (GameRenderer.java:36) at com.manumade.tiltr.screens.GameScreen.render(GameScreen.java:39) at com.badlogic.gdx.Game.render(Game.java:46) at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:208) at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:114)
