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（如果我的英语错了，对不起，我是巴西人。）Libgdx错误（NullPoinerException）
我在Libgdx新手，我发现了一个错误，而试图创建自己的比赛。我正在使用“学习Libgdx游戏开发”一书，并在我的项目中出现错误。
错误是：在com.keerp.game.WorldRenderer.renderTestObjects（WorldRenderer.java:43） 在com.keerp
在异常线程 “LWJGL应用程序” 显示java.lang.NullPointerException 。 game.WorldRenderer.render（WorldRenderer.java:35） at com.keerp.game.MainClass.render（MainClass.java:62） at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop（LwjglApplication.java： 223） at com.badlogic.gdx.backends.lwjgl.LwjglApplication $ 1.run（LwjglApplication.java:124）
这里是我的代码：
MainClass：
package com.keerp.game;
import com.badlogic.gdx.Application;
import com.badlogic.gdx.ApplicationAdapter;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.GL20;
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.ApplicationListener;
public class MainClass implements ApplicationListener {
private static final String TAG = MainClass.class.getName();
private WorldController worldController;
private WorldRenderer worldRenderer;
private boolean paused;
@Override
public void create()
{
// set libgdx log level to DEBUG
Gdx.app.setLogLevel(Application.LOG_DEBUG);
// initialize controller and renderer
worldController = new WorldController();
worldRenderer = new WorldRenderer(worldController);
// game world is active on start
paused = false;
}
@Override
public void dispose()
{
worldRenderer.dispose();
}
@Override
public void render() {
if(!paused)
{
worldController.update(Gdx.graphics.getDeltaTime());
}
// setting screen color
Gdx.gl.glClearColor(0x64/255.0f, 0x95/255.0f, 0xed/255.0f, 0xff/255.0f);
// clear the screen
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
// render game world to screen
worldRenderer.render();
}
@Override
public void resize(int width, int height)
{
worldRenderer.resize(width, height);
}
@Override
public void pause()
{
paused = true;
}
@Override
public void resume()
{
paused = false;
}
}
常量：
package com.keerp.game;
public class Constants {
// setting constants tag
private static final String TAG = Constants.class.getName();
public static final float VIEWPORT_WIDTH = 5.0f;
public static final float VIEWPORT_HEIGHT = 5.0f;
}
WorldController：
package com.keerp.game;
import com.badlogic.gdx.graphics.Pixmap;
import com.badlogic.gdx.graphics.g2d.Sprite;
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 WorldController {
private static final String TAG = WorldController.class.getName();
public Sprite[] testSprites;
public int selectedSprite;
public WorldController()
{
init();
}
private void initTestObjects()
{
testSprites = new Sprite[5];
int width = 32;
int height = 32;
Pixmap pixmap = createProceduralPixmap(width, height);
Texture texture = new Texture(pixmap);
for(int i = 0; i < testSprites.length; i++)
{
Sprite spr = new Sprite(texture);
spr.setSize(1, 1);
spr.setOrigin(spr.getWidth()/2.0f, spr.getHeight()/2.0f);
// calculating random position for each sprite
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;
}
selectedSprite = 0;
}
private Pixmap createProceduralPixmap(int width, int height)
{
Pixmap pixmap = new Pixmap(width, height, Format.RGBA8888);
// fill square with red color at 50% opacity
pixmap.setColor(1, 0, 0, 0.5f);
pixmap.fill();
// draw a yellow-colored X shape on square
pixmap.setColor(1, 1, 0, 1);
pixmap.drawLine(0, 0, width, height);
pixmap.drawLine(width, 0, 0, height);
// draw a cyan-colored border around square
pixmap.setColor(0, 1, 1, 1);
pixmap.drawRectangle(0, 0, width, height);
return pixmap;
}
private void updateTestObjects(float deltaTime)
{
// get current rotation from selected sprite
float rotation = testSprites[selectedSprite].getRotation();
// rotate sprite by 90 degrees per second
rotation += 90 * deltaTime;
// wrap around at 360 degrees
rotation %= 360;
// set new rotation value to selected sprite
testSprites[selectedSprite].setRotation(rotation);
}
private void init()
{
}
public void update(float deltaTime)
{
}
}
WorldRenderer：
package com.keerp.game;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.g2d.Sprite;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.utils.Disposable;
public class WorldRenderer implements Disposable
{
private static final String TAG = WorldRenderer.class.getName();
private OrthographicCamera camera;
private SpriteBatch batch;
private WorldController worldController;
public WorldRenderer(WorldController worldController)
{
this.worldController = worldController;
init();
}
private void init()
{
batch = new SpriteBatch();
camera = new OrthographicCamera(Constants.VIEWPORT_WIDTH, Constants.VIEWPORT_HEIGHT);
camera.position.set(0, 0, 0);
camera.update();
}
public void render()
{
renderTestObjects();
}
private void renderTestObjects()
{
batch.setProjectionMatrix(camera.combined);
batch.begin();
for(Sprite sprite : worldController.testSprites)
sprite.draw(batch);
batch.end();
}
public void resize(int width, int height)
{
camera.viewportWidth = (Constants.VIEWPORT_HEIGHT/height) * width;
camera.update();
}
@Override
public void dispose()
{
batch.dispose();
}
}
我不知道这是否是一个容易的错误来解决，但我真的很想得到帮助。
谢谢！
谢谢！就是这样。 – kibe