Question

我正在使用libgdx在Java上进行游戏，现在缩放存在问题。这是我的代码：

1：

public class TileMap implements Screen {
    private TiledMap tiledMap;
    private OrthographicCamera camera;
    private OrthogonalTiledMapRenderer mapRenderer;
    private TiledMapStage tiledMapStage;

    public TileMap(){
        tiledMapStage = new TiledMapStage(camera,this);

        camera = new OrthographicCamera();
        camera.setToOrtho(false);
        camera.translate(Gdx.graphics.getWidth()/2,Gdx.graphics.getHeight()/2);
        camera.update();

        tiledMap = new TmxMapLoader().load("gameMap.tmx");
        mapRenderer = new OrthogonalTiledMapRenderer(tiledMap);


    }
    @Override
    public void render (float delta) {


   float x = Gdx.input.getDeltaX();
    float y = Gdx.input.getDeltaY();
    Gdx.gl.glClearColor(135/255f, 206/255f, 235/255f, 1);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
    camera.position.add(-x, y, 0);
    camera.update();
    mapRenderer.render();
    mapRenderer.setView(camera);
    tiledMapStage.render();
}

2：

public class TiledMapStage {

    private TileMap tileMap;
    private Stage stage;
    private OrthographicCamera Camera;

    TiledMapStage(OrthographicCamera camera, TileMap tileMap){
        this.tileMap = tileMap;
        this.Camera = camera;
        ScreenViewport viewport = new ScreenViewport();
        stage = new Stage(viewport);
        Gdx.input.setInputProcessor(stage);
        MapActor zoomIn = new MapActor(new Texture("zoomIn.png"),"zoomIn", Camera, this);
        stage.addActor(zoomIn);
    }
    public void render(){
        stage.draw();
    }

3：

public class MapActor extends Actor {
private OrthographicCamera camera;
Sprite sprite;
TiledMapStage tiledMapStage;

public MapActor(Texture texture, final String actorName, final OrthographicCamera camera, final TiledMapStage tiledMapStage){
    this.camera = camera;
    this.tiledMapStage = tiledMapStage;
    int width = Gdx.graphics.getWidth();
    int height = Gdx.graphics.getHeight();
    sprite = new Sprite(texture);
    setTouchable(Touchable.enabled);
    if(actorName.equals("zoomIn")) {
        sprite.setSize(width/10f,height/7f);
        sprite.setPosition(width-width/10f-sprite.getWidth()/2,height/7f-sprite.getHeight()/2);
        addListener(new InputListener() {
            @Override
            public boolean touchDown(InputEvent event, float x, float y, int pointer, int button) {
                Gdx.app.log("2222222222222222","tochdow");
                camera.zoom = (float) (camera.zoom + 0.02);

                return true;
            }
        });
    }
    spritePos(sprite.getX(), sprite.getY());
    setBounds(sprite.getX(),sprite.getY(),sprite.getWidth(),sprite.getHeight());
}
@Override
public void act(float delta) {
    super.act(delta);
}

@Override
public void draw(Batch batch, float parentAlpha) {
    batch.setColor(1, 1, 1, parentAlpha);
    sprite.draw(batch);
}
public void spritePos(float x, float y){
    sprite.setPosition(x, y);
    setBounds(sprite.getX(), sprite.getY(), sprite.getWidth(), sprite.getHeight());
}

}

问题是

E / AndroidRuntime：严重例外：GLThread 7412 流程：com.mygdx.game，PID：8137 java.lang.RuntimeException：Actor：MapActor 在com.badlogic.gdx.scenes.scene2d.Actor.notify（Actor.java:202）在com.badlogic.gdx.scenes.scene2d.Actor.fire（Actor.java:152）在com.badlogic.gdx.scenes.scene2d.Stage.touchDown（Stage.java:281）在com.badlogic.gdx.backends.android.AndroidInput.processEvents（AndroidInput.java:405）在com.badlogic.gdx.backends.android.AndroidGraphics.onDrawFrame（AndroidGraphics.java:492）在android.opengl.GLSurfaceView $ GLThread.guardedRun（GLSurfaceView.java:1571）在android.opengl.GLSurfaceView $ GLThread.run（GLSurfaceView.java:1270）原因：java.lang.NullPointerException：尝试从字段“ float com.badlogic.gdx.graphics.OrthographicCamera.zoom”中读取空对象引用在com.mygdx.game.Actor.MapActor $ 1.touchDown（MapActor.java:33）在com.badlogic.gdx.scenes.scene2d.InputListener.handle（InputListener.java:57）在com.badlogic.gdx.scenes.scene2d.Actor.notify（Actor.java:188）在com.badlogic.gdx.scenes.scene2d.Actor.fire（Actor.java:152）在com.badlogic.gdx.scenes.scene2d.Stage.touchDown（Stage.java:281）在com.badlogic.gdx.backends.android.AndroidInput.processEvents（AndroidInput.java:405）在com.badlogic.gdx.backends.android.AndroidGraphics.onDrawFrame（AndroidGraphics.java:492）在android.opengl.GLSurfaceView $ GLThread.guardedRun（GLSurfaceView.java:1571）在android.opengl.GLSurfaceView $ GLThread.run（GLSurfaceView.java:1270）

java.lang.NullPointerException：尝试从null对象引用

0 个答案: