在 libgdx 中，发生碰撞时如何从屏幕上删除/删除 object？

Question

所以在我正在制作的游戏中，我在球撞到砖块（块）时进行了碰撞检测，但我似乎无法弄清楚如何移除/删除被球击中的砖块。 积木存储在 ArrayList 中。 然后在我的碰撞检测 class 中，当砖与球接触时，我尝试将其移除，但它似乎不起作用。 球从砖块上弹开，但砖块只是停留在那里。

主游戏 Class：

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Input;
import com.badlogic.gdx.ScreenAdapter;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.graphics.g2d.TextureRegion;
import com.badlogic.gdx.graphics.glutils.ShapeRenderer;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.math.Vector3;
import com.badlogic.gdx.physics.box2d.Box2DDebugRenderer;
import com.badlogic.gdx.physics.box2d.World;
import com.pongbreaker.helper.Constants;
import com.pongbreaker.objects.*;

import java.util.ArrayList;

public class GameScreen extends ScreenAdapter {
    private OrthographicCamera camera;
    private SpriteBatch batch;
    private World world;
    private Box2DDebugRenderer box2DDebugRenderer;

    //Game Objects
    private Player player, player2;
    private AI playerAI, playerAI2;
    private Ball ball;
    private Arena arenaTop, arenaBottom;
    ArrayList<Brick> brickArrayList = new ArrayList<Brick>();
    private Brick brick, brick2, brick3, brick4, brick5, brick6,
            brick7,brick8, brick9, brick10, brick11, brick12, brick13, brick14,
            brick36,brick37, brick38, brick39, brick40, brick41, brick42;

    private GameContactListener gameContactListener;
    private TextureRegion[] numbers;

    public GameScreen(OrthographicCamera camera) {
        this.camera = camera;
        this.camera.position.set(new Vector3(Main.INSTANCE.getScreenWidth() / 2, Main.INSTANCE.getScreenHeight() / 2, 0));
        this.batch = new SpriteBatch();
        this.world = new World(new Vector2(0, 0), false);
        this.box2DDebugRenderer = new Box2DDebugRenderer();
        this.gameContactListener = new GameContactListener(this);
        this.world.setContactListener(this.gameContactListener);

        this.player = new Player(316, Main.INSTANCE.getScreenHeight() / 2, this);
        this.player2 = new Player(1260, Main.INSTANCE.getScreenHeight() / 2, this);
        this.playerAI = new AI(1260, Main.INSTANCE.getScreenHeight() / 2, this);
        //this.playerAI2 = new AI(316, Main.INSTANCE.getScreenHeight() / 2, this);
        this.ball = new Ball(this);
        this.arenaTop = new Arena(32, this);
        this.arenaBottom = new Arena(Main.INSTANCE.getScreenHeight() - 32, this);

        brick = new Brick(33, 104, this);
        brick2 = new Brick(33, 176, this);
        brick3 = new Brick(33, 248, this);
        brick4 = new Brick(33, 320, this);
        brick5 = new Brick(33, 392, this);
        brick6 = new Brick(33, 464, this);
        brick7 = new Brick(33, 536, this);
        brick8 = new Brick(91.4f, 104, this);
        brick9 = new Brick(91.4f, 176, this);
        brick10 = new Brick(91.4f, 248, this);
        brick11 = new Brick(91.4f, 320, this);
        brick12 = new Brick(91.4f, 392, this);
        brick13 = new Brick(91.4f, 464, this);
        brick14 = new Brick(91.4f, 536, this);
        brick36 = new Brick(1523, 104, this);
        brick37 = new Brick(1523, 176, this);
        brick38 = new Brick(1523, 248, this);
        brick39 = new Brick(1523, 320, this);
        brick40 = new Brick(1523, 392, this);
        brick41 = new Brick(1523, 464, this);
        brick42 = new Brick(1523, 536, this);

        brickArrayList.add(brick);
        brickArrayList.add(brick2);
        brickArrayList.add(brick3);
        brickArrayList.add(brick4);
        brickArrayList.add(brick5);
        brickArrayList.add(brick6);
        brickArrayList.add(brick7);
        brickArrayList.add(brick8);
        brickArrayList.add(brick9);
        brickArrayList.add(brick10);
        brickArrayList.add(brick11);
        brickArrayList.add(brick12);
        brickArrayList.add(brick13);
        brickArrayList.add(brick14);
        brickArrayList.add(brick36);
        brickArrayList.add(brick37);
        brickArrayList.add(brick38);
        brickArrayList.add(brick39);
        brickArrayList.add(brick40);
        brickArrayList.add(brick41);
        brickArrayList.add(brick42);

        this.numbers = loadTextureSprite("core/src/com/pongbreaker/recources/numbers.png", 10);
    }


    public void update() {
        world.step(1 / 60f, 6, 2);

        this.camera.update();
        this.player.update();
        this.player2.update();
        this.playerAI.update();
        //this.playerAI2.update();
        this.ball.update();
        this.brick.update();
        this.brick2.update();
        this.brick3.update();
        this.brick4.update();
        this.brick5.update();
        this.brick6.update();
        this.brick7.update();
        this.brick8.update();
        this.brick9.update();
        this.brick10.update();
        this.brick11.update();
        this.brick12.update();
        this.brick13.update();
        this.brick14.update();
        this.brick36.update();
        this.brick37.update();
        this.brick38.update();
        this.brick39.update();
        this.brick40.update();
        this.brick41.update();
        this.brick42.update();

        batch.setProjectionMatrix(camera.combined);

        if(Gdx.input.isKeyPressed(Input.Keys.ESCAPE)) {
            Gdx.app.exit();
        }

        if(Gdx.input.isKeyPressed(Input.Keys.R)) {
            this.ball.reset();
            this.player.setScore(0);
            this.player2.setScore(0);
            this.playerAI.setScore(0);
            this.playerAI2.setScore(0);
        }
    }

    @Override
    public void render (float delta) {
        update();

        Gdx.gl.glClearColor(0,0,0,1);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

        batch.begin();
        this.player.render(batch);
        //this.player2.render(batch);
        this.playerAI.render(batch);
        //this.playerAI2.render(batch);
        this.ball.render(batch);
        this.arenaTop.render(batch);
        this.arenaBottom.render(batch);

        this.brick.render(batch);
        this.brick2.render(batch);
        this.brick3.render(batch);
        this.brick4.render(batch);
        this.brick5.render(batch);
        this.brick6.render(batch);
        this.brick7.render(batch);
        this.brick8.render(batch);
        this.brick9.render(batch);
        this.brick10.render(batch);
        this.brick11.render(batch);
        this.brick12.render(batch);
        this.brick13.render(batch);
        this.brick14.render(batch);
        this.brick36.render(batch);
        this.brick37.render(batch);
        this.brick38.render(batch);
        this.brick39.render(batch);
        this.brick40.render(batch);
        this.brick41.render(batch);
        this.brick42.render(batch);




        drawNumbers(batch,player.getScore(), 64, Main.INSTANCE.getScreenHeight() - 55, 30, 42);
        drawNumbers(batch, player2.getScore(), Main.INSTANCE.getScreenWidth() - 96, Main.INSTANCE.getScreenHeight() -55, 30, 42);

        batch.end();

       // this.box2DDebugRenderer.render(world, camera.combined.scl(Constants.PPM));
    }

    private void drawNumbers(SpriteBatch batch, int number, float x, float y, float width, float height) {
        if(number < 10) {
            batch.draw(numbers[number], x, y, width, height);
        }else{
            batch.draw(numbers[Integer.parseInt(("" + number).substring(0,1))], x, y, width, height);
            batch.draw(numbers[Integer.parseInt(("" + number).substring(1,2))], x + 20, y, width, height);
        }
    }
    private TextureRegion[] loadTextureSprite(String filename, int columns) {
        Texture texture = new Texture(filename);
        return TextureRegion.split(texture, texture.getWidth() / columns, texture.getHeight())[0];
    }

    public World getWorld() {
        return world;
    }

    public Ball getBall() {
        return ball;
    }

    public Player getPlayer() {
        return player;
    }

    public Player getPlayer2() {
        return player2;
    }

    public Brick getBrick() {
        return brick;
    }

    @Override
    public void dispose () {

    }

    public ArrayList<Brick> getBricksArrayList() {
        return brickArrayList;
    }


}

碰撞检测 Class：

import com.badlogic.gdx.physics.box2d.*;
import com.badlogic.gdx.utils.Array;
import com.pongbreaker.helper.ContactType;
import com.pongbreaker.objects.Brick;

import java.util.ArrayList;

import static com.pongbreaker.helper.ContactType.BRICKS;

public class GameContactListener implements ContactListener {

    private GameScreen gameScreen;
    public boolean remove = false;



    //private ArrayList<Body> brickDeletionList = new ArrayList<Body>();

    public GameContactListener(GameScreen gameScreen) {
        this.gameScreen = gameScreen;
    }
    @Override
    public void beginContact(Contact contact) {
        Fixture a = contact.getFixtureA();
        Fixture b = contact.getFixtureB();

        if(a == null || b == null) return;
        if(a.getUserData() == null || b.getUserData() == null) return;

        if(a.getUserData() == ContactType.BALL || b.getUserData() == ContactType.BALL) {
            //Ball - Player
            if(a.getUserData() == ContactType.PLAYER || b.getUserData() == ContactType.PLAYER) {
                gameScreen.getBall().reverseVelocityX();
                gameScreen.getBall().increaseSpeed();
            }

            //Ball - Arena
            if(a.getUserData() == ContactType.ARENA || b.getUserData() == ContactType.ARENA) {
                gameScreen.getBall().reverseVelocityY();
            }

            //Ball - Brick
            if(a.getUserData() == ContactType.BRICKS || b.getUserData() == ContactType.BRICKS) {
                gameScreen.getBall().reverseVelocityX();
                gameScreen.getBall().increaseSpeed();
                gameScreen.getBricksArrayList().remove(gameScreen.brickArrayList);
            }
        }
    }

    @Override
    public void endContact(Contact contact) {

    }

    @Override
    public void preSolve(Contact contact, Manifold oldManifold) {
        /*WorldManifold manifold = contact.getWorldManifold();
        for (int j = 0; j < manifold.getNumberOfContactPoints(); j++) {
            if (contact.getFixtureA().getUserData() != null && contact.getFixtureA().getUserData().equals("p"))
                contact.setEnabled(false);
            if (contact.getFixtureB().getUserData() != null && contact.getFixtureB().getUserData().equals("p"))
                contact.setEnabled(false);

        }

         */
    }

    @Override
    public void postSolve(Contact contact, ContactImpulse impulse) {
        /*Body body = null;
        if(contact.getFixtureA() != null && contact.getFixtureA().getUserData() != null && contact.getFixtureA().getUserData().equals("b"))
            body = contact.getFixtureA().getBody();
        if(contact.getFixtureB() != null && contact.getFixtureB().getUserData() != null && contact.getFixtureB().getUserData().equals("b"))
            body = contact.getFixtureB().getBody();
        if(body != null) {
            body.setActive(false);
            world.destroyBody(body);
        }

         */
    }

}

和砖 Class：

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Input;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.graphics.glutils.ShapeRenderer;
import com.badlogic.gdx.math.Rectangle;
import com.badlogic.gdx.physics.box2d.Body;
import com.pongbreaker.game.GameScreen;
import com.pongbreaker.helper.BodyHelper;
import com.pongbreaker.helper.Constants;
import com.pongbreaker.helper.ContactType;

import java.util.ArrayList;

public class Brick {
    private Body body;
    private float x, y, width;
    private int height,score, row, column;
    private Texture texture;
    private GameScreen gameScreen;
    private int map [][];


    public Brick(float x, float y, GameScreen gameScreen) {
        this.x = x;
        this.y = y;
        this.gameScreen = gameScreen;
        //this.map = new int[row][column];
        this.width = 50.4f;
        this.height = 64;

        /*for(int i = 0; i < row; i++) {
            for(int j = 0; j < column; j++) {
                map[i][j] = 1;
            }
        }

         */


        this.texture = new Texture("core/src/com/pongbreaker/recources/redTexture.png");
        this.body = BodyHelper.createBody(x, y, width, height, true, 10000, gameScreen.getWorld(), ContactType.BRICKS);
    }

    public void update() {
        x = body.getPosition().x * Constants.PPM - (width / 2);
        y = body.getPosition().y * Constants.PPM - (height / 2);

    }

    public void render(SpriteBatch batch) {
        /*for(int i = 0; i < map.length; i++) {
            for(int j = 0; j < map.length; j++) {
                if(map[i][j] > 0) {
                    batch.draw(texture,x, y,width,height);
                }
            }
        }

         */


        batch.draw(texture, x, y, width, height);



    }

    public boolean collidesWith(Brick brick) {
        return x < this.x + this.width && y < this.y + this.height && x + width > this.x && y + height > this.height;
    }

    public void setBrick(int value, int row, int column) {
        map[row][column] = value;
    }


    public void score() {
        this.score++;
    }

    public int getScore() {
        return score;
    }

    public void setScore(int score) {
        this.score = score;
    }

    public void dispose () {

    }
}

Answer 1

如果您不需要图形 memory，它没有连接到dispose ，它只会释放 ram。

box2D 的 object 存根的工作方式与您使用的方式不同，尽管我想知道为什么这个gameScreen.getBricksArrayList().remove(gameScreen.brickArrayList);

，你 - 不能 - 移除你拥有的一块砖。 对于每个 box2D 砖，您关联ContactType.BRICKS但这意味着您无法查找单个砖，因为它们都具有该枚举的相同 box2D object 存根。 您需要有一个新的 Object 专门与 -single-brick 相关联。 我认为这会导致部分重写，所以我认为您现在无法修复它，因为无论如何您都无法识别要移除的单个砖块。

无论如何， this.body = BodyHelper.createBody(x, y, width, height, true, 10000, gameScreen.getWorld(), ContactType.BRICKS); 应该是this.body = BodyHelper.createBody(x, y, width, height, true, 10000, gameScreen.getWorld(), this); 从而直接将该特定砖块存储在 object 存根中。 和 go 从那里。