Java LibGDX刪除項目符號問題

我試圖刪除創建的項目符號時（bullet.position.y < = 0）。但是遊戲給出了錯誤。我無法刪除創建的子彈。我該如何解決它？我使用一個紋理（64×64），這些都是我的課：
Java LibGDX刪除項目符號問題

的Game1（主類）

package com.outlook.anil136.game1; 

import com.badlogic.gdx.ApplicationAdapter; 
import com.badlogic.gdx.Gdx; 
import com.badlogic.gdx.Input; 
import com.badlogic.gdx.graphics.Color; 
import com.badlogic.gdx.graphics.GL20; 
import com.badlogic.gdx.graphics.OrthographicCamera; 
import com.badlogic.gdx.graphics.Texture; 
import com.badlogic.gdx.graphics.g2d.Sprite; 
import com.badlogic.gdx.graphics.g2d.SpriteBatch; 
import com.badlogic.gdx.graphics.glutils.ShapeRenderer; 
import com.badlogic.gdx.math.Rectangle; 
import com.badlogic.gdx.math.Vector2; 
import com.badlogic.gdx.math.Vector3; 
import java.util.ArrayList; 

public class Game1 extends ApplicationAdapter { 
    private ShapeRenderer shapeRenderer; 
    private SpriteBatch batch; 
    private OrthographicCamera camera; 
    private Texture blueTexture; 
    private Player player1; 
    private ArrayList<Bullet> bullets; 
    private Sprite blueSprite; 

    @Override 
    public void create() { 
     shapeRenderer = new ShapeRenderer(); 
     batch = new SpriteBatch(); 
     camera = new OrthographicCamera(); 
     camera.setToOrtho(false, 480, 800); 
     blueTexture = new Texture("BlueRectangle.png"); 
     player1 = new Player(blueTexture, new Vector2(240, 600)); 
     bullets = new ArrayList<Bullet>(); 
     blueSprite = new Sprite(blueTexture); 
    } 

    @Override 
    public void render() { 
     Gdx.gl.glClearColor(0.1f, 0.1f, 0.1f, 1); 
     Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT); 
     shapeRenderer.setProjectionMatrix(camera.combined); 
     shapeRenderer.begin(ShapeRenderer.ShapeType.Filled); 
     shapeRenderer.rectLine(0, 401, 480, 401, 2); 
     shapeRenderer.end(); 
     batch.setProjectionMatrix(camera.combined); 
     batch.begin(); 
     player1.draw(batch); 
     for (Bullet bullet : bullets) { 
      bullet.draw(batch); 
      bullet.update(Gdx.graphics.getDeltaTime()); 
      if (bullet.position.y <= 0) 
       bullet.remove(bullets); 
     } 
     blueSprite.setPosition(416, 736); 
     blueSprite.setColor(1, 1, 1, 0.5f); 
     blueSprite.draw(batch); 
     batch.end(); 
     player1.update(Gdx.graphics.getDeltaTime()); 
     for (int i = 0; i < 20; i++) { 
      Vector3 touchPosition = camera.unproject(new Vector3(Gdx.input.getX(i), Gdx.input.getY(i), 0)); 
      if (Gdx.input.isTouched(i) && touchPosition.y >= 401 && touchPosition.y > 64 && !new Rectangle(416, 736, 64, 64).contains(touchPosition.x, touchPosition.y)) 
       player1.touchPosition = touchPosition; 
      if (Gdx.input.justTouched() && new Rectangle(416, 736, 64, 64).contains(touchPosition.x, touchPosition.y)) 
       bullets.add(new Bullet(blueTexture, new Vector2(player1.position), -player1.speed)); 
     } 
     if (player1.position.y + 32 > 800) 
      player1.position.y = 768; 
     else if (player1.position.y - 32 < 402) 
      player1.position.y = 434; 
    } 

    @Override 
    public void dispose() { 
     shapeRenderer.dispose(); 
     batch.dispose(); 
     blueTexture.dispose(); 
    } 
}

球員

package com.outlook.anil136.game1; 

import com.badlogic.gdx.ApplicationAdapter; 
import com.badlogic.gdx.Gdx; 
import com.badlogic.gdx.Input; 
import com.badlogic.gdx.graphics.Color; 
import com.badlogic.gdx.graphics.GL20; 
import com.badlogic.gdx.graphics.OrthographicCamera; 
import com.badlogic.gdx.graphics.Texture; 
import com.badlogic.gdx.graphics.g2d.Sprite; 
import com.badlogic.gdx.graphics.g2d.SpriteBatch; 
import com.badlogic.gdx.graphics.glutils.ShapeRenderer; 
import com.badlogic.gdx.math.Rectangle; 
import com.badlogic.gdx.math.Vector2; 
import com.badlogic.gdx.math.Vector3; 

import java.util.ArrayList; 

import javafx.scene.input.KeyCode; 
import sun.security.provider.SHA; 

public class Game1 extends ApplicationAdapter { 
    private ShapeRenderer shapeRenderer; 
    private SpriteBatch batch; 
    private OrthographicCamera camera; 
    private Texture blueTexture; 
    private Player player1; 
    public static ArrayList<Bullet> bullets; 
    private Sprite blueSprite; 

    @Override 
    public void create() { 
     shapeRenderer = new ShapeRenderer(); 
     batch = new SpriteBatch(); 
     camera = new OrthographicCamera(); 
     camera.setToOrtho(false, 480, 800); 
     blueTexture = new Texture("BlueRectangle.png"); 
     player1 = new Player(blueTexture, new Vector2(240, 600)); 
     bullets = new ArrayList<Bullet>(); 
     blueSprite = new Sprite(blueTexture); 
    } 

    @Override 
    public void render() { 
     Gdx.gl.glClearColor(0.1f, 0.1f, 0.1f, 1); 
     Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT); 
     shapeRenderer.setProjectionMatrix(camera.combined); 
     shapeRenderer.begin(ShapeRenderer.ShapeType.Filled); 
     shapeRenderer.rectLine(0, 401, 480, 401, 2); 
     shapeRenderer.end(); 
     batch.setProjectionMatrix(camera.combined); 
     batch.begin(); 
     player1.draw(batch); 
     for (Bullet bullet : bullets) { 
      bullet.draw(batch); 
      bullet.update(Gdx.graphics.getDeltaTime()); 
      if (bullet.position.y <= 0) 
       bullet.remove(bullets); 
     } 
     blueSprite.setPosition(416, 736); 
     blueSprite.setColor(1, 1, 1, 0.5f); 
     blueSprite.draw(batch); 
     batch.end(); 
     player1.update(Gdx.graphics.getDeltaTime()); 
     for (int i = 0; i < 20; i++) { 
      Vector3 touchPosition = camera.unproject(new Vector3(Gdx.input.getX(i), Gdx.input.getY(i), 0)); 
      if (Gdx.input.isTouched(i) && touchPosition.y >= 401 && touchPosition.y > 64 && !new Rectangle(416, 736, 64, 64).contains(touchPosition.x, touchPosition.y)) 
       player1.touchPosition = touchPosition; 
      if (Gdx.input.justTouched() && new Rectangle(416, 736, 64, 64).contains(touchPosition.x, touchPosition.y)) 
       bullets.add(new Bullet(blueTexture, new Vector2(player1.position), -player1.speed)); 
     } 
     if (player1.position.y + 32 > 800) 
      player1.position.y = 768; 
     else if (player1.position.y - 32 < 402) 
      player1.position.y = 434; 
    } 

    @Override 
    public void dispose() { 
     shapeRenderer.dispose(); 
     batch.dispose(); 
     blueTexture.dispose(); 
    } 
}

子彈

package com.outlook.anil136.game1; 

import com.badlogic.gdx.graphics.Texture; 
import com.badlogic.gdx.graphics.g2d.SpriteBatch; 
import com.badlogic.gdx.math.Vector2; 

import java.util.ArrayList; 

public class Bullet { 
    private Texture texture; 
    Vector2 position; 
    private int speed; 

    public Bullet(Texture texture, Vector2 position, int speed) { 
     this.texture = texture; 
     this.position = position; 
     this.speed = speed; 
    } 

    public void draw(SpriteBatch batch) { 
     batch.draw(texture, position.x - 16, position.y - 16, 32, 32); 
    } 

    public void update(float deltaTime) { 
     position.y += speed; 
    } 

    public void remove(ArrayList<Bullet> bullets) { 
     bullets.remove(this); 
    } 
}

來源

2016-08-30 Peter Parker

看起來這是造成'ConcurrentModificationException'，這可以通過創建一個新的'ArrayList'加子彈的物體，如果他們需要被刪除，然後刪除所有的循環之後被避免。 – Orin

你可以當您迭代它時，不會從列表中移除元素。要在迭代時刪除元素，您需要將子彈標記爲刪除，迭代後從主列表中實際刪除所有標記的項目符號。

List<Bullet> bulletsToRemove = new ArrayList<Bullet>(); 
for (Bullet bullet : bullets) { 
    bullet.draw(batch); 
    bullet.update(Gdx.graphics.getDeltaTime()); 
    if (bullet.position.y <= 0) 
     bulletsToRemove.add(bullet); 
} 
bullets.removeAll(bulletsToRemove);

來源

2016-08-30 17:31:09 pr0gramist

如何檢查beetwen子彈相撞？我需要在子彈陣列中獲得其他子彈。當兩顆子彈相撞時我想毀滅。 –

那麼這是一個不同的問題，但我會檢查libGDX Intersector類。 https://libgdx.badlogicgames.com/nightlies/docs/api/com/badlogic/gdx/math/Intersector.html也許將您的項目符號設置爲矩形，並使用'overlaps'方法是您的正確解決方案。 – pr0gramist

Java LibGDX刪除項目符號問題

回答

相關問題