LibGDX中实现定时射击敌人与弹道管理

import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.math.Vector2;
import java.util.Random;
import com.badlogic.gdx.utils.Array; // 用于管理多个子弹

public class Ghost {
    private Texture topGhost, bottomGhost;
    private Vector2 posTopGhost;
    private Vector2 posBotGhost;
    private Random rand;
    private static final int FLUCT = 130;
    private int ghostGap;
    public int lowOpening;
    public static int width;

    // 子弹相关属性
    private Texture bulletTexture;
    private Array<Bullet> activeBullets; // 管理所有在飞行中的子弹
    private float shootTimer; // 射击计时器
    private static final float SHOOT_INTERVAL = 2.0f; // 射击间隔（秒）
    private static final float BULLET_SPEED = 200.0f; // 子弹速度（像素/秒）

    public Ghost(float x) {
        ghostGap = 120;
        lowOpening = 90;
        bulletTexture = new Texture("Bird.png"); // 子弹纹理
        topGhost = new Texture("Bird.png");
        bottomGhost = new Texture("Bird.png");
        rand = new Random();
        width = topGhost.getWidth();

        posBotGhost = new Vector2(x + 120, rand.nextInt(FLUCT));
        posTopGhost = new Vector2(x + 113, posBotGhost.y + bottomGhost.getHeight() + ghostGap - 50);

        activeBullets = new Array<>();
        shootTimer = 0; // 初始化计时器
    }

    // 内部类或单独的Bullet类，用于封装子弹的属性和行为
    public static class Bullet {
        public Vector2 position;
        public Texture texture;
        public boolean active; // 标记子弹是否存活

        public Bullet(Vector2 startPos, Texture texture) {
            this.position = new Vector2(startPos); // 创建新的Vector2，避免引用问题
            this.texture = texture;
            this.active = true;
        }

        public void update(float dt, float speed) {
            if (active) {
                position.x += speed * dt; // 帧率无关的X轴移动
                // 可以添加Y轴移动、重力等
            }
        }

        public void render(com.badlogic.gdx.graphics.g2d.SpriteBatch batch) {
            if (active) {
                batch.draw(texture, position.x, position.y);
            }
        }
    }

    public void update(float dt) {
        // 更新射击计时器
        shootTimer += dt;
        if (shootTimer >= SHOOT_INTERVAL) {
            shootTimer = 0; // 重置计时器
            shoot(); // 触发射击
        }

        // 更新所有活跃子弹的位置
        for (int i = activeBullets.size - 1; i >= 0; i--) {
            Bullet bullet = activeBullets.get(i);
            bullet.update(dt, BULLET_SPEED);
            // 检查子弹是否出界或发生碰撞，如果需要则标记为不活跃或移除
            if (bullet.position.x > Gdx.graphics.getWidth() || !bullet.active) { // 假设屏幕宽度为Gdx.graphics.getWidth()
                activeBullets.removeIndex(i);
            }
        }
    }

    private void shoot() {
        // 创建一个新的子弹实例，并添加到活跃子弹列表中
        // 子弹从敌人顶部位置发射
        activeBullets.add(new Bullet(new Vector2(posTopGhost.x + topGhost.getWidth() / 2, posTopGhost.y + topGhost.getHeight() / 2), bulletTexture));
        // 如果需要从底部发射，则：
        // activeBullets.add(new Bullet(new Vector2(posBotGhost.x + bottomGhost.getWidth() / 2, posBotGhost.y + bottomGhost.getHeight() / 2), bulletTexture));
    }

    public void render(com.badlogic.gdx.graphics.g2d.SpriteBatch batch) {
        batch.draw(topGhost, posTopGhost.x, posTopGhost.y);
        batch.draw(bottomGhost, posBotGhost.x, posBotGhost.y);

        // 渲染所有活跃子弹
        for (Bullet bullet : activeBullets) {
            bullet.render(batch);
        }
    }

    public void reposition(float x) {
        posTopGhost.set(x + 75, rand.nextInt(FLUCT) + 200);
        posBotGhost.set(x + 75, posTopGhost.y + ghostGap - bottomGhost.getHeight() - 247);
    }

    // 销毁纹理，防止内存泄漏
    public void dispose() {
        topGhost.dispose();
        bottomGhost.dispose();
        bulletTexture.dispose();
        // 如果Bullet类内部也加载了纹理，也需要dispose
    }
}