Question

我有一个游戏课，我正在做所有的创作和绘画，但我不知道如何获得子弹生成时的起点（x，y）。因为x y总是在变化。我有想法创建一个子弹类，但我不知道如何更改mygame以适应它。我需要的只是产生子弹的简单x，y coordiante以任何方式来保存它？我认为我的子弹课应该是这样的：

    public class Bullet {
private Circle circle;
private int startX;
private int startY;

public Bullet(int startX, int startY){
    circle = //create circle from startX and startY
    this.startX = startX;
    this.startY = startY;
}
//getters and setters here...
  }

这是我的游戏类

                        public class MyGame extends ApplicationAdapter {
SpriteBatch batch;
Texture ballImage, bulletImage;
OrthographicCamera cam;
Circle ball;
Array <Circle> bullets;
//long lastShot;

@Override
public void create ()
{
    System.out.println("game created");
    ballImage = new Texture(Gdx.files.internal("ball.png"));
    bulletImage = new Texture(Gdx.files.internal("bullet.png"));

    cam = new OrthographicCamera();
    cam.setToOrtho(true,320,480);//true starts top left false starts bottom left

    batch = new SpriteBatch();  

    ball = new Circle();
    ball.radius=20;
    ball.x=320/2-ball.radius; // half screen size - half image
    ball.y=480/2-ball.radius;

    bullets = new Array<Circle>();
    spawnBullet();      
}

public void spawnBullet()
{
    Circle bullet = new Circle();
    bullet.radius=8;
    bullet.x=bullet.radius; // half screen size - half image
    bullet.y=MathUtils.random(0, 480-bullet.radius);
    bullets.add(bullet);
    System.out.println("x: "+bullet.x+" Y: "+bullet.y);     
}

@Override
public void render ()
{
    Gdx.gl.glClearColor(0, 0, 0, 1);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
    cam.update();
    batch.setProjectionMatrix(cam.combined);
    batch.begin();
    batch.draw(ballImage,ball.x-ball.radius,ball.y-ball.radius);
    for(Circle bullet: bullets)
    {
        batch.draw(bulletImage, bullet.x-bullet.radius, bullet.y-bullet.radius);
    }
    batch.end(); 

    if(Gdx.input.isTouched())
    {           
        Vector3 pos = new Vector3();
        pos.set(Gdx.input.getX(), Gdx.input.getY(),0);
        cam.unproject(pos); 
        ball.y = pos.y ;    
    }


    if(ball.y<0+ball.radius)ball.y=ball.radius;
    if(ball.y>480-ball.radius)ball.y=480-ball.radius;

    Iterator<Circle> i = bullets.iterator();    

     while(i.hasNext())
    {

        Circle bullet = i.next();   
        //System.out.println("x2: "+bullet.x+" Y2: "+bullet.y);


        if(bullet.y>240){
        bullet.x++;
        bullet.y--;}

        bullet.x++;

        //right border collision
        if(bullet.x>320)
        {
            i.remove();
            spawnBullet();
        }
         //circle collision
            if(ball.overlaps(bullet))
            {
            i.remove();
            spawnBullet();
            }   
    } 



}   
 }

Answer 1

首先，你根本不使用Bullet类。你的子弹类应该扩展Circle，然后你可以在你的主类而不是Circle中使用它。

public class Bullet extends Circle {
    private int startX;
    private int startY;

    public Bullet(int startX, int startY){
        super();
        this.startX = startX;
        this.startY = startY;
    }
    // I added some constructors.
    public Bullet(Circle circle, int startX, int startY){
        super(circle);
        this.startX = startX;
        this.startY = startY;
    }

    public Bullet(float x, float y, float radius, int startX, int startY){
        super(x, y, radius);
        this.startX = startX;
        this.startY = startY;
    }

    public Bullet(Vector2 position, float radius, int startX, int startY){
        super(position, radius);
        this.startX = startX;
        this.startY = startY;
    }

    //getters and setters here...
}

如何创建一个子弹类来获取起始位置？似乎是一个简单的修复

1 个答案: