java - Android libgdx... Sprite 水平来回移动

Question

我不知道这段代码有什么问题。当 Sprite 到达右端角时，它应该向左移动。但这段代码会在它( Sprite )到达右端角时执行， Sprite 就会停止。

The startM is the left end corner, and the endM is the right end corner

 //in constructor
 position = new Vector2(ShootingTreys.WIDTH*0.48f, ShootingTreys.HEIGHT*0.025f);

  // in update
 delta = Gdx.graphics.getDeltaTime();
 if(ps.touch == false){

        if(leftEnd == false && (startM <= ballMeter.getX()) ){
            position.x = ballMeter.getX();
            position.x += 20 *delta;

            if(endM == ballMeter.getX()){
                leftEnd =true;
            }
        }
        else {
            position.x = ballMeter.getX();
            position.x -= 20 *delta;

            if(startM == ballMeter.getX()){
                leftEnd = false;
            }
        }

        ballMeter.setPosition(position.x , ballMeter.getY() );

Answer 1

对代码进行一些小的更改。

if(endM == ballMeter.getX()){
       leftEnd =true;
}

转换为

if(endM <= ballMeter.getX()){
       leftEnd =true;
}

和

if(startM == ballMeter.getX()){
   leftEnd = false;
}

到

if(startM >= ballMeter.getX()){
       leftEnd = false;
}