2D Java游戏编程动画问题

Question

我正在制作一个游泳动画。当玩家与waterTile发生碰撞时，当玩家离开（lt）时游戏动画不会播放，当玩家向右移动（rt）时，游戏动画会播放。

以下是Player.java的Render方法： -EDITED -

if (isSwimming){
        if (up) {
            swimUp.render(g, x, y, Game.TILESIZE * Game.SCALE, Game.TILESIZE * Game.SCALE);
        } 
        if (dn){
            swimDown.render(g, x, y, Game.TILESIZE * Game.SCALE, Game.TILESIZE * Game.SCALE);
        }
        if (rt){
            swimRight.render(g, x, y, Game.TILESIZE * Game.SCALE, Game.TILESIZE * Game.SCALE);
        }
        if (lt){
            swimLeft.render(g, x, y, Game.TILESIZE * Game.SCALE, Game.TILESIZE * Game.SCALE);
        }
    }       
 if (!isSwimming){
        if(up){
            upAnimation.render(g, x, y, Game.TILESIZE * Game.SCALE, Game.TILESIZE * Game.SCALE);
        } 
        if (dn){
            downAnimation.render(g, x, y, Game.TILESIZE * Game.SCALE, Game.TILESIZE * Game.SCALE);
        }
        if (rt){
            rightAnimation.render(g, x, y, Game.TILESIZE * Game.SCALE, Game.TILESIZE * Game.SCALE);
        }
        if (lt){
            leftAnimation.render(g, x, y, Game.TILESIZE * Game.SCALE, Game.TILESIZE * Game.SCALE);
        } else
            idle.render(g, x, y, Game.TILESIZE * Game.SCALE, Game.TILESIZE * Game.SCALE);

}

此外，值得注意的是，没有显示错误。