Question

考虑到超出界限的位置是6和-6。

我想让船转向并向相反的方向移动。

这是我的代码..它仍然没有100％我想要的工作。我很想知道是否有人有任何想法如何改进。这是我的代码的逻辑。

//If the ship hits a boundary it turns around and moves in the opp.
//direction. To do this, the ship's velocty should be flipped from a 
//negative into a positive number, or from pos to neg if boundary
//is hit.

//if ship position is -5 at velocity -1 new ship pos is -6
//if ship position is -6 at velocity -1 new ship velocity is +1
//                                      new ship position is +5

这是我的代码：

public void move() 
{
    position = velocity + position;

    if (position > 5)
    {
        velocity = -velocity;
    }
    else if (position < -5)
    {
        velocity = +velocity;
    }
}

Answer 1

你可以这样做：

public void move() 
    {
    //first check where the next move will be:
    if ((position + velocity) > 5 || (position + velocity) < -5){

        // Here we change direction (the velocity is multiplied for -1)
        velocity *= -1;

    }

    position += velocity;
}

Answer 2

代码velocity = +velocity;不会将负速度变为正速度。这样做相当于将速度乘以+1，这不会改变符号。

要在超出范围时翻转速度符号，您需要始终乘以-1。

我不清楚界限是什么，所以我认为它们是6和-6。

position += velocity;
//make sure the ship cannot go further than the bounds
//but also make sure that the ship doesn't stand still with large velocities
if (position > 6)
{
    velocity = -velocity;
    position = 6;
}
if (position < -6)
{
    velocity = -velocity;
    position = -6;
}

Answer 3

当它到达边界时，将速度乘以-1。

Answer 4

首先，你的逻辑看起来有点瑕疵。如果位置 -6 且速度 -1 ，要开始向相反方向移动，您的新位置应 -5 （而不是 +5 ）和速度 +1 。

此外，只要您的位置达到边界条件，您就需要反转速度符号。

public void move() {
    if (Math.abs(position + velocity) > 5) { // Check for boundary conditions
        velocity *= -1;
    }
    position = position + velocity; // position += velocity;
}

Answer 5

如果你想改变方向，你需要翻转标志。这与* -1相同或否定它。

public void move() {    
    // prevent it jumping through the wall.
    if (Math.abs(position + velocity) > 5)
        velocity = -velocity;

    position += velocity;
}

如何转动物体并向相反方向移动？

5 个答案: