转义窗口框架的Java对象

Question

So I made a game and I want the enemies to bounce off the wall when they hit in a random x and y speed. However, somehow these little buggers are still getting out of the window. Most the time it works but every like 10ish times it will sneak out the border and I can't figure out how.

@Override
    public void tick()
    {
        x += speedX;
        y += speedY;
        Random r = new Random();

        //BUGS
        if(y <= 0 || y >= Game.HEIGHT - 48) //This is correct size of the window edges
        {
            if(speedY <= 0)
                speedY = (r.nextInt(8) + 1);
            else
                speedY = -(r.nextInt(8) + 1);
        }
        if(x <= 0 || x >= Game.WIDTH - 32) //This is correct size of the window edges
        {
            if(speedX <= 0)
                speedX = (r.nextInt(8) + 1);
            else
                speedX = -(r.nextInt(8) + 1);
        }

Answer 1

Issues:

• Don't re-create Random as it's wasteful and sometimes dangerous. Better to create one Random object and assign it to an instance field of the class, and use it throughout.
• Avoid "magic numbers". So instead of y >= Game.HEIGHT - 48 , do y >= Game.HEIGHT - WINDOW_EDGES (or something similar)
• Don't swap speed as you're doing but instead check for y <= 0 or y >= Game.HEIGHT -SOME_CONSTANT separately, and gear the results based on this finding to avoid getting caught in a speed "trap". This is your main problem in fact.

eg,

if (y <= 0) {
    speedY = r.nextInt(8) + 1; // change 8 to a constant
} else if (y >= Game.HEIGHT - SOME_CONSTANT) {
    speedY = -(r.nextInt(8) + 1);
}

Same for x and speedX

Regarding:

2) I would like to do that but since I have multiple object sizes, I have to change the edges.

Then each object should have a method that returns its edge size (or whatever property is needed), and you should use this, again, not magic numbers

3) I tried swapping and they just shot off the screen.

I don't know what you mean by this or what specific code changes you may have made.

If still stuck, consider creating and posting a valid Minimal Reproducible Example