2D Gaming - How to reflect a ball off the bat?

问题

I am pretty new to XNA & game dev and stuck at ball reflection. My ball is reflecting once it hits the bat, but only in one angle, no matter which angle the bat is at.

Here's the code:

if (BallRect.Intersects(BatRect))
    {
        Vector2 NormBallVelocity = Ball.velocity;
        NormBallVelocity.Normalize();
        NormBallVelocity = Vector2.Reflect(Ball.velocity, NormBallVelocity);
        Ball.velocity = NormBallVelocity;
    }

The ball is retracting its way back. How do I make it look like the ball is reflecting off the bat?

I have seen other posts but they are on 3D front I am too new to translate it to 2D terms...

回答1:

I'm pretty sure you need to reflect off the bat's normal instead of the ball's velocity and it's normal.

回答2:

Referring to MSDN Reflect Method, it looks like you want to reflect from the bat's velocity and normal.

回答3:

You should probably first calculate how far off horizontal the bat is (as in, how far along it is in the swing), then rotate it 90 degrees to get the angle you need for the ball.

来源：https://stackoverflow.com/questions/2707059/2d-gaming-how-to-reflect-a-ball-off-the-bat