HitWallExample

    public void HitWall(Collision2D collision)
    {
        // We don't want the reflect to decide the x direction.
        // Store the current direction.
        var direction = desiredVelocity.x;

        // Get the surface we contacted.
        ContactPoint2D contact = collision.GetContact(0);

        // DesiredVelocity is a variable defined at the top of the class. It is used to keep track of the desiredDirection, and speed.
        // Figure out the new y trajectory.
        desiredVelocity = Vector2.Reflect(desiredVelocity, contact.normal);

        // Set x back to the stored direction.
        desiredVelocity.x = direction;

        // Use the new desiredVelocity to adjust the rigidbody velocity.
        AdjustVelocity();
    }