偏移旋转

Question

我有一个代码在俄罗斯方块游戏中旋转一块，但我不知道xOffset和yOffset变量的含义。你能为我解释一下吗？非常感谢!!

double xOffset = width / 2.0 - .5;         double yOffset = height / 2.0 - .5;

    //Create a new body
    TPoint[] newBody = copyBody(body);
    for(TPoint p : newBody){

        //Rotoate 90 degrees counter clockwise about the origin
        double newX = p.x;
        double newY = p.y;

        newX -= xOffset;
        newY -= yOffset;

        double temp = newX;
        newX = -newY;
        newY = temp;

        newX += yOffset;
        newY += xOffset;

        p.x = (int) newX;
        p.y = (int) newY;
    }
    return new Piece(newBody); 

Answer 1

通过阅读代码段很难说清楚，但在我看来，xOffset和yOffset值是指旋转的中心点。