Java Rotating Rectangle Results In Weird Values

Question

I am making a game engine in Java. I am trying to add box collision to my game and this box needs to have the ability to rotate with the player. I have searched and found a formula which is supposed to calculate the new point of a rotated point, however, when I rotate my points they seem to follow a weird out of proportion figure 8 path instead of a circle around the center of my box.

for (Point p : points) {
        //Loops through every point on the box (Square)
        //top, left, bottom, right          

        float pointX = p.getX();
        float pointY = p.getY();

        //rotation as radians
        float cos = (float) Math.cos(rotation);
        float sin = (float) Math.sin(rotation);

        pointX = centerX +(pointX-centerX) * cos + (pointY-centerY) * sin;

        pointY = centerY -(pointY-centerY) * cos + (pointX-centerX) * sin;

        p.setPos(pointX, pointY);

}

Here is what happens to the box as I rotate my player: https://gyazo.com/ff801ce8458269c2385e24b2dc5404f5

Any help would be greatly appreciated, I have been tackling this for almost a week now with the same results.

Answer 1

The problem is that you calculate pointY with the new value of pointX.

Thanks to @Imus answer for the proper calculation.

Try:

float pointX = p.getX();
float pointY = p.getY();

//rotation as radians
float cos = (float) Math.cos(rotation);
float sin = (float) Math.sin(rotation);

float newPointX = centerX +(pointX-centerX) * cos + (pointY-centerY) * sin;
float newPointY = centerY +(pointY-centerY) * cos - (pointX-centerX) * sin;

p.setPos(newPointX, newPointY);