Question

I have a small rectangle, with a point at the center. I also have another point, just outside of the rectangle, 10 pixels to the left of the rectangle’s center point when the rectangle is sitting vertically, not rotated. How would i go about keeping this outside point in the same place relative to the rectangle when the rectangle is rotated about its center?

thanks

Answer 1

Here is an example of how to rotate one point around another point in XNA:

public Vector2 RotatePoint(Vector2 pointToRotate, Vector2 centerOfRotation, float angleOfRotation)
{
    Matrix rotationMatrix = Matrix.CreateRotationZ(angleOfRotation);
    return Vector2.Transform(pointToRotate - centerOfRotation, rotationMatrix);
}