iPhone SDK：如何存储触摸事件期间生成的坐标对？

I'm trying to create a rotating object for the iPhone. I have it calculating all the trig. The problem is that for my project I have need to have the program reset the x and y every time a finger is dragged more over then 30 degrees around the center point. Whenever I link a variable to the x and y of the current location within the touchesMoved function they link permanently and continually change along with the drag event instead of staying constant and updating every 30 degrees. Is there a way to statically store an x and y?I'm trying to create a rotating object for the