BitmapData getPixel on rotating movieClip?

This may be more of a math question as I try variations on this problem. I’m trying to get the rgb value from a pixel area on the stage that a bitmap is rotating in. I made it work for the y by adjusting the getPixel location in the bitmap, but I think I need to use some sin/cos to “rotate” the x/y location for the getRGB…

am I making this harder than it needs to be?

any ideas?? fla attached…

Thanks!