Abstract: A first method is performed by a computing device to generate rect objects for visible portions of objects of a display that have changed from a previous to current update cycle. The first method comprises dividing a visible portion of at least one of a plurality of overlapping objects that has changed from a previous to current update cycle, into at least one rect object. In dividing the changed visible portion, the computing device uses a graphical hierarchy defining precedence for display of the objects. By determining changed areas of the display, the computing device can be programmed to avoid using processing power on portions of the display that have not changed from a previous to current update cycle or that is not visible in the display. In addition, the computing device can determine the portions of the display requiring update relatively rapidly through use of the rect object(s).