Rendering changed portions of composited images

Rendering graphics on a display of a device. In a portable or wireless device, a list of instructions needed to refresh or generate a frame is first created. The created instructions are then parsed or optimized to remove instructions that result in unnecessary processing instructions. The optimized list is then executed. During generation of a given frame, a view hierarchy is traversed to identify damaged portions of a display. The damaged portions are not copied to the frame. Also, information that has not changed is likewise not usually copied. Damage from the previous frame less damage from the current frame is copied to the appropriate buffer. The instructions are optimized to render only the portion of the frame that is necessary. Portions of the display that are not visible are not traversed in the view hierarchy and are not considered until visible on the display.