Patent ID: 7012622

Claim:
A computing device executing a graphics rendering software program providing instructions to one or more processors to render graphics on a display, the computing device configured to establish a network connection with at least one other computing device, comprising: a graphics driver configured to render a plurality of drawing surfaces, including a first drawing surface and a second drawing surface, on the display, and a memory storing graphic objects having a plurality of attributes, wherein attributes from the plurality of attributes are selected from a group consisting of: color and font, wherein each graphic object represents a drawing surface of the plurality of drawing surfaces, wherein the graphics driver is configured to render the first drawing surface on the display at least partially overlapping where a portion of the second drawing surface was as a set of rectangular clip segments, wherein when the first drawing surface is rendered as partially overlapping the second drawing surface, the visible portion of the second drawing surface is rendered as the set of rectangular clip segments, wherein the set of rectangular clip segments is selected from a group consisting of: one rectangular clip segment, two rectangular clip segments, three rectangular clip segments and four rectangular clip segments, wherein the plurality of attributes of the graphic objects also includes the set of rectangular clip segments, and wherein the graphics driver is configured to determine the second drawing surface comprising the portion of the second drawing surface and the visible portion of the second drawing surface, wherein the graphics driver is further configured to increment a visibility tag corresponding to the second drawing surface when the portion of the second drawing surface is to be overlapped by a portion of the first drawing surface, and wherein the graphics driver is configured to compute the set of rectangular clip segments if the visibility tag corresponding to the second drawing surface is dissimilar to a visibility tag corresponding to the first drawing surface.