This is a United States patent for an anti-aliasing technique that may be used to reduce the appearance of jagged edges in raster based graphical systems. Dynamic coverage anti-aliasing provides comparable quality to multisample anti-aliasing (and others), but incurs, on average, only about half the storage cost.
(Abstract) The following discloses antialiasing systems and methods. Information about one or more fragments or primitives in a pixel area may be dynamically stored. The stored information may include, for example, depth, color, location and coverage. The coverage and depth information may be tracked at a higher frequency across the pixel than the number of fragments or primitives. Fragments or primitives that enter into a pixel area may be compared with fragments or primitives that have been stored. The comparisons may be based on depth and coverage. Either the incoming fragment or the stored fragment may be deleted based on the comparisons. Information associated with fragments that are preserved may be sampled at any location associated with their coverage area of a pixel. Fragments or primitives that are not discarded may be preserved for a final resolve process, which may incorporate information available from neighboring pixel areas.
Full Title: Dynamic Fragment Coverage Anti-aliasing
Patent Number: 8,686,999