Image Number 12 for United States Patent #5990904.
A method for merging pixel fragments to reduce memory usage in a graphics rendering system. In rendering a graphics scene, geometric primitives of objects in the scene are rasterized to create pixel data including pixel fragments representing partially covered pixels. Lists of pixel fragments having color, depth, and coverage data are stored in a fragment buffer. When a new fragment is generated, an attempt is made to merge the fragment with the last fragment stored for a corresponding pixel location. Fragments are merged if they are within predefined depth and color tolerances.