US Patent 7385604 Fragment scattering

A fragment program may configure a fragment processor to compute several output positions and associated data for a fragment, effectively scattering the fragment. Each output position may be independent of a position computed for the fragment during rasterization of a primitive. Each output position may be computed based on a point light source position to compute a shadow map corresponding to the point light source. A raster operation unit writes processed fragment data to each output position. Furthermore, the fragment program may configure the fragment processor to compute per-output position parameters for the fragment such as stencil and alpha values.