Methods and control stream generators for generating a control stream for a tile group in a graphics processing system

Abstract

Methods and control stream generators for generating a control stream for a tile group comprising at least two tiles, the control stream identifying primitive blocks that are relevant to rendering at least one tile in the tile group. Information is received identifying one or more primitive blocks relevant to rendering at least one tile in the tile group, each primitive block comprising one or more primitives; generating a primitive block entry for each of the identified primitive blocks; and adding each primitive block entry to the control stream; wherein generating the primitive block entry for at least one of the identified primitive blocks comprises: (i) identifying a bounding box encompassing the one or more primitives of the primitive block; (ii) generating a coverage mask that indicates which tiles of the tile group that intersect the bounding box for the primitive block are valid for the primitive block, a tile being valid for a primitive block if at least one primitive of the primitive blocks falls, at least partially, within the bounds of the tile; and (iii) including the coverage mask in the primitive block entry.