Video controller system with object display lists

Abstract

A graphics controller which performs display list-based video refresh operations that enable objects with independent frame rates to be efficiently assembled is disclosed. The graphics controller maintains a virtual display refresh list (VDRL) comprising a plurality of pointers to scan line segments in memory. The graphics controller also creates, maintains, and deletes draw display lists (DDLs) that comprise pointers to object display list subroutines (ODLs) that independently draw objects in memory. The ODLs may allocated one or more buffers in memory into which different frames of the objects are drawn. When an ODL has completed executing, the corresponding pointer in the DDL may be updated to point to the buffer location in memory that stores the newly completed object frame. The VDRL is maintained independently (and may be doubled-buffered) and is updated using the DDLs. Motion estimation may be performed by the graphics controller using the different frames of objects that are drawn into memory by the ODLs. The different object frames may also be animated by the graphics controller once they are drawn into memory. The object frames stored in memory may be compressed to conserve memory.