Method and apparatus for graphical panning

摘要

A system and method for rapid panning of graphics images stored as objects in an object records database. The system comprises a computer with memory or memories divided into a several memory regions. The computer is coupled to a monitor for displaying graphics files stored in the database. The memory regions include: a virtual map (VMAP) region including cell maps comprising pointers to linked lists of objects in the database; a backing store region storing a bitmapped image of an entire file, and having the same effective dimensions as the VMAP; a main store region storing a smaller portion of the bitmapped image, the main store region having the same pixel dimensions as a viewing region on the monitor and a movable main store viewing window which permits a view of the subset of the bitmap. When the user pans across the image, the ready, bitmapped image from the large backing store is rapidly copied to the main store and blitted to the screen, avoiding delays due to rendering a bitmapped image from the database or VMAP. Alterations to the image or to the viewing window will update the VMAP and the backing store simultaneously, eliminating update delays to the monitor when panning is executed.