Storage hierarchy for smooth bitmap scrolling.

摘要

Smooth scrolling of a document on an all points addressable system which provides fast response and scrolling in increments of a single display row, while being storage efficient. The document is completely stored in compact format and a portion of the document which encompasses the current display window is stored in bitmap image format. There is smooth scrolling between displays completely within the bitmap image. The scroll is only interrupted for a scroll outside the portion of the document in bitmap image format, in which case the bitmap image is adjusted using the compact format to include that portion of the document with the desired display.