×

Method and apparatus for pixel clipping source and destination windows in a graphics system

  • US 5,193,148 A
  • Filed: 12/04/1991
  • Issued: 03/09/1993
  • Est. Priority Date: 03/16/1990
  • Status: Expired due to Term
First Claim
Patent Images

1. A method of moving blocks of pixel data from a source area to a destination area within a frame buffer in a computer graphics system, said pixel data including a window identifier and a pixel identifier for each pixel, the method comprising the steps of:

  • reading a block of pixel data from said source area into a memory according to a plurality of source tiles;

    comparing pixel window identifiers read from the frame buffer with a pixel window identifier previously stored in the memory to determine whether the pixel window identifiers read from the frame buffer match the pixel window identifier previously stored in the memory;

    discarding each pixel whose corresponding window identifier does not match the previously stored window identifier with which the corresponding window identifier was compared; and

    updating the frame buffer with the pixel data not discarded, wherein the respective window identifiers each comprise a data indicative of one of a plurality of visible windows associated with said graphics system.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×