Patent ID: 6091432
Filing Date: 2000-07-18
Classification: G06F,G09G

Abstract:
A method of transferring a block of pixel data from a source multi-line frame buffer area to a destination multi-line frame buffer area in a raster-type computer graphics display system, said method comprising the steps of:a) determining whether the first raster line corresponding to said destination multi-line frame buffer area is at least a minimum number of raster lines ahead of the current raster line; and if so, proceeding to step b); but if not, proceeding to step c);b) transferring lines of pixel data one line at a time from said source multi-line frame buffer area to said destination multi-line frame buffer area until the last line of pixel data in said block of pixel data has been transferred, then stopping the transfer operation;c) determining whether the first raster line corresponding to said destination multi-line frame buffer area is behind the current raster line; and if not, beginning step c) again; but if so, proceeding to step d);d) transferring one line of pixel data from said source multi-line frame buffer area to said destination multi-line frame buffer area in accordance with a next source line indicator and a next destination line indicator;e) if the line of pixel data transferred during step d) was the last line in said block of pixel data, stopping the transfer operation; otherwise, updating said next source line indicator and said next destination line indicator and proceeding to step f);f) determining whether the raster line corresponding to said next destination line indicator is ahead of the current raster line; and if so, proceeding to step b); but if not, proceeding to step g);g) determining whether the raster line corresponding to said next destination line indicator is behind the current raster position; and if not, beginning step g) again; but if so, proceeding to step d).