(65) Prior Publication Data
US 2006/0119614 Al Jun. 8, 2006
(30) Foreign Application Priority Data
Nov. 15,2004 (JP) 2004-331224
(51) Int. CI.
(52) U.S. CI 345/611
(58) Field of Classification Search None
See application file for complete search history.
(56) References Cited
U.S. PATENT DOCUMENTS
5,278,949 A * 1/1994 Thayer 345/426
5,325,474 A * 6/1994 Kumazaki et al 345/611
6,774,897 B2 * 8/2004 Moriwaki 345/427
6,982,723 Bl * 1/2006 Szymaniak 345/611
The present invention provides a three dimensional graphics processing apparatus for performing an anti-aliasing processing in an sufficient manner, without using the conventional area DDA, by using a line buffer as an area for storing display image data to reduce the required memory area, while the increase of the calculation time is restricted by performing calculation suitable for the polygon edge without degrading the precision of the calculation. In the three dimensional graphics processing apparatus, the coordinates of the intersection points between the polygon edge and the scanning lines are calculated from information on the starting vertex and the ending vertex of the polygon edge and information on the scanning lines. The calculation method is changed in accordance with the characteristics of the polygon edge. Further, a blending coefficient for the anti-aliasing process is obtained by calculating an area ratio of an internal region of the polygon occupied within a pixel.
16 Claims, 8 Drawing Sheets