| 摘要 |
PURPOSE: To speed up the plotting of graphics by omitting hidden line/hidden surface erasing processing at the time of displaying a three-dimensional graphic. CONSTITUTION: This graphic display device has a display memory 120 for storing graphic to be displayed on a display device 200, a Z buffer memory 130 for storing the Z value of each picture element in the graphic stored in the memory 120, a graphic plotting circuit 110 for plotting a graphic to be stored in a display memory 120 while taking the Z value of the displayed graphic and the Z value stored in the memory 130 into consideration, a dirty area register 140 for holding the coordinate value of an area updated in the past in the memory 130, a coordinate comparing circuit 150 for comparing the coordinates of the graphic to be displayed with coordinates stored in the register 140, and a dirty area updating circuit 160 for updating the contents of the register 140. |
