| 摘要 |
PURPOSE:To paint out a polygon at a high speed by adding a state information holding means and an XPK to a segment memory in addition to a Y packet PK, an edge table ET and an active edge table AET. CONSTITUTION:An XPK 23 is provided to a segment memory 15 in addition to a YPK/ET 21 which sets side information on each scan line SCL and a polygon to the painted out an a screen and an AET 22 which sets the side information on a desired SCL. The XPK 23 contains a means for holding the 0th and 1st-3rd state information according to a fact whether or not the points on the SCL can exist in a prescribed quadrant within the polygon and on the outer and inner orthogonal lines of the polygon and the state transition factor information consisting of bits E, R and P which show the presence or absence of the input/output relation of those points to the sides of the polygon in response to each (x) coordinate value of the SCL. A display processor 16 refers to the AET 22 to invert the bits E and P together with replacement of the AET 22 and paints out the points with respect to the polygon according to the contents held by the XPK 23. |
