| 摘要 |
PURPOSE: To accurately fill a polygon successively traversing boundaries and selecting a minimum value and a maximum value of plural selectable picture elements related to each of plural scanning lines of the polygon and drawing a filling line between the minimum value and the maximum value. CONSTITUTION: In the case of a projecting polygon, the processing time required for polygon filling is optimized by a first polygon filling algorithm. In the case of a recessed polygon, the processing time required for correct polygon filling is optimized by storing two of minimum value and maximum value for each scanning line of the polygon. Next, the filling line is drawn from the smallest minimum value to the largest maximum value. The first polygon filling algorithm fills the projecting polygon in an exact meaning, and a second polygon filling algorithm fills a larger set of polygons than that for the first algorithm. The second polygon filling algorithm fills all of polygons which can be accurately filled by one continuous line per scanning. |
