| 摘要 |
PURPOSE:To realize the clipping processing with high memory using efficiency and high plotted picture quality by obtaining the coordinate value of the intersecting point of a clip pattern or a plotted pattern and each scanning line, and deciding the superposed part of the clip pattern and the plotted pattern from each coordinate value, and plotting a pattern corresponding to the superposed part. CONSTITUTION:A coordinate calculating means 106 extracts an outline part from a clip pattern storing means 104 and a drawn pattern storing means 103, and obtains the coordinate value of the intersecting point with the scanning line (scan line in raster scan). An effective plotting range deciding means 107 decides the superposed part of the clip pattern and the plotted pattern on the scanning line from the coordinate of this intersecting point. Then, the pattern corresponding to the superposed part decided by the effective plotting range deciding means 107 in the drawn pattern is drawn. Thus, the clipping processing can be executed without using a clip frame memory and besides, without executing rectangle approximation, and the clipping processing with high memory using efficiency and high plotting picture quality can be realized. |
