| 摘要 |
PURPOSE:To perform an oblique line drawing with an oblique line of a line width beyond the right end part of a frame buffer by providing a means for drawing an oblique line of a line width of a distance between the end point of a straight line as a reference line and the edge part of the frame buffer and an oblique line of a predetermined width using a straight line connecting an end point to a start point as a reference line and a means for erasing parts of said oblique lines extending over a printing limit. CONSTITUTION:When an oblique line to be drawn is projected from a right edge part 8 of a frame buffer over the width of the frame buffer, an oblique line drawing correction part detects this overwidth state and draws an oblique line by using a straight line 11 connecting a start point 12 to an end point 13 as a reference line and a distance l between the end point 13 and the frame buffer right edge part 8 as a line width. Thereafter, a point 20 from which a distance to the frame buffer right edge part 8 is equal to an required line width L is found on the straight line 11 connecting the start point 12 to the end point 13. Then, using a straight line 19 between the point 20 as an end point and the start point 12 as a reference line, an oblique line of a line width L is drawn. With respect to the drawn oblique lines, parts 22 extending over a printing limit 7 are erased and a drawing oblique line is obtained. |
