| 摘要 |
PURPOSE:To quickly plot a straight line having the width given by four apexes by providing a parallelogram area painting-out means which successively paints out insides of plural rectangles approximated to a parallelogrammic area. CONSTITUTION:Area dividing program data, rectangle generating program data, line dot generating program data, and plotting processing program data are stored in a ROM 2. A CPU 1 divides a line K having the width given by four apexes A to D into triangles and a parallelogram by horizontal lines Aa and bC. With respect to triangular areas, lattice points are generated on right and left sides and lattice points are connected to horizontal lines to paint out the triangular areas. With respect to the parallelogrammic area, plural lattice points approximated to right and left sides are generated, and numbers of vertical and horizontal lattice points of rectangles and lattice points as the reference for plotting are determined by respective generated lattice points, and plural rectangles approximated to the parallelogrammic area are successively painted out. |
