| 摘要 |
PURPOSE:To improve the using efficiency of a memory by generally judging based on information whether a line can be newly plotted or not in respective blocks obtained by dividing a display screen into a matrix with a prescribed size or the information of a feature point indicating the start and the end points, the inflection point, the branch or the like of the line and plotting the line. CONSTITUTION:A CPU 1 reads the address 1 of a line information memory 5, namely, the data of a line number Li (=1). Thereby, the CPU 1 reads that a first line L1 is a digital line whose start point is a corner C1 and whose branch is nor present. The CPU 1 reads corner information from a corner information memory 3, however, since the address is situated at a position corresponding to the corner number Ci (=1) read from the line information memory 5, it reads that a first corner C1 is a coordinate value (200, 100) and a next corner number Ci is 2. Then, when it is judged that the first line L1 can be plotted, it shifts to a processing for plotting the line L1. |
