| 摘要 |
PROBLEM TO BE SOLVED: To perform the developing processing of a horizontal straight line and a rectangle high in use frequency without performing operation at every one dot by forming bit map data on the basis of stored coordinates data and the word length of a memory access and plotting the formed bit map data in an external memory. SOLUTION: The start coordinates and completion coordinates of inputted data are stored in a coordinates memory means 1 and bit map data is formed on the basis of the stored coordinates data and the word length of a memory access by a bit map forming means 3 equipped with a left end edge forming part 6, an intermediate forming part 7 and a right end edge forming part 8. The bit map data formed by the bit map forming means 3 is plotted in on an external memory by a bit map drawing means 4 equipped with a DMA circuit operation part 9 and a bit map selection part 11. By this constitution, a horizontal straight line and a rectangle high in use frequency can be subjected to developing processing without performing operation at every one dot. |
