| 摘要 |
PURPOSE:To apply smearing-out at high speed by obtaining in advance an address of a start point group and an end point group of plural straight lines so as to provide the corresponding address of the start point and the end point sequentially to a straight line drawing circuit in smearing out an area by plural straight lines. CONSTITUTION:A CPU1 calculates the address of both end points A and B of the start point group of a smear-out area from a data read out of a memory 2 and outputs the result to a register 6. A straight line drawing circuit (DDA)3 calculates an address of each dot on a straight line AB based on the data in the register 6 and stores the result in a memory 5. This is performed similarly as to the end point group, and an address of each dot on a straight line CD is stored also in the memory 5. Then, the CPU1 extracts the address of the start point and the end point corresponding thereto from the memory 5 and gives the address to the register 6, and a data is written on a picture memory 4 via the DDA3. The CPU1 sets the address of the next start point and end point to the register 6 during the operation of the DDA3. |
