| 摘要 |
<p>PURPOSE:To redisplay a part which is hidden in an existent screen efficiently by comparing the hidden data with stored bit map data with specific bit width and redisplaying saved bit map data at the time of coincidence when the hidden part is redisplayed by erasing a new screen displayed on the existent screen. CONSTITUTION:When the new screen 2 is displayed on the existent screen 1 the bit map data 2-1 of the part is saved and bit map data 2-2 with specific bit width of the outer periphery of the part where the new screen 2 is to be displayed is saved; and then the new screen 2 is displayed. Then when the new screen 2 is erased and the existent screen 1 is redisplayed, the bit map data 2-2 is compared with the bit map data of the corresponding part of the current existent screen 1 and when they match each other, the saved bit map data 2-1 is redisplayed at its original position. When they do not match each other, the entire screen is redisplayed. Thus, the hidden part of the existent screen plane can be redisplayed efficiently.</p> |
