| 摘要 |
PURPOSE:To avoid the excess consumption of planes and to attain the easy clipping of a high speed by comparing the same coordinates of the two planes and generating a clipping graphic only with setting a compared result to the same coordinate of the display plane. CONSTITUTION:A plane 1 is set to be used for the clipping out of plural memory planes. Then, a pixel corresponding to the internal part of a clipping area 5 is turned on and a pixel out of the area is turned off. After that, for the graphic to be prepared, a pixel to be displayed in another plane 2 is formed to be turned on and the other pixel is formed to be turned off. The plane for clipping and the pixel in the same coordinates of the plane in the prepared graphic are compared and decided, and only the pixel to be turned on and to be in the same coordinates of a plane 4 for display is turned on. Then clipping graphic is generated and displayed. Thus, without holding the information of the clipping area in a memory table, etc., and providing a means to execute the decision for the inside and outside of the clipping area and computation at all, the arbitrary graphic can be easily generated in the arbitrary clipping area at the high speed. |
