| 摘要 |
PURPOSE:To execute clipping with an area consisting of arbitrary polygons at high speed with only one clipping processing by controlling the writing in a display frame buffer by means of a working frame buffer instead of using a geometric operation processing. CONSTITUTION:The paint-out drawing of polygons corresponding to a clipping ared in a working frame buffer 10 is implemented, and the writing of graphic data and image data into a display frame buffer 20 is executed by writing the result of the AND of the painted-out area with the graphic data and image data to be drawn into the display frame buffer 20. By eliminating display elements such as the given graphic data and image data outside the designated boundary of the arbitrary polygons, the clipping processing is executed. Thus, the clipping with the area consisting of the arbitrary polygons can be executed at high speed with only one clipping operation. |
