| 摘要 |
PROBLEM TO BE SOLVED: To realize boundary vignetting plotting while using a platform plotting mechanism not having transparency and a boundary vignetting function. SOLUTION: A virtual plotting area 25 is formed, an object 21 to be plotted by vignetting a boundary in a VRAM is plotted in the virtual plotting area 25, a black-and-white bit map 26 (of a plotting state 203) of a prescribed gradation value is generated based on the object 21 plotted in the area 25, boundary gradation processing is applied to the generated bit map 26, and each pixel of the boundary-gradated bit map 26 (of a plotting state 204) is set to the transparency value of a prescribed level. Then transparency processing (of a picture display state 205) for plotting corresponding pixels of the object 21 in the area 25 in the VRAM by the transparency value is performed. |
