| 摘要 |
PROBLEM TO BE SOLVED: To perform appropriate image display processing of a translucent polygon that reduces processing load of an image display device by performing write control of a Z coordinate of the pixel to a depth buffer in accordance with the transparency of the pixel. SOLUTION: Polygon data converted into a three-dimensional coordinate of a view point coordinate system is sent to a rendering processing circuit 21. The processing circuit discriminates an opaque state of a pixel, sets 1st and 2nd flags which control the writing of a Z coordinate of pixels which are opaque and are not opaque and controls the writing of the Z coordinate of pixels to a depth buffer 23 based the flag states. Also, the circuit 21 compares fore and after relations of plural polygons and the Z-coordinate of a pixel that is arranged at this nearest side of a Z direction is stored in the buffer 23. Thus, data of a pixel that undergoes processing is stored in a frame buffer 24 and after that, it is successively sent to a monitor 25 and is shown as an image. |
