| 摘要 |
PURPOSE:To suppress complication and price increase by performing texture mapping on a polygon at the same speed as that in the plot processing of the polygon without providing texture cache. CONSTITUTION:An image memory is formed with doubel buffers 7, 8, and respective address line, data line, and memory control line and formed separately, and a frame buffer and texture data memory are formed on each of them. Data in the texture data memory is expressed in one-dimension mode instead of two-dimensional mode, and size is set at a value less than the maximum value of a column address. One of the buffers is used as the one for the readout of image data in a SAM port and the texture data, and the other for the write of the image data, and buffer switching is performed in a vertical flyback period, and the buffer for readout detects the completion of readout of the image data in a row direction, and the refresh of a texture area is performed in the vertical flyback period by deciding that no texture mapping is performed on the polygon in a horizontal flyback period. |
