| 摘要 |
PROBLEM TO BE SOLVED: To reduce a data amount while maintaining the acceleration of a processing speed by displaying a vertex that is common to plural polygons with coordinate data of one vertex and its positional data. SOLUTION: Polygon data, etc., stored in an external storage medium are read from an I/O 13 by the control of a CPU 11 and is stored in a data memory 16 through a data control circuit 15. The stored polygon data converts a vertex coordinate of a polygon that is arranged at a view port by such a manner that the CPU 11 executes geometry processing into a three-dimensional coordinate in a view point coordinate system that makes a prescribed view point coordinate a reference based on the control of the circuit 15. The vertex coordinate data that undergoes geometry processing is once stored in a cache memory 14. Then, when an overlapping vertex coordinate exists, it is possible to reduce a polygon data amount by reading vertex coordinate data of a position indicated by the CPU 11 from the memory 14. |
