| 摘要 |
A three-dimensional graphic display system having an increased speed hidden-surface process capability. At a time when a depth buffer memory would be initialized in a conventional three-dimensional graphic display system, the depth buffer memory itself is not initialized and only bits of a high-speed memory corresponding to bits to be initialized in the depth buffer memory are initialized. When a hidden-surface process is executed, if the bits of the high-speed memory have been initialized, those initialization bits are changed to a non-initialized state and the latest Z coordinate data from a line generator is unconditionally written in the depth buffer memory. When the initialization bits of the high-speed memory are in a non-initialized state, a comparator compares Z coordinate data supplied from the depth buffer memory with the latest Z coordinate data supplied from the line generator. On the basis of the results of such comparison, a hidden-surface process is executed to display a three-dimensional graphic image. |
