Dynamic switching of texture mip-maps based on depth

摘要

A graphics subsystem includes hardware and/or software for permitting mip-maps to be dynamically switched based upon depth (Z) values. In addition, the system generates a SHIFT signal to permit automatic adjustment of texture parameters to facilitate retrieval of texture maps. The system includes a mip-map select logic or routine that compares the depth value of a pixel to be rendered with predetermined depth values. The depth values may be stored in a plurality of depth registers, and compared with the depth value of a pixel in a plurality of associated comparators. A mip-map is selected based upon the comparisons, and the SHIFT signal is generated to indicate the order of change with respect to a base reference mip-map. A texture engine receives the SHIFT signal and uses the associated base address of the selected mip-map and shifted texture parameters to define an address for the texture map.