COMMAND PROCESSOR FOR A THREE-DIMENSIONAL GRAPHICS ACCELERATOR WHICH INCLUDES GEOMETRY DECOMPRESSION CAPABILITIES

A 3-D graphics accelerator which includes a command block with geometry data decompression capabilities and thus includes improved performance over prior art designs. The 3-D graphics accelerator couples to a system bus in the computer system and receives compressed geometry data from the system memory. The 3-D graphics accelerator includes a command block or preprocessor, a plurality of floating point processors or blocks, and one or more draw processors or blocks. The command processor includes a first data path which transmits non-compressed geometry data, and a second data path which receives the compressed geometry data and decompresses the compressed geometry data. In the preferred embodiment, the command processor includes one or more input buffers, a geometry decompression unit, and multiplexer logic. The input buffers couple to the system bus for receiving geometry input data. The geometry input data includes compressed geometry input data and non-compressed geometry input data. The geometry decompression unit couples to an output of the input buffers and receives and decompresses the compressed geometry input data. The multiplexer receives the non-compressed output from the input buffers and receives the decompressed output from the geometry decompression unit. The multiplexer includes an output which selectively provides either the non-compressed geometry data or the decorepressed geometry input to other logic in the system.