A raster engine for computer graphics and image composition

A raster engine (RE) is designed and implemented to improve the performance of computer graphics and image composition. The RE hardware can release more than 50% CPU loads. Furthermore, if the approximated Phong method which is proposed is applied, 89% CPU operations are reduced by the RE. As the features of this design, the techniques including modified digital differential analyser (DDA), 2-level pipeline, and constant execution time for calculating cos/sup n/ /spl theta/ are proposed in RE. Three operation modes, Gouraud and Phong shading algorithm and image composition are incorporated in RE. This accelerator will be implemented by 0.8 um SPDM CMOS VLSI technology.